>>EPA
United States
Environmental Protection
Agency
Office of Research and
Development
Washington DC 20460
EPA/625/R-96/010a
'September 1997
Compendium of
Methods for the
Determination of Inorganic
Compounds in Ambient Air
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EPA/625/R-96/OJO;?
September 1997
COMPENDIUM OF METHODS
FOR THE
DETERMINATION OF INORGANIC
COMPOUNDS IN
AMBIENT AIR
U. S. Environmental Protection Agency
Office of Research and Development
Center for Environmental Research Information
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
Printed on Recycled Paper
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DISCLAIMER
Tlie information in this document has been compiled wholly or in
part by the United States Environmental Protection Agency (EPA)
under contract No. 68-C3-0315, W.A. 2-10 to Eastern Research
Group (ERG). Tfie work was performed by Midwest Research
Institute (MRI) under subcontract to ERG. It has been subjected
to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade
names or commercial products does not constitute endorsement or
recommendation for use.
11
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TABLE OF CONTENTS
Acknowledgements
Foreword
Chapter IO-1: CONTINUOUS MEASUREMENT OF PM
10
SUSPENDED PARTICIPATE MATTER (SPM) IN
AMBIENT AIR
Page
XI
MethodIO-1.1:
MethodIO-1.2:
Method IO-1.3:
Chapter IO-2:
Method IO-2.1:
Method IO-2.2:
Method IO-2.3:
Method IO-2.4:
OVERVIEW
Determination of PM10 in Ambient Air Using the
Graseby Continuous Beta Attenuation Monitor
Determination of PM 10 in Ambient Air Using the
Thermo Environmental Inc. (formally Wedding and
Associates) Continuous Beta Attenuation Monitor
Determination of PM10 in Ambient Air Using a
Continuous Rupprecht and Patashnick (R&P) TEOM®
Particle Monitor
INTEGRATED SAMPLING OF SUSPENDED
PARTICULATE MATTER (SPM) IN AMBIENT
AIR
OVERVIEW
Sampling of Ambient Air for Total Suspended
Particulate Matter (SPM) and PM,0 Using High
Volume (HV) Sampler
Sampling of Ambient Air for PM10 Using a Graseby
Dichotomous Sampler
Sampling of Ambient Air for PM,0 Concentration
Using the Rupprecht and Patashnick (R&P) Low
Volume Partisol® Sampler
Calculations for Standard Volume
1.0-1 through 1.0-6
1.1-1 through 1.1-29
1.2-1 through 1.2-31
1.3-1 through 1.3-40
2.0-1 through 2.0-10
2.1-1 through 2.1-75
2.2-1 through 2.2-27
2.3-1 through 2.3-35
2.4-1 through 2.4-1
ill
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Chapter IO-3:
Method IO-3.1:
Method IO-3.2:
Method IO-3.3:
Method IO-3.4:
Method IO-3.5:
Method IO-3.6:
Method IO-3.7:
Chapter IO-4:
Method IO-4.1:
Method IO-4.2:
Chapter IO-5
Method IO-5:
TABLE OF CONTENTS (continued)
CHEMICAL SPECIES ANALYSIS OF FILTER-
COLLECTED SUSPENDED PARTICULATE
MATTER
OVERVIEW
Selection, Preparation and Extraction of Filter Material
Determination of Metals in Ambient Particulate Matter
Using Atomic Absorption (AA) Spectrometry
Determination of Metals in Ambient Particulate Matter
Using X-Ray Fluorescence (XRF) Spectroscopy
Determination of Metals in Ambient Particulate Matter
Using Inductively Coupled Plasma (ICP) Spectrometry
Determination of Metals in Ambient Particulate Matter
Using Inductively Coupled Plasma/Mass Spectrometry
(ICP/MS)
Determination of Metals in Ambient Particulate Matter
Using Proton Induced X-Ray Emission (PIXE)
Spectroscopy
Determination of Metals in Ambient Particulate Matter
Using Neutron Activation Analysis (NAA) Gamma
Spectrometry
DETERMINATION OF REACTIVE ACIDIC AND
BASIC GASES AND STRONG ACIDITY OF
ATMOSPHERIC FINE PARTICLES IN AMBIENT
AIR USING THE ANNULAR DENUDER
TECHNOLOGY
OVERVIEW
Determination of the Strong Acidity of Atmospheric
Fine-Particles (<2.5 jim)
Determination of Reactive Acidic and Basic Gases and
Strong Acidity of Atmospheric Fine Particles
SAMPLING AND ANALYSIS FOR
ATMOSPHERIC MERCURY
Sampling and Analysis for Vapor and Particle Phase
Mercury in Ambient Air Utilizing Cold Vapor Atomic
Fluorescence Spectrometry (CVAFS)
Page
3.0-1 through 3.0-10
3.1-1 through 3.1-24
3.2-1 through 3.2-25
3.3-1 through 3.3-30
3.4-1 through 3.4-32
3.5-1 through 3.5-35
3.6-1 through 3.6-16
3.7-1 through 3.6-46
4.0-1 through 4.0-3
4.1-1 through 4.1-39
4.2-1 through 4.2-67
5.0-1 through 5.0-36
IV
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Acknowledgements
These Methods were prepared for publication in the Compendium of Methods for the Determination of
Inorganic Compounds in Ambient Air (EPA/625/R-96/060a), which was prepared under Contract
No. 68-C3-0315, WA No. 2-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern
Research Group, Inc. (ERG), and under the sponsorship of the U. S. Environmental Protection
Agency (EPA). Justice A. Manning and John O. Burckle, Center for Environmental Research
Information (CERI), and Frank F. McElroy, National Exposure Research Laboratory (NERL), both
in the EPA Office of Research and Development, were the project officers responsible for overseeing
the preparation of this Compendium. Additional support was provided by other members of the
Compendia Workgroup which include:
• John O. Burckle, U.S. EPA, ORD, Cincinnati, OH
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• foseoh B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• Heidi Schultz, ERG, Lexington, MA
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
These Methods are the result of the efforts of many individuals. Gratitude goes to each person
involved in the preparation and review of this methodology.
Chapter IO-1: CONTINUOUS MEASUREMENT OF PM10 SUSPENDED PARTICULATE
MATTER (SPM) IN AMBIENT AIR
Method IO-1.1: Determination of PM10 in Ambient Air Using the Graseby Continuous
Beta Attenuation Monitor
Authors: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
• Stephe Edgerton, Midwest Research Institute, Gary, NC
Peer Reviewers:
• Richard Shores, Research Triangle Institute, RTP, NC
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• Charles Rodes, Research Triangle Institute, RTP, NC
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
- • Danny France, U.S. EPA, Region 4, Athens, GA
• David Harlos, Environmental Science and Engineering, Gainesville, FL
• Jim Tisch, Graseby, Village of Cleves, OH
• Justice Manning, U.S. EPA, Cincinnati, OH
• William Bope, South Coast Air Quality Management District, Diamond Bar, CA
• Femi Durosinmi, Clark County Health District, Las Vegas, NV
• Rob Ford/Tom Merrifield, Graseby, Atlanta, GA
• Bill Vaughan, Environmental Solutions, St. Louis, MO
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Method IO-1.2: Determination of PM1Q in Ambient Air Using the Thermo Environmental Inc.
(Formerly Wedding and Associates) Continuous Beta Attenuation Monitor
Authors: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
• Stephe Edgerton, Midwest Research Institute, Gary, NC
Peer Reviewers:
• Rick Taylor, Missouri Department of Natural Resources, Jefferson City, MO
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Charles Rodes, Research Triangle Institute, RTF, NC
• Danny France, U.S. EPA, Region 4, Athens, GA
• David Harlos, Environmental Science and Engineering, Gainesville, FL
• Jim Tisch, Graseby, Cleves, OH
• Al Wehr, Texas Natural Resource Conservation Commission, Austin, TX
• Richard Shores, Research Triangle Institute, RTP, NC
Method IO-1.3: Determination of PM1Q in Ambient Air Using a Rupprecht and Patashnick
Continuous TEOM® Particle Monitor
Authors: • Erich Rupprecht, Rupprecht and Patashnick, Albany, NY
• William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
* John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Charles Rodes, Research Triangle Institute, RTP, NC
• Danny France, U.S. EPA, Region 4, Athens, GA
• David Harlos, Environmental Science and Engineering, Gainesville, FL
• Jim Tisch, Graseby, Cleves, OH
• Michael B. Meyer, Rupprecht and Patashnick, Albany, NY
• Richard Shores, Research Triangle Institute, RTP, NC
Chapter IO-2: INTEGRATED SAMPLING OF SUSPENDED PARTICIPATE MATTER (SPM)
IN AMBIENT AIR
Method IO-2.1: Sampling of Ambient Air for Total Suspended Particulate Matter (SPM) and
PM1Q Using High Volume (HV) Sampler
Author: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
* Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
VI
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Method IO-2.2: Sampling of Ambient Air for PM1Q Using a Graseby Dichotomous Sampler
Author: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Cary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
Method IO-2.3: Sampling of Ambient Air for PM10 Using the Rupprecht and Patashnick
(R&P) Low Volume Partisol® Sampler
Author: • Erich Rupprecht, Rupprecht and Patashnick, Albany, NY
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Neil Olsen, Utah Department of Health, Salt Lake City, UT
Method IO-2.4: Calculations for Standard Volume
Author: • William T. "Jerry" Winberry, Jr., MRI, Cary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
Chapter IO-3: CHEMICAL SPECIES ANALYSIS OF FILTER-COLLECTED SUSPENDED
PARTICULATE MATTER
Method IO-3.1: Selection, Preparation, and Extraction of Filter Material
Authors: • Avie Mainey, Midwest Research Institute, Kansas City, MO
• William T. "Jerry" Winberry, Jr., MRI, Cary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Dewayne Ehman, Texas Natural Resource Conservation Commission, Austin, TX
• Gary Wester, Midwest Research Institute, Kansas City, MO
Vll
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Method IO-3.2: Determination of Metals in Ambient Particulate Matter Using Atomic
Absorption (AA) Spectrometry
Author: • William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Eric Prestbo, Frontier GeoScience, Seattle, WA
• Anne M. Falke, Frontier GeoScience, Seattle WA
• Gary Wester, Midwest Research Institute, Kansas City, MO
• Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
• Doug Duckworth, Martin Marietta Energy Systems, Inc., Oak Ridge, TN
Method IO-3.3: Determination of Metals in Ambient Particulate Matter Using X-Ray
Fluorescence (XRF) Spectroscopy
Authors: • Bob Kellog, ManTech, RTF, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Roy Bennet, U.S. EPA, RTP, NC
• Charles Lewis, EPA, RTP, NC
• Ray Lovett, West Virginia University, Morgantown, WV
Method IO-3.4: Determination of Metals in Ambient Particulate Matter Using Inductively
Coupled Plasma (ICP) Spectrometry
Author: • William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers:
• Dewayne Ehman, Texas Natural Resource Conservation Commission, Austin, TX
• David Harlos, Environmental Science and Engineering, Gainesville, FL
• Doug Duckworth, Martin Marietta Energy Systems, Inc. Oak Ridge, TN
Method IO-3.5: Determination of Metals in Ambient Particulate Matter Using Inductively
Coupled Plasma/Mass Spectrometry (ICP/MS)
Author: • William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers:
• Doug Duckworth, Martin Marietta Energy Systems, Inc. Oak Ride, TN
• David Brant, West Virginia University, Morgantown, WV
• Jiansheng Wang, Midwest Research Institute, Kansas City, MO
vru
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Method IO-3.6: Determination of Metals in Ambient Particulate Matter Using Proton Induced
X-Ray Emission (PIXE) Spectroscopy
Authors: • J. William Nelson, Florida State University, Tallahassee, FL
• Thomas Lapp, Midwest Research Institute, Gary, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• David Harlos, Environmental Science and Engineering, Gainesville, FL
Method IO-3.7: Determination of Metals in Ambient Particulate Matter Using Neutron
Activation Analysis (NAA) Gamma Spectrometry
Author: • Jack Weaver, North Carolina State University, Raleigh, NC
Peer Reviewers:
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• Ron Fleming, Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI
• Joseph Lambert, Raleigh, NC
Chapter IO-4: DETERMINATION OF REACTIVE ACIDIC AND BASIC GASES AND
STRONG ACIDITY OF ATMOSPHERIC FINE PARTICLES IN AMBIENT AIR
USING THE ANNULAR DENUDER TECHNOLOGY
Method IO-4.1: Determination of the Strong Acidity of Atmospheric Fine-Particles (<2.5/wn)
Authors: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Cary, NC
• Thomas Ellestad, U.S. EPA, RTP, NC
• Bob Stevens, U.S. EPA, RTP, NC
Peer Reviewers:
• Delbert Eatough, Brigham Young University, Provo, UT
• Shere Stone, University Research Glassware Corp., Chapel Hill, NC
• Petros Koutrakis, Harvard School of Public Health, Boston, MA
• J. Waldman, Robert Wood Johnson Medical School, New Brunswick, NJ
Method IO-4.2: Determination of Reactive Acidic and Basic Gases and Strong Acidity of
Atmospheric Fine Particles (<2.5/tm)
Authors: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Cary, NC
• Thomas Ellestad, U.S. EPA, RTP, NC
• Bob Stevens, U.S. EPA, RTP, NC
Peer Reviewers:
• Delbert Eatough, Brigham Young University, Provo, UT
• Shere Stone, University Research Glassware Corp., Chapel Hill, NC
• Petros Koutrakis, Harvard School of Public Health, Boston, MA
• J. Waldman, Robert Wood Johnson Medical School, New Brunswick, NJ
ix
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Method IO-4.2: Determination of Reactive Acidic and Basic Gases and Strong Acidity of
Atmospheric Fine Particles (<2.5/«n)
Authors: • William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
• Thomas Ellestad, U.S. EPA, RTP, NC
• Bob Stevens, U.S. EPA, RTP, NC
Peer Reviewers:
• Delbert Eatough, Brigham Young University, Provo, UT
• Shere Stone, University Research Glassware Corp., Chapel Hill, NC
• Petros Koutrakis, Harvard School of Public Health, Boston, MA
• J. Waldman, Robert Wood Johnson Medical School, New Brunswick, NJ
Chapter IO-5: SAMPLING AND ANALYSIS FOR ATMOSPHERIC MERCURY
Method IO-5: Sampling and Analysis for Vapor and particle Phase Mercury in Ambient Air
Utilizing Cold Vapor Atomic Fluorescence Spectrometry (CVAFS)
Authors: • Gerald Keeler, University of Michigan, Ann Arbor, MI
• Jim Barres, University of Michigan, Ann Arbor, MI
Peer Reviewers:
• Susan Kilmer, Michigan Department of Natural Resources, Lansing, MI
• Eric Prestbo, Frontier GeoSciences, Seattle, WA
• Anne M. Falke, Frontier GeoSciences, Seattle, WA
• Jamie Brown, Supelco Inc., Bellefonte, PA
• Alan Zaffird, International Technology Corporation, Cincinnati, OH
Editorial Reviewers and Document Production
Finally, recognition is given to the following Administrative Services staff of Midwest Research
Institute (MRI), whose dedication and persistence during the development of this manuscript has
enabled it's production.
• Lisa Mumford, Technical Editor, MRI, Gary, NC
• Frances Beyer, Manager of Administrative Services, MRI, Gary, NC
• Lynn Kaufman, Document Production Coordinator, MRI, Gary, NC
• Debbie Bond, Document Production, MRI, Cary, NC
• Margo Evrenidis, Document Production, MRI, Cary, NC
• Kathy Johnson, Document Production, MRI, Cary, NC
• Lisa Scruggs, Document Production, MRI, Cary, NC
• Cathy Whitaker, Document Production, MRI, Cary, NC
Cover
The cover is printed with permission from Varian Associates Instruments, Palo Alto, CA.
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FOREWORD
The U. S. Environmental Protection Agency is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. To meet this mandate, EPA's research program is
providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for reducing risks from threats to human health
and the environment. The focus of the Laboratory's research program is on methods for the prevention
and control of pollution to air, land, water, and subsurface resources; protection of water quality in public
water systems; remediation of contaminated sites and ground water; and prevention and control of indoor
air pollution. The goal of this research effort is to catalyze development and implementation of
innovative, cost-effective environmental technologies; develop scientific and engineering information
needed by EPA to support regulatory and policy decisions; and provide technical support and information
transfer to ensure effective implementation of environmental regulations and strategies.
Measurement of inorganic pollutants in ambient air is often difficult, in part because of the variety of
inorganic substances of potential concern, the variety of potential techniques for sampling and analysis,
and lack of standardized and documented methods. This Compendium is one of three Compendia of
methods which provide documented and technically reviewed methodology for determining concentrations
of selected pollutants of frequent interest in ambient and indoor air. The methods contained in this
Compendium provide sampling and analysis procedures for a variety of inorganic pollutants and
suspended particulate matter in ambient air. As with the previous Compendia methods, these methods are
provided only for consideration by the user for whatever potential applications for which they may be
deemed appropriate. In particular, these methods are not intended to be associated with any specific
regulatory monitoring purpose and are offered with no specific endorsement for fitness or
recommendation for any particular application, other than for an attempt at standardization.
This publication has been prepared by the Center for Environmental Research Information (CERI)
with support from the National Exposure Research Laboratory (NERL) to continue NRMRL's goal of
providing technical support and information transfer. It is published and made available by EPA's Office
of Research and Development to assist the user community and to link researchers with their clients.
E. Timothy Oppelt, Director
National Risk Management Laboratory
XI
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EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Chapter IO-1
CONTINUOUS MEASUREMENT OF PM1O
SUSPENDED PARTICUIATE MATTER
(SPM) IN AMBIENT AIR
OVERVIEW
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
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Chapter IO-1
Continuous Measurements of PMjQ Suspended Particulate Matter (SPM)
In Ambient Air
OVERVIEW
Under authority granted in Section 109 of the Clean Air Act (the Act) and its amendments, the
U.S. Environmental Protection Agency (EPA) has promulgated primary and secondary national ambient
air quality standards (NAAQS) for six criteria pollutants: SC^, NOX, CO, 03, PMjQ and Pb. These
primary (health-related) and secondary (welfare-related) pollutant standards are contained in Title 40, Part
50 of the Code of Federal Regulations (40 CFR 50). The reference methods for monitoring ambient
atmospheres for these criteria pollutants are in the Appendices of 40 CFR 50, A through G.
Section 109 of the Act requires EPA to evaluate, at 5-year intervals, the criteria for which standards
have been promulgated and to issue any new standards as may be appropriate.
The issuance of reference methods designed to monitor these criteria pollutants has a legal basis in
Section 301 of the Act, which states that the regulations necessary to carry out the provisions of the Act
may be promulgated by the Administrator. To evaluate and ascertain the status of air quality with regard
to the criteria pollutants, uniform analytical methods are used to ensure consistency and accuracy in the
data generated.
Suspended particulate matter (SPM) in air generally is considered to be all airborne solid and low
vapor pressure liquid particles. Suspended particulate matter in indoor air is a complex, multi-phase
system consisting of a spectrum of aerodynamic particle sizes ranging from below 0.01 jum to 100 /xm
and larger. Historically, particulate matter (PM) measurement has concentrated on total suspended
particulates (TSP), with no preference to size selection. The EPA's approach toward regulating and
monitoring TSP matter has evolved over time. When EPA first regulated TSP, the NAAQS was stated
in terms of particulate matter captured on a filter with an aerodynamic particle size of < 100 pm as
defined by the TSP sampler. Recently, the primary standard for TSP was replaced with a PMjQ
standard, which includes only particles with an aerodynamic diameter of 10 pm or less. More recently,
interest has centered on "respirable" particles (<2.5 fim), those particles small enough to be drawn into
and deposited in the respiratory system. Particles in this size range can have direct health effects. The
depth to which these particles can penetrate the respiratory system as a function of particle size is shown
in Figure 1.
Respirable particles are attributed to growth of particles from the gas phase and subsequent
agglomeration; most coarse particle (sizes 2.5-10 /tm) are made of mechanically abraded or ground
particles. Particles that have grown from the gas phase, either because of condensation, transformation,
or combustion, occur initially as very fine nuclei (0.05 /mi). These particles tend to grow rapidly to
accumulation mode particles around 0.5 pm which are relatively stable in the air. Coarse particles, on
the other hand, are mainly produced by mechanical forces, such as crushing and abrasion. These coarse
particles therefore normally consist of finely divided minerals, soil, or dust that result from entrainment
by the motion of air or from other mechanical action within their area. Since the mass of these particles
is normally > 3 fim, their retention time in the air parcel is shorter than-that of the fine particle fraction.
The EPA is considering further narrowing the primary NAAQS to even smaller particles, those
<2.5 jum in aerodynamic diameter. As shown in Figure 1, these smaller particles penetrate deeply into
the lung, where the potential for health effects is the greatest. In addition, the smaller particles typically
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.0-1
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Chapter IO-1
Overview _ Continuous FM-^Q Analyzers
are man-made. TSP typically has a bimodal distribution, with naturally occurring particles centered at
about 10 fan and man-made particles centered at about 0.4 pm (as shown in Figure 2).
Sampling options for PM10 compliance monitoring fall into two categories: "reference" methods and
"equivalent" methods. This Chapter, IO-1, "Continuous Measurements of Suspended Particulate Matter
(SPM) in Ambient Air," contains the equivalent methods approved for real-time monitoring of PM10
mass loading. Chapter IO-2, "Integrated Sampling of SPM,". contains the reference methods. The
equivalent methods for PM1Q presented in this chapter are instrumental and provide continuous
measurements of ambient PMjg concentration. Instruments using two different measurement principles
have received EPA's approval as equivalent methods: The first uses Beta-radiation; the second uses an
oscillating pendulum. Unlike the reference methods, the equivalent methods allow concentrations to be
tracked in real-time. This property is useful when parameters such as the diurnal variation in
concentration or the change in concentration associated with certain activities are of interest.
The beta attenuation monitor samples at ambient temperatures, relative humidities, and gas
concentrations to minimize particle volatilization biases. These monitors operate at a low-volume flow
rate (nominally 16.7 liters/minute [L/min]) using either a virtual impact or cyclonic flow operating
principal to determine the 50% cut-point. For beta attenuation monitors, low-energy beta rays (i.e.,
0.01-0.1 MeV electrons) are focused on deposits on a filter tape and attenuated according to the
approximate exponential function of particulate mass (i.e., Beer's Law). These automated samples
employ a continuous filter tape. Typically, the attenuation through an unexposed portion of the filter tape
Is measured, and the tape is then exposed to the ambient sample flow where a deposit is accumulated.
The beta attenuation is repeated, and the difference in attenuation between the blank filter and the deposit
is a measure of the accumulated concentration. Blank corrected attenuation readings can be converted
to mass concentrations for averaging times as short as 30 minutes. While these monitors are capable of
producing half-hourly average mass concentrations, 2-24-hour averaging periods are frequently required
with typical ambient concentrations to obtain sufficient particulate deposition for an accurate
determination.1 The two types of beta-gauges are the Graseby Beta-Gauge (Method IO-1.1) and the
Thermo Environmental, Inc. (formally Wedding and Associates) Beta-Gauge (Method IO-1.2).
o
The Graseby monitor directly measures particulate mass at concentrations of 0.005-20 mg/m on a
real-time basis. This instrument provides half-hourly and daily averages and allows for subsequent
chemical analysis of the particulate samples. With certain specifications, the Graseby instrument has been
designated as an equivalent method for determining 24-hour average PMjQ concentration in ambient air
by the EPA under Designation No. EQPM-0990-076, effective September 18, 1990. The monitor
described in detail in Method IO-1.1 presents the configuration and operation of the instrument as an
equivalent method for
With the Graseby instrument, ambient air enters the monitor through a PM^Q inlet head at a flow rate
volume of 16.7 L/min. The air containing PMjQ enters the instrument where it is pulled through the
glass fiber filter tape, and the particles are deposited on the tape. Low level beta radiation is emitted
from a stainless steel capsule, containing Krypton-85 gas, towards the filter tape containing deposited
PMin. The particle matter on the tape reduces the intensity of the beta radiation reaching the measuring
'Chow, J.C., "Measurement Methods to Determine Compliance with Ambient Air Quality Standards for Suspended Particles," /. Air &
Waste Manage. Assoc., Vol. 45: 320-382, 1995.
Page 1.0-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter 10-1
Continuous PM^Q Analyzers Overview
chamber on the opposite side of the tape. To compensate for the effect of the filter tape on the reduction
of the level of beta radiation, the source directs a second beam of beta particles through a "foil" that
mimics clean filter tape to a second measuring chamber (compensation chamber). No air flow is directed
to the compensation foil so the effect of the foil on the beta radiation intensity remains constant. The
instrument compares the measurement of the compensation foil to the measurement of the filter tape with
deposited PM1Q to determine the mass of the paniculate matter. Because changes in temperature,
pressure, or humidity can affect PM^Q measurement on the filter tape, the measurements made through
the compensation foil are impacted to the same degree. The foil measurements provide baseline data to
compensate for these meteorological effects. This monitor is less sensitive to temperature, pressure, and
humidity fluctuations than some other types of continuous particle monitors because the compensation foil
measurements provide baseline data. Because the measuring mechanism lacks moving parts, the
instrument is not as sensitive to vibrational effects as other types of continuous particulate monitors.
The Graseby monitor has certain limitations or interferences. In high-humidity or rainy climates,
water may collect on the filter tape and cause artificially high mass readings. In these same climates
where the instrument is housed in an air-conditioned environment, the ambient air inlet tube should be
insulated to avoid condensation or the inlet tube heater should be to ensure that any water drawn into the
unit is vaporized. For the particular beta particle source used in this instrument, any replacement or
maintenance work on the source may be performed only by trained personnel with radiological
authorization.
The Thermo Environmental, Inc., beta gauge operates under the same basic principles as the Graseby
monitor, but with some differences. This instrument was designated as an equivalent method for PMi0
by the EPA under Designation No. EQPM-0391-081, effective March 5, 1991. The configuration and
operation of this instrument is described in detail in Method IO-1.2. The Thermo monitor can measure
ambient mass concentration with a resolution of about 3 jig/m3 for a 1-h sampling period. A constant
volumetric flow rate for the PM1Q inlet of 18.9 L/min is used compared to the 16.67 L/min for the
Graseby unit. A major difference between the two monitors is the beta source. The Thermo monitor
uses a carbon-14 beta source compared to Krypton-85 gas for the Graseby monitor. The carboh-14
source does not require a license by the Nuclear Regulatory Commission, whereas the Krypton-85 does.
Apparatus and operational differences between the two instruments are described in Methods IO-1 1 and
IO-1.2.
Different from the beta-gauges, the Rupprecht and Pataschnick (R&P) PM1Q monitor is based upon
a tapering element oscillating microbalance (TEOM®) as a filter-based measurement system to
continuously measure particulate mass at concentrations between 5 /ig/m3 and several g/m3 on a real-time
mass monitoring basis. The instrument calculates mass rate, mass concentration, and total mass
accumulation on exchangeable filter cartridges that are designed to allow for future chemical and physical
analysis. In addition, this instrument provides for hourly and daily averages. This system operates on
the principal that particles are continuously collected on a filter cartridge mounted on the tip of a tapered
hollow glass element. The element oscillates in an applied electric field. With this monitor, particle-
laden air enters through an air inlet and then passes to the sensor unit containing the patented
microbalance system. The inlet system may or may not be equipped with an optional sampling head to
pre-separate particles at either a 2.5 or 10 fim diameter. The R&P PM1Q inlet is designed to allow only
particulate matter ^ 10 /*m in diameter to remain suspended in the sample air stream as long as the flow
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.0-3
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Chapter IO-1
Overview Continuous PM10 Analyzers
rate of the system is maintained at 16.67 L/min. The monitor can be operated as a TSP monitor or as
a PMjQ monitor.
In operation, the sample stream passes into the microbalance system, which consists of a filter
cartridge and oscillating hollow tube, where the stream is heated to a predetermined temperature. The
filter cartridge is a 1/2 diameter thin aluminum base (foil-like) assembly. A water resistant plastic cone,
which fits onto the oscillating element, is attached to the aluminum base. An automatic flow controller
pulls the sample stream through the monitor at flow rates between 0.5 and 5 L/min. The wider end of
the hollow element is fixed to a platform and is vibrated at its natural frequency. The oscillation
frequency of the glass element is maintained based on the feedback signal from an optical sensor.
As mass accumulates on the filter cartridge, the resonant frequency of the element decreases, resulting
in a direct measurement of inertial mass. Based upon the direct relationship between mass and frequency,
the monitor's microcomputer calculates the total mass accumulation on the filter and the mass rate and
mass concentration in real-time.
The TEOM® monitor is very sensitive to mass concentration changes and can provide precise
measurements for sampling durations of 1-h or less. To achieve this level of precision, the hollow glass
element must be maintained at a constant temperature to minimize the effects of thermal variations.
Because the instrument's primary operating mechanism is the microbalance system, the instrument should
be isolated from mechanical noise and vibration. The operating temperature of the element can be
lowered to minimize the potential particle loss bias for more volatile compounds but must be maintained
above the maximum ambient temperature encountered during the field sampling. The tapered element
oscillating microbalance is discussed in detail in Method IO-1.3, Rupprecht and Pataschnick TEOM®.
Page l.(M Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter 10-1
Continuous
Analyzers
Overview
30 microns
9.2 - 30 microns
5.5 - 9.2 microns
3.5 - 5.5 microns
2.0 - 3.3 microns
1.0 - 2.0 microns
0.3-1.0 microns
0.1 -3.0 microns
Trachea & primary
bronchi
Secondary
bronchi
Terminal
bronchi
Alveoli
Alveoli
Figure 1. Depth of respiratory system penetration based on particle size.
Source: U.S. EPA, Air Pollution Training Institute (APTI), Course No. 435.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.0-5
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Overview
Chapter IO-1
Continuous PM10 Analyzers
a
\
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EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-1.1
DETERMINATION OF PM10
IN AMBIENT AIR USING
THE GRASEBY CONTINUOUS
BETA ATTENUATION MONITOR
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method KM. 1
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA
No. 2-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc.
(ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A.
Manning, Center for Environmental Research Information (CERI), and Frank F. McElroy, National
Exposure Research Laboratory (NERL), both in the EPA Office of Research and Development, were
the project officers responsible for overseeing the preparation of this method. Other support was
provided by the following members of the Compendia Workgroup:
James L. Cheney, Corps of Engineers, Omaha, NB
Michael F. Davis, U.S. EPA, Region 7, KC, KS
Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC/
Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
William A. McClenny, U.S. EPA, NERL, RTP, NC
Frank F. McElroy, U.S. EPA, NERL, RTP, NC
William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
• Stephe Edgerton, Midwest Research Institute, Gary, NC
Peer Reviewers
Richard Shores, Research Triangle Institute, RTP, NC
David Brant, National Research Center for Coal and Energy, Morgantown, WV
Charles Rodes, Research Triangle Institute, RTP, NC
John Glass, SC Department of Health and Environmental Control, Columbia, SC
Danny France, U.S. EPA, Region 4, Athens, GA
David Harlos, Environmental Science and Engineering, Gainesville, PL
Jim Tisch, Graseby, Cleves, OH
Justice Manning, U.S. EPA, Cincinnati, OH
William Bope, South Coast Air Quality Management District, Diamond Bar, CA
Femi Durosinmi, Clark County Health District, Las Vegas, NV
Rob Ford/Tom Merrifield, Graseby, Atlanta, GA
Bill Vaughan, Environmental Solutions, St. Louis, MO
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
-------
Method IO-1.1
Determination of PM10 in Ambient Air
Using the Graseby Continuous Beta
Attenuation Monitor
TABLE OF CONTENTS
1. Scope 11-1
2. Applicable Documents 1 1_3
2.1 ASTM Standards '.'.'.'.'.'.'.'.'.'.'.'.'.'. 1.1-3
2.2 Other Documents : 11-3
3. Summary of Method 1 1_3
4. Significance 1.1-4
5. Definitions . . 11-4
6. Interferences 11-5
7. Apparatus . 11-6
7.1 Air Inlet -........'.'.'.'.'.'.'.'.'.'.'. 11-6
7.2 Central Instrument 1.1-6
7.3 Vacuum Pump 11-7
7.4 Accessories 11-7
8. Assembly 11-8
8.1 Connections 11-8
8.2 Startup '.'.'.'.'.'.'.'.'.'.'.'.'.' 11-8
9. Installing the Filter Tape '.'.'.'.'.'.'.'.'.'.'. 11-8
10. Operation and Data Storage '.'.'.'.'.' 11-9
11. System Calibration j j_15
11.1 Particle Mass 1 1-15
11.2 Air Flow Rate '.'.''.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. 1.1-16
11.3 Leak Check 1 1-18
12. Method Safety •-. '.'.'.'.'.'.'.'.'.'.'. 1 1-18
13. Maintenance 1 1-18
13.1 Vacuum Pump 1 j_jg
13.2 PM10 Inlet '.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. 1 1-18
13.3 Radioactive Source j \-\9
13.4 Air Flow Regulator Bleed Valve '.'.'.'.'.'.'.'. 1.1-19
14. Performance Criteria and Quality Assurance (QA) '.'.'.'.'. 1.1-19
14.1 Standard Operating Procedures (SOPs) !.!!!!.! Ll-19
14.2 Quality Assurance Program I 1_19
15. References 11-20
in
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Chapter IO-1
CONTINUOUS PM1Q ANALYZERS
Method IO-1.1
DETERMINATION OF PM10 IN AMBIENT AIR
USING THE GRASEBY CONTINUOUS BETA ATTENUATION MONITOR
1. Scope
1.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has enabled U. S. Environmental Protection Agency (EPA) to
identify the elemental composition of atmospheric aerosol into components and relate them to specific
emission sources. The assessment of human health impacts resulting in major decisions on control actions
by federal, state, and local governments is based on these data. Accurate measures of toxic air pollutants
at trace levels are essential to proper assessment.
1.2 Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01 jum to
100 jim and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.3 The EPA reference method for TSP is codified at 40 CFR 50, Appendix B. This method uses a
high-volume sampler (hi-vol) to collect particles with aerodynamic diameters of approximately 100 ^m
or less. The hi-vol samples 40 and 60 fr/min of air with the sampling rate held constant over the
sampling period. The high-volume design causes the TSP to be deposited uniformly across the surface
of a filter located downstream of the sampler inlet. The TSP high volume can be used to determine the
average ambient TSP concentration over the sampling period, and the collected material subsequently can
be analyzed to determine the identity and quantity of inorganic metals present in the TSP.
1.4 Research on the health effects of TSP in ambient air has focused increasingly on those particles that
can be inhaled deeply into the respiratory system, i.e., particles of aerodynamic diameter less than 10 jim.
The health community- generally recognizes that these particles may cause significant, adverse health
effects.
1.5 On July 1, 1987, the EPA promulgated a new size-specific air quality standard for ambient
particulate matter. This new primary standard applies only to particles with aerodynamic diameters
<10 micrometers (PM^) and replaces the original standard for TSP. To measure concentrations of
these particles, the EPA also promulgated a new federal reference method (FRM). This method is based
on the separation and removal of non-PMjQ particles from an air sample followed by filtration and
gravimetric analysis of PM^Q mass on the filter substrate.
1.6 The new primary standard (adopted to protect human health) limits PMjQ concentrations to
150 jig/std m , averaged over a 24-h period. These smaller particles are able to reach the lower regions
of the human respiratory tract and, thus, are responsible for most of the adverse health effects associated
with suspended particulate pollution. The secondary standard, used to assess the impact of pollution on
public welfare, has also been established at 150 jig/std. nA
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-1
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Method IO-1.1 Chapter IO-1
Graseby Beta Gauge Continuous PM^Q Analyzers
1.7 Monitoring methods for participate matter (PM) are designated by the EPA as reference or equivalent
methods under the provisions of 40 CFR Part 53, which was amended in 1987 to add specific
requirements for PM^Q methods. Part 53 contains functional specifications and other requirements that
reference methods and equivalent method must meet, along with explicit test procedures for candidate
methods or samplers. General requirements and provisions for reference and equivalent methods are also
given in Part 53, as are the requirements for submitting an application to the EPA for a reference or
equivalent method determination.
1.8 Under the Part 53 requirements, reference methods for PM^Q must use the measurement principle
and meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a PM^Q
sampler that meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies a
measurement principle based on extracting an air sample from the atmosphere with a powered sampler
that incorporates inertial separation of the PMjQ size range particles followed by collection of the PMjQ
particles on a filter over a 24-h period. The average PM^Q concentration for the sample period is
determined by dividing the net weight gain of the filter over the sample period by the total volume of air
sampled. Other specifications are prescribed in Appendix J for flow rate control and measurement, flow
rate measurement device calibration, filter media characteristics and performance, filter conditioning
before and after sampling, filter weighing, sampler operation, and correction of sample volume to EPA
reference temperature and pressure. In addition, sampler performance requirements in Subpart D of
Part 53 include sampling effectiveness (the accuracy of the PM^Q particle size separation capability) at
each of three wind speeds and "50% cutpoint" (the primary measure of 10-micron particle size
separation). Field tests for sampling precision and flow rate stability are also specified. In spite of the
instrumental nature of the sampler, this method is basically a manual procedure, and all designated
reference methods for PMjQ are therefore defined as manual methods.
1.9 The operational procedures of a continuous PMjQ monitor that directly measures particulate mass
at concentrations of 0.005-20,000 [ig/nr on a real-time basis, as illustrated in Figure 1, is described in
this method.
1.10 The instrument periodically (averaging ranges from 1A hours to daily) 'determines total mass
accumulation on a filter medium and calculates mass concentration. It uses a continuous filter tape system
that reduces the need for frequent manual filter changes and allows for later chemical analysis of the
acquired
1.11 With certain specifications, the instrument has been designated as an equivalent method for
determining 24-h average PMjg concentration in ambient air by the EPA under
Designation No. EQPM-0990-076, effective September 18, 1990 (1). Except as otherwise noted, this
protocol addresses the configuration and operation of the instrument as an equivalent method for
1.12 The methodology detailed hi this method is employed by organizations such as the EPA, the
Northwest Air Pollution Authority, the Palm Beach County Health Department, and Echo Bay Minerals
Company for indoor and outdoor air quality monitoring.
Page 1.1-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.1
Continuous PM^Q Analyzers Graseby Beta Gauge
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2 Other Documents
• U. S. Environmental Protection Agency Technical Assistance Document (2).
• U. S. Environmental Protection Agency Quality Assurance Handbook (3).
• Graseby PM^Q Beta Attenuation Monitor Operator Manual (4).
3. Summary of Method
3.1 In operation, suspended particles in ambient air are pulled through the PM10 inlet head at a flow
rate of 16.7 L/min. The inlet head consists of a series of impaction plates to segregate particulate matter
by size. Because of the design of the inlet, accurate sampling is accomplished independent of wind speed
and direction.
3.2 Air is drawn into the inlet and deflected downwards into the acceleration jet of the impact unit.
Because of their greater mementum, particles larger than the 10 micron cutpoint impact out and are
retained in the middle plenum impaction chamber, as illustrated in Figure 2. The particle fraction smaller
than 10 microns is carried upward by the air flow and down the vent tubes to the beta gauge sampler.
3.3 After traversing the inlet configuration, the PM1Q particles are deposited on a glass fiber filter tape.
A low level of beta radiation is emitted from the source and passes through the filter tape and deposited
particles. The increase of particles collected on the tape causes a lower beta-ray measurement in the
measuring chamber, as illustrated in Figure 3. This filter-spot position results in a continuous observation
of the increasing particulate mass and corresponding concentration. A compensation chamber receives
an equal portion of the beta-ray and is used as a reference by comparing the sample measurement in the
measuring chamber with transmitted radiation through a compensation chamber foil that exhibits the same
absorbtivity as clean filter tape.
3.4 As particles collect on the filter, the differential reading changes, and the signal is converted by a
on-board computer to PMjQ concentrations.
3.5 Changes in temperature, pressure, and humidity affect the PMjQ measurement on the filter tape; the.
measurements made through the compensation foil are affected to the same degree. Thus, the foil
measurement supplies baseline information to the internal computer that allows the instrument to
compensate for environmental effects.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-3
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Method IO-1.1 Chapter IO-1
Graseby Beta Gauge _ _ Continuous PM10 Analyzers
3.6 By measuring the accumulated mass of particles on the tape and the volumetric flow rate of air
through the instrument, the instrument can calculate the mass concentration of particles in the ambient
air.
3.7 The unit controls allow the user to define the operating parameters of the instrument by menu-driven
routines.
3.8 Output from the monitor maybe in the form of visual display, on-board computer storage, telemetry,
printout, or storage in an auxiliary disc. Output can be in digital or analog form.
4. Significance
4.1 SPM in outdoor air presents a complex multiphase system consisting of a spectrum of particle sizes
ranging in aerodynamic diameter from below 0.01 /*m to greater than 100 /mi. Historically, the
measurement of suspended particulate matter encompassed all suspended particulates, with no preference
to size selection. Research on the health effects of TSP in ambient air has focused increasingly on those
particles that can be inhaled into the respiratory system (i.e., PM^Q). Researchers generally recognize
that, except for toxic materials, this fraction (< 10 fim) of the total particulate loading is of major
significance in health effects. As a result, the primary NAAQS for PM is now specified as PM1Q.
4.2 Because of the health effects of PM1Q, this continuous particulate monitor has been developed to
allow mass measurement of PM concentration on a real-time basis.
4.3 The monitor utilizes a filter-based measuring system for providing real-time mass monitoring
capability. With certain specifications, the monitor has been designated by EPA as an equivalent method
for determining the 24-h average ambient concentration of PM^Q. ^n addition, the instrument can be
operated outside the equivalent method specifications to perform other types of PM sampling programs.
4.4 The particulate sample is retained on the filter tape, allowing for subsequent analysis. The
instrument can be equipped with an optional date and time stamper for labeling each sample spot on the
filter tape.
5. Definitions
[Mote: Terms used in this document are consistent with the definitions found in ASTMD1356. All
abbreviations and symbols are defined within this document at the point of first use. Any user-prepared
standard operating procedures (SOP) should also conform to the definitions ofASTM D1356.J
5.1 Air Pollution. The presence of unwanted material in the air. The term "unwanted material" here
refers to material in sufficient concentrations, present for a sufficient time, and under circumstances to
interfere significantly with comfort, health, or welfare of persons or with the full use and enjoyment of
property.
5.2 Beta Particle. An elementary particle emitted by radioactive delay, that may cause severe burns.
Page 1.1-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.1
Continuous PM^ Analyzers Graseby Beta Gauge
5.3 Coarse and Fine Particles. Coarse particles are those with diameters (aerodynamic) greater than
2.5 /trn that are removed by the sampler's inlet; fine particles are those with diameters (aerodynamic) less
than 2.5 p.m. These two fractions are usually defined in terms of the separation diameter of a sampler.
5.4 Filter. A porous medium for collecting particlulate matter.
5.5 Mass Concentration. Concentration expressed in terms of mass of substance per unit volume of
gas.
5.6 Particle. A small discrete mass of solid or liquid matter.
5.7 Particle Concentrations. Concentration expressed in terms of number of particles per unit volume
of air or other gas. NOTE: On expressing particle concentration the method of determining the
concentration should be stated.
5.8 Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In
air or gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous
isolation of selected components.
5.9 Sampling, Continuous. Sampling without interruptions throughout an operatoin or for a
predetermined time.
6. Interferences
6.1 In high humidity or rainy climates, water may collect on the filter tape, causing artificially high mass
readings. In hot, humid environments where the instrument is housed in an air-conditioned shelter, the
inlet tube within the shelter should be insulated to avoid condensation. In rainy climates, the instrument's
inlet tube heater may be used to ensure that any water drawn into the unit is in vapor phase as it passes
through the filter. The heater should be set at the lowest effective temperature to avoid volatilizing any
semivolatiles in the PMjQ. A brief accumulation of water on the filter tape that subsequently evaporates
as drier air is pulled through the instrument will cause erroneous short-term readings, but the 24-h
average value will not be adversely affected.
6.2 The instrument's primary operating mechanism is the radiometric microbalance system, which relies
on changes in the strength of a beta ray beam passing through the filter paper to determine changes in
particulate mass collected. Because this mechanism lacks moving parts, the instrument is not sensitive
to vibrations (i.e., vacuum pump vibration or mechanical noise) that might hurt the accuracy of some
other types of continuous particulate monitors.
6.3 The instrument is also less sensitive to temperature, pressure, and humidity fluctuations than some
other types of continuous particulate monitors because of the second beta ray measurement that provides
baseline information to the internal computer. Because the instrument compensates for fluctuations in
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-5
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Method 10-1.1 Chapter IO-1
Graseby Beta Gauge Continuous PM10 Analyzers
temperature, the ambient air stream does not need to be heated to a particular standard temperature as
long as the ambient air is within the operating range (-20 to 40°C). Heating the ambient air stream can
eliminate some semivolatile chemicals that would normally be detected by the instrument, leading to
inaccuracies in both mass measurements and later chemical analyses. The heating for moisture control
is discussed in Section 6.1.
6.4 The instrument's electronic and mechanical parts should be protected against rain, condensation, and
rapid temperature fluctuations.
7. Apparatus
The Graseby Beta Attenuation Monitor is comprised of three main components: the PM JQ air inlet, the
central instrument, and the vacuum pump. In addition, a number of accessories are required. The
following sections describe these components.
7.1 Air Inlet
7.1.1 To qualify as an EPA equivalent method for PM10, the instrument must be fitted with a model
SA 246b air inlet. When operated at the design flow rate of 1,000 L/h, this air inlet separates particles
larger than 10 pm from the airstream, allowing particles smaller than 10 jim to pass into the measurement
device for detection. The manufacturer also offers a TSP and fine particle (<2.5 /tm) inlets.
7.1.2 As illustrated in Figure 4, the air inlet has an upper and lower assembly. The upper assembly
comprises a top plate, deflector, acceleration nozzle, insect screen, and lower plate and rain deflector.
The lower assembly comprises a particle collector unit, vent tubes, and water collection jar. An inlet
tube also is supplied to connect the PMjQ inlet to the central instrument.
7.2 Central Instrument
The central instrument is illustrated in Figures 5 and 6 (front and back, respectively). The front of the
instrument is sealed with a transparent protective cover, which can be removed by unscrewing the two
black knobs on its surface. Removing the cover exposes the measuring chamber, the filter tape advance
system, and the operating controls. The controls consist of a liquid crystal display (LCD) and keyboard
located in the upper right corner of the front panel. Also located on the front panel is a label indicating
that the instrument has been designated by EPA as an equivalent method for PM^Q. (If this label is not
present, contact the manufacturer.) The power switch for the instrument, connection points for power,
vacuum tubing, and data input/output devices are located on the back of the instrument. The socket for
connecting the inlet tube is located on the top of the instrument. The major components of the central
instrument are discussed below.
7.2.1 Filter Tape System. The instrument draws ambient air from the air inlet and inlet tube
through glass fiber filter tape, depositing the PMjQ on the tape. (Glass fiber filter tape must be used for
designation as an equivalent method for PMjQ.) The filter tape system consists of two filter tape reels:
the left reel holds the spool of clean tape and the right reel receives the used tape with deposited PMjQ.
The left reel holds up to 42 meters of tape. The internal computer advances the tape according to preset
parameters (e.g., mass accumulation limits, pressure or flow rate changes, and timed intervals). The
Page 1.1-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.1
Continuous PM10 Analyzers _ Graseby Beta Gauge
mass collected on the filter tape is measured, along with the volume of air that has passed through
the tape, to determine the concentration of PMjQ in the ambient air.
7.2.2 Measurement System. The main components of the measurement system (radiometric
microbalance) are the radiation source and the measurement and compensation chambers. .The radiation
source is a stainless steel capsule containing Krypton 85 gas. The measurement chamber is situated above
the radiation source and is separated from the radiation source by the spot on the filter tape where the
PMjQ is currently being deposited. The compensation chamber is to the side of the radiation source and
is separated from the radiation source by a piece of foil that absorbs approximately the same amount of
radiation as clean filter tape. During operation, the radiation source focuses radiation beams towards both
the measurement and compensation chambers. The particle-laden filter tape absorbs more radiation than
the compensation foil. The difference in measurements indicates the PM^Q mass collected on the filter.
7.2.3 Flowmeter and Flow Controller. The flow rate of air through the filter tape is an important
parameter in the calculation of the ambient PM^g concentration. To measure this parameter, an orifice-
type flowmeter is located inside the cabinet just prior to the connector for the vacuum tubing to the pump.
For proper particle size selection at the PM^g inlet, the instrument must maintain a stable flow rate at
the design level of 1,000 L/h. To achieve constant flow, the instrument is fitted with an airflow regulator
bleed valve interposed in the intake line of the pump. The regulator valve is mounted on the inside of
the back of the cabinet with the air intake and air filter on the back panel. The valve servomotor is
actuated by thyristors controlled by the internal computer. The system maintains the selected flow rate
within a deviation of ±0.5%, regardless of changes in temperature, pressure, or pressure drop across
the filter (which increases as PM^Q accumulates). The flow metering and control system is diagrammed
in Figure 7.
7.2.4 Internal Computer. The internal computer calculates and records PM^Q measurements
reported by the measurement mechanism. Based on the mass of particles collected and the volumetric
flow rate of air, the computer calculates ambient concentration. The computer also serves as an interface
between the operator and the instrument. The operator can use the computer to set operating parameters,
transmit information about monitored air quality, and perform maintenance operations.
7.2.5 Control Keys and LCD. The control keys and LCD allow the operator to view the measured
values and to change the settings of the instrument's operational parameters. The controls are based on
a menu system. Above the LCD are a number of small lights that indicate the status of various
instrument systems. The keyboard and control system are described more fully in Section 10.1.
7.3 Vacuum Pump
The external vacuum pump is connected to the monitor by a power cord and air hose. When the monitor
is in operation, the pump continuously draws 1,000 L/h of ambient air through the monitor. The pump
has a rotary vane construction that is known for low maintenance during continuous operation. The pump
is fitted with protective filters.
7.4 Accessories
7.4.1 Calibration Kit. Each instrument comes with a set of two calibration foils. During periodic
maintenance, these foils are used to recalibrate the instrument. The foils are designed to absorb a certain
percentage of the beta ray beam. With the zero foil inserted into the measurement chamber, the
instrument is automatically rezeroed. When the span foil is inserted, the calibration "potentiometer" on
the control panel is used to adjust the mass reading to the known span foil value. The recalibration
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-7
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Method IO-1.1 Chapter IO-1
Graseby Beta Gauge Continuous PM10 Analyzers
procedure is described in Section 11. The calibration foils are included in EPA's designation of the
instrument as an equivalent method for PMjQ.
7.4.2 Vacuum Tubing. A length of vacuum tubing is supplied to link the central instrument to the
vacuum pump.
7.4.3 Power Cord. An unattached power cord is supplied with the instrument. The cord must be
attached to the back of the instrument at the appropriate location and plugged into the power supply.
7.4.4 Filter Tape. Two rolls of filter tape are supplied with the instrument. The lifetime of a roll
depends on the frequency with which the tape is advanced to a new sampling spot. At 40 meters, each
roll has the capacity for about 1,300 sample spots. Normal PM10 operation uses 1 to 2 spots in 24 hrs.
7.4.5 Input/Output Connectors. The instrument can be used with a variety of input and output
devices. Consult the Operator Manual or the manufacturer for specifics on the options that are available
and the appropriate connection cords.
8. Assembly
{Note: When the instrument is used outdoors, protect if from the elements, particularly rain. When the
central instrument is installed in the outdoor environmental shelter, be certain the sampler tube leading
out of the shelter roof has a watertight fit.]
8.1 Connections
Connection points are numbered on Figures 5 and 6. The following instructions refer to those numbers.
1. Connect the inlet tube to the male connector (1) on the top of the central instrument. Tighten
union nut firmly.
2. Connect the pump to the hose socket (26) on the back of the central instrument.
3. Connect the vacuum pump power cord to the back of the central instrument (24).
4. As applicable, connect the selected input and output devices to the appropriate connection points
on the back of the central instrument.
5. Connect the power eord to the socket on the back of the central instrument (23) and to a 115 volt
(V), 60 Hertz (Hz) power supply.
8.2 Startup
After establishing all connections, the device is ready to use and can be turned on with the power switch
(22) on the back of the central instrument. The unit automatically starts a filter change and zero. To
prevent soiling of the measuring chambers, install the filter tape immediately after switching on the power
if the filter tape has not been installed previously.
9. Installing the Filter Tape
[Note: Upon arrival, a new Graseby Beta Gauge Sampler will already be equipped with filter tape.
Follow the procedures outlined below to prepare the instrument for operation. Follow these same
procedures to replace used filter tape reels.]
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Chapter IO-1 Method IO-1.1
Continuous PM10 Analyzers Graseby Beta Gauge
9.1 Switch the sampler power on if this has not yet been done.
9.2 Remove the front cover of the sampler.
9.3 Unscrew and remove the nut from the left reel spindle and place a new filter tape reel on the spindle.
Place the reel so that it will turn counter clockwise as the tape unwinds.
9.4 Press the BACK key on the keyboard until the LCD reads "Maintenance and Calibration."
(Additional information on the operation of the control keys is presented in Section 10.1.)
9.5 Press the YES key and then the NO key to enter interactive maintenance mode.
9.6 Press the NEXT key and then the YES key to switch the vacuum pump off.
9.7 Press the NEXT key and then the YES key to raise the measuring head.
9.8 Unwind about 1 meter of filter tape and thread it around the rollers and through the gap in the dust
collection chamber as shown in Figure 5.
9.9 Unscrew and remove the nut from the right reel spindle. Place an empty filter tape reel on the
spindle. Secure the free end of the filter tape to the empty reel with adhesive tape.
9.10 Rotate the empty reel counter-clockwise to remove slack from the filter tape between the reels.
9.11 Return the nuts to both spindles.
9.12 Initiate the filter change cycle by pressing the FC + Z control key (right key).
9.13 The instrument will sense if the feed reel does not turn (i.e., if the feed reel is empty or if the slack
has not been taken out of the tape between the reels). Consequently, the pump will not switch on after
the filter change. If the pump does not come on, check the filter strip tension and initiate another filter
change cycle or switch the pump on with the control keys (see Section 10.1).
10. Operation and Data Storage
[Note: After the filter tape has been installed, the appropriate operating parameters must be set using
the control system. The functioning of the control system is explained below in Section 10.1, and the
initial settings are discussed in Section 10.2. Additional topics are covered in Sections 10.3 through
10.7. The manufacturer presets all PMjQ parameters at the factory except local time, elevation and
outputs.
The instrument can be operated within an ambient temperature range of-20 to +40°C. Storage and
transport are possible without damage within a temperature range of-30 to +60°C. The instrument
should be protected from rain, condensation, and rapid temperature fluctuation during operation.]
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Method 10-1.1 ChaPter I(M
Grascby Beta Gauge Continuous PM10 Analyzers
10.1 Control System
10.1.1 The control keyboard and status lights are illustrated in Figure 8. The control menu tree is
diagrammed in Figure 9. By moving through the menu, the control keys can be used to view measured
values on the LCD or to change the operating parameters of the instrument.
10.1.2 Keyboard/Interface Enable.
10.1.2.1 The keyboard and data interface are enabled alternatively. In normal operating mode,
the "On line" status light is lit. Under these conditions,, the keyboard is disabled. No parameters can
be changed and a filter change cannot be initiated manually. The serial and parallel interface are active.
10.1.2.2 When the concentration value is displayed on the LCD, the keyboard can be enabled by
the key sequence YES, NO, NEXT. (See Figure 8 and Sections 10.1.2 through 10.1.4 for information
about the control keys.) This sequence enables the keyboard and disables the control via the interfaces.
(The keyboard also can be enabled from the first screen under the "Maintenance and Calibration?"
parameter group.) The "On line" status light is switched off. All parameters can be changed with UP
and DOWN. Filter change and printout can be initiated with the FC + Z key.
10.1.2.3 If no key is struck for 4 min, the device reverts automatically to normal operating mode.
The keyboard is disabled, and interfaces are enabled again. The keyboard can also be disabled from the
first screen under the "Maintenance and Calibration?" parameter group.
10.1.3 The two keys on the left have a dual function, depending on the LCD display.
Parameters shown on the display can be altered:
DOWN key for lower values,
UP key for higher values.
A question asked on the display can be answered with YES or NO.
10.1.4 The next two keys (BACK and NEXT) are used for interactive and display control. The
NEXT key advances to the next dialog text; the BACK key backspaces. Pushing the NEXT key will
consecutively call up the following text and displays on the LCD (see Figure 9).
(1) DUST CONCENTRATION: XXX jig/m3
(2) DUST MASS: XXX us
(3) OBSERVING TIME:
(4) THRESHOLDS?
(5) DATE/TIME 86-02-19 8:45:23 (EXAMPLE)
(6) LAST CHANGE 90-08-22 13:12 (EXAMPLE)
(7) CHANGE FILTERSTRIP?
(8) CALIBRATION FACTORS AND AIR FLOW RATE?
(9) OUTPUTS?
(10) MAINTENANCE AND CALIBRATION?
The first two points above are measured value displays. Lines 3-10 are the beginnings of parameter
groups. In Group 10, it is possible to implement all action necessary for maintenance and calibration
(e.g., raise measuring head).
When a parameter group heading is being displayed, press the YES key to access the parameter group;
press the NEXT key to advance the parameters, displays, or questions within the group; or press the
BACK key to reverse the process.
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Chapter IO-1 Method IO-1.1
Continuous PM10 Analyzers ^ Graseby Beta Gauge
Example: If the LCD reads "Change Filterstrip ?", the following texts will be called up by the key
sequence YES, NEXT, NEXT, NEXT, NEXT, NEXT (see Figure 9):
CHANGE FILTERSTRIP? YES
FILTER CHANGE IF MASS > 2,400 ^g NEXT
CHANGE IF PRESSURE >300kPa NEXT
CHANGE IF FLOW RATE <9501/h NEXT
FILTER CHANGE BY CYCLE: 420 min NEXT
FILTER CHANGE BY TIME: 24:00 h NEXT
CALIBRATION FACTORS AND
AIR FLOW RATE?
Each displayed parameter can be altered by means of the UP and DOWN keys. When the NEXT key
is struck, the edited value is entered. When the BACK key is struck, edited values are not entered.
10.1.5 The right key is labeled "FC + Z/PRINT." The function of this key depends on the status
of the interactive system. Pressing this key initiates a filter change and zeroing sequence except when
the system is accessing the digital interface; then, depressing this key causes the preset parameters to be
printed.
10.2 Initial Settings
After the filter tape has been installed (see Section 9), set the appropriate operating parameters for the
instrument. If the instrument was purchased to operate as an EPA equivalent method for PM10, a label
should be on the front of the central instrument showing this designation, and the parameter settings
should be correct when the instrument is turned on. (If the equivalent method designation label is not
present, contact the manufacturer to determine whether the instrument can be operated as an equivalent
method.) Follow the instructions below to verify that the operating parameters are set properly and to
correct any that are wrong. See Figure 9 for the menu tree diagram to facilitate movement through the
control system software.
10.2.1 Enable Keyboard. Enable the keyboard as discussed in Section 10.1.1. (This action will
disable the serial and parallel interfaces.) The "On line" status light will go out when the keyboard is
enabled.
10.2.2 Observing Time. After the keyboard has been enabled, press the NEXT key until the LCD
displays "OBSERVATION TIME: CON VARIABLE = N CONST = Y." Press the YES key to select
a constant observing time. Display shows "EPA - MODE: NO." Press NEXT key, UP and DOWN
keys to set observing time at 60 minutes. This is a required setting for equivalent method for PM1n.
Press the NEXT key to enter this value.
10.2.3 Date/Time. Press the NEXT key until the LCD reads "Date/Time." If the displayed date
and time are correct, proceed to Section 10.2.4. If the date and time are not correct, enter this parameter
group by pressing the YES key. Set the correct year using the UP and DOWN keys, then press NEXT
to advance to "month." Use the UP and DOWN keys to set the correct month and press NEXT to
advance to "day." Proceed in this manner until the year, month, day, hour (24-h clock), minute, and
second have been set. After the second has been set, press NEXT to enter the new date and time into
the instrument.
10.2.4 Automatic Filter Change. Press the NEXT key until the LCD reads "Filter Change?" and
press the YES key to enter this parameter group. In this group, the user sets parameters that
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-11
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Method 10-1.1 . ,
Graseby Beta Gauge _ Continuous PM1ft Analyzers
automatically initiate a filter tape advance. For each parameter, use the UP and DOWN keys to set the
desired value and press the NEXT key to enter the selected value and advance to the next parameter.
See Table 1 for the sequence of parameters.
10.2.5 Calibration Factor. Press the NEXT key until the LCD reads "Calibration and Air Flow
Rate?" and press the YES key to enter this parameter group. The LCD will read "Calibration Factor."
Use the UP and DOWN keys to set this parameter at 2400, which is a required setting for the equivalent
method for PM10. Press the NEXT key to enter this value.
10.2.6 Standard Volume. When the NEXT key is pressed to enter the required calibration factor,
the menu advances to the screen for selecting the terms in which the PM10 concentration will be
expressed. Press the NO key to toggle back and forth between EPA standard conditions (298 K,
1013 kilopascals [kPa]) and scientific STP (273 K, 1013 kPa). Press the YES key to select actual
operating conditions. When the LCD shows the desired terms (generally EPA standard conditions), press
the NEXT key to enter the selection.
10.2.7 Elevation. When the NEXT key is pushed to enter the desired terms for concentration, the
menu advances to the screen for entering the "altitude above sea level" (in meters) at which the
instrument will be operated. Use the UP and DOWN keys to set this parameter. This value is used by
the instrument to calculate the theoretical ambient barometric pressure at the monitor site to determine
the flow rate (The instrument does not directly measure the ambient barometric pressure.) See
Section 3.6.1 of the Operator Manual for the details of the calculation. If desired, the user can calculate
the elevation that corresponds to the seasonal average barometric pressure at the site and enter this
elevation in place of the actual elevation. When the desired elevation has been set, press the NEXT key
to enter the selection. . .
10.2.8 Air Flow Rate. When the NEXT key is pressed to enter the desired elevation, the LCD will
display the current measured value for the flow rate. Press the YES key to advance the menu to the
screen where the flow rate can be set; use the UP and DOWN keys to set the flow rate at 1,000 L/h.
(This is a required setting for the equivalent method for PM1Q.) Press the NEXT key to enter the
required flow rate. ... i
10.2.9 Flow Rate Minimum and Maximum. The EPA sampling guidelines require that the actual
flow rate be within ± 10% of the nominal flow rate. The next two LCD screens allow the user to set the
minimum and maximum acceptable flow rates. If the measured flow rate is outside the acceptable range,
the green "Air Flow" status light goes out and the yellow status light comes on. In addition, the
electronic output will indicate an "alarm" status for the air flow rate.
When the NEXT key is pressed to enter the required air flow rate (Section 10.2.8), the menu advances
to the screen for entering the minimum acceptable flow rate. Use the UP and DOWN keys to set this
parameter to 900 L/min. Press the NEXT key to enter this value and to advance to the menu screen for
entering the maximum acceptable flow rate. Use the UP and DOWN keys to set this parameter to
1,100 L/min. Press the NEXT key to enter this value.
10.2.10 Inlet Heater Temperature. When the NEXT key is pressed to enter the maximum
acceptable flow rate, the menu advances to the screen for entering the desired inlet tube heater
temperature. This heater should be used only as necessary in rainy climates to prevent water from
collecting on the filter tape (see Section 6.1). The minimum effective temperature should be used. Use
the UP and DOWN keys to set the desired temperature (0°-100°C) and press the NEXT key to enter the
selected value. Turn the heater on with the switch in the upper left corner of the front panel (see
Figure 5).
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Chapter IO-1 Method IO-1.1
Continuous PM10 Analyzers Graseby Beta Gauge
10.2.11 Outputs. A variety of output devices (analog or digital) can be used to record measured
values and monitor the instrument's operation. The appropriate output settings will depend upon the
device(s) used and the data desired. Press the NEXT key unt.il the LCD reads "Outputs" and press the
YES key to enter this parameter group. Consult the Operator Manual (Section 4.1.10) to determine the
appropriate settings for each individual instrument setup.
10.2.12 Reset Measuring Cycle Buffer. When beginning operation for the first time or after a
significant break in operation, the existing measuring cycle buffer should be deleted so that computed
concentrations will reflect only current ambient conditions. Press the NEXT key until the LCD reads
"Maintenance and Calibration?" and press the YES key to enter this parameter group. Press the NEXT
key five times to reach the "Measuring Cycle" screen. Press the YES key to reset the buffer. The "On"
status light will flash for 1A h, then burn constantly. The concentration will not be computed and
displayed until 6 min have passed.
10.2.13 Disable Keyboard. Disable the keyboard as discussed in Section 10.1.1. This action will
enable the serial and parallel interfaces. The "On line" status light will come on.
10.3 Other Menu Functions
A number of other functions can be carried out using the enabled keyboard. See the Operator Manual
(Section 4.1) for details.
10.4 Summary of Instrument Operation
Automatic operation is accomplished in a microprocessor controlled cycle with four phases: filter change,
mass zero balance, concentration zero balance, and measurement.
10.4.1 Filter Change. The pump shuts off automatically, and the particle collection chamber lifts
off the filter tape. The filter feed advances a fresh, unused section of the filter tape under the particle
collection and measuring chamber (increment 30 mm). This process lasts exactly 30 s. During this
phase, the "Filter change" status light blinks rapidly. The integrated filter tape controller ensures that
the pump is shut off automatically if the filter tape breaks or the end of the tape is reached.
10.4.2 Mass Zero Balance. The mass readout is zeroed automatically with the particle collection
chamber closed and pump switched on. This balance is carried out in a processor-controlled cycle. The
ionization chamber amplifier is fed an offset voltage until the amplifier output supplies zero volts. This
balancing takes 90 sec. During this phase, the "Filter change" status light blinks slowly.
10.4.3 Concentration Zero Balance. During this phase, the sampling cycle for particle mass values
has already started, but no new concentration value is yet computed. The first six measured mass values
are used to determine the starting point for the new particle mass/time curve, and the difference between
this point and the end point before the filter change is subtracted from the old curve. With this
correction, the old measured values (from before the filter change) can continue to be used after the filter
change so that the observing time is not altered and continuous concentration readout is possible, even
during the period of filter change. This phase constitutes 10% of the observing time, which is 6 min
when the instrument is operated as an EPA equivalent method for PM JQ. The "Filter change" status light
is lit continuously during this phase. All output channels display the last computed concentration value
from before the filter change during all three filter change phases.
10.4.4 Measurement Phase. After the zero balances, the routine particle collection and measurement
process commences. A current particle concentration value is computed 60 times per observing time
from the increasing mass. To qualify as an EPA equivalent method, the observing time must be set to
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-13
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Method IO-1.1 Chapter IO-1
Graseby Beta Gauge Continuous PM^0 Analyzers
60 min, which results in a particle concentration value being calculated every 1 min. The current particle
mass and concentration values pass continuously to the output channels. The measurement phase is
terminated by the next filter change. This phase may last from a few minutes to several days depending
on which parameters are selected to initiate the filter change cycle. (For the PM^Q equivalent method,
a filter change must be carried out each midnight.) The instrument repeats the cycle discussed above
when the preset conditions for a filter change are met.
10.5 Data and Measured Value Memory
The instrument manages four measured value files that all take the form of cyclic memories. The
memories are only erased if an error has been found in the random access memory (RAM) after
connection of power supply. Normally, the last 40 or 60 blocks of data are always stored. The file
contents can be displayed on the LCD or output via the serial interface.
10.5.1 Measured Values. The current measured values are always entered in File 1 after execution
of the print cycle.
Block structure:
• date/time of day
• concentration
• particle mass
• observing time
• analog 1
• analog 2
In the case of a print cycle time of 0 min, no entry will take place. The measured value file contains
40 blocks.
10.5.2 Half-hour averages (Total of 60 half-hour averages are stored). The half-hour averages
of PMjQ concentration and of the two analog channels are computed. Totalling for averaging is carried
out once per second if the air flow rate is not disturbed, the filter tape has not broken, and the measured
value buffer memory is at least half full. Entry in File 2 takes place every half hour.
Block structure:
• date/time of day
• concentration
• analog 1
• analog 2
The half-hour average file contains 60 blocks, with the newest data replacing the oldest.
10.5.3 Daily Averages (Total of 40 daily averages stored, midnight to midnight). The daily
averages of concentration and of the two analog channels are obtained from the sum of the half-hour
averages divided by their number. Entry in File 3 always takes place at the end of a day at 24:00 h.
The date belonging to a data block is entered at the beginning of the day at 00:00 h.
Block structure:
• date
* concentration
• analog 1
• analog 2
The daily average file contains 40 blocks, with newest data replacing oldest.
[Note: analog 2 = airflow [L/h]]
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Chapter IO-1 Method IO-1.1
Continuous PM10 Analyzers Graseby Beta Gauge
10.5.4 Histogram Memory. At the end of a day at 24:00 h, the half-hourly averages of the past day
are divided into 21 concentration classes. A histogram is formed for dust concentration. The level of
the concentration classes is specified by the histogram threshold. A "3" in the first class signifies three
half-hourly averages of the day were between 0 fig/nr and the threshold value. A "5" in the second class
signifies 5l/2 averages of the day were between 1 and 2 times the value of the histogram threshold. (See
Operator Manual Section 4.1.9 for information on selecting the histogram threshold value.)
Block structure:
• date
• histogram threshold
• 21 concentration classes
The histogram file contains 40 blocks.
10.6 Data Output
The measured values averaged by the instrument are passed to several output channels. The channels are
discussed below.
10.6.1 LCD Display. In its basic state, the LCD display will always show the averaged PM10
particle concentration value. Pressing the NEXT key also allows the display of the collected particle dust
mass. For test purposes, it is possible to call up all 8 analog channels simultaneously on the display.
10.6.2 Analog Outputs, Chart Recorder. Analog outputs for PM10 concentration and dust mass
are available to record the measured value with analog chart recorders. Voltage outputs of 0-10 V as
well as potential-free current outputs (0-20 mA, offset 0, 2 or 4 mA) are available. It is possible to
choose linear or logarithmic output. The full-scale and zero-point voltages for the output range may also
be selected. (See Operator Manual Section 4.1.10.1 for information on analog output settings.)
10.6.3 Serial Interface, Printer. Data and measured values can be passed to a printer or computer
via this interface. Output takes place in 7 bit ASCII code with even parity and 2 stop bits. Commercially
available printers with suitable interface can be connected. With the print format selections, the data that
will be output may be selected. With the print cycle selections, the printout frequency may be
determined. (See Operator Manual Section 4.1.10.2 for information on setting the print format and print
cycle.)
10.7 Remote Control
All control functions for the instrument can be accomplished from a remote location using the serial
interface. See Operator Manual Section 4.2.1 for information and control codes. Limited remote control
functions can be accomplished using the parallel interface. See Section 4.2.2 of the Operator Manual for
information.
11. System Calibration
11.1 Particle Mass
The instrument has been factory calibrated with a primary particle generator. The "calibration factor"
has been preset to a standard of 2,400 /j,g (2,400 /tg corresponds to + 10V at the amplifier or analog
output). Mass readings are compared between the standardized particle generator and the instrument.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-15
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Method KM.l Chapter IO-1
Grascby Beta Gauge _ _ Continuous PM10 Analyzers
When factor calibration has been completed, the instrument is checked with a factory set of "mother"
foils. Zero and high mass readings are checked to insure good factory agreement, and a factory test
certificate is included with the instrument.
11.1.1 Mass Measurement Function Check. A function check should be conducted after starting
the instrument, after maintenance activities, or when the measurement system may not be working
properly.
11.1.1.1 Remove the test probe from its holder on the face of the instrument and insert the probe
into the aperture on the measuring chamber (see Figure 5).
11.1.1.2 After 1 min, the displayed concentration or mass value should rise significantly. This
indicates that the measurement system is functioning.
11.1.1.3 After completing the function check, remove the test probe from the measuring chamber!
The probe should be stored in the holder provided on the instrument.
11.1.2 Mass Calibration Using Zero/Span Foil Kit. Calibrate the instrument every 2-3 months and
after repairs with the calibration foils. Do not touch the calibration foil sheets; additional oil or dust
on the foil may change the mass calibration. The foils must be kept in their original storage box.
11.1.2.1 Raise the measuring head as directed in Section 9 for installing the filter tape
(Sections 9.1 through 9.7). It is important to turn off the vacuum pump to prevent foil damage.
11.1.2.2 2. With the chamber raised, remove the filter tape from the dust collection point and
insert the guide bar (included in the calibration kit) between top and bottom chamber from the front.
(Inserting the guide bar requires some force; this will not harm the spring-loaded upper chamber.)
11.1.2.3 Insert the foil holder with the zero foil.
11.1.2.4 Press the NEXT and YES keys; lower the chamber and initiate zero. To switch to. offset
and mass display, press the NEXT key again.
11.1.2.5 After completion of zeroing ("Filter change" status light stops blinking and main on),
remove the zero foil and insert the calibration span foil.
11.1.2.6 Wait at least 4 min until the measured value has stabilized (can be read best on a chart
recorder). Compare the LCD value to the value inscribed on the span foil.
11.1.2.7 If the LCD value does not agree with the value on the span foil, adjust the instrument
using the "Calibration" potentiometer on the front panel of the instrument (note value). Repeat steps 3
through 6.
11.1.2.8 Following adjustment, remove the foil holder and guide bar, raise the measuring head
again, re-insert the filter tape, and press FC + Z.
[Note: Be sure to turn on the pump and disable the keyboard to provide data output.]
11.2 Air Flow Rate
The particle size separation characteristics of the Graseby PM^Q inlet require that specific volumetric air
flow rates be maintained during operation. Particle laden air passing through the inlet is forced to take
a sharp turn upon entry. A change in the inlet entrance velocity will result in a change in the nominal
particle size collected. For this reason, the air flow rate must be maintained at a constant air flow rate
of 16.7 actual L/min (1 m3/hr) ±10%.
11.2.1 Flow Rate Audit. To insure an accurate measurement of PMjQ concentrations, the EPA
stipulates air flow rate audit frequencies for all samplers used to report data into the national data base.
Please refer to Quality Assurance Handbook for Air Pollution Measurement Systems, Volume 2,
Section 2. 10 for basic requirements. The instrument's air flow rate should be checked upon installation,
Page 1.1-16 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.1
Continuous PM^Q Analyzers Graseby Beta Gauge
after maintenance activities, and at routine intervals throughout the year (at least once per calendar
quarter).
11.2.1.1 Several commercially available air flow rate measurement standard devices are available.
The manufacturer recommends a (calibrated) dry gas test meter with a display that is easily read to tenths
and preferably hundredths of a liter. A dry gas test meter has a low pressure drop across the meter and
is reproducible, rugged, and relatively inexpensive. Other measuring devices may be used; however, the
manufacturer does not recommend mass flow meters with high pressure drop across the meter.
11.2.1.2 The SA 247 air flow rate measuring cap is used to replace the SA 246b PM^Q inlet to
audit the air flow rate. Remove the SA 246b inlet and place the SA 247 cap with hose barb connector
on top of the inlet drift tube. An O-ring seal inside the SA 247 air flow measuring cap assures an airtight
seal. Attach a leak-free vacuum hose from the hose barb on the cap to the outlet side of the dry gas test
meter. Open the inlet side of the dry gas test meter to the atmosphere for no resistance.
11.2.1.3 Set the instrument to measure flow rate in terms of actual operating conditions (see
Section 10.2.6). Use the dry gas test meter and a stopwatch to measure the flow rate of the instrument.
If the dry gas test meter is calibrated in units of standard volume at EPA reference conditions (298K,
1013 kPa), use a thermometer and barometer to measure the actual ambient air temperature and pressure
so that the measured flow rate in standard units (std L/h) can be converted to actual units (actual L/h)
using the following equation:
Qa = Qstd (pstd)/Crstd)Cra/pa)
where:
Qa = measured flow rate in actual L/hr.
Qstcj = measured flow rate in std L/hr.
Pstcj = EPA reference pressure (1013 kPa).
Tstd = EPA reference temperature (298K).
Ta = actual ambient temperature (K).
Pa = actual barometric pressure (kPa).
11.2.1.4 To insure a good reproducible air flow rate measurement, the time from start to stop of
an audit with the dry gas test meter should be 10 min. While the air flow rate audit is being made with
the dry gas test meter, monitor the air flow rate indicated by the instrument.
11.2.1.5 Compare the air flow rate measured with the dry gas test meter to the instrument's preset
air flow rate (design flow rate of SA 246b inlet = 1,000 actual L/h) and to the sampler indicated flow
rate. If the audited air flow rate differs from the set or indicated flow rates of the instrument by more
than 10%, contact the manufacturer for assistance and service.
11.2.2 Flow Rate Calibration.
11.2.2.1 As discussed in Section 7.2.3, the air flow rate for the instrument is held constant (within
±0.5%) using a regulator valve that is adjusted based on input from the instrument's flow rate
measurement system.
11.2.2.2 The manufacturer recommends no periodic recalibrationby the user. However, the field
audit described in Section 11.2.1 is required quarterly for .any instrument operating as an EPA equivalent
method for
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Method IO-1.1 Chapter IO-1
Graseby Beta Gauge Continuous PM^Q Analyzers
11.3 Leak Check
The manufacturer has not developed any recommended leak checking procedures. Do not put the system
under high positive or negative pressure; damage to the measurement system could result.
12. Method Safety
This instrument uses a radioactive source to measure PMjQ. Only trained personnel with radiological
authorization, e.g., by the Graseby Service Division may work on the source (e.g., cleaning the
measuring chambers). The source has been secured with tamper-proof hardware and may not be
disassembled without authorization.
13. Maintenance
To ensure proper instrument performance, the following maintenance steps must be consistently followed.
13.1 Vacuum Pump
The vacuum pump is the reliable rotary vane vacuum pump (multi-chamber system) with a dry rotor,
which is known for its minimal maintenance during continuous service. The pump is supplied.as an
external unit and is fitted with protective filters.
13.1.1 Protective filter 1 in the suction line is used to protect the pump inlet. If the pump runs for
any length of time with a defective sample filter strip or without any sample filter strip at all, check or
replace the pump inlet filter. If a dirty pre-filter in the pump if the carbon vanes are intact and the pump
does not reach the necessary air delivery rate may be the cause.
13.1.2 Protective filter 2 is mounted on the vacuum pump exhaust and is used to collect the worn
carbon vane dust and act as a noise muffler for the vacuum pump. The cloth filter in the pump exhaust
should be removed, soap and water cleaned and dried, and replaced each 6 months of pump operation.
13.1.3 Because the pump normally operates with pre-filtered air, carbon vane wear is very slight.
The life of a set of carbon vanes is typically more than 1 yr. For this reason, check the carbon vanes
at intervals of 2,000-3,000 operating hours (i.e., 3 months) or change yearly. The rotary pumps should
be maintained in accordance with the instructions of the pump manufacturer.
13.2 PM10 Inlet
Graseby recommends removing, cleaning, and checking the O-ring of the Model SA 246b PMjQ Inlet
six times per year based on sampling every day for a 24-h period. Sampling locations where PM^Q levels
are in nonattainment may require more frequent maintenance. See Operator Manual Section 5,3 for
detailed maintenance procedures.
Page 1.1-18 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.1
Continuous PM1Q Analyzers Graseby Beta Gauge
13.3 Radioactive Source
As discussed in Section 12, maintenance of the radioactive source may only be carried out by authorized
individuals. Contact the manufacturer for more information.
13.4 Air Flow Regulator Bleed Valve
The air inlet for the regulator bleed valve is located on the back panel of the instrument (see Figure 6).
The inlet is fitted with a protective filter that must be replaced annually, or more often in very dusty
environments. An inexpensive automobile fuel filter is suitable for this purpose.
14. Performance Criteria and Quality Assurance (QA)
Required quality assurance measures and guidance concerning performance criteria that should be
activated within each laboratory are summarized in the following sections.
14.1 Standard Operating Procedures (SOPs)
14.1.1 SOPs should be generated by the users to describe and document the following activities in
their laboratories:
• Assembly, calibration, leak check, and operation of the specific sampling system and equipment
used;
• Preparation, storage, shipment, and handling of the sampler system;
• Purchase, certification, and transport of standard reference materials; and
• All aspects of data recording and processing, including lists of computer hardware and software
used.
14.1.2 Specific stepwise instructions should be provided in the SOPs and should be readily available
to and understood by the personnel conducting the monitoring work.
14.2 Quality Assurance Program
The user should develop, implement, and maintain a quality assurance program to ensure that the
sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted on a regularly scheduled basis and should be part of
the quality assurance program. Calibration verification procedures provided in Section 11, operation
procedures in Section 10, and the manufacturer's instruction manual should be followed and included in
the QA program. Additional QA measures (e.g., trouble shooting) as well as further guidance in
maintaining the sampling system are provided by the manufacturer. For detailed guidance in setting up
a quality assurance program, the user is referred to the Code of Federal Regulations (4) and the
U. S. EPA Handbook on Quality Assurance (3).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.1-19
-------
Method IO-I.1 Chapter IO-1
Graseby Beta Gauge Continuous PM10 Analyzers
15. References
1. Equivalent Method Designation, Andersen Instruments Model FH62I-N PM10 Beta Attenuation
Monitor, Federal Register, Vol. 55, September 18, 1990, p. 38387.
2. Andersen Instruments, Inc., Operator Manual: FH 62 I-N PM1Q Beta Attenuation Monitor,
Atlanta, GA.
4. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II-Ambient Air Specific
Methods (Interim Edition), EPA 600/R-94/038b.
5. 40 CFR, part 58, Appendices A and B.
Page 1.1-20 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1
Continuous
Analyzers
Method IO-1.1
Graseby Beta Gauge
TABLE 1. SEQUENCE OF PARAMETERS
Parameter
Mass
Pressure
Air Flow
Cycle
Time
Value
< 2,400 fig
User select
>900 L/hr
User select
24:00
Comments
Mass on filter; a higher setting could result in "pegged" readings.
Pressure drop across filter; increases with mass loading.
Flow rate through instrument; can drop with mass loading.
Minutes since last change; select > 1,440 mi^i to minimize changes.
Filter change at midnight; required for equivalent method.
Figure 1. Graseby PM^Q Beta gauge monitor.
January 1997
Compendium of Methods for Inorganic Air Pollitta>its
Page 1.1-21
-------
Method IO-1.1
Graseby Beta Gauge
Continuous
Chapter IO-1
Analyzers
HCMCt
ANM.OC 1—»OUASS
OUTPUT I—*OCONCEN1RA1K>N
WC = MEASURING CHAMBER
CC = COMPENSATION CHAMBER
RS = RADIOACTIVE SOURCE
C = CHAMBER FOR PARTICULATE DEPOSITION AND MEASUREMENT
RS-C-WC = MEASUREMENT SECTION
RS-CC = COMPENSATION MEASUREMENT SECTION
Fj, F2= FILTER REELS
Figure 2. Schematic diagram of the Graseby beta gauge monitor.
Page 1.1-22
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.1
Graseby Beta Gauge
DEPOSITION OF
PARTICULATE
MATTER
DETECTOR
RADIATION INTENSITY, I
ZT:
FIBROUS
FILTER
RADIATION INTENSITY, lo
Figure 3. Measurement principle of the Graseby beta gauge monitor.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.1-23
-------
Method IO-1.1
Graseby Beta Gauge
Chapter IO-1
Continuous PM^Q Analyzers
• HOLEB
GLASS JAR
RAIN DRAIN
CASKET TOP-
6-32 X 3/8 PAN HEACL
W/STAR WASHER
IMPACTOR
NOZZLE
IMPACTOR
NOZZLE
10 MICRON
IMPACTOR NO
TOP CAP
10 MICRON
UPPER INLET
SECTION
SCREEN
RAIN
DEFLECTOR
NOZZLE ENTRY
PAN HEAD
10 MICRON
IMPACTOR
ASSEMBLY
NIPPLE SHORT
PLUG
\r- GLASS JAR
ANDUD
Figure 4. Graseby beta monitor PM-10 inlet.
Page 1.1-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.1
Graseby Beta Gauge
LEGEND
1 . Air inlet
2. Heated air inlet
3. Opening for test probe
4, LED's indication operating/error status
A "ON"
3 "ON LINE"
C "Alarm"
0 "FS Break"
E "Flowrate"
F "Flowrate"
G "Pump"
H "Filter change"
5. Display for readout
6. Control keys
7/8. Filter strip reels
9. Test probe
10. Calibration potentiometer
(green)
(green)
(red)
(yellow)
(green)
(yellow)
(green)
(red)
Continuously lit: power ON. no error
Flashing slowly (O.SHz): measured value buffer contains
<30 sample values
Flashing rapidly (2Hz): zero no longer reached
Auto, On Line, keyboard disabled
Concentration alarm Threshold 1 exceeded flashing -
Threshold 2 exceeded
Filter tape feed reel not turning on filter change;
end of filter tape or break
Air flow rate OK
Air flow rate outside limits
Pump running
Filter change cycle running 3-phase, flashing see
Section 10.4
Figure 5. Front of Graseby beta gauge monitor.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.1-25
-------
Method IO-1.1
Graseby Beta Gauge
Continuous
Chapter IO-1
Analyzers
22
^ 20 '26 {jjjj 27 as
e»
\
32
25 *=7
LEGEND
20. 4 amp power fuse for pump/controller
21. 1 amp power fuse for electrical
22. Power switch
23. 115 VAC power
24. Pump connecting socket
25. Air flow rate regulator valve connection socket
26. Pump connection socket
27. Data interface RS 232
28. Relay contacts
29. Analog inputs
30. Concentration output
31. Mass concentration output
32. Network computers output
Figure 6. Rear of Graseby beta-gauge monitor.
Page 1.1-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PMjn Analyzers
Method IO-1.1
Graseby Beta Gauge
Pa
Filter
Temperature
Transducer
top
Orifice
Pressure
Transducer
(Pa-P1)
Pressure
Transducer
(Pa - P2)
V / Flow Regulator
}(\ Bleed Valve
ft
Figure 7. Air flow rate measurement and control for the
Graseby beta gauge monitor.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.1-27
-------
Method IO-1.1
Grascby Beta Gauge
Chapter IO-1
Continuous PMIQ Analyzers
e
On
On line
Alarm
FS
Break
Air Flow
Pump
Filter
Change I
DOWN
NO
UP
YES
BACK
NEXT
FW+NP
PRINT
Calibration
Figure 8. Instrument control system for the Graseby gauge monitor.
Page 1.1-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM| /»Analyzers
Method IO-1.1
Graseby Beta Gauge
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-------
-------
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-1.2
DETERMINATION OF PM1Q
IN AMBIENT AIR USING
THE THERMO ENVIRONMENTAL
INSTRUMENTS (FORMERLY
WEDDING AND ASSOCIATES)
CONTINUOUS BETA
ATTENUATION MONITOR
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-L2
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of die U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), botii in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KG, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved
in the preparation and review of this mernodology.
Author(s)
• William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
• Stephe Edgerton, Midwest Research Institute, Gary, NC
Peer Reviewers
Rick Taylor, Missouri Department of Natural Resources, Jefferson City, MO
David Brant, National Research Center for Coal and Energy, Morgantown, WV
John Glass, SC Department of Health and Environmental Control, Columbia, SC
Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
Charles Rodes, Research Triangle Institute, RTP, NC
Danny France, U.S. EPA, Region 4, Athens, GA
David Harlos, Environmental Science and Engineering, Gainesville, PL
Jim Tisch, Graseby, Cleves, OH
Al Wehr, Texas Natural Resource Conservation Commission, Austin, TX
Richard Shores, Research Triangle Institute, RTP, NC
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
u
-------
Method IO-1.2
Determination of PM^Q in Ambient Air
Using the Thermo Environmental Instruments
(formerly Wedding) Continuous Beta Attenuation Monitor
TABLE OF CONTENTS
1. Scope 1.2-1
2. Applicable Documents 1.2-3
2.1 ASTM Standards 1.2-3
2.2 Other Documents 1.2-3
3. Summary of Method 1.2-3
4. Significance 1.2-3
5. Definitions 1.2-4
6. Interferences 1.2-5
7. Apparatus 1.2-5
7.1 Sampler PM|Q Inlet 1.2-6
7.2 Analog Board 1.2-6
7.3 Micro-Controller Board 1.2-6
7.4 Tape Drive and Sampling Module 1.2-6
7.5 Filter Media 1.2-7
7.6 Radioactive Source 1.2-7
7.7 Detector Assembly 1.2-7
7.8 Data Output Devices 1.2-7
7.9 Critical Flow Device 1.2-8
7.10 Vacuum Pump 1.2-9
8. Assembly 1.2-9
9. Instrument Operation 1.2-10
9.1 Instrument Start-up 1.2-10
9.2 Loading the Filter Tape 1.2-10
9.3 Setting Up the Instrument 1.2-11
9.4 Commencing Sampling 1.2-13
9.5 Other Control Keys 1.2-14
10. Replacing the Filter Tape 1.2-15
11. Printer Paper Replacement (if applicable) 1.2-15
12. Maintenance 1.2-16
12.1 Detector 1.2-16
12.2 Sampling Inlet . 1.2-16
13. Instrument Calibration 1.2-16
13.1 Mass Determination 1.2-16
13.2 Flow Rate 1.2-17
13.3 Single-Point External Flow Rate Audit Procedure Using a Flow Transfer
Standard 1.2-17
13.4 Mass Determination Audit 1.2-19
13.5 Leak Checking 1.2-19
14. Safety 1.2-19
15. Performance Criteria and Quality Assurance (QA) 1.2-19
15.1 Standard Operating Procedures (SOPs) 1.2-19
15.2 QA Program 1.2-20
16. References 1.2-20
111
-------
-------
Chapter IO-1
CONTINUOUS MEASUREMENT OF SUSPENDED
PARTICULATE MATTER (SPM)
IN AMBIENT AIR
Method IO-1.2
DETERMINATION OF PM10 IN AMBIENT AIR
USING THE THERMO ENVIRONMENTAL INSTRUMENTS
(FORMERLY WEDDING) CONTINUOUS BETA ATTENUATION MONITOR
1. Scope
1.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels are essential to proper assessment.
1.2 Suspended paniculate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low-vapor pressure liquid particles having aerodynamic particle sizes from below 0.01 /im to
100 jim and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.3 The EPA reference method for TSP is codified at 40 CFR 50, Appendix B. This method uses a
high-volume sampler (hi-vol) to collect particles with aerodynamic diameters of approximately 100 pm
or less. The hi-vol samples 40 and 60 fr/min of air with the sampling rate held constant over the
sampling period. The high-volume design causes the TSP to be deposited uniformly across the surface
of a filter located downstream of the sampler inlet. The TSP high volume can be used to determine the
average ambient TSP concentration over the sampling period, and the collected material subsequently can
be analyzed to determine the identity and quantity of inorganic metals present in the TSP.
1.4 Research on the health effects of TSP in ambient air has focused increasingly on those particles that
can be inhaled into the respiratory system, i.e., particles of aerodynamic diameters < 10 /an.
Researchers generally recognize that these particles may cause significant, adverse health effects.
1.5 On July 1, 1987, the U. S. Environmental Protection Agency (EPA) promulgated a new size-specific
air quality standard for ambient particulate matter. This new primary standard applies only to particles
with aerodynamic diameters <10 micrometers (PM^) and replaces the original standard for TSP. To
measure concentrations of these particles, the EPA also promulgated a new federal reference method
(FRM). This method is based on the separation and removed of non-PMjQ particles from an air sample,
followed by filtration and gravimetric analysis of PM^Q mass on the filter substrate.
1.6 The new primary standard (adopted to protect human health) limits PMjQ concentrations to
150 jim/std m3) during a 24-h period. These smaller particles are able to reach the lower regions of the
human respiratory tract and.,, t^ujs, are, responsible for most of the adverse health effects associated" with
suspended particulate .pollution. The secondary standard, used to assess the impact of pollution o '
welfare, has also "Been established at 150 /un/std nrV ..........
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-1
-------
Method IO-1.2 Chapter IO-1
Thermo Beta Gauge _ _ Continuous PM-^ Analyzers
1.7 Monitoring methods for paniculate matter are designated by the EPA as reference or equivalent
methods under the provisions of 40 CFR Part 53, which was amended in 1987 to add specific
requirements for PM^g methods. Part 53 sets forth functional specifications and other requirements that
reference and equivalent methods for each criteria pollutant must meet, along with explicit test procedures
by which candidate methods or samplers are to be tested against those specifications. General
requirements and provisions for reference and equivalent methods are also given in Part 53, as are the
requirements for submitting an application to the EPA for a reference or equivalent method determination.
1.8 Under the Part 53 requirements, reference methods for PM10 must use the measurement principle
and meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a PM10
sampler that meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies a
measurement principle based on extracting an air sample from the atmosphere with a powered sampler
that incorporates inertia! separation of the PMjQ size range particles followed by collection of the PMjQ
particles on a filter over a 24-h period. The average PMjQ concentration for the sample period is
determined by dividing the net weight gain of the filter over the sample period by the total volume of air
sampled. Other specifications are prescribed in Appendix J for flow rate control and measurement, flow
rate measurement device calibration, filter media characteristics and performance, filter conditioning
before and after sampling, filter weighing, sampler operation, and correction of sample volume to EPA
reference temperature and pressure. In addition, sampler performance requirements in Subpart D of
Part 53 include sampling effectiveness (the accuracy of the PM^Q particle size separation capability) at
each of three wind speeds and "50% cutpoint" (the primary measure of 10-micron particle size
separation). Field tests for sampling precision and flow rate stability are also specified. In spite of the
instrumental nature of the sampler, this method is basically a manual procedure, and all designated
reference methods for PM are therefore defined as manual methods.
1.9 This document describes the protocol for the operation of a continuous particulate mass monitor that
directly measures mass concentrations of atmospheric particulate matter as PMjQ on a real-time basis.
1.10 The instrument uses the beta gauge method, which is based on the attenuation of beta particles as
they pass through the particulate matter that has been deposited on a filter.
1.11 With certain specifications, the instrument has been designated as an equivalent method for
(24-h average concentration) by the EPA under Designation No. EQPM-039 1-081, effective March 5,
1991 (1). Except as otherwise noted, this protocol addresses the configuration and operation of the
instrument as an equivalent method for
Page 1.2-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-1 Method IO-1.2
Continuous PM^Q Analyzers Thermo Beta Gauge
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2 Other Documents
• Thermo Environmental Instruments Technical Manual (2).
3. Summary of Method
3.1 Particle-laden air is drawn through a sampling inlet at a constant volumetric flow rate of 18.9 L/min,
the design flow rate for the Thermo Environmental Instruments (formerly Wedding and Associates) PM1Q
inlet. The sample air stream passes downward through a filter tape collection substrate where the
particles are deposited.
3.2 Upon completion of the sampling cycle, the filter tape is shifted to the beta source/detector to
measure the attenuated count rate due to the presence of collected particles.
3.3 The silicon semiconductor beta detector has high sensitivity and fast response, enabling the
instrument to measure the ambient mass concentration with a resolution of approximately 3 jag/m^ of
collected particles for a 1-h sampling period.
3.4 The Thermo Critical Flow Device maintains a constant volumetric flow rate through the instrument.
3.5 A microcomputer-based data acquisition system controls the filter tape drive, monitors temperature
and pressure, calculates flow rate and mass concentration values, and provides the necessary analog
outputs for a telemetry system. Custom system software can be provided by Thermo to assist the users
to meet the particular, unique requirements of their application.
[Note: The PMjQ concentrations calculated by the original instrument are in terms of fig per actual m?.
These values must be converted by the user into fig per standard m? for purposes of demonstrating
attainment of the national ambient air quality standard (NAAQS) for PM^Q. Instruments modified with
a manufacturer-provided retro-fit kit (described later) report concentrations in either fig per actual or
standard nr.]
4. Significance
4.1 SPM in air generally is a complex, multi-phase system of aerodynamic particle sizes from below
0.01 jim to greater than 100 pm. Historically, SPM measurement has concentrated on TSP, with no
preference to size selection. Research on the health effects of TSP in ambient air has focused increasingly
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-3
-------
Method 10-1.2 ChaPter I(M
Thermo Beta Gauge Continuous PM10 Analyzers
on those particles that can be inhaled into the respiratory system (i.e., particles of aerodynamic diameter
less than 10 urn [PM10]). Researchers generally recognize that those particles may cause significant
adverse health effects. Therefore, the primary NAAQS for PM is now in terms of PM10.
4.2 Because of the health effects of PM10, this continuous paniculate monitor has been developed to
allow mass measurement of PMjQ concentration on a quasi, real-time basis.
4.3 The monitor utilizes a filter-based measuring system for providing quasi, real-time mass monitoring
capability. With certain specifications, the monitor has been designated by EPA as an equivalent method
for determining the 24-h average ambient concentration of PM1Q. In addition, the instrument can be
operated outside the equivalent method specifications to perform other types of PM sampling programs.
4.4 The particulate matter sample is retained on the filter tape, providing the potential for subsequent
analysis,
5. Definitions
[Note: Definitions used in this method are consistent with the definitions found in AS1MD1356. All
abbreviations and symbols are defined within this document at the point of first use. Any user prepared
standard operating procedures (SOPs) should also conform to the definitions ofASTM D1356.J
5.1 Air pollution. The presence of unwanted material in the air. The term "unwanted material" here
refers to material in sufficient concentrations, present for a sufficient time, arid under concentrations,
present for a sufficient time, and under circumstances to interfere significantly with comfort, health, or
welfare or persons or with the full use and enjoyment of property.
5.2 Beta particle. An elementary particle emitted by radioactive decay, that may cause skin burns.
5.3 Coarse and fine particles. Coarse particles and those with diameters (aerodynamic) greater than
2.5 urn that are removed by the sampler's inlet; fine particles are those with diameters (aerodynamic) less
than 2.5 /im. These two fractions are usually defined in terms of the separation diameter of a sampler.
5.4 Filter. A porous medium for collecting particulate matter.
5.5 Mass concentration. Concentration expressed in terms of mass of substance per unit volume of gas.
5.6 Particle. A small discrete mass of solid or liquid matter.
5.7 Particle concentration. Concentration expressed in terms of number of particles per unit volume
of air or other gas.
[Note: On expressing particle concentration the method of determining the concentration should be
stated.]
Page 1.2-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method KM.2
Continuous PM^Q Analyzers Thermo Beta Gauge
5.8 Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In
air or gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous
isolation of selected components.
5.9 Sampling, continuous. Sampling without interruptions throughout an operation or for a
predetermined time.
6. Interferences
6.1 Because the measurement mechanism has no moving parts, the instrument is not sensitive to
vibrations (e.g., vacuum pump vibration or mechanical noise) that can affect the accuracy of some other
types of continuous PM monitors.
6.2 Unlike some types of continuous PM monitors, this instrument does not require the ambient air
stream to be heated to a particular standard temperature. This feature eliminates a potential source of
inaccuracy; heating can volatilize some semivolatile materials that would otherwise be deposited on the
filter, leading to inaccuracies in both mass measurements and later chemical analyses.
6.3 The instrument should be protected against condensation in the sampling system, which can affect
the accuracy of the mass measurements.
7. Apparatus
The instrument includes two custom cabinets, one for PM sampling and control and one for the vacuum
pump. The insulated main particle sampling cabinet (shown in Figure 1) is heated and cooled so that it
can operate under ambient conditions. However, the instrument should be housed in a heated and air
conditioned shelter. The heating and cooling are independently controlled to preclude temperature
extremes within the cabinet.
After assembly, the inlet tube extends upward from the main sampling cabinet and is topped by the W&A
PMjQ Inlet (see Figure 2). The front cabinet door opens to reveal the filter reels, LCD define display,
particle sampling module, the source/detector fixture, communication ports, keypad, and printer, as
shown in Figure 1. Newer units are not equipped with a printer because users typically connect the unit
to a data logger or computer for data storage and access. Figure 3 illustrates the back of the cabinet,
where the main power cord enters and the power supply cord and vacuum tubing that lead to the vacuum
pump emerge.
A modification kit, available (at no charge) from the manufacturer, includes new temperature sensors,
new software contained on a new EPROM chip, a calibration foil, installation instructions, and a manual
supplement, and provides improved accuracy of flow measurement and other features.
The vacuum pump cabinet contains a separate cooling fan that is activated when the pump operates. As
illustrated in Figure 3, the vacuum sampling tube is connected from a fitting on the pump cabinet to a
fitting on the particle sampling cabinet. The power to the pump cabinet also comes from the main
cabinet. The major components of the instrument are described below.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-5
-------
Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PM^Q Analyzers
7.1 Sampler PM1Q Inlet
A modified Thermo PM10 inlet, originally developed for the dichotomous sampler (Wedding et al. 1982),
is used as the sampling inlet for the PM10 beta Sauge- T"6 inlet achieves proper particle size separation
at a sampling rate of 18.9 L/min, the design flow rate of the instrument. A TSP inlet with a cut point
of 100 /zm is also available from the manufacturer.
The PM10 sampling inlet is illustrated in Figure 4. The inlet employs an omnidirectional cyclone
fractionator, which allows the particles to enter from any angle of approach. An angular impetus is
imparted to the particle motion via the eight, evenly-spaced entrance vanes. As the particles enter the
inlet, they follow the fluid stream lines along the lower radius and enter the cyclone fractionator through
the vane system. Particle removal is realized on the oiled surfaces of the inner collection tube. The
transmitted particles then enter the middle tube, where the flow direction is altered 180°. A final turn
is made giving the particles a downward trajectory to the collection substrate.
7.2 Analog Board
The Analog Board consists of the various circuits used for supplying DC power, motor control, relaying,
temperature sensing, and signal conditioning needs for the instrument. Most of the wiring for the
instrument is provided by the Analog Board.
7.3 Micro-Controller Board
The micro-controller board provides operational controls, time and flow-rate data recording, and all data
calculations and conversions.
7.4 Tape Drive and Sampling Module
The instrument uses a bi-directional tape drive system. First, a background beta count is taken on the
area of the filter tape that is situated in the measurement position (i.e., between the beta source and the
detector). When the background count is completed, the particle sampling module opens, the tape
advances, and the filter spot on which the background count was taken is positioned beneath the sample
inlet tube. The particle sampling module then closes and seals, and sampling is initiated by starting the
vacuum pump. After the 1-h sampling cycle is completed, the sampling module opens, the filter tape
with deposited PMjQ is shifted back to the measurement position, the sample module closes, and a beta
count is taken. Mass concentration is determined based on the mass of PM^Q accumulated and the
volumetric flow rate of the instrument during the sampling cycle.
The standard instrument is programmed to repeat the sampling and measurement cycle four times on a
single spot before the filter tape advances to an unused spot. Thus, total sampling time on each spot is
4 h. The instrument also is programmed to go to a shorter cycle if PM^Q is accumulating so fast that
the flow rate will be reduced to an unacceptable level hi less than 4 h. The manufacturer can supply
software for different sampling cycles, but the current model of the instrument does not allow the user
to select the sampling cycle.
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Chapter IO-1 Method IO-1.2
Continuous PM^Q Analyzers Thermo Beta Gauge
7.5 Filter Media
Thermo offers two choices of filter substrates-glass fiber (P/N BG-320) and membrane (P/N BG-310).
The instrument is designated as an equivalent method for PMjQ using the glass fiber filter medium. This
filter medium can accumulate extremely high PM loadings without incurring a significant increase hi
pressure drop across the filter. The membrane medium is made of Teflon®, which is ideal for subsequent
chemical analysis and is not affected by moisture.
The filter medium is supplied as a tape on a reel. The tape is threaded from the supply reel, through the
measurement and sampling positions, to the takeup reel. Instructions for replacing the filter tape are
presented in Section 10.
7.6 Radioactive Source
A carbon-14 radioactive source is mounted into the fixture positioned beneath the filter tape. In no case
should the front (top) surface of the source or source fixture be touched. Should the source laminate
become scratched, the radioactive material may leak. A damaged source must be returned to Thermo
for disposal and replacement. The radioactive source has the following characteristics: (1) an isotope
of 14C, (2) an activity of < 100 j^Ci, (3) a half-life of 5,730 yr, (4) a maximum energy of 155KeV, and
(5) a laminate-sealed housing. In addition, this source is described as a Thermo 1 186 Series C Source.
The long half-life of carbon-14 precludes the need for recalibration and replacement of the source. The
use of the fast-response, low noise semiconductor detector makes it possible to use a low activity, low
energy beta source. Carbon-14 also has the added advantage of being a pure beta emitter without residual
gamma radiation.
The radioactive labels, positioned on the side of the cabinet, clearly provide instructions to the user for
disposition of the device and by-product material if necessary. At no time should the labels be removed.
See Section 14 for a discussion of safety considerations.
7.7 Detector Assembly
An ion-implanted silicon semi-conductor (IISS) detector and a preamplifier acquisition board (PACB) are
packaged in one fixture. The IISS detector is used to stop beta particles and permit counting of particles
that penetrate the filter medium. The IISS detector accepts an exceptionally high incidence of beta,
having a maximum count-rate of 100,000 cps, possesses ultra low-noise characteristics, and is a ruggedly
designed. The detector is optimized individually for each unit to stop beta particles emitted from the
carbon-14 source. The IISS detector has low leakage current (1-10 nA/cm2/100 jim), which makes it
well suited for measuring low-energy beta particles.
7.8 Data Output Devices
/Note: The instrument does not store measurement or calculation data. The user must provide a suitable
data handling system to maintain a record of measured and calculated parameters.]
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Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PMjn Analyzers
7.8.1 Parallel Printer. Older units are equipped with a built-in parallel printer, but the units now
being shipped do not have this feature. When activated, this printer records all measurements and
calculated values generated by the instrument. However, this printer should not be operated when the
instrument is unattended because the printer paper can interfere with the filter tape drive mechanism.
7.8.2 Telemetry (Analog) Output. The instrument provides up to six channels of 0-5 volts direct
current (VDC) output for use with telemetry applications (two channels are standard). These data
channels are available through a 25-pin connector located on the main instrument panel.
7.8.3 RS-232 (Digital) Output. A second 25-pin connector on the main instrument panel serves as
the connection point for a serial printer or digital communications device, such as a data logger or
computer. In communications mode, this port can be used for remote control over the instrument.
7.9 Critical Flow Device
The collection of accurate and meaningful PMj0 or TSP concentrations is intimately related to proper
flow control. Flow control provides an accurate denominator for the calculation of mass concentrations,
whether PMjg or TSP is being measured, and maintains the design flow rate of the PMjQ fractionating
element so that it operates at the specific air velocities for which it was intended.
The Critical Flow Device (CFD), a critical flow system requiring no periodic calibration, is used as a
flow control device for the instrument. Use of the CFD provides for accurate flow rate measurement.
The critical flow orifice within the CFD is sized specifically for use with only one type of filter medium
(i.e., either glass fiber of Teflon®) to provide the flow rate necessary for proper particle size selection
by the PMjQ inlet. Each instrument is calibrated at the factory, and an instrument-specific flow
coefficient constant is supplied with each unit for accurately calculating the flow rate during operation.
This constant is entered into the instrument's battery-backed random access memory (RAM) at the factory
and duplicated on a label affixed to the instrument panel. In the event of battery failure, the user must
re-enter the constant into RAM (see Section 9.3.1).
Caution: Use of a filter medium other than that originally specified for the instrument may result in a
flow rate different from that for which the PMjQ inlet is designed.
The flow rate through the filter tape is continuously monitored during operation by the micro-controller
board. Atmospheric pressure is measured with an electronic pressure transducer when the pump is off
between sampling periods. The stagnation pressure (i.e. , the absolute pressure downstream from the filter
medium) is measured while the vacuum pump is operating during the sampling cycle. The
microcomputer outputs the flow rate and the average values of temperature and pressure for the sampling
period.
A modification kit, which is available (at no charge) from the manufacturer and is highly recommended,
provides a temperature sensor to measure ambient (outdoor) temperature to allow the instrument to more
accurately calculate the actual volumetric flow rate at the sample air inlet. This modification also allows
the instrument to report flow rates in either actual or standard volume units and likewise calculate mass
concentrations in either fig per actual of EPA-standard cubic meters.
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Chapter IO-1 Method IO-1.2
Continuous PM10 Analyzers Thermo Beta Gauge
7.10 Vacuum Pump
The vacuum pump cabinet houses a Cast Model #523-101Q-G.18DX or G21DX vacuum pump for power
supplies of 115 volts alternating current (VAC)/60 Hertz (Hz) or 220-240 VAC/50 Hz, respectively. A
cooling fan is activated when the pump operates. The pump is connected to the main sampling cabinet
with a vacuum tube supplied by the manufacturer. Power to the pump cabinet comes from the main
cabinet.
8. Assembly
8.1 The instrument is delivered on a pallet protected by foam packaging and a cardboard outer container.
Remove the instrument from the packaging by cutting the metal bands on the outside of the container.
Save the container in the event that the instrument needs to be transported or repackaged.
8.2 After removing the metal bands and opening the cardboard container, locate and remove the
instrument components from the foam packing material. The separate pieces are as follows: main
sampling cabinet, pump cabinet, inlet, inlet tube, inlet tube support ring, cleaning brush, cabinet keys,
and manual. (The inlet tube support ring, cleaning brush, and keys should be in a plastic bag.)
8.3 Once all components have been located and removed from the box, assemble the instrument. First,
insert the inlet onto the end of the inlet tube (it will only fit on one end of tube).
8.4 If the instrument is to be operated with either an extension to the inlet tube or under ambient
conditions where high winds may be encountered, install the support ring onto the inlet tube. Slide the
support ring onto the inlet tube and tighten the four screws. Do not overtighten the screws or
indentations in the tube could be run and, thus, alter the air flow. Attach guide or support wires to the
heads of the four screws. If a nonstandard inlet tube (such as an extension) is to be used, contact Thermo
for guidance.
8.5 Insert the inlet tube into the main cabinet of the instrument. Use extreme caution because forcing
the tube into the cabinet could damage the instrument. Rotate the tube and push it carefully into the
cabinet to avoid damaging the O-rings inside the coupler. The tube is fully inserted when resistance from
the coupler is felt. When assembled with the standard inlet tube, the inlet is at a height of about 2 meters
above the base of the main cabinet.
8.6 Insert the key into the rear door of the main cabinet and rotate the key counterclockwise until the
door opens. Check all electrical connections. Make sure there are no loose or unattached cables.
8.7 Instruments sold before November, 1996 should be modified with the modification kit provided by
thermo. Install the kit according to instructions provided by Thermo. The kit provides new temperature
sensors and electronics for improved accuracy of flow measurements, enabling reporting of concentration
in either pg per actual of EPA-standard cubic meters.
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Method 10-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PMto Analyzers
8.8 Attach the vacuum pump to the main cabinet with the Tygon® tubing inside the vacuum pump
cabinet. This step requires a 9/16" open end wrench or adjustable wrench to tighten the bulkhead
fittings.
8.9 Plug the pump cabinet power cord (male) into the power supply cord (female) extending from the
rear of the main cabinet.
8.10 Open the door of the main cabinet that houses the instrument panel. First, make sure that the
power switch at the top of the instrument panel is in the "OFF" position. Then supply power to the unit
(115 VAC/60 Hz or 220 VAC/50 Hz) through the power-in cord (male) located on the rear door of the
cabinet. The instrument is now ready for start-up and operation.
9. Instrument Operation
The instrument is operated with the keypad located in the main particle sampling cabinet (see Figure 1).
Records of stored data can be obtained from the unit using the built-in 20-column parallel printer (when
so equipped), the RS-232 communications port, or the telemetry port. When activated, the 20-column
parallel printer, which is part of the instrument, provides a continuous printout of all sampling data. If
needed, the RS-232 port is used to communicate with a separate computer. The telemetry port (labeled
Analog Port on the instrument) provides the necessary signals to send data to an off-site source via
telemetry.
9.1 Instrument Start-up
To begin operation, move the power ON/OFF rocker switch at the top of the instrument panel to the
NONM position (the red light should be on). The LCD will show several messages followed by the
"PRESS A KEY" prompt. The valid control keys are shown in Figure 5, and a brief summary of each
key, including the location and function, is shown in Table 1.
9.2 Loading the Filter Tape
Caution: NEVER turn the take-up (right side) tape drive manually, or the drive system will be damaged.
The filter tape drive system is illustrated in Figure 6. The filter substrate is a continuous tape. The tape
lifetime is based upon the total number of samples and the ambient concentration levels. A reel of glass
fiber tape lasts approximately 8 months using the standard sampling cycle.
9.2.1 The tape replacement commands are accessed from the keypad, but the loading procedure must
be followed as written in this section. Press the key titled "LOAD TAPE." The following message is
displayed:
LOAD NEW TAPE
OPENING SYSTEMS
After the instrument has performed the necessary mechanical functions for the loading of a new filter tape
reel, the following message is displayed:
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Chapter IO-1 Method IO-1.2
Continuous PM10 Analyzers Thermo Beta Gauge
LOAD NEW TAPE
OPENING SYSTEMS
REFER TO MANUAL &
PRESS A KEY TO LOAD
9.2.2 Install an empty take-up reel on the right tape drive. First, remove the black plastic pronged
knob from the right tape drive. Place the empty reel on the right tape drive, being sure to slide the hub
onto the shaft so that the shaft pin fits into the slot on the hub. Replace the black knob and tighten
snugly.
Caution: Tighten the knob and hold the reel at the same time. Do not apply excessive torque to the drive
shaft, or the motor may be damaged.
9.2.3 Place a new filter supply reel on the left tape drive, ensuring that the pin on the shaft fits
snugly into the slot on the black hub of the reel. (Note that these slots and pins define the vertical plane
of the tape. The drive system will malfunction if the pins are not secured in the slots.) Replace the black
knob.
9.2.4 Unwind about 24" (60 centimeters) of filter tape by rotating the supply side (left tape drive)
in a counterclockwise direction. Feed the free end of the tape over the left side of the No. 1 translational
roller, as illustrated in Figure 6. Pass the free end of the tape, from left to right, between the No. 1
upper compression shaft and No. 1 lower compression roller, through the detector/sampling module and
between the No. 2 upper compression shaft and the No. 2 lower compression roller. Continue by passing
the tape on the right side of the No. 2 translational roller. Wrap the tape in a counterclockwise fashion
on the hub of the right (take-up) reel.
9.2.5 Tape the free end to the center of the take-up hub. Be sure that the filter tape is parallel to
the edges of the reels. The tape must be in the same vertical plane along its entire path.
[Note: Be sure that the tape passes approximately in the center of all rollers and the sampling module
so the tape is centered as it passes through the source, detector, inlet, and both (supply and take-up)
reels.]
9.2.6 Depress any key to start the tape advancement, which is pre-programmed to operate for a
specific time period (about 1 min). When the tape advancement is complete, ensure that the tape is
properly positioned approximately in the center of both the No. 1 and No. 2 translational rollers, that the
tape is smooth and flat against each roller, and that it lies in the same vertical plane between supply and
take-up reel. Additionally, the tape should be perfectly aligned between the upper compression shafts
and the lower compression rollers and should be in the center of the detector/sampling module.
9.3 Setting Up the Instrument
9.3.1 The "C" key is used to set the calibration constant in battery-backed RAM in case it has been
lost through battery failure. The five-digit constant, which is unique to each unit, is supplied by W&A
and displayed on a label between the filter reels. To set the calibration constant, press the "C" key and
input the five-digit constant as given on the label. After entering the fifth digit, the prompt "CHANGE
(Y/N)?" will appear on the LCD. If the constant is incorrect, restart the procedure by pressing the
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Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PM10 Analyzers
"YES" key. If the constant is correct, press the "NO" key. The "PRESS A KEY" prompt will return
to the screen. (This step is not necessary for instruments equipped with the CFCASF flow controller.)
9.3.2 The "D" key is used to set the expected maximum mass concentration for the sampling site in
battery-backed RAM. This five-digit constant contains no decimal point, and five digits must be entered.
For example, if the maximum anticipated concentration is 250 /*g/nr*, the input constant is 00250. To
set the constant, press the "D" key and enter the five-digit constant. After entering the fifth digit, the
prompt "CHANGE (Y/N)?" will appear on the LCD. If the constant is incorrect, restart the procedure
by pressing the "YES" key. If the constant is correct, press the "NO" key. The "PRESS A KEY"
prompt will return to the screen.
[Note: Do not set an upper limit that is arbitrarily high because this will reduce the resolution of the
telemetry (analog) output.]
9.3.3 The "SETUP" key is used to enter the correct date and time into the computer. When the
"SETUP" key is pressed, the date and time will appear on the LCD followed by the prompt "CHANGE?
(Y/N)H. If the displayed date and time are incorrect, press the "YES" key. The prompt "INPUT DATE"
will appear on the LCD. Enter the six-digit date with zeros preceding single digit days or months.
Following the input of the date, the prompt "INPUT TIME" will appear on the LCD. Enter the six-digit
time (hours, minutes, and seconds) based on a 24-h clock; the new date, time,- and the prompt
"CHANGE? (Y/N)" will appear on the LCD. When the correct date and time are displayed, press the
"NO" key to complete the setup operation.
9.3.4 Press the "PROGRAM SAMPLING SCHEDULE" key to program the time at which the
instrument is to begin a sampling cycle. The programmed date and time will appear on the LCD,
followed by the prompt "CHANGE? (Y/N)". If the displayed date and time are incorrect, press the
"YES" key. The prompt "INPUT START DATE" will appear on the LCD. Enter the six-digit start
date, with zeros preceding single digit days or months; the prompt "INPUT START TIME" will appear
on the LCD. Enter the six-digit start tune (hours, minutes, and seconds) based on a 24-h clock; the
prompt "PRESS A KEY" will appear on the LCD.
(Note: The input start time must be at least 15 min later than the actual time as indicated by the
real-time clock.]
9.3.5 Verify that the "FLOW TEMP CORR" is ON (modified units) and select "STAN COND=ON"
if flow and concentration are desired in standard volume units.
9.3.6 Press the "PARALLEL PRINTER ON/OFF" key to enable or disable the parallel printer (if
so equipped). One of two messages will appear: "PARALLEL PRINTER ON" or "PARALLEL
PRINTER OFF." To change the printer mode, press the "PARALLEL PRINTER ON/OFF" key again.
If the unit is left unattended, the built-in parallel printer should be in the off mode because the paper may
interfere with the mechanical movements.
9.3.7 The "RS-232 PRINTER ON/OFF" key operates in the same manner as the "PARALLEL
PRINTER ON/OFF" key described above. A serial printer cannot be enabled at the same time the
RS-232 communication port is on. (Only one device, a serial printer or a communications device, can
be connected to the RS-232 port on the instrument panel.)
9.3.8 Press the "RS-232 COMM ON/OFF" key to enable or disable the communication port that
provides the necessary signals to transmit data off-site. One of the following two messages will appear
on the LCD. (1) If the communication port was in the off mode, the current baud rate is displayed
Page 1.2-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1
Continuous
Analyzers
Method IO-1.2
Thermo Beta Gauge
followed by the prompt "CHANGE? (Y/N)". To change the baud rate, press the "YES" key and select
a baud rate using the numbered key that corresponds to the desired baud rate shown on the LCD. To
accept the baud rate, press the "NO" key; the message "COMM. PORT ON" will appear on the LCD.
(2) If the communication port was in the on mode, the message "COMM PORT OFF" will appear on the
LCD. This communication port cannot be enabled at the same time the RS-232 serial printer is on.
9.4 Commencing Sampling
9.4.1 To check the instrument prior to commencing sampling, press the "TROUBLE SHOOT" key
to initiate a series of 13 diagnostic tests. The results of each test will appear on the LCD with a "PASS"
or "FAIL" message. The following four LCD messages illustrate all 13 tests and their results.
:
1) MODULE DN
2) COMP. UP
3) ADVANCE
4) COMP. DN.
5) TRANS. RT.
6) TRANS. LT
7) MODULE UP
8) PRESSURE
9) BETA CNT.
10) FLOWRATE
11) PS15
12) PS12
13) PS5
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
PASS
If a "FAIL" indication is displayed for any of the tests, make sure that all sampling information was
entered correctly. Also, check the instrument for loose cables or other obvious problems (e.g., make
sure the filter tape has been loaded). Press the "TROUBLE SHOOT" key again, and if the "FAIL"
message still appears, contact the manufacturer for further service information.
9.4.2 Press the "STATUS" key to confirm the status (on/off) of the parallel printer port, serial
printer port, and communications port. Press this key twice to confirm the actual status of these ports.
If the status is not as desired, use the appropriate keys as described in Sections 9.3.5 through 9.3.7 to
enable the desired output device(s).
fNote: The RS-232 serial printer and RS-232 communications cannot be on at the same time.]
9.4.3 Press the "BEGIN SAMPLING" key to begin sampling operations. The LCD will show the
messages "INITIALIZING SYSTEM" and "PLEASE STANDBY" while the unit undergoes the necessary
mechanical movements and checking procedures to permit the system to begin operation. When
initialization is finished, the LCD shows the actual date and time, the sampling period, the mass
concentration of the previous sampling period, and the message "A OR B TO TERMINATE."" (All other
control keys are disabled.) To immediately terminate sampling, press the "B" key. To terminate
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Compendium of Methods for Inorganic Air Pollutants
Page 1.2-13
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Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PM10 Analyzers
sampling at the end of the sampling period (approximately at the end of each hour), press the "A" key;
the prompt "PRESS A KEY" will appear on the LCD. At this time, all valid control keys are enabled.
9.5 Other Control Keys
These keys are enabled only when the instrument is not in sampling mode.
9.5.1 A description of the "LOAD TAPE" key, which is used when loading a new filter tape, is
provided in Section 9.2.1.
9.5.2 Press the "RESET" key to reinitialize the instrument. The LCD messages and prompts will
be the same as when the instrument was turned on.
9.5.3 Press the "MODULE UP/DOWN" key to activate the sampling module motor. The sampling
manifold will open and must be closed by pressing the "MODULE UP/DOWN" key again.
9.5.4 Press the "COMP UP/DOWN key to activate the compression rollers. The compression
rollers will open and must be closed by pressing the "COMP UP/DOWN" key again.
9.5.5 Press the "TRANS LEFT/RIGHT" key to translate the tape left or right. Following the first
translation from left to right (i.e., from the measurement position to the sampling position), the message
"ROLLERS MUST BE TRANSLATED LEFT TO EXIT" will be displayed. Press the "TRANS
LEFT/RIGHT" key again to move the translation mechanism back to the original position (i.e., from
the sampling position back to the measurement position).
9.5.6 Press the "VACUUM PUMP ON/OFF" key to test the vacuum pump. This action turns the
vacuum pump on, and the message "VACUUM PUMP MUST BE TURNED OFF TO EXIT" will be
displayed. Press the key again to turn the vacuum pump off.
Note: This key is only for testing the vacuum pump. Turn off the pump after testing for proper automatic
operation of the instrument.]
9.5.7 Press the "ADVANCE TAPE" key to advance the filter tape one position. The message
"ADVANCING" will be displayed on the LCD as the necessary operations take place. The operation
may take up to 2 min because it requires the sampling module and compression rollers to be opened
before the tape is advanced.
9.5.8 Press the "TEMP/PRESSURE" key to display the current cabinet temperature and atmospheric
pressure.
9.5.9 Press the "BETA COUNT" key to determine if the beta count is acceptable. After a period
of time, the message "COUNT ACCEPTABLE" or "COUNT UNACCEPTABLE" will appear on the
LCD. If the "COUNT UNACCEPTABLE" message is displayed, make sure that all sampling
information was entered correctly. Also, check the instrument for loose cables or other obvious
problems. If the beta count remains unacceptable, fill out the troubleshoot questionnaire provided in
Addendum 1 of the operating manual and contact the manufacturer for further service information.
9.5.10 Press the "FLOWRATE" key to display the actual flow rate of air through the instrument
in cm^/min. If the displayed flow rate is unacceptable (off by more than 10% of the design flow rate
of 18,900 crcr/min), make sure that all sampling information was entered correctly. Also, check the
instrument for loose cables or other obvious problems such as obstructions in the inlet tube or system
vacuum tubing. If the flow rate remains unacceptable, fill out the troubleshoot questionnaire provided
in Addendum 1 of the operating manual, follow the procedures outlined in Section 13.3 of the operation
manual (flow rate audit procedure), and contact the manufacturer for further service information.
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Chapter IO-1 Method IO-1.2
Continuous PM10 Analyzers Thermo Beta Gauge
10. Replacing the Filter Tape
Caution: NEVER turn the take-up (right side) tape drive manually, or the drive system will be damaged.
The filter tape drive system is illustrated in Figure 6.
10.1 Press the "LOAD TAPE" key. The functioning of this key is described in Section 9.2.1.
10.2 Remove the full take-up reel from the tape drive on the right. Hold the reel firmly to keep it from
rotating, loosen the black plastic pronged knob, and slide the reel off the shaft.
10.3 Move the previous supply reel (now empty) from the left tape drive to the right drive. First, loosen
the black plastic pronged knob. Next, remove the reel and place it on the now-vacant right tape drive.
Be sure to slide the hub onto the shaft so that the shaft pin fits into the slot on the hub. Replace the black
knob and tighten snugly.
Caution: Tighten the knob and hold the reel at the same time. Do not apply excessive torque to the drive
shaft or the motor may be damaged.
10.4 Complete the tape replacement by following the steps described in Sections 9.2.3 through 9.2.6.
11. Printer Paper Replacement (if applicable)
In instruments with a built-in printer, a full roll of paper is initially supplied with the parallel printer.
The printer system is illustrated in Figure 7.
11.1 To replace an empty roll, gently press the printer faceplate latches and pull to remove.
11.2 Locate the metal tab adjacent to the paper sensor (LED), press it, and gently slide the printer out
until it stops.
11.3 Remove the old roller and insert a fresh roll of printer paper. The printing surface of the paper
is on the outside of the roll. Make certain the roll turns in a counterclockwise direction (referenced from
the paper access area) as the paper unrolls.
11.4 Locate the paper slot in front of the small white roller at the bottom of the printer. Insert or feed
the paper into the slot, pressing the feed switch until the paper comes out the printer head.
11.5 Gently slide the printer back into the housing and replace the faceplate.
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Method 10-1.2 .
Thenno Beta Gauge Continuous PM10 Analyzers
12. Maintenance
The instrument is specifically designed to require minimal maintenance by the user. Four principal areas
require attention. Two of these, replacing the filter tape and replacing the parallel printer paper, are
discussed in Sections 10 and 11, respectively. Maintenance of the detector and sampling inlet are
discussed below.
12.1 Detector
In general, the IISS detector should not be disturbed or removed from its mounting. If testing indicates
that the detector surface is contaminated, the surface of the detector may be cleaned, very carefully, by
using a suitable cleaning agent supplied by the manufacturer.
Caution: The sensitive area of the detector is delicate and should never be touched, except very lightly
wth a soft cotton swab.
12.2 Sampling Inlet
After operating for an extended period of time under high mass concentration conditions, the sampling
inlet must undergo periodic maintenance. The maintenance procedure is a simple brushing technique to
remove accumulated PM from the primary deposition area in the inlet.
Remove the maintenance access port and run the supplied cleaning brush down through the inner tube
three times, twisting the handle between the fingers to insure that the brush touches all surfaces. This
procedure should be repeated once after every 15 days of sampling operations.
13. Instrument Calibration
The instrument calibration may be checked and changed, if necessary, by the user. This section describes
the initial calibration procedures used by the manufacturer for the instrument as well as field audit
procedures for the user.
13.1 Mass Determination
13.1.1 The Thermo Beta Gauge system has undergone a complete calibration procedure using
aerosol standards hi the laboratory. The laboratory calibration involves the generation of monodisperse
solid particles injected into the Thermo Wind Tunnel Facility. The concentration level in the facility can
be adjusted over the range of 25 to 300 /xg/m3. The calibration procedure is performed to determine the
attenuation coefficient, which is used in the instrument's internal calculations to determine the mass of
collected on the filter.
In the calibration procedure, parallel samples of the particle cloud are collected using identical Wedding
Inlets. One sample is collected using an appropriate filter substrate and subsequently analyzed
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Chapter IO-1 Method IO-1.2
Continuous PM^Q Analyzers Thermo Beta Gauge
fluorometrically to determine mass concentration. This mass concentration is then used to calculate mass
density of particles on the filter tape. The second sample is analyzed using the Thermo Beta Gauge.
The procedure is repeated for a range of particle loadings. The beta attenuation values from the beta
gauge are then related to the mass density levels determined from the first sampler. The attenuation
coefficient for the beta gauge system is determined by a least-squares fit to a straight line on a plot of the
various mass density values vs. corresponding attenuation values.
13.1.2 The manufacturer has performed this calibration procedure to determine generally-applicable
attenuation coefficients for instruments that use glass fiber and membrane filter media. (The attenuation
coefficient differs slightly depending on filter medium.) Each individual instrument is subjected to the
same procedures before shipment to confirm that the generally-applicable attenuation coeffient is accurate
for that instrument.
13.1.3 The long half-life of carbon-14 minimizes the need for recalibrating and replacing the beta
source. During operation, the instrument continually runs internal diagnostic checks to ensure the proper
operation of the source/detector system. The foil calibration feature, available on new or kit-modified
units, may be used by the operator to check the calibration of the instrument and, if necessary, to change
the calibration constant (attenuation coefficient), using a calibration foil provided by the manufacturer.
Follow the instructions for this feature in the Operator's Manual or Manual Addendum.
13.2 Flow Rate
13.2.1 As discussed in Section 7.9, flow control for the instrument is achieved using a critical flow
system. Each instrument is calibrated by the manufacturer to determine the instrument-specific flow
coefficient that is used in internal calculations to determine the flow rate.
13.2.2 The manufacturer recommends no periodic recalibration by the user. However, a quarterly
field audit is required by EPA for any instrument operating as an equivalent method for PM JQ. The audit
procedure is presented in the following section.
13.3 Single-Point External Flow Rate Audit Procedure Using a Flow Transfer Standard
13.3.1 Background. This section describe an external means of auditing the volumetric flow rate
of the instrument. An NIST-traceable primary standard is used to calibrate a transfer standard which,
in turn, is used to verify the calibration of the instrument's CFD.
Several commercially available transfer standards can be used in this audit procedure. Table 2 lists
recommended transfer standards, their applicable flow ranges, references for transfer calibration
procedures, and necessary equipment to perform calibrations. (This table has been adopted from the EPA
Quality Assurance Handbook for air pollution measurement systems [EPA 600/4-77-027 A].) Because
the design flow rate for the PM^Q inlet is 18.9 L/min, the transfer standard should be calibrated in the
flow rate range of approximately 15 to 20 L/min. The transfer standard should not cause a pressure drop
of more than 4.0" of water.
After selecting a transfer standard, use a leak-tight adapter to connect the transfer standard to the
instrument inlet tube as depicted in Figure 8. The adapter may be fabricated by a third party, purchased
commercially, or requested from the manufacturer (part no. BG-590).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-17
-------
Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PM^0 Analyzers
Normally, a station log book or audit data sheet is used to document audit information. This information
normally includes, but is not limited to, an identification of the transfer standard, its serial number,
traceability documentation for the audit information, and the ambient temperature and pressure as well
as the actual audit data collected during audit procedures.
13.3.2 Audit Procedure.
13.3.2.1 Remove the PMjQ inlet from the instrument. Install the adapter, referring to Figure 8
for details. Connect the flow transfer standard, as depicted in Figure 9, using suitable tubing.
13.3.2.2 Press the key on the keypad titled "FLOWRATE". (This command will establish
necessary audit conditions, such as advancing the tape to a new/unused area of the medium.) Be sure
that the filter tape is fully loaded and the sampling module is in the closed position.
13.3.2.3 Allow time for the flow transfer standard to equilibrate, which requires operating the
system for approximately 5 min. During this operation, the inlet of the transfer standard is open to
ambient air, and the outlet of the transfer standard is connected via the adapter to the inlet tube of the
instrument.
13.3.2.4 Record all pertinent parameters required to make calculations from the flow transfer
standard's previous calibration. These parameters may include, but are not limited to, ambient pressure
and temperature and transfer standard readings such as volts, pressure drop, timings or revolutions, etc.
During this time the instrument's computer will calculate, and the LCD will display, a continuing series
of flow rate values based upon measured flow conditions. Time-averaged flow rate values will be
produced and updated every 2 min. These values allow the operator to make comparisons between
readings of the flow transfer standard and the. values output to the LCD by the computer.
[Note: New or modified instruments displays flow rates in either standard or actual cnr/min. Always
be sure that the instrument and transfer standard flow rates are in the same terms (actual or standard)
before comparing them.]
13.3.2.5 Depending upon the purpose or nature of the audit, the flow rate values displayed on the
LCD should agree within a specified percentage of the flow rate transfer standard values. For purposes
of flow rate audits required by EPA, all values displayed on the LCD should agree within ±7% of the
flow rate transfer standard values. If not, check all calculations to ensure that the flow rates are in the
same terms (actual or standard volumes). These values need not necessarily be the design flow rate value
of 18.9 L/min.
13.3.2.6 If the flow transfer standard and the instrument do not agree within ±7%, refer to
Section 9.4.1 (Trouble Shooting). Fill out the detailed trouble-shooting check list in the Addendum to
the manufacturer's technical manual (2). In particular, items 4-10 relate directly to flow rate verification.
Report these results to Thermo for further information.
13.3.2.7 To compare the design flow rate of 18.9 L/min to the actual flow rate displayed on the
LCD, remove both the external transfer standard and the external transfer standard adapter. Replace the
PM^Q inlet onto the inlet tube. Allow approximately 1-2 min for the flow to equilibrate; observe the
series of flow rate values displayed on the LCD. Make sure that the instrument is reading the flow rate
In actual volumetric units, and apply and percentage correction determined in Section 13.3.2.5. These
values should be within ±10% of the design flow rate value of 18.9 L/min; if not, refer to
Section 13.3.2.6.
Page 1.2-18 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-1 Method IO-1.2
Continuous PM10 Analyzers Thermo Beta Gauge
13.4 Mass Determination Audit
As noted in Section 13.1.3, the foil calibration feature, available on new or kit-modified units, may be
used by the operator to check the calibration of the instrument and, if necessary, to change the calibration
constant (attenuation coefficient), using a calibration foil provided by the manufacturer. Follow the
instructions for this feature in the Operator's Manual of Manual Addendum.
13.5 Leak Checking
The instrument is assembled and leak checked before it is shipped to the user. No routine definitive leak
checking procedures are conducted thereafter. The manufacturer does not recommend positive or
negative pressure leak checking because this activity could rupture the gaskets in the sampling module.
To check for leaks, examine the vacuum tubing and verify that all connections at the inlet, inlet tube, and
vacuum tubing are secure. Examine the filter tape to verify that all spots where PM has been collected
are sharply-defined circles. Poorly-defined sample spots indicate leaking sampling module gaskets.
14. Safety
This instrument uses a radioactive source to measure PM1Q. The Nuclear Regulatory Commission does
not require the user of this low-energy, beta-emitting source to be licensed (however, Thermo is so
licensed). The beta source is sealed at the factory and should never be opened or tampered with. The
entire instrument should be returned to Thermo for service or disposal of the beta source.
15. Performance Criteria and Quality Assurance (QA)
Required quality assurance measures and guidance concerning performance criteria that should be
activated within each laboratory are summarized and provided in the following section.
15.1 Standard Operating Procedures (SOPs)
15.1.1 SOPs should be generated by the users to describe and document the following activities in
their laboratory:
• Assembly, calibration, leak check, and operation of the specific sampling system and equipment
used;
• Preparation, storage, shipment, and handling of the sampler system;
• Purchase, certification, and transport of standard reference materials; and
• All aspects of data recording and processing, including lists of computer hardware and software
used.
15.1.2 Specific instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the monitoring work.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-19
-------
Method IO-1.2 Chapter IO-1
Thermo Beta Gauge Continuous PM10 Analyzers
15.2 QA Program
The user should develop, implement, and maintain a quality assurance program to ensure that the
sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted on a regularly scheduled basis and should be part of
the quality assurance program. Calibration verification procedures provided in Section 13, operation
procedures in Section 9, and the manufacturer's instruction manual should be followed and included in
the QA program. Additional QA measures (e.g., trouble shooting) as well as further guidance in
maintaining the sampling system are provided by the manufacturer. For detailed guidance in setting up
a quality assurance program, the user is referred to the Code of Federal Regulations (3) and the
U. S. EPA Handbook on Quality Assurance (4).
16. References
1. Equivalent Method Designation: PM10 Beta Gauge Automated Particle Sampler, Federal Register,
Vol. 56, No. 43, March 5, 1991, pp. 9216-9217.
2. Wedding, J. B., and Weigland, M.A., Wedding & Associates'PMW (or TSP) Beta Gauge Automated
Particle Sampler Operations and Maintenance Manual. Fort Collins, CO, February 1991.
3. 40 CFR, Part 58, Appendices A and B.
4. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II-Ambient Air Specific
Methods, (Interim Edition), EPA 600/R-94/038b.
5. U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution Measurement
Systems, Volume I: A Field Guide for Environmental Quality Assurance, EPA-600/R-94/038a.
Page 1.2-20 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.2
Thermo Beta Gauge
TABLE 1. SUMMARY OF KEYPAD CONTROL KEYS
ROW COLUMN
i i
1 2
1 3
1 4
1 5
2 1
2 2
2 3
2 4
2 5
3 1
3 2
3 3
3 4
3 5
4 1
4 2
7 1
8 1
8 3
5 1
6 2
LETTERING ON KEY
PROGRAM SAMPLING
SCHEDULE
MODULE
UP/DN
TEMP/
PRESS
PARALLEL PRINTER
ON/OFF
SETUP
BEGIN SAMPLING
COMP.
UP/DN
BETA COUNT
RS-232
PRINTER ON/OFF
STATUS
LOAD TAPE
TRANS.
LEFT/RIGHT
FLOW RATE
RS-232 COMM.
ON/OFF
TROUBLE SHOOT
ADVANCE TAPE
VACUUM PUMP ON/OFF
C
D
RESET
A
B
DESCRIPTION
allows input of the desired start date and start time
in which the sampling cycle will begin
moves the sampling module one full cycle (i.e.,
move down and back up)
displays the cabinet temperature and pressure
readings on the LCD
output directed to parallel printer (telemetry output
still active)
allows viewing and resetting of the battery-backed
real-time clock
starts or begins the sampling cycle
moves the compression rollers one full cycle
(i.e., move up and back down)
determines if beta particles are being counted
acceptably or unacceptably
output directed to RS-232/serial printer (telemetry
output still active) -
reads and displays the status of the external I/O
devices (i.e., parallel printer, serial printer,
RS-232 communications)
refers user to manual, opens mechanical systems
moves the translation assembly one full cycle
(i.e., move right and back left)
displays the sampler flow rate reading on the LCD
allows setting the RS-232 baud rate for off-site
communications
executes a series of analog, digital, and mechanical
diagnostics and displays the results on the LCD
advances the filter media one location
tests the vacuum pump
allows input of the calibration constant in
battery-backed RAM if lost through battery failure
allows setting the maximum mass concentration
limit in battery-backed RAM
resets the computer
interrupts sampling at the conclusion of the current
sampling/measurement cycle (key enabled only
while in sampling mode)
interrupts sampling immediately (key enabled only
while in sampling mode)
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-21
-------
Method IO-1.2
Thermo Beta Gauge
Continuous
Chapter IO-1
Analyzers
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-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.2
Thermo Beta Gauge
Figure 1. The Thermo Beta Gauge Main Particle Sampling Cabinet.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-23
-------
Method IO-1.2
Thermo Beta Gauge
Chapter IO-1
Continuous PM10 Analyzers
6.100 DIA
1.250 DIA
•*!
^ — —
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^•— Temperature
Sensor
S
m
S ».
•& » <•
Figure 2. Main Cabinet with PM-10 Inlet and Inlet Tube.
Page 1.2-24 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.2
Thermo Beta Gauge
8
•9
u
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o
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o
-------
Method IO-1.2
Thermo Beta Gauge
INSECT
SCREiTM
TAPERED
COUPLING
Chapter IO-1
Continuous PM-|Q Analyzers
INNER TUBE
(PERFECT
ABSORBER
SURFACE)
HOUSING-DEFLECTOR
SPACING
MAINTENANCE
ACCESS PORT
VANES
VANE
ASSEMBLY
BASE
PROTECTIVE
HOUSING
AERODYNAMIC INLET
PATHWAY
AERODYNAMIC FLOW
DEFLECTOR
W&A BETA GAUGE
INLET TUBE
Figure 4. Thermo PM-10 Inlet for the W&A Beta Gauge.
Page 1.2-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM<« Analyzers
Method IO-1.2
Thermo Beta Gauge
VALID
CONTROL
KEYS
Figure 5. Instrument Keypad.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.2-27
-------
Method 10-1.2
Thermo Beta Gauge
Chapter KM
Continuous PM|Q Analyzers
NO, 1 UPP1R
COMPRESSION
SHAFT
NO, ROWER
CO.V.P B88ION ROLLER
DETECTOR/
SOURCE
O "
o)
SAMPLING
MODULE
1 1
1
r ©
1 (o-
TRANSLATiONAL
ROLLER
MEDIA SUPPLY REEL
3vJ
NO, 2 UPPER
COMPRESSION
SHAFT
NO. 8 LOWER
COMPRESSION ROUE
MEDIA TAKE-UP REEL,
Figure 6. Filter Tape Drive System.
Page 1.2-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM^Q Analyzers
Method IO-1.2
Thermo Beta Gauge
MAIN UNIT
PAPER END SENSOR
(LED)
PAPER CUTTER
MAIN UNIT FITTING
FEED SWITCH
HOOK FOR REMOVING FRONT PANEL
PRINTING SURFACE
PRINTER
PAPER ROLL
PAPER ROLL SHAFT
PRINT HEAD
PRINTING
SURFACE
Figure 7. Replacing Paper in the Parallel Printer.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.2-29
-------
Method IO-1.2
Thermo Beta Gauge
Chapter IO-1
Continuous PM10 Analyzers
TD EXTERNAL
TRANSFER STANDARD
0.375 NPT TO BARB
CONNECTOR
D-RING
• ALUMINUM EXTERNAL
CALIBRATION ADAPTER
CW&A'-P/N BG590)
V&A BETA GAUGE
INLET TUBE
Figure 8. Adapter for External Flow Transfer Standard.
Page 1.2-30
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous
Analyzers
Method IO-1.2
Thermo Beta Gauge
EXTERNAL
TRANSFER
STANDARD
REMOVED
PM10 INLET
EXTERNAL
TRANSFER
STANDARD
ADAPTER
INLET
TUBE
Figure 9.: Configuration of External Flow Transfer Standard.
January 1997 Compendium of Methods for Inorganic Air Pollutants
Page 1.2-31
-------
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-1.3
DETERMINATION OF PM1O IN
AMBIENT AIR USING A CONTINUOUS
RUPPRECHT AND PATASHNICK (R&P)
TEOM® PARTICLE MONITOR
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
September 1996
-------
Method IO-1.3
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry"Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Authors)
Erich Rupprecht, Rupprecht and Patashnick, Albany, NY
William T. "Jerry" Winberry, Jr., Midwest Research Institute, Cary, NC
Peer Reviewers
David Brant, National Research Center for Coal and Energy, Morgantown, WV
John Glass, SC Department of Health and Environmental Control, Columbia, SC
Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
Charles Rodes, Research Triangle Institute, RTP, NC
Danny France, U.S. EPA, Region 4, Athens, GA
David Harlos, Environmental Science and Engineering, Gainesville, FL
Jim Tisch, Graseby, Cleves, OH
Michael B. Meyer, Rupprecht and Patashnick, Albany, NY
Richard Shores, Research Triangle Institute, RTP, NC
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
-------
Method IO-1.3
Determination of PM10 in Ambient Air
Using a Continuous Rupprecht and Patashnick (R&P)
TEOM® Particle Monitor
TABLE OF CONTENTS
7.4 TEOM® PM1Q Inlet
Page
1. Scope [[[ 1.3-1
2. Applicable Documents ........................................ 1.3.3
2. 1 ASTM Standards ........................... ..... '.'.'.'.'.'.'.'.'. 1.3-3
2.2 Other Documents ............. ................ .......... 1.3-3
3. Summary of Method ..... .................................... 1.3-3
4. Significance ................................... . ...... 1.3-4
5. Definitions ............................................... 1.3-5
6. Interferences ................................. ............. 1.3-5
7. Apparatus . . .............................................. 1 3.5
7.1 TEOM® 1400a Control Unit ............ ............. . . . 13-6
7.2 TEOM® 1400a Sensor Unit ................................ ' 13-6
7.3 TEOM® Sensor/Preheater Assembly . ............. 13-6
'
7.5 TEOM® Flow Splitter Assembly ..................... ......... 1.3-7
7.6 Electric and Air Cable Assembly .............................. 1.3-7
7.7 Filter Cartridge .................................. ...... 1.3-7
7.8 Filter Exchange Tool .......................... , .......... 1.3-7
7.9 Other Components ....................................... 1.3_8
8. Assembling the TEOM® Series 1400a Monitor ................. ........ 1.3-8
9. Installing the Flow Splitter and PM^Q Inlet ............... .......... . . 1.3.9
10. Exchanging the Filter Cartridge .................................. 1.3-10
10.1 Loading the Filter Cartridge ............. .................... 1.3-10
10.2 Removing the Filter Cartridge ................... ............ 1.3-11
11. System Operation and Data Storage ................................ L3-12
11.1 Instrument Start-Up ...................................... 1.3-12
11.2 Instrument Shutdown and Shipping .......... .... ............ . . 1.3-13
11.3 Information Shown on the Main Screen ......................... 1.3-13
11.4 When to Exchange TEOM® Filter Cartridges ............... ....... L3-15
11.5 Summary of Instrument Operation .............. ............. 1.3-15
12. System Calibration .......................................... 1.3-16
12. 1 Overview of Calibration Procedures .................. .......... 1-3-16
12.2 Flow Controller Calibration (Software) ....................... ... 1.3-16
12.3 Procedures for Analog Calibration ............................ ' 1.3-17
12.4 Flow Controller Calibration (Hardware) .................. ....... 1.3-18
12.5 Mass Transducer Calibration Verification ........................ 1.3-20
12.6 Flow Audit Procedure ....................... . ..... 1 3.21
13. Method Safety ............................................. 13-22
14. Performance Criteria and Quality Assurance (QA) ....................... L3-22
14.1 Standard Operating Procedures (SOPs) ............... ........... 1.3-22
14.2 QA Program ................. 13-23
-------
-------
Chapter IO-1
CONTINUOUS MEASUREMENT OF SUSPENDED
PARTICULATE MATTER (SPM)
IN AMBIENT AIR
Method IO-1.3
DETERMINATION OF PM10 IN AMBIENT AIR
USING A CONTINUOUS RUPPRECHT AND PATASHNICK (R&P)
TEOM® PARTICLE MONITOR
1. Scope
1.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels are essential to proper assessment.
1.2 Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01 jim to
100 fim and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.3 The U. S. Environmental Protection Agency (EPA) reference method for TSP is codified at 40 CFR
50, Appendix B. This method uses a high-volume sampler (hi-vol) to collect particles with aerodynamic
diameters of approximately 100 jwn or less. The hi-vol samples 40 and 60 ftVmin of air with the
sampling rate held constant over the sampling period. The high-volume design causes the TSP to be
deposited uniformly across the surface of a filter located downstream of the sampler inlet. The TSP high
volume can be used to determine the average ambient TSP concentration over the sampling period, and
the collected material subsequently can be analyzed to determine the identity and quantity of inorganic
metals present in the TSP.
1.4 Research on the health effects of TSP in ambient air has focused increasingly on those particles that
can be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10 /mi.
Researchers generally recognize that these particles may cause significant, adverse health effects.
1.5 On July 1, 1987, the EPA promulgated a new size-specific air quality standard for ambient
•particulate matter. This new primary standard applies only to particles with aerodynamic diameters
-------
Method 10-1.3 Chapter IO-1
TEOM* Monitor Continuous PM10 Analyzers
with suspended paniculate pollution. The secondary standard, used to assess the impact of pollution on,
public welfare, has also been established at 150 jtg/std mr.
1.7 Monitoring methods for paniculate matter are designated by the EPA as reference or equivalent
methods under the provisions of 40 CFR Part 53, which was amended in 1987 to add specific
requirements for PM10 methods. Part 53 sets forth functional specifications and other requirements that
reference and equivalent methods for each criteria pollutant must meet, along with explicit test procedures
by which candidate methods or samplers are to be tested against those specifications. General
requirements and provisions for reference and equivalent methods are also given in Part 53, as are the
requirements for submitting an application to the EPA for a reference or equivalent method determination.
1.8 Under the Part 53 requirements, reference methods for PM10 must use the measurement principle
and meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a PM10
sampler that meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies a
measurement principle based on extracting an air sample from the atmosphere with a powered sampler
that incorporates inertial separation of the PM10 size range particles followed by collection of the PM10
particles on a filter over a 24-h period. The average PM10 concentration for the sample period is
determined by dividing the net weight gain of the filter over the sample period by the total volume of air
sampled. Other specifications are prescribed in Appendix J for flow rate control and measurement, flow
rate measurement device calibration, filter media characteristics and performance, filter conditioning
before and after sampling, filter weighing, sampler operation, and correction of sample volume to EPA
reference temperature and pressure. In addition, sampler performance requirements in Subpart D of
Part 53 include sampling effectiveness (the accuracy of the PM10 particle size separation capability) at
each of three wind speeds and "50% cutpoint" (the primary measure of 10-micron particle size
separation). Field tests for sampling precision and flow rate stability are also specified. In spite of the
instrumental nature of the sampler, this method is basically a manual procedure, and all designated
reference methods for PM10 are therefore defined as manual methods.
1.9 The protocol for operating the only continuous particulate mass monitor that directly measures
paniculate mass at concentrations between 5 jig/m3 and several g/m3 on a real-time basis is described
in this method.
1.10 The Ruppecht and Patashnick TEOM® continuous monitor calculates mass rate, mass concentration,
and total mass accumulation on exchangeable filter cartridges that are designed to allow for future
chemical and physical analysis. In addition, the instrument provides hourly and daily averages. _
1.11 The methodology detailed in this document is currently employed by such U.S. research
organizations as the U.S. EPA, Argonne National Laboratory, R.J. Reynolds Tobacco Company, and
Philip Morris, Inc. for indoor and outdoor air quality studies, aerosol behavior studies, and cigarette
smoke behavior studies. It is used for ambient monitoring by agencies such as the California Air
Resource Board (CARS), South Coast Air Quality Management District (SCAQMD), Northwest Air
Pollution Authority, Puget Sound Air Pollution Control District and many others throughout the United
States.
Page 1.3-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.3
Continuous PM10 Analyzers TEOM® Monitor
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2 Other Documents
• Technical Manuals (1-2).
• Laboratory and Field Studies (3-19).
3. Summary of Method
3.1 Particle-laden air is drawn into the TEOM® monitor through an air inlet followed by an exchangeable
filter cartridge, where the paniculate mass collects. The inlet system may or may not be equipped with
the optional sampling head, which pre-separates particles at either a 2.5 or 10 /*m diameter.
3.2 The filtered air then proceeds through the sensor unit, which consists of a patented microbalance
system.
3.3 As the sample stream moves into the microbalance system (filter cartridge and oscillating hollow
tapered tube), it is heated to the temperature specified by the control unit. This is done to minimize the
deposition of water due to changes in ambient humidity.
3.4 The control unit contains the automatic flow controller, which pulls the sample stream through the
monitor at flow rates between 0.5 and 5 Lpm. The hollow tube is attached to a platform at its wide end
and is vibrated at its natural frequency.
3.5 As paniculate mass gathers on the filter cartridge, the tube's natural frequency of oscillation
decreases. The electronic microbalance system continually monitors this frequency.
3.6 Based upon the direct relationship between mass and frequency, the instrument's microcomputer
computes the total mass accumulation on the filter, as well as the mass rate and mass concentration, in
real time. ~
3.7 The control unit contains software that allows the user to define the operating parameters of the
instrumentation through menu-driven routines.
3.8 During sample collection, the program plots total mass, mass rate and/or mass concentration, and
operating conditions on the 4-line liquid crystal display (LCD). Figure 1 illustrates the assembled
TEOM® control and sensor unit.
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TEOM* Monitor Continuous PM10 Analyzers
4. Significance
4.1 SPM in ambient air generally is a complex, multi-phase system of all airborne solid and low vapor
pressure particles from below 0.01 pm up to 100 /im and larger. Historically, measurement of particulate
matter (PM) has concentrated on TSP, with no preference to size selection. Research on the health
effects of TSP in ambient and outdoor air has focused increasingly on particles that can be inhaled into
the respiratory system, i.e., particles of aerodynamic diameter less than 10 jim. Researchers generally
recognize that these particles may cause significant, adverse health effects.
4.2 Particles are formed by two processes: (1) the grinding or atomization of matter and (2) the
nucleation of supersaturated vapors. The particles formed in the first process are products of direct
emissions into the air, whereas particles formed in the second process usually result from reaction of
gases, then nucleation to form secondary particles. Particle growth in the atmosphere occurs through gas-
particle interactions and particle-particle (coagulation) interaction.
4.3 Recent studies involving particle transport and transformation suggest strongly mat atmospheric
particles commonly occur in two distinct modes. The fine, or accumulation, mode is attributed to the
growth of particles from the gas phase and subsequent agglomeration, while the coarse mode is made up
of mechanically abraded or ground particles. Particles that have grown from the gas phase, either
because of condensation, transformation, or combustion, occur initially as very fine nuclei~0.05 /*m.
These particles tend to grow rapidly to accumulation mode particles around 0.5 ^m, which are relatively
stable in the air. Because of their initially gaseous origin, this range of particle sizes includes inorganic
ions such as sulfate, nitrate, ammonia, combustion-form carbon, organic aerosols, metals (Pb), cigarette
smoke by-products, and consumer spray-products.
4.4 Coarse particles, on the other hand, mainly are produced by mechanical forces such as crushing and
abrasion. Coarse particles, therefore, normally consist of finely divided minerals such as oxides of
aluminum, silicon, iron, calcium, and potassium. Coarse particles of soil or dust result from entrainment,
the motion of air, or other mechanical action within their area. Since the mass of these particles is
normally >3 /tm, their retention time in the air parcel is shorter than the fine particle fraction.
4.5 The composition and sources of coarse particles are not as thoroughly studied as those of fine
particles; coarse particles are more complex than fine particles and similar in chemical composition.
However, dozens of particle types, such as soil, limestone, flyash, and oil soot, are possible to recognize
based on microscopic examination.
4.6 Outdoor concentrations of TSP are of major concern in estimating air pollution effects on visibility,
ecological and material damage, and health effects. Consequently, a continuous particulate monitor has
been developed to allow mass measurement of particulate concentration on a real-time basis. The monitor
utilizes the filter-based measurement system for providing real-time mass monitoring capability.
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5. Definitions
/Note: Definitions used in this document and any user prepared SOPs should be consistent with ASTM
D1356. All abbreviations and symbols are defined with this document at the point of use.]
5.1 Air Pollution. The presence of unwanted material in the air. The term "unwanted material" here
refers to material in sufficient concentrations, present for a sufficient time, and under circumstances to
interfere significantly with comfort, health, or welfare of persons or with the full use and enjoyment of
property.
5.2 Coarse and Fine Particles. Coarse particles are those with diameters (aerodynamic) greater than
2.5 jim that are removed by the sampler's inlet; fine particles are those with diameters (aerodynamic) less
than 2.5 f«n. These two fractions are usually defined in terms of the separation diameter of a sampler.
5.3 Filter. A porous medium for collecting particulate matter.
5.4 Mass Concentration. Concentration expressed in terms of mass of substance per unit volume of
gas.
5.5 Particle. A small discrete mass of solid or liquid matter.
5.6 Particle Concentrations. Concentration expressed in terms of number of particles per unit volume
of air or other gas. NOTE: On expressing particle concentration the method of determining the
concentration should be stated.
5.7 Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In
air or gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous
isolation of selected components.
5.8 Sampling, Continuous. Sampling without interruptions throughout an operation or for a
predetermined time.
6. Interferences -
6.1 The R&P TEOM® primary operating mechanism is the microbalance system, which relies upon
changes in the frequency of an oscillating tapered element to determine changes in the particulate mass
collected. Because of this characteristic, the instrument should be isolated from mechanical noise and
should be located in the area to be measured so that external objects are not likely to disturb the
instrument's enclosure or the air sampling tube. Additionally, the instrument should be located in an
environment with minimal temperature fluctuations. The units operate effectively in environments with
temperatures ranging between 7.2 and 52°C.
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6.2 Although the instrument may retrieve a sample from indoor or outdoor environments, the sample
stream temperature should be maintained within as narrow a range as possible. Large abrupt temperature
fluctuations (7-8°F/min) of the sample stream may cause measurement accuracy to decrease due to the
inlet system's inability to adjust the temperature of the sample to that specified by the software before
travelling to the microbalance system. Sample temperature can range from ambient to 60°C.
[Note: For aerosols, such as cigarette smoke, that may contain substantial fractions of dissolved
semivolatiles, heating the aerosol may decrease the apparent mass and may introduce errors into
subsequent chemical analyses. As a precaution the TEOM® may be operated at low inlet temperatures
(-30-35°C).J
7. Apparatus
The R&P TEOM® Series 1400a Ambient Paniculate Monitor is comprised of two main components (see
Figure 1): the TEOM® 1400a Control Unit and the TEOM® Sensor Unit. However, when purchased,
these units are not fully assembled. Therefore, the following section describes the components contained
in these two main units which are available separately as needed.
7.1 TEOM® 1400a Control Unit
The control unit (see Figure 2) houses the mass flow controllers and the control electronics for operation
of the TEOM® instrument.
7.1.1 The main electrical and air connections to the main power supply, the auxiliary control, and
the main vacuum pump connections are located on the back panel.
7.1.2 The main power switch, status light, and the keypad for operating the control unit are located
on the front panel. The keypad allows the user to define and adjust system parameters and functions once
the software has been uploaded to the control unit. The status light flashes when there is a problem with
mass flow rate, temperature, or filter loading.
7.2 TEOM® 1400a Sensor Unit
7.2.1 The sensor unit houses the mass transducer sensing unit and an electronic circuit board with
the appropriate wiring for electricity and frequency signal output (inside enclosure on left hand side).
Located on the outside left panel are the main electric and air connections. The enclosure houses the
mass transducer sensing unit, sensor unit heater, and an amplifier circuit board that processes all signals
from the mass transducer.
7.2.2 The back side of the enclosure contains a shipping latch that secures the sensor/preheater unit
when moving or shipping the instrument.
7.3 TEOM® Sensor/Preheater Assembly
7.3.1 The TEOM® sensor/preheater assembly (see Figure 3) consists of the sensor inlet and the
microbalance. The sensor inlet consists of a 1A" diameter metal tube. The upper end of the tube is
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inserted directly into the flow splitter assembly, which allows a small portion of the total flow to be
drawn through the sensor unit and the remaining air sample to be drawn through the bypass line. The
lower end of the sensor inlet tube is connected to the micrqbalance top outer wall. The connection
accommodates an air temperature probe assembly that controls the temperature of the air in the inlet tube.
The V6" metal tubing between the flow splitter and the sensor unit is surrounded by thick insulation to
help maintain a constant temperature of the inlet air stream.
7.3.2 The microbalance is an insulated cylindrical enclosure that houses a metal cylinder (the sensor
head) the size of the inlet tube. The metal cylinder contains an oscillating tapered element, an electronic
feedback system, and a filter cartridge. The tapered element is attached to a platform at its wide end
(bottom) and has a small metal tip onto which the filter cartridge sits. The electronic feedback system
consists of an amplifier board, which maintains the elements oscillation, and the electronics, which allow
frequency signals to be transcribed to mass units. At the bottom of the microbalance, a silicone tube,
which is connected to the mass flow controller in the control unit, carries the air sample.
7.4 TEOM® PM1Q Inlet
The PM1Q inlet (see Figure 4) is designed to allow only paniculate matter <. 10 urn in diameter to remain
suspended in the sample air stream as long as the flow rate of the system is maintained at 16.67 L/min.
The monitor can be operated as a total suspended paniculate monitor or as a PM10 monitor.
7.5 TEOM® Flow Splitter Assembly
The flow splitter assembly (see Figure 5) consists of two concentric hollow metal tubes. The outer tube
is approximately 24" long and 1V£" in diameter. The inner tube is approximately 12" long and 1A" in
diameter. The top of the assembly (outer tube) is configured to accommodate the PM1Q Inlet (normal
use) or the flow audit adapter (for calibration only). The lower end of the assembly consists a pipe fitting
that allows for the inner tube to enter into the outer tube and make a leak-proof connection. Also at the
bottom of the flow splitter assembly is the bypass air outlet. The inner tube is connected directly to the
inlet tube of the sensor unit, and the bypass air outlet is connected to the bypass air line.
7.6 Electric and Air Cable Assembly
The electric and air cable assembly is used to connect the control unit to the sensor unit.
7.7 Filter Cartridge
The filter cartridge (see Figure 6) is a W diameter thin aluminum base (foil-like) assembly. The foil
is crimped around the filter edges to contain it. Attached to the aluminum base is a water resistant plastic
cone that fits onto the metal tip of the oscillating element.
7.8 Filter Exchange Tool
The filter exchange tool is a small fork with a 4" long handle, as illustrated in Figure 6. The lower part
of the tool has two perpendicular connections. The top connection is an aluminum disc that is slightly
smaller than Vfc" in diameter, which is made to fit over the filter face when assembling and disassembling.
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TEOM® Monitor Continuous PM^Q Analyzers
The bottom connection is a "U-shaped" fork. The tines of the fork straddle the cone of the filter
cartridge during assembling and disassembling.
7.9 Other Components
The TEOM® has both a coarse and fine filter located within the sensor unit to protect additional
components downstream. In addition, an oil-free pump is located in this unit to provide a constant
vacuum during sampling.
8. Assembling the TEOM® Series 1400a Monitor
The TEOM* 1400a Monitor consists of two components: (1) the control unit and (2) the
sensor/preheater unit. A schematic diagram of the flow system is illustrated in Figure 7.
8.1 If the barbed hose fitting is not installed, attach the supplied barbed hose fitting to the back of the
TEOM® control unit at the connection marked "Pump", as illustrated in Figure 8.
8.2 Make sure that the voltage setting on the card below the fuse (see Figure 8) is appropriate for
installation. If not, remove the card and reinsert with proper voltage facing upward. The allowable
voltage settings are 120 and 240 VAC. Contact your distributor representative if you need additional
information about the proper voltage setting.
8.3 Insert the power cord into the socket.
8.4 Install the mating section of the mounting bracket (packaged separately from the control unit) by
sliding the slotted end onto the Mounting Bracket section on the control unit and inserting the in-line
filters into the push-to-connect fitting. Secure the two parts of the bracket together with thumb screws.
8.5 Attach the bypass fine paniculate assembly (the dual-filter device) to the bypass flow fitting on the
Mounting Bracket.
8.6 Identify the end of the electric and air connecting cable whose electrical connection fits into the
"Sensor Unit" connector of the control unit. Insert the V*" sensor flow line into the sensor flow fitting
on the Mounting Bracket. Insert the %" bypass flow line into the open end of the bypass fine paniculate
assembly. ~~
8.7 Attach the 28-pin electrical connector.
8.8 Attach an oil-free vacuum pump to the barbed hose fitting using a vacuum hose of at least V4" inside
diameter. The pump must be capable of maintaining 20" Hg vacuum at a flow of 16.7 L/min.
8.9 Install the sensor unit on a sturdy surface below the location of the flow splitter assembly. The
sensor inlet should be directly below the flow splitter. Otherwise the paniculate may settle out of the air
stream and collect on the tubing walls.
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8.10 Route the electric and air connecting cable to the sensor unit (see Figure 10) so that the cable is
protected and the sample and bypass tubings are not kinked.
8.11 Make the electrical connection of the electric and air connecting cable at the 28-pin connector on
the left panel of the TEOM® Sensor Unit (see Figure 10).
8.12 Connect the end of the small air tube (14" diameter) to the air outlet on the left side wall of the
sensor unit.
8.13 Remove the end cap from the top of the air inlet on the sensor unit.
8.14 Carefully remove all packaging materials, such as molded foam pack, from within the enclosure
of the sensor unit. Then release the shipping latch located on the back panel of the sensor unit (see
Figure 9). To do so, hold the mass transducer with one hand and use a coin or screwdriver in the other
hand to turn the slot in the shipping latch counter clockwise. To retract the shipping latch fully, continue
turning the slot until it will not turn any further. The mass transducer should be able to swing freely
when it is unlocked.
8.15 Make sure that the electrical connection and air connection are in their attached positions, as
illustrated in Figure 10.
[Note: The Series 1400a monitor uses push-to-connect fittings for all air lines. To engage the
connection, the air tube must be pushed completely into the fitting so that the tube cannot be pulled out.
To disengage the connection, push the small collar toward the fitting and pull on the tube.]
9. Installing the Flow Splitter and PM10 Inlet
The isokinetic flow splitter is used in combination with a second automatic flow controller to divide the
sample flow into two components after the air steam passes through the PMjg sample inlet: 1) a main
flow of 3 L/min for the TEOM® mass transducer and 2) an auxiliary flow of 13.67 L/min that is
maintained by the second flow controller. The flow splitter should be located directly above the sample
inlet of the TEOM® Sensor Unit (see Figure 11).
9.1 Loosen the nut on the bottom of the flow splitter and adjust the inner tube so that the end of the
inner tube is 15.5 cm (6") from the open end of the outer tube (see Figure 5). Tighten the nut. -
9.2 Mount flow splitter assembly in optional tripod or other rigid mounting device.
9.3 Drill a hole in roof to allow the sample tube to connect the flow splitter assembly and the TEOM®
sensor unit (make sure the sensor unit can be placed directly underneath the flow splitter assembly).
9.4 Connect any sample tube extensions to exit of flow splitter and to the sample inlet on the TEOM®
Sensor Unit with the push-to-connect fittings.
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TEOM* Monitor ' Continuous PM10 Analyzers
9.5 Install the bypass flow tubing ( %" diameter) from the control unit to the bypass flow exit of the flow
splitter through the same hole in the roof as the sample tube (see Figure 11).
9.6 Weatherseal the opening in the roof to avoid leaks.
9.7 Install the rain collection jar in the port on the side of the PM^Q sample inlet.
9.8 Install the PMjg sample inlet over the open end of the flow splitter assembly.
9.9 Reverify that the inlet to the PM1Q sample inlet is 1.8 to 2.1 m above the roof.
10. Exchanging the Filter Cartridge
Upon arrival of a new TEOM® series 1400a Ambient Particulate Monitor, the sensor unit will not be
equipped with a filter cartridge. Therefore, follow the filter exchange procedures outlined below to
prepare the instrument for operation. The new instrument comes with a box of 20 blank filter cartridges.
Before proceeding with the exchange, some special precautions must be taken:
• Do not handle new TEOM® filter cartridges with fingers. Use the filter tool provided with the
instrument to exchange filters.
• Do not exchange filter cartridges when the TEOM® system is taking data, i.e., when the
instrument is in the Run Mode. Filter cartridges should be exchanged either when the
instrument is in the Initialization Mode, Data Stop Mode, or when the instrument is turned off.
• Keep the sample pump running to facilitate filter exchange.
• Store the box of filter cartridges and filter exchange tool inside the sensor unit enclosure to
provide a warm, dry, safe storage location.
10.1 Loading the Filter Cartridge
10.1.1 Open the door of the sensor unit.
10.1.2 Locate the horizontal handle on the TEOM® mass transducer (shown in its upward position
in Figure 3). Carefully rotate this handle upward. The TEOM® mass transducer then swings into its
filter changing position (see Figure 6).
(fiJpM: When the mass transducer is in this open position, the tapered element automatically rtops
vibrating to facilitate filter exchange.]
10.1.3 Remove a clean filter cartridge from its shipping/storage box using the filter exchange tool.
The tool's upper metal disc should cover the filter's surface, while the lower tines of the fork should
straddle the hub of the filter base.
10.1.4 Hold the filter exchange tool in line with the tapered element and lightly insert the hub of the
filter cartridge onto the tip of the tapered element, as illustrated in Figure 12. Ensure that the filter is
seated properly. The tools metal disc should be centered over the filter before pressure is applied. Apply
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Chapter IO-1 Method IO-1.3
Continuous PM10 Analyzers , TEOM® Monitor
downward pressure to set it firmly in place, which will reduce the chances of distorting the crimped filter
(see Figure 6).
10.1.5 Remove the filter exchange tool by retracting it sideways until it clears the filter. Do not
disturb the filter.
10.1.6 Gently move the horizontal handle to the down position to close the mass transducer. Allow
the springs to pull it closed for the last centimeter so that the distinct sound of metal-to-metal contact is
heard.
[Note: Do not let the TEOM® mass transducer slam closed from the full open position.]
10.1.7 Close and latch the door to the TEOM® Sensor Unit. Keep the door open for as short a time
as possible to minimize the temperature upset to the system.
10.1.8 If the instrument is turned on, reset it by pressing or on the keypad of the
TEOM® Control Unit.
10.1.9 After 5 min, open the sensor unit and mass transducer again. Press straight down on the filter
cartridge with the bottom of the filter exchange tool. This pressure ensures that the filter cartridge is
properly seated after is has experienced an increase in temperature. Then close the mass transducer and
enclosure.
10.2 Removing the Filter Cartridge
[Note: Filter lifetime depends upon the nature and concentration of the paniculate sampled. The lifetime
is determined by the filter loading, as shown on the status line of the Main Screen of the TEOM® Control
Unit. TEOM® filter cartridges must be exchanged when the filter loading value approaches 100%, which
generally corresponds to a total mass accumulation of approximately 3 to 5 mg (about 14 to 21 days of
sampling at an average PMjQ concentration of 50 (ng/nr).]
10.2.1 Open the door of the sensor unit.
10.2.2 Locate the horizontal handle on the TEOM® mass transducer (shown in its upward position
in Figure 3). Carefully rotate this handle upward. The TEOM® mass transducer then swings into its
filter changing position (see Figure 6).
[Note: When the mass transducer is in this open position, the tapered element automatically stops
vibrating to facilitate filter exchange.]
10.2.3 Using the filter exchange tool (see Figure 12), remove the filter cartridge from the mass
transducer. Carefully insert the lower fork of the tool under the filter cartridge so that the fork straddle
the hub of the filter cartridge. The tool's upper metal disc should be centered over the filter's surface,
but not touching it. Gently lift the filter from the tip of the tapered element with a straight pull.
[Note: Never twist the filter or apply sideways force to the tapered element.]
10.2.4 Store the used filter or discard as necessary.
10.2.5 Use a Kimwipe to remove any particulate from the back side of the metal disc and the tines
of the fork on the filter exchange tool. During the filter removal process, the filter may be heavily
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Method IO-1.3
TEOM8 Monitor
Chapter IO-1
Continuous PM10 Analyzers
loaded with paniculate. When the tool comes in contact with the filter, the paniculate often will transfer
to the tool due to a small static charge. Cleaning the filter exchange tool will prevent any paniculate
from being transferred to a new filter and thus increase filter life.
10.2.6 Remove a clean filter cartridge from its shipping/storage box using the filter exchange tool.
Grasp the clean filter as instructed hi Section 10.1.2. Do not touch the filter cartridge with your fingers;
only use the exchange tool.
10.2.7 Follow the procedures detailed in Sections 10.1.3 through Section 10.1.8 to insert the clean
filter cartridge onto the sensor head and resort the instrument to operation mode.
11. System Operation and Data Storage
Before the instrument procedures are implemented, follow the instructions detailed helow or those found
in Section 4 of the TEOM* Operator's Manual. Appendices A and B of the Operator's Manual contain
helpful information about the program variables and instrument screens, respectively. Each variable and
parameter used by the program is represented by a 3-digit code called a Program Register Code (PRC).
The monitor's entire menu structure is summarized at the beginning of Appendix B of the Operator's
Manual. •
11.1 Instrument Start-Up
11.1.1 Supply power to the instrument at the appropriate voltage.
11.1.2 Press the "Power" button on the front panel of the TEOM® Control Unit. A screen appears
on the instrument's four-line display showing the name of the instrument. Soon thereafter, the Main
Screen appears (see Figure 13).
11.1.3 Turn on the pump to draw the sample stream through the system. After turning on the
instrument, the "Check Status" light appears because the flow rates and tsmperatures are outside of
tolerance when the monitor is powered up. The status light automatically turns off after all flow rates
and temperatures return to within tolerance.
11.1.4 The instrument automatically resets itself when it is turned on. As part of this initialization
procedure, the monitor waits until the flow rates and temperatures remain stable (within a narrow band)
for Vfc h before starting data collection, which ensures the validity of all data points computed by the
system
11.1.5 Press < t > and < i > to move the cursor (" > ") up and down through the four-line display.
The informational lines of the display scroll up as the < J > is pressed repeatedly.
11.1.6 If the Series 1400a monitor was received directly from R&P, the only change that needs to
be made before the instrument can be used for EPA equivalent PMjQ measurements is the input of the
proper seasonal average temperature and average pressure. The instructions for doing so are found in
the unit's operating manual. If the instrument has been used before and the user desires to return it to
its original settings, the user should first re-initialize the unit according to Section 11.5.1 before entering
the seasonal average temperature and average pressure. Once these actions are taken, no additional
keystrokes are necessary for the instrument to commence its operation.
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11.2 Instrument Shutdown and Shipping
11.2.1 Press the "Power" button on the front panel of the TEOM® Control Unit. The four-line
display becomes blank.
11.2.2 Turn off the vacuum pump.
11.2.3 Disconnect the TEOM® Control Unit from the electric supply.
11.3 Information Shown on the Main Screen
As is the case with all screens shown by the TEOM® Series 1400a monitor, the Main Screen is divided
into two sections: (1) the status line on the top of the screen and (2) the three informational lines. If the
screen contains more informational lines than can be viewed at one time, pressing the < I > repeatedly
makes the informational lines scroll upward. The status line always remains visible. The Main Screen,
which contains the most important data generated by the instrument and is the screen that is normally
displayed by the monitor during operation of the unit, is shown in Figure 13.
The status line of the main screen provides an overview of important parameters such as filter loading,
the instrument status condition, various types of operational settings, and the keypad protection status.
The informational lines display mass concentration results in jig/rcr for a number of averaging times, the
total mass accumulation on the filter in /*g, the current system temperature and flow rates, and diagnostic
indicators.
11.3.1 Status Line on the Main Screen. The status line of the Main Screen provides a quick
summary of the current operational condition of the instrument. The information contained in the fields
of this line is summarized in Figure 13.
11.3.1.1 Status Condition. The status condition is a 1-4 number character code that summarizes
the operational status of the instrument, indicating whether any exception condition exists. Whenever a
status code other than "OK" is shown on the display, the instrument automatically turns on the light
labelled "Check Status" on the front panel of the control unit. The status condition shown by the TEOM®
Series 1400a monitor can consist of one or more codes, which are summarized in Table 1. Press
< Main/Status > when the instrument is in the Main Screen to view an explanation of the current status
conditions of the Status Code Screen. The < Main/Status > key toggles the instrument between the Main
Screen and the Status Code Screen.
11.3.1.2 Operating Mode. The operating mode indicates the instrument's current operating
setting and the type of data being computed by the monitor. An explanation of the different operating
modes of the TEOM® are documented in Table 2. _
11.3.1.3 Analog Output 1 Mode. The instrument normally transmits the values of three chosen
variables in analog format through its three user-defined analog outputs. Analog output channel 1,
however, can be defined to act in one of two different ways:
• If the "A/O 1" field of the Main Screen status line is blank, analog output 1 operates in its usual
fashion; or
• If a " +" appears in the A/O a field, analog output 1 is also used as status watch indicator. When
defined this way, analog output 1 transmits a full-scale signal (for example, 5 VDC if the channel
is configured for 0-5 VDC operation) if a status condition exists in the temperatures, flow(s) or
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TEOM81 Monitor Continuous PM10 Analyzers
oscillation of the mass transducer. If no such status condition exists, analog output channel 1
operates in its usual fashion.
Press to toggle the "+" in the A/O 1 field
11.3.1.4 Filter Loading. The value for filter loading indicates the fraction of the TEOM® filter
cartridge's total capacity that has been used. Since this value is determined by the pressure drop of the
main (sample) flow line, the instrument shows a non-zero value even if no filter is mounted in the mass
transducer. New filters generally exhibit figures of 15-30%.
11.3.1.4.1 TEOM® filter cartridges must be exchanged before this figure reaches 100% to ensure
the validity of the data generated by the instrument. At some point above 100%, the main flow drops
below its set point.
11.3.1.4.2 If the filter loading percentage is high when a new TEOM® filter is placed on the mass
transducer, or if the lifetime of TEOM® filter cartridges becomes noticeably shorter, this usually indicates
the in-line filter in the main flow line probably needs to be exchanged.
11.3.1.5 RS-232 Mode. The RS-232 mode defines the current usage of the 9-pin RS-232
connectors on the front and back panels of the TEOM® Control Unit. The selection of the current
RS-232 mode is made in the Set RS-232 Mode Screen (Section XXXXX). Alternatively, the instrument
can be toggled between the None Mode (N) and Print On Line Mode (P) by pressing .
11.3.1.5.1 Use the supplies 9-to-9 pin RS-232 cable when connecting the instrument to an IBM
AT-compatible computer with a 9-pin RS-232 connector. If the computer has a 25-pin RS-232 connector,
use the 9-to-9 pin RS-232 cable in combination with the 2-to-25 pin Computer Adapter.
11.3.1.5.2 The 9-to-25 pin Serial Cable is designed to connect the Series 1400a monitor to a serial
printer.
{Note: Never connect two serial devices to the RS-232 ports of the instrument at once, which may cause
the RS-232 features of the monitor to malfunction.}
11.3.1.6 Protection. The Series 1400a monitor incorporates three states of password protection.
The user has access to all capabilities of the instrument when it is unlocked (U). In the low-lock setting
(L), the user is prevented from editing any of the system parameters, but may view all screens and
change the operating mode of the instrument to perform such functions as filter exchange. When the
monitor is in its high lock mode (H), the user cannot make any changes from the keypad, including
scrolling, except for turning off the high-lock mode with the proper password.
11.3.1.7 Time. Time is displayed on the instrument in 24-h format. _
11.3.2 Informational Lines on the Main Screen. The informational lines of the Main Screen show
the current values of important system variables. Additional lines of information can be viewed by
scrolling this display up and down. Press < t > to move the cursor upward and < I > to move it
downward. Because the Main Screen displays data computed by the instrument, none of these values can
be edited by the user. An explanation of the data that can be viewed on the display is illustrated in
Figure 13.
Page 1.3-14 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.3
Continuous PM10 Analyzers TEOM® Monitor
11.4 When to Exchange TEOM® Filter Cartridges
TEOM® filter cartridges must be exchanged before the figure, for filter loading on the status line of the
Main Screen reaches 100%. The "Check Status" light turns on and status code F is shown on the status
line of the Main Screen when the filter loading percentage is greater then 90%.
11.5 Summary of Instrument Operation
The monitor is always in operating mode 1 when it is turned on. In this mode, the instrument waits until
temperatures and flows have equilibrated before successively entering modes 2, 3, and 4. The unit
normally resides in operating mode 4 and is fully operation in this setting. The location of the operating
mode on the instrument's Main Screen is documented in Figure 13.
11.5.1 The instrument all operates in modes S and X. Switching the monitor to either of these modes
causes data collection to stop.
11.5.2 When in the Setup Mode (S), the user may change all of the possible system parameters.
During instrument operation, on the other hand, the user is restricted to changing the values of only
certain system variables.
11.5.3 Press from any of the data collection modes (1, 2, 3, or 4) or when in the Stop
All Mode (X) to enter the Setup Mode. The instrument automatically re-enters operating mode 1 if no
keystrokes are entered on the keypad for 5 min when the monitor is in the Setup Mode. Otherwise, press
or to re-enter operating mode 1.
[Note: The instrument enters the Stop All Mode (X) after the key is pressed. The Stop All
Mode is meant to be an emergency mode. When the instrument resides in this mode, the flow and output
to the temperature control circuits ate turned off.]
11.5.4 Press or to reset the instrument from any operating mode. This action
causes the instrument to enter operating mode 1.
11.5.5 Reinitialize the Instrument. The instrument operating parameters shown in this manual are
the initial settings for the monitor. Reinitialization resets the instrument to its original configuration.
11.5.5.1 If the Main Screen is not displayed on the instrument, press < Main/Status > to return
the monitor to the Main Screen.
11.5.5.2 Press to enter the Setup Mode.
11.5.5.3 Press to reset the system variables to their original values. _
11.5.5.4 Enter the appropriate average temperature and pressure for the sampling location.
[Note: The listing of Program Register Codes (PRC's) in Appendix A and the listing of screens in
Appendix B in the Operator's Manual both contain a column entitle "Re-Init. " These columns contain
the new settings of each program variable after the above re-initialization routine is executed.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.3-15
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Method 10-1.3 Chapter IO-1
TEOM® Monitor ^ Continuous PM10 Analyzers
12. System Calibration
This Section describes the calibration procedures for the TEOM® PM10 Monitor and the method for
auditing flow rates and mass.
12.1 Overview of Calibration Procedures
The routine calibration procedures recommended fo.r the instrument are as follows: flow controller
calibration (software) is recommended every 6 mo, analog calibration every 1-2 yr, flow controller
calibration (hardware) every yr, and mass calibration verification every 2 yr.
[Note; These calibration intervals provided are guidelines. Requirements for routine calibration are site-
specific and may be defined better by the user as necessary.]
12.2 Flow Controller Calibration (Software)
12.2.1 Turn off the TEOM® Control Unit.
12.2.2 Disconnect the electric cable that links the control unit with the sensor unit.
12.2.3 Remove the Mounting Bracket with the in-line filters and flow lines from the back panel of
the TEOM® Control Unit.
12.2.4 Turn on the TEOM® Control Unit and make sure that the pump is on.
12.2.5 Display the Set Temps/Flows Screen on the instrument by selecting "Set Temps/Flows" from
the Menu Screen, or by typing 12. Press and to position the screen so that
"F-Main" and "F-Aux" appear. Record the set points for the main and auxiliary flows.
12.2.6 Press and to position the cursor so that the lines entitled "T-A/S" and "P-A/S"
appear on the screen. N-rte the existing settings for Average Temperature., (on the left) and Average
Pressure (on the left). If the monitor is not in the Setup Mode, press . Then set the
Average Temperature and Average pressure to the current local conditions at the flow meter.
12.2.7 Press and to position the cursor so that the lines entitled "FAdj Main" and "FAdj
Aux" appear on the screen.
12.2.8 Attach a reference flow meter (such as a bubble meter, dry gas meter, or mass flow meter)
to the location labelled "Sensor Flow" on the back panel of the TEOM® Control Unit. This reference
flow meter should have been recently calibrated to a primary standard and should have an accuracy of
1 % at 3 L/min. ~~
12.2.9 Compare the TEOM® Series 1400a set point recorded in step 5 above with the flow rate
indicated by the flow meter. This set point indication is in volumetric L/min. If a mass flow meter is
being used, its reading must be adjusted for temperature and pressure to obtain volumetric flow under
the test conditions. No adjustment is necessary in the case of a volumetric flow meter.
12.2.10 If necessary, edit the values for "FAdjMain" so that the volumetric flow rates indicated by
the flow meter match the set point recorded in step 5 above. The value for "FAdjMain" can be
incremented and decremented easily by pressing and keys during editing.
12.2.11 If a step adjustment greater than ±5% is necessary to calibrate the mass flow controller, a
hardware calibration must be performed as documented in the Operator's Manual.
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Chapter IO-1 Method IO-1.3
Continuous PM1Q Analyzers ^ TEOM® Monitor
12.2.12 If your system has an auxiliary flow controller, repeat Sections 12.2.8 to 12.2.11 above,
replacing the references to the Main Flow with Auxiliary (Bypass) Flow. Connect the flow meter to the
port labelled "By-pass Flow" on the rear panel of the TEOM® Control Unit.
12.2.13 Change the values for Average Temperature and Average Pressure to their original values
recorded in Section 12.2.6 (the seasonal average temperature and barometric values).
12.2.14 Turn off the TEOM® Control Unit.
12.2.15 Reattach the air lines and Mounting Bracket to the back panel of the TEOM® Control Unit.
12.2.16 Reconnect the electric cable that links the control unit with the sensor unit.
12.2.17 Turn on the TEOM® Control Unit.
12.3 Procedures for Analog Calibration
[Note: The following equipment is required to calibrate the instrument's analog input and output sections.
• Calibrated 3 *A digit multimeter
• 30 cm Jumper wire (12").]
12.3.1 Turn off the TEOM® Control Unit.
12.3.2 Remove the external cables from the Sensor and Auxiliary connectors on the back of the
control unit.
12.3.3 Remove the bottom cover of the control unit.
12.3.4 Detach the ribbon cables connected to P2, P3 and P4 on the L-shaped analog Input/output
board.
12.3.5 Note which channels are set for 0-2 VDC and 0-10 VDC (check jumpers W40-W47) on the
analog output section and which ones are set of +2 VDC and jf 10 VDC (check jumpers W1-W15) on
the analog input section.
12.3.6 Turn on the TEOM® Control Unit.
12.3.7 Press to enter the Setup Mode.
12.3.8 Bring the Analog Calibration Screen onto the four-line display by selecting "Analog
Calibration" from the Menu Screen or by typing 11 < Enter > when in any screen.
12.3.9 Enter "YES" on the line entitled "Calibrate" by pressing .
12.3.10 Move the cursor to the line shown as "A/O Value."
12.3.11 Place the " +" lead of the multimeter on white analog output test point 0 and the "-" lead on
a black GND (ground) test point.
[Note: The readings on the Analog Calibration Screen are in percent of full scale (% FS) for both the
inputs and outputs. Therefore, to output 6.500 VDC on a 0-10 VDC output channel, enter 65.000 on the
line entitled "A/O Value." For a ±2 VDC input with 1 VDC applied to the channel, 50.000 would
display for the analog input channel, indicating 50% of full scale.]
[Note: The potentiometers labelled TEMP and ALL GAIN should not be adjusted. They are preset at the
factory.]
12.3.12 Set the "A/O Value" at 90.000 by entering < Edit>90 < Enter>. This value causes the
output on all installed analog output channels to be 90% of full scale. Monitor the multimeter for the
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.3-17
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Method IO-1.3 Chapter IO-1
TEOM® Monitor Continuous PM10 Analyzers
proper readout while adjusting the appropriate GAIN ADJUSTMENT potentiometer for the analog output
channel being calibrated.
12.3.13 Move the " +" lead of the meter to successive analog output channels; adjust the appropriate
potentiometer if necessary. Be careful to note which channels are set for 2 VDC or 10 VDC output.
12.3.14 After the analog outputs are calibrated, set the "A/O Value" to 0.00. Then calibrate the
analog input (A/D) section of the Analog Card by placing the " +" lead of the meter on the 0 test point
of the analog outputs. Also, place the jumper from the 0 test point of analog outputs to the red 0 test
point of the analog inputs.
12.3.15 Select analog input channel 0 on the Analog Calibration Screen by typing
0< Enter > when the cursor is on the line entitled "A/1 Chan." Enter a 90% of full scale output
on the "A/O Value" line appropriate for the analog input channel being calibrated (either 90% of
±2 VDC or 90% of +10 VDC). Monitor the meter to ensure that the proper voltage is being applied
and look at the 4-line display to see what percentage of full scale the analog input is measuring. Adjust
the appropriate potentiometer for the channel being calibrated to achieve the proper-percentage of full
scale.
12.3.16 Repeat Sections 12.3.10 through 12.3.15 for each analog input channel populated on the
board. Remember to move the jumper to the new analog input channel.
12.3.17 Once the analog input calibration is complete, switch off the power to the instrument and
replace all cables and connectors before restarting normal operation.
12.4 Flow Controller Calibration (Hardware)
[Note: R&P recommends that the analog calibration be performed prior to the mass flow controller
(MFC) calibration. The procedure set forth in this Section specifies the use of a volumetric flow meter.
If a non-volumetric flow meter (such as a mass flow meter) is used, convert the flow meter's indicated
flow rate to a volumetric flow rate using the local temperature and pressure conditions at the flow meter.
Follow the steps below to perform a hardware calibration of the main and auxiliary mass flow controllers
in the TEOM9 Control Unit. If the MFC's in the TEOM® Control Unit cannot be properly adjusted using
the procedure below, refer to the Tylan FC-280 MFC Manual for more detailed troubleshooting,
adjustment and repair techniques.]
12 A.I Turn off the TEOM® Control Unit.
12.4.2 Disconnect the electric cable that links the control unit with the sensor unit.
12.4.3 Remove the top cover of the TEOM® Control Unit.
12.4.4 Remove the three-lobed knob that holds the hinged MFC mounting bracket to the chassis.
Swing the bracket upward so that the MFC's are more easily accessed and place a support beneath the
bracket.
12.4.5 Remove the wiring connectors from the tops of the MFC's. Then remove the silver-colored
circuit board covers of the MFC's. Reinstall the wiring connectors.
12.4.6 Remove the Mounting Bracket with the in-line filters and flow lines from the back panel of
the TEOM® Control Unit.
12.4.7 Turn on the TEOM® Control Unit.
12.4.8 Note the settings for Average Temperature and Average Pressure shown on the Set
Tempa/FIows Screen. Press to place the instrument in the Setup Mode. Then set the
Average Temperature and Average Pressure to the current local conditions at the flow meter.
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Chapter IO-1 Method IO-1.3
Continuous PM1Q Analyzers TEOM® Monitor
12.4.9 Reset the adjustment factors for both MFC's by changing the settings for "FAdjMain" and
"FAdjAux" on the Set Tempa/Flows Screen to 1,000.
12.4.10 Perform the remaining steps of this procedure only after the TEOM® monitor has been run
for at least 1 h.
12.4.11 Connect a reference volumetric flow meter (such as a piston meter, bubble meter, or dry gas
meter) that has been recently calibrated to a primary standard to the port labeled-Sensor Flow (Bypass
Flow for the auxiliary flow controller). Non-volumetric flow meters such as mass flow meters may also
be used but must be corrected for ambient temperature and barometric pressure to equivalent volumetric
readings. This reference flow meter should have a range of 0-5 L/min with an accuracy of better than
±0.5%. If an auxiliary flow controller is incorporated in the TEOM® system, a reference should be
used.
12.4.12 If a non-volumetric flow meter is used, calculate the readings on the reference flow meter
that correspond to volumetric flow rates of 2.50, 5.00, 10.00 and 20.00 L/min using local temperature
and barometric pressure.
12.4.13 With the Sample Pump line closed to the vacuum source (place a hose clamp on the vacuum
line to ensure zero flow), adjust the ZERO potentiometer, R3, of the MFC until a reading of
0.00 ± 0.02 L/min is shown on the Set Temps/Flows Screen. The potentiometer R3 is located on the
edge of the MFC circuit board closest to the base of the MFC.
12.4.14 Set the flow set point on the Set Temps/Flows Screen to the rated full scale flow of the test
MFC. With the vacuum line open, adjust the GAIN pot, R9 (the potentiometer nearest the edge card
connector on the MFC circuit board), until a full-scale reading (corresponding to 4.00 L/min or
20.0 L/min as computed in Section 12.4.11) is obtained on the reference flow meter to within
±0.02 L/min (main flow) or ±0.1 L/min (auxiliary flow).
12.4.15 Alternately close and open the vacuum source line while repeating the adjustments of steps 13
and 14 until both zero and full-scale readings are correct.
12.4.16 Set the flow set point on the Set Temps/Flows Screen to 50% of the full scale flow of the
test MFC. Adjust the LINEARITY pot, R19, until a 50% full scale reading (corresponding to 2.5 L/min
or 10.0 L/min as computed in step 11) is obtained on the reference flow meter to within ±0.02 L/min
(main flow) or ±0.1 L/min (auxiliary flow).
12.4.17 Repeat a flow check at all three flows to confirm that correct final calibration values are
within limits.
12.4.18 Repeat Sections 12.4.13 through 12.4.17 for the auxiliary MFC if one is present.
12.4.19 Reset the Average Temperature and Average Pressure on the Set Temps/Flows Screen to
their original values as noted in Section 12.4.7 above through the Setup Routine. Exit the Setup Routine
12.4.20 Turn off the TEOM® Control Unit.
12.4.21 Remove the wiring connectors from the tops of the MFC's. Replace the silver covers on
the appropriate flow controllers, and reinstall the connectors.
12.4.22 Swing the MFC mounting bracket into its normal position. Lock it with the knob screw.
12.4.23 Remove the reference flow meter and reconnect the Mounting Bracket and flow lines to the
TEOM® Control Unit. Replace the top cover of the TEOM® Control Unit.
12.4.24 Connect the electric cable that links the control unit with the sensor unit.
12.4.25 Turn on the TEOM® Control Unit.
12.4.26 Perform a system leak test.
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Method IO-1.3 Chapter IO-1
TEOM® Monitor Continuous PMj^ Analyzers
12.5 Mass Transducer Calibration Verification
(Note: The calibration of the TEOM® mass transducer in the TEOM® Series 1400a monitor is determined
by the mass transducer's physical mechanical properties. Under normal circumstances, the calibration
does not change materially over the life of the instrument.
Tlie TEOM9 Series 1400a monitor is calibrated using entire TEOM® filter cartridges as calibration
weights. Since the mass of the filter cartridge with paniculate differs from the mass of a new filter
cartridge by only a small fraction, calibrating the system with a calibration mass equivalent to the filter
mass allows all measurements to be made at essentially the same operating point as the original
calibration.]
12.5.1 Using a calibrated gravimetric balance, weigh five unused TEOM® filter cartridges to the
nearest 0.1 mg. Keep each filter in a suitable storage container marked with its associated weight. If
desired, these preweighed filters may be kept for future use.
[Note: It is not necessary to condition the filters to a constant temperature or relative humidity before
this test since the filter material is relatively hydrophobic. Filter weights vary by less than 50 fig due to
moisture content, out of a total filter weight of approximately 75 mg. Since the calibration constant error
is proportional to the calibration weight error, the worst case KQ error is only 0.05/75 mg or 0.06%.]
12.5.2 Confirm that the Calibration Constant shown on the Set Hardware Screen is the same as that
shown on the nameplate located on the left side of the mass transducer support cage.
12.5.3 Remove the PMjQ sampling inlet. Replace the inlet with the Flow Audit Adapter (see
Figure 14) that was supplied with the instrument. Open the valve of the Flow Audit Adapter and place
the R&P-provided prefilter over the valve.
12.5.4 Disconnect the Bypass Flow Line where it connects to the Flow Splitter. Plug the exit of the
Flow Splitter with the 3/8" Swagelok and cap supplied with the Flow Audit Adapter Kit.
12.5.5 Warm the TEOM® system with any filter cartridge that is not a calibration filter so that all
temperatures are at their normal operating conditions for at least 1 h. The air flow through the system
should be at its normal value during this period. Scroll through the Main Screen by pressing < 1 > and
< I > until the Frequency is shown.
12.5.6 Open the mass transducer and remove the filter from the tip of the tapered element using the
filter exchange procedure described earlier. Close the mass transducer and enclosure door. After the
frequency has stabilized, record the frequency to within 0.001 Hz. Label this frequency FQ(1).
12.5.7 Open the mass transducer and place one of the preweighted filters on the tapered element using
the filter exchange procedure earlier. Close the mass transducer and enclosure door. After the frequency
has stabilized, record the frequency to within 0.001 Hz. Label this frequency Fl(l).
12.5.8 Repeat Sections 12.5.6 and 12.5.7 for the remaining four filters. Use a consistent force in
attaching all filters. Repeat the frequency measurement of FO (no filter) each time to remove the effects
of varying temperature from opening and closing the mass transducer.
12.5.9 For each of the 5 sets of data, calculate the KQ of the balance using the following formula:
K0 = (Mfflter)/[(l/f12)-.(l/f02)]
Page 1.3-20 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-1 Method IO-1.3
Continuous PM1Q Analyzers ^ TEOM® Monitor
where:
^filter = gravimetric filter mass, g.
f0 = frequency without filter, Hz.
fj = frequency with filter, Hz.
12.5.10 Calculate the mean of the 5 values of KQ. Record this value.
12.5.11 Compute the standard deviation of the 5 values. Record this value both in gm-Hz and as a
percentage of the mean. If the standard deviation is less than 1 % of the mean, the mean value is the KQ
of the instrument.
12.5.12 If the computed KQ differs by more than 2.5% from the KQ value shown on the nameplate
located on the left side of the mass transducer support cage, contact R&P for further assistance. If this
difference is less than 2.5%, do not change the Calibration Constant setting on the Set Hardware Screen.
12.5.13 Remove the Flow Audit Adapter and 3/8" Swagelok cap from the system and replace the
PM10 sample inlet and Bypass Flow Line.
12.6 Flow Audit Procedure
[Note: This audit procedure for checking the flow rates in the TEOM® Series 1400a monitor is not
difficult and can be done with minimal disturbance to the instrument's normal operating configuration.]
12.6.1 Reset the TEOM® Series 1400a monitor by pressing the or keys on the front
panel of the control unit. Please note that any data generated by the instrument during this audit
procedure are invalid. Thus, a flow audit should be combined with a filter exchange.
12.6.2 Remove the PMjQ sample inlet. Replace the inlet with the Flow Audit Adapter (see
Figure 14) that was supplied with .the instrument. Turn the valve of the Flow Audit Adapter to its open
position to allow for air flow.
12.6.3 Scroll the Main Screen using < f > and < j > until the Main Flow and Auxiliary Flow appear
on the four-line display. These data represent the actual volumetric flows as measured by the monitor's
flow controllers. Confirm that these flows are within ±2% of their set points (3.0 L/min for the main
Flow and 16.7 L/min for the Main Flow plus Auxiliary Flow). Any greater deviation may indicate
plugged in-line filters or other blockages in the system. If this is the case, correct the condition before
proceeding.
12.6.4 Connect the Flow Audit Adapter to a suitable flow auditing device (such as a soap-bubble
meter, dry gas meter, mass flow meter, etc.), capable of measuring 3.0 L/min and 16.7 L/min to an
accuracy of ±1 % and having a pressure drop of less than 0.07 bar (1 psi). This flow meter should"have
been recently calibrated to a primary standard.
12.6.5 Read the total flow (nominally 16.7 L/min) on the audit flow meter. If a nonvolumetric flow
meter is being used, make any corrections necessary to translate this reading to volumetric L/min at the
current ambient temperature and barometric pressure. The volumetric flow measured by the audit flow
meter must be 16.7 ±1.0 L/min to be acceptable.
12.6.6 Disconnect the Bypass Flow Line where it connects to the Flow Splitter. Plug the exist of
the Flow Splitter with the 3/8" Swagelok cap supplied with the Flow Audit Adapter Kit.
12.6.7 Read the main flow (nominally 3.0 L/min) on the audit flow meter. In a nonvolumetric audit
flow meter is being used, translate this reading to volumetric L/min at the current ambient temperature
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.3-21
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Method IO-1.3 Chapter IO-1
TEOM® Monitor Continuous PM^Q Analyzers
and barometric pressure. The volumetric flow indicated by the audit flow meter must be
3.0 ± 0.2 L/min to be acceptable.
12.6.8 If either the Main or Auxiliary Flow is outside acceptable limits, the calibration procedures
in Sections 12.2 and 12.4 must be performed.
12.6.9 Remove the cap from the exit of the Flow Splitter and replace the Bypass Flow Line.
12.6.10 To perform a system leak check, close the valve on the Flow Audit Adapter. Both the Main
Flow and Auxiliary Flow should read less than 0.15 L/min on Main Screen. If one of the flows is
greater than 0.15 L/min, the system is not leak tight. In this case, check hose fittings and other critical
locations in the flow system for leaks.
12.6.11 Remove the Flow Audit Adaptor. Replace the PMjQ inlet on the top of the Flow Splitter.
The instrument is now back to its normal operating configuration.
12.6.12 Reset the TEOM® monitor by pressing or . The instrument will
automatically begin data collection after temperatures and flow rates have remained stable at their set
points for 14 h.
13. Method Safety
This procedure may involve hazardous materials, operations, and equipment. This method does not
purport to address all of the safety problems associated with its use. The user must establish appropriate
safety and health practices and determine the applicability of regulatory limitations prior to the
implementation of this procedure. These activities should be part of the user's SOP manual.
14. Performance Criteria and Quality Assurance (QA)
Required quality assurance measures and guidance concerning performance criteria that should be
activated within each laboratory are summarized and provided in the following section.
14.1 Standard Operating Procedures (SOPs)
14.1.1 SOPs should be generated by the users to describe and document the following activities in
their laboratory:
• Assembly, calibration, leak check, and operation of the specific sampling system and equipment
used;
• Preparation, storage, shipment, and handling of the sampler system;
• Purchase, certification, and transport of standard reference materials; and
• All aspects of data recording and processing, including lists of computer hardware and software
used.
14.1.2 Specific instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the monitoring work.
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Chapter IO-1 Method IO-1.3
Continuous PM10 Analyzers TEOM® Monitor
14.2 QA Program
The user should develop, implement, and maintain a quality assurance program to ensure that the
sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted regularly and should be part of the QA program.
Calibration verification procedures provided in Section 13, operation procedures in Section 11, and the
manufacturer's instruction manual should be followed and included in the QA program. Additional QA
measures (e.g., trouble shooting) as well as further guidance in maintaining the sampling system are
provided by the manufacturer. For detailed guidance in setting up a quality assurance program, the user
is referred to the Code of Federal Regulations (see Section 15, Notation 18) and the U. S. EPA Handbook
on Quality Assurance (see Section 15, Notation 19).
15. REFERENCES
1. Rupprecht & Patashnick Co., Inc., TEOM® Hardware Manual (TEOMPLUS® Software Version 3),
Albany, NY, April 1988.
2. Rupprecht & Patashnick, Co., Inc., TEOM® Mass Monitoring Instrumentation: TEOM® Software
Manual (TP3), Albany, NY, April 1988.
3. Patashnick, H., and G. Rupprecht, "Microweighing Goes on Line in Real Time," Research &
Development, June 1986.
4. Patashnick, H., and G. Rupprecht, "Advances in Microweighing Technology," American
Laboratory, July 1986.
5. Walters, S., "Clean-up in the Colliery," Mech. Eng., 105:46, 1983.
6. Whitby, R., et al., "Real-Time Diesel Paniculate Measurement Using a Tapered Element Oscillating
Microbalance," Soc. Automotive Eng., Paper 820, 463, 1982.
7. Whitby, R., R. Johnson, and R. Gibbs, "Second Generation TEOM® Filters: Diesel Particulate
Mass Comparison Between TEOM® and conventional Filtration Methods," Soc. Automotive Eng.,
Paper, 850, 403, 1985.
8. Hales, J. M., and M. P. May, "Transient Cycle Emissions Reductions at Ricardo: 1988 and
Beyond," Soc. Automotive Eng., Paper 860, 456, 1986.
9. Patashnick, H., and G. Rupprecht, "A New Real Time Aerosol Mass Monitoring Instrument: The
TEOM®," Proc.: Advances in Particulate Sampling and Measurement, EPA-600/9-80-004, Daytona
Beach, FL, 1979.
10. Wang, J. C. F., H. Patashnick, and G. Rupprecht, "New Real Time Isokinetic Dust Mass
Monitoring System," J. Air Pollution Control Assn., 30(9): 1018, 1980.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.3-23
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Metiiod IO-1.3 Chapter IO-1
TEOM* Monitor Continuous PM10 Analyzers
11. Wang, J. C. F., et al., "Real-Time Total Mass Analysis of Particulates in.the Stack of an Industrial
Power Plant," J. Air Pollution Control Assn., 33(12): 1172, 1983.
12. Patashnick, H., G. Rupprecht, and D. W. Schuerman, "Energy Source for Comet Outbursts,"
Nature, 250(5464), July 1974.
13. Hidy, G. M., and J. R. Brock, "An Assessment of the Global Sources of Tropospheric Aerosols,"
Proceedings of the Int. Clean Air Congr. 2nd, pp. 1088-1097, 1970.
14. Hidy, G. M., and J. R. Brock, The Dynamics ofAerocolloidal Systems, Pergamon Press, New York,
NY, 1970.
15. Lee, R. E., Jr., and S. Goranson, "A National Air Surveillance Cascade Impactor Network:
Variations in Size of Airborne Paniculate Matter Over Three-Year Period," Environ. Sci. TechnoL,
10:1022, 1976.
16. Appel, B. R., E. M. Hoffer, E. L. Kothny, S. M. Wall, M. Haik, and R. M. Knights, "Diurnal and
Spatial Variations of Organic Aerosol Constituents in the Los Angeles Basin," Proceedings:
Carbonaceous Particles in the Atmosphere, March 20-22, 1978. T. Nonokov, ed., Lawrence
Berkeley Laboratory, University of California, LBL-9037, pp. 84-90, 1979.
17. Nagda, N. L., H. E. Rector, and M. D. Koontz, Guidelines for Monitoring Indoor Air Quality,
Hemisphere Publishing Corporation, New York, NY, 1987.
18. 40 CFR, Part 58, Appendix A, B.
19. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II - Ambient Air
Specific Methods (Interim Edition), EPA 600/R-94/038b.
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Chapter IO-1
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Method IO-1.3
TEOM® Monitor
TABLE 1. EXPLANATION OF STATUS CONDITION CODES
Codes
OK
M
T
F
X
.Explanation ' ' .: -. ; '.-.;;. 'C^Y \" ••••'....,.: ";:: '•'.',./'• .' /.: ."'.• '•••''••'..•. '•''•-• " '' •-. '; ••''^ Y-:Y:
No current exception conditions
Control unit is not receiving a frequency signal
Temperature(s) outside of operational bounds
Flow(s) outside of operational bounds
Filter nearing capacity-exchange filter. This status becomes active when the filter
loading reaches 90%
TABLE 2. TEOM® OPERATING MODES
Mode
X
Operation
Mass values are not currently being computed because temperatures and flow rates are
stabilizing. The temperatures and flow rates must remain within a very narrow band for
'/z hr before the instrument enters mode 2. The system automatically enters mode 1 when
it is turned on.
Data collection has begun, but the first total mass value has not yet been computed
The first total mass value has been computed, but mass concentration and mass rate are
not yet available
Normal operation. All mass values are being computed.
Set Mode. Certain operating parameters such as temperatures and flow rates can only be
changed in this mode because doing so during data collection (modes 1 and 4) would
adversely affect the data from the instrument. Press < Dress Stop> to enter the Setup
Mode from any other operating mode. To leave the Setup Mode and start data collection
jress either or (monitor returns to mode 1). If the instrument remains in
the Setup Mode for 5 min without any key being pressed on the keypad, the monitor
automatically returns to mode 1.
Stop All Mode. This mode indicated that the normal operation of the instrument has been
suspended, and that the monitor is "sleeping." In this mode, data collection ceases, the
flow rates in the system drop to 0, and the output to the temperature circuits is turned off.
This emergency state is activated by pressing on the instrument keypad. To
eave this mode, press either or to restart data collection (modes 1 to 4),
or < Data Stop > to enter the Setup Mode.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-25
-------
Method IO-1.3
TEOM® Monitor
Continuous
Chapter IO-1
Analyzers
TABLE 3. EXPLANATION OF DATA NOTATION
Data notation
30-min MC
1-h MC
8-hMC
24-h MC
Total mass
Case temperature
Air temperature
Cap temperature
Enclosure temperature
Main flow
Auxiliary flow
Noise
Frequency
Explanation
30-min average mass concentration. This value is updated every 30 min on the
half hour (/tg/m3).
1-h average mass concentration. This value is updated every 60 min on the
hour (/tg/m3).
8-h average mass concentration. This value is updated every 8 h (jig/m )
24-h average mass concentration. This value is updated every 60 min on the
hour (fig/nr).
The amount of mass that has accumulated on the TEOM* filter cartridge since
the most recent instrument reset (done by turning on the instrument,
or pressing or
Temperature of the TEOM® mass transducer (set point 50 °C).
Temperature of the sample stream at the base of the heated air inlet (set point
50°C).
Temperature of the upper part of the TEOM® mass transducer (set point 50 °C).
Temperature inside the sensor unit enclosure (set point 40 °C).
Actual volumetric flow rate through the main flow controller (set point
3 L/min), as measured by the main flow controller.
Actual volumetric flow rate through the auxiliary flow controller (set point
13.67 L/min), as measured by the auxiliary flow controller.
Indication of how well the TOM mass transducer is performing. This figure
should be less than 0.10 after the system has bene hi operating mode 4 for at
least 1A. h.
The oscillating frequency of the tapered tube in the TEOM® mass transducer.
This figure varies from one Series 1400a monitor to another, but generally
ranges between 150 and 400 Hz.
Page 1.3-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PMjQ Analyzers
Method KM.3
TEOM® Monitor
Figure 1. TEOM® control and sensor unit.
January- 3997 Compendium of Methods for Inorganic Air Pollutants
Page 1.3-27
-------
Mvihod IO-1.3
TEOM1" Monitor
Chapter IO-1
Continuous PMjn Analyzers
V
- -• •'";" ' ,. '•/'• *•&*•*•••''•'••~:''-''.' - i-JiV1^"'" S i ' f \
•;-• . •"' .:-vfe-3:?:^r7. S'^,4 •* " tf>
Page 1.3-28
Figure 2. TEQM® control unit front panel.
Compendium of Methods for Inorganic Air Pollutants
Januarj 1997
-------
Chapter IO-1
Continuous PM^Q Analyzers
Method IO-1.3
TEOM® Monitor
Inlet
To Flow-
Controller
MICRO BALANCE
SYSTEM
Inlet
I 1 Filter
[_.J—V*"'' Cartridge
i-J
Tapered
Element
AIR-TEMP
PROBE
ASSEMBLY
FILTER
EXCHANGE
LEVER
RIBBON CABLE
3-PRONGED CONNECTOR
Figure 3. TEOM® sensor/preheater assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-29
-------
Method IO-1.3
TEOM® Monitor
Chapter IO-1
Continuous PM^Q Analyzers
AIR IN
AIR IN
Figure 4. TEOM® PM10 inlet.
Page 1.3-30
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM^Q Analyzers
Method IO-1.3
TEOM® Monitor
FLOW
SPLITTER
FLOW AUDIT
ADAPTER
Figure 5. TEOM® flow splitter assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-31
-------
Method IO-1.3
TEOM® Monitor
Chapter IO-1
Continuous PM-^Q Analyzers
Filter
Exchange
Tool
REMOVAL
Figure 6. TEOM® filter cartridge assembly illustrating loading and removing filter.
Page 1.3-32
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM<« Analyzers
Method IO-1.3
TEOM* Monitor
AIR IN
BYPASS
FLOW LINE
TEOM® FILTER
AIR TUBES
(CABLE-TIED)
• BYPASS FINE
PARTICLE FILTER
ASSEMBLY
IN-LINE FILTERS
PM10 INLET
FLOW SPUTTER
SAMPLE TUBE
TEOM® SENSOR
UNIT
-MAIN TRANSDUCER
TEOM CONTROL
UNIT
MAIN FLOW
CONTROLLER
(3 L/min)
AUXILIARY FLOW
CONTROLLER
(13.67 Umin)
VACUUM PUMP
Figure 7. Schematic diagram of the assembled TEOM® monitor.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 1.3-33
-------
Method IO-1.3
TEOM3" Monitor
Chapter IChl
Continuous PM|Q Analyzers
Figure 8. Back pane! of TEQM® monitor.
Page 1.3-34
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM1Q Analyzers
Method IO-1.3
TEOM® Monitor
Unlock
Lock
Figure 9. Location of shipping latch on back panel of the TEOM® monitor.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-35
-------
Method IO-1.3
TEOM* Monitor
Chapter TO-l
Continuous P^^p Analyzers
Figure 10. Inside view of TEOM® sensor unit.
Page 1.3-36
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PM^Q Analyzers
Method IO-1.3
TEOM* Monitor
AIR IN
BYPASS
FLOW LINE
TO CONTROL UNIT
* TEOMe SENSOR UNIT
ELECTRIC AND AIR
CONNECTING CABLE
TABLE OR
LAB BENCH
Figure 11. Schematic of typical TEOM® PM1Q installation with flow splitter.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-37
-------
Method 1O-1.3
TEOM» Monitor
Chapter IO4
Continuous PMj.Q Analyzers
Figure 12. Replacing filter cartridge in sensor unit using filter exchange tool.
Page 1.3-38
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-1
Continuous PMj Q Analyzers
Method IO-1.3
TEOM® Monitor
MAIN SCREEN
(Screen 00)
Screen on
Instrument
OK 4 38% NU 09:39
Mass Cono 76.4
30-Min MC 72.3
01-Hr MC 78.4
08-Hr MC 85.8
24-Hr MC 69.3
Tot Mass 974.38
Case Temp 50.00
Air Temp 50.01
Cap Temp 49.98
Encl Temp 40.00
Main Flow 3.00
Aux Flow 13.66
Noise 0.034
Frequency 187.05738
— »
— *•
— >
— »
— *
— *
-*.
-
— *
: Description of Screen
Units
N/A
//g/m3
//g/m3
fjg/m3
fjg/m3
fjg/m3
fJQ
°C
°C
°C
°C
l/min
l/min
N/A
fjg
hz
Edit in
Modes
N/A
not editable
not editable
not editable
not editable
not editable
not editable
not editable
not editable
not editable
not editable
not editable
not editable
N/A
not editable
not editable
Default
N/A
N/A
N/A
N/A
N/A
N/A
N/A
50
50
50
40
3
13.67
N/A
N/A
N/A
Re-lnli
N/A
N/A
N/A
N/A
N/A
N/A
N/A
50
50
50
40
3
13.67
N/A
N/A
N/A
Comments
Status Line
Short-term average
Updated every 30 min
Updated every 1 hr
Updated every 1 hr
Updated every 1 hr
Mass since last reset
Current temperature
Current temperature
Current temperature
Current temperature
Current flow rate
Current flow rate
Diagnostic measure
Mass transducer
To enter this screen press:
< Main/Status > or 00
Next screen (using }: -
Menu Screen (Screen 02)
Figure 13. TEOM® main menu screens.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 1.3-39
-------
Method IO-1.3
TEQM8 Monitor
Chapter IO-1
Continuous PMj0 Analyzers
Figure 14, Auditing of the TEOM® flow control system.
Pago 1.3-40
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
EPA/625/R-96/OlOa
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Chapter IO-2
INTEGRATED .-SAMPLING OF
SUSPENDED PARTICULATE MATTER
(SPM) IN AMBIENT AIR
OVERVIEW
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
-------
Chapter IO-2
Integrated Sampling of Suspended Particulate
Matter (SPM) in Ambient Air
Overview
Under authority granted in Section 109 of the Clean Air Act (the Act) and its amendments the
U. S. Environmental Protection Agency (EPA) has promulgated primary and secondary national ambient
air quality standards (NAAQS) for six criteria pollutants: SO2, NOX, CO, O-,, PM10 and Pb These
primary (health-related) and secondary (welfare-related) pollutants standards are contained in Title 40
Part 50 of the Code of Federal Regulations(40 CFR 50). The reference methods for monitoring ambient
atmospheres for these criteria pollutants are in the Appendices of 40 CFR 50, A through G.
Section 109 of the Act requires EPA to evaluate; at 5-yr intervals, the criteria for which standards
have been promulgated and to issue any new standards as may be appropriate.
The issuance of reference methods designed to monitor these criteria pollutants has a legal basis in
Section 301 of the Act, which states that the regulations necessary to carry out the provisions of the Act
may be promulgated by the Administrator. To evaluate and ascertain the status of air quality with regard
to the criteria pollutants, uniform analytical methods are used to ensure consistency and accuracy in the
data generated. J
Suspended particulate matter (SPM) in air generally is considered to be all airborne solid and low
vapor pressure liquid particles, involving a complex, multi-phase system consisting of a spectrum of
aerodynamic particle sizes ranging from below 0.01 pm to 100 ^m and larger. Historically, particulate
matter (PM) measurement has concentrated on total suspended particulates (JSP), with no preference to
size section. The EPA's approach toward regulating and monitoring TSP matter has evolved over time
When EPA first regulated TSP, the NAAQS was stated in terms of particulate matter captured on a filter
with an aerodynamic particle size of < 100 Mm as defined by the TSP sampler. Recently, the primary
standard for TSP was replaced with a PM1Q standard, which includes only particles with an aerodynamic
diameter of 10 /j.m or less.
Researchers generally recognize that these particles (< 10 ^m) may cause significant, adverse health
ertects. Recent studies involving particle transport and transformation strongly suggest that atmospheric
particles commonly occur in two distinct modes: the fine (<2.5 ^m) mode and the coarse (2 5-10 0 am)
mode The fine or accumulation mode (also termed the respirable particulate matter) is attributed to
. growth of particles from the gas phase and subsequent agglomeration, while the coarse mode is made of
mechanically abraded or ground particles. Particles that have grown from the gas phase (either because
ot condensation, transformation, or combustion) occur initially as very fine nuclei-0 05 urn Thee
particles tend to grow rapidly to accumulation mode particles around 0.5 ^m, which are relatively stable
in the air. Because of their initially gaseous origin, particle sizes in this range include inorganic ions such
as sulrate, nitrate, ammonia, combustion-form carbon, organic aerosols, metals, and other combustion
products. Coarse particles, on the other hand, are produced mainly by mechanical forces such as
crushing and abrasion. Pollen and spores also inhabit the coarse particle range, thus providing dominance
by materials of geological origin. Coarse particles, therefore, normally consist of finely divided minerals
such as oxides of aluminum, silicon, iron, calcium, and potassium. Coarse particles of soil or dust
mostly result from entrainment by the motion of air or from other mechanical action within their area
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.0-1
-------
Chapter IO-2
Overview Integrated Sampling of SPM
Since the size of these particles is normally >2.5 pm their retention time in the air parcel is shorter than
the fine particle fraction.
The EPA is considering further narrowing the primary NAAQS to even smaller particles (^2.5
As shown in Figure 1, these smaller particles penetrate deeply into the lung, where the potential for
health effects is greatest. Current knowledge indicates that this size fraction (<2.5 jim) is composed of
varying amounts of sulfate, ammonium, and nitrate ions, elemental carbons, organic carbon compounds,
water, and small amounts of soil dust, lead compounds, and trace species. This size fraction is generally
man made.
Consequently, a wide variety of PM is found in a typical atmosphere which is constantly changing.
Such factors as size, chemical composition, affinity for water and chemical reactivity, to name a few,
determine the lifetime for the PM in the atmosphere. Generally, the lifetime of coarse particles in the
atmosphere are measured in day, whereas fine particles tend to be transported over large areas. As
illustrated in Figure 2, the atmosphere is characterized by a typical bimodel distribution of PM.
The sampling methods for characterizing PM in ambient air are divided into two categories:
"reference" methods and "equivalent" methods. Equivalent methods were presented in Chapter IO-1.
This chapter will present the reference methods and a discussion of filter media and filter holders. The
reference methods are manual methods established by EPA for determining TSP and PM10 concentrations
in ambient air. In these methods, a known volume of air is drawn through the sampler and the particulate
fraction of interest (TSP or PM10) is collected. The mass of particulate matter subsequently is
determined gravimetrically, and the average ambient concentration over the sampling period is calculated.
The reference method for TSP is codified at 40 CFR 50, Appendix B. This method uses a
high-volume sampler (hi-vol) to collect particles with aerodynamic diameters of approximately 100 jim
or less. The hi-vol samples 40-60 cubic feet per minute (ft3/min) of air with the sampling rate held
constant over the sampling period. The hi-vol's design causes the TSP to be deposited uniformly across
the surface of the filter. The TSP hi-vol can be used to determine the average ambient TSP concentration
over the sampling period, and the collected material can be analyzed subsequently to determine the
identity and quantity of inorganic metals present in the TSP.
The federal reference method for PMjQ measurements is based on particulate selection by inertial
separation followed by filtration and gravimetric determination of the PM10 mass on the filter substrate.
The reference method for PM10 is codified in 40 CFR 50, Appendix J. The standard for this method
specifies the features for a reference PM10 measurement method. These features are summarized as
follows:
• The sampling inlet has a cut-point of 10 ± 0.5 /im aerodynamic diameter, as determined in a wind
tunnel using liquid particles of specified diameter at specific wind speeds.
• Flow-rate remains stable over a 24-h period, independent of filter loading, within ±5% of the
initial average flow reading and within ±10% of the initial flow rate for instantaneous flow
measurements. ._
• Measurement precision for a 24-h period should be within +5 jig/nr for concentrations less than
80 jiglrr? or ±7 jig/m3 of measured PM^Q for concentrations greater than 80
Page 2.0-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter 10-2
Integrated Sampling Of SPM
Overview
• For a nominal air volume sampled over a 24-h period, the filter media should collect more than
99% of a 0.3 fj.m particles and have an alkalinity of <25 microequivalents per gram and a net
equivalent weight gain or loss of not more than 5 /tg/m3.
• Prior to weighing, the filter should be equilibrated at a constant temperature (±3%) between 15°
and 30°C and constant relative humidity (±5%) between 20 and 45%.
Two technologies have qualified as meeting the sampling requirements of the reference method: a
hi-vol with a PM10 inlet and a dichotomous sampler. The PM10 hi"vo1 is identical to the TSP hi-vol
except that it is equipped with an inlet that directs only PM1Q to the filter. Dichotomous samplers also
collect only PM10, which is split into fractions above and below 2.5 jim. Both samplers collect the
particulate matter uniformly across the surface of the filters. Both can be used to determine average
ambient PM1Q concentration over the sampling period, and the collected material from both can
subsequently be analyzed for inorganic metals and other materials present in the collected sample. The
dichotomous sampler has the advantage of collecting two fractions so that information can be obtained
about total PM10 and/or both of the two fractions. This property may take on added importance if EPA
decides to revise the primary NAAQS to address smaller particles. In addition, the dichotomous sampler
operates at a low flow rate (about 0.6 fe/min), which allows the use of filter media that would otherwise
quickly clog at hi-vol flow rates. However, because of its higher-flow rates, the PM1Q hi-vol collects
more material so lower ambient concentrations of inorganic materials can be detected (assuming identical
filter medium and analysis technique).
The relationship between sampler type and the type of particulate matter sampled is as follows:
HI-VOL SAMPLER
-TSP
-PMtO
AVERAGE TSP
CONCENTRATION
LOW VOL SAMPLER
- DICHOTOMOUS
SAMPLER
- PARTISOL*
SAMPLER
AVERAGE PMo
CONCENTRATION
AVERAGE PMo
CONCENTRATION AND
CONCENTRATION
(<&5 iM and 2.5-10 /M)
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.0-3
-------
Chapter IO-2
Overview Integrated Sampling of SPM
The major prerequisite in selecting a sampling system is to determine what size range of particles are
to be monitored and the method of analysis (if applicable). The analytical method selection is very
important, because test will dictate the type of filter media compatible with the sampling system. Several
air sampling filter types are available, and the specific filter used depends upon the desired physical and
chemical characteristics of the filter and the analytical methods used. No single filter medium is
appropriate for all desired analyses. Particle sampling filters consist of a tightly woven fiber mat or
plastic membrane penetrated by microscopic pores. Several characteristics are important in selecting a
filter media; these characteristics include:
Particle sampling efficiency;
Mechanical stability;
Chemical stability;
Temperature stability;
Blank concentrations;
Flow resistance and loading capacity; and
Cost and availability.
A comparison of several air sampling filter types with their chemical and physical characteristics and the
corresponding chemical analytical methods that can be used for analyzing the sample is presented in
Table 1.
Filter holders are also constructed from different types of material, and the material type must be
taken into account if reactive components of suspended particles are collected. Filter holders are
constructed in either an in-line or open-face configuration. In-line holders have a small diameter opening
into a small chamber that contains the filter media. This holder type may concentrate the particles in the
center of the filter media, which could lead to a bias in the results if the analyses are not performed on
the entire filter. Open-face holders have exposed filters with no constrictions upstream of the filter media
and are a better option for ambient aerosol sampling systems. The exposed filters must be protected from
excessive vibration that might dislodge the particles on the filter surface. A brief listing of common filter
holders, sizes, and physical characteristics is presented in Table 2. A more detailed discussion of filter
media, holders, and the determination of mass concentration is provided in Method IO-2.4.
Unfortunately, no one sampling method or filter media can address all data quality objectives for a
particular ambient air monitoring program. Each method and filter type has its own attributes,
specificities, advantages, and disadvantages, as previously discussed. However, Compendium
Method IO-2 attempts to encompass into one chapter the various options, in a step-by-step methodology,
to facilitate accurate and reliable data for sampling SPM and in the ambient air.
Page 2.0-4 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter 10-2
Integrated Sampling Of SPM
Overview
TABLE 1. REPRESENTATIVE FILTER MEDIA FOR PARTICLE SAMPLING1
Filter type ;
Ringed Teflon*
membrane
Teflon* membrane-
polypropylene backed
Nylon membrane
Silver membrane
Cellulose esters
membrane (cellulose
nitrate mixed esters and
cellulose acetate)
Filter sizes,
mm
25
37
47
47
25
37
47
25
37
37
47
••;. ' ,:;" Characteristics : •,'\^-. ''./•:':.
Chemical .•'• : >•• '.
• Low blank levels
• Low blank weight
• No carbon analysis
• Low hygroscopic
tendency
• Inert to gas
adsorption
• Low blank levels
• No carbon analysis
• High blank weight
• Inert to gas
adsorption
• High background
levels for PEXE and
XRF
• Low hygroscopic
tendency
• Low blank weight
• Low hygroscopic
tendency
• HighHNO3
poUection efficiency
• Passive adsorption of
low levels of NO,
NO-,, PAN, and SO7
• Resistant to chemical
attack
• Passive adsorption of
organic vapors
• High blank weight
• Low hygroscopic
tendency
• Dissolved by several
organic solvents
• Negligible ash
content
• Highly hygroscopic
• Low blank weight
Physical v
• Thin membrane
• White, nearly
transparent surface
• High particle
collection efficiency
• High flow resistance
• Melts at ~60°C
• Cannot be accurately
sectioned
• Multiple pore sizes
available
• Minimal diffusion of
transmitted light
• Thin membrane
• White opaque surface
• High particle
collection efficiency
• Melts at -60°C
• High flow resistance
• Diffuses transmitted
light
• Thin pure nylon
membrane
• Diffuses transmitted
light
• High flow resistance
• Melts at -60°C
• 1 pm pore size
• Thin membrane
• Gray-white surface
• Diffuses transmitted
light
• High flow resistance
• Melts at ~350°C
• Thin membrane
• White opaque surface
• Multiple pore sizes
available
• Surface diffuses
transmitted light
• High flow resistance
• Melts at ~700C
Analysis methods ; :
• GRAY, XRF, OA,
PKE, INAA, AAS,
ICP/AES, ICP/MS,
1C, AC
• GRAY., PIXE,
XRF, INAA, AAS,
ICP/AES, ICP/MS,
1C, AC
• 1C, AC
• GRAY., XRD
• GRAY., OM, TEM,
SEM, XRD
• Biomed. appl.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.0-5
-------
Overview
Chapter IO-2
Integrated Sampling of SPM
Filter type
Polycarbonate
membrane
Pure quartz filter
Mixed quart fiber
(quartz filters with
—5% borosilicate
content)
Teflon*-coated glass
fiber (borosilicate glass
fiber mat with surface
layer of Teflon*)
PiIf**T* ^?7PQ
JP11XCI QLL&O)
mm
47
25
37
47
203 x 254
203 x 254
37
47
: .' •;':... Characteristics
Chemical : !:. :-
• No carbon analysis
• Low blank levels
• Low blank weight
• Low hygroscopic
tendency
• Contains large and
variable quantities of
Aland Si
• Low blank level for
ions
• Passive adsorption of
organic vapors
• Little adsorption of
HNO3, NO2, and
SO2
• Low hygroscopic
tendency
* Contains large and
variable quantities of
Na, Al, and Si plus
variable levels of
other metals
• Passive adsorption of
organic vapors
• Little adsorption .of
HN03, NO,, and
so2
« High blank weight
• Low hygroscopic
tendency
• Inert to adsorption of
HNO3, NO2, and
so2
• Low blank level for
ions
• High blank weight
• Low hygroscopic
tendency
• Physical
• Smooth, thin surface
with straight capillary
holes
• Light gray, nearly
transparent surface
• Minimal diffusion of
transmitted light
• Multiple pore sizes
available
• Use for particle size
classification
• Low particle collec-
tion efficiency for
some pore sizes
• Retains static charge
• Moderate flow
resistance
• Melts at ~609C
• White opaque surface
• Diffuses transmitted
light
• Edges of filter flake
in holders
• High particle collec-
tion efficiency
• Moderate flow
resistance
• Melts at >900°C
• White opaque surface
• Diffuses transmitted
light
• High particle collec-
tion efficiency
• Low flow resistance
* Becomes brittle on
heating
• Can melt at ~500°C
• Low flow resistance
• High particle collec-
tion efficiency
• Melts at ~60°C;
glass at -500°C
Analysis methods
• GRAY., OA, OM,
SEM, XRF, PEXE
• ICP/AES, ICP/MS,
1C, AC, OA, T,
TOR, TMO, TOT
• GRAY., XRF,
PKE, AA,
ICP/AES, ICP/MS,
1C, AC, T, TOR,
TMO, TOT
• GRAY., 1C, AC
Page 2.0-6
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter 10-2
Integrated Sampling Of SPM
Overview
Filter type
Glass fiber (borosilicate
glass fiber)
Cellulose fiber ("paper"
filter)
Filter sizes,
mm
203 x 254
25
37
47
. ... \,:: j^^Cfiaracteristics, ,; ,
Chemical : -::. :,
• Adsorbs HNO3,
NO2, SO2, and
organic vapors
• High blank levels
• High blank weight
• Low hygroscopic
tendency
• No carbon analysis
• Low blank levels;
high purity
• Most useful for
adsorption of gases,
e.g., HN03, S02,
NH3, and NO? after
impregnated with
reactive chemicals
• High blank weight
• Highly hygroscopic
• Adsorbs gases,
particularly water
vapor
v!\: ; Physical
• White opaque surface
• Diffuses transmitted
light
• Low flow resistance
• High particle collec-
tion efficiency
• Melts at -500°C
• White opaque surface
• Diffuses transmitted
light
• High mechanical
strength
• Low particle collec-
tion efficiency
possible
• Variable flow
resistance
• Burns at ~ 150°C
Analysis methods
• GRAY., OA, XRF,
PKE, INAA, AAS,
ICP/AES, 1C, AC
• GRAY., XRF,
PKE, INAA, AAS,
ICP/AES, ICP/MS,
1C, AC
Analysis Methods Abbreviations (alphabetical order)
AAS
AC
GRAY
1C
ICP/AES
ICP/MS
INAA
OA
OM
Atomic absorption spectrophotometry
Automated colorimetry
Gravimetry
Ion chromatography
Inductively-coupled plasma with atomic
emission spectrophotometry
Inductively-coupled plasma with mass
spectrophotometry
Instrumental neutron activation analysis
Optical absorption or light transmission (b^g)
Optical microscopy
PIXE = Proton-induced X-Ray emissions
SEM = Scanning electron microscopy
T= Thermal carbon analysis
TEM —• Transmission electron microscopy
TMO = Thermal manganese oxidation carbon analysis
TOR = Thermal/optical reflectance carbon analysis
TOT — Thermal/optical transmission carbon analysis
XRD -= X-Ray diffusion
XRF = X-ray fluorescence
Source: Chow, J. C., "Measurement Methods to Determine Compliance with Ambient Air Quality Standards for
Suspended Particles," J. Air and Waste Manage. Assoc., Vol. 45:320-382, 1995.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.0-7
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Overview
Chapter IO-2
Integrated Sampling ofSPM
TABLE 2. REPRESENTATIVE FILTER HOLDERS
Holder type
Polycarbonate
Polypropylene
Aluminum or stainless
steel
Stainless steel
Perfluoroalkoxy (PFA)
Teflon*
Teflon*
Filter size,
mm
25
47
13
25
37
47
25
47
25
47
203 x254
47
47
Physical characteristics
• In-line or open-face configuration
• Base has flow resistant outlet
• Support grid has polyethylene O-ring
• Extender section for multi-stage filter pack sampling
• In-line or open-face (37 mm only) configuration
• Polypropylene or glass-filled polystyrene base
• Support grid has silicon O-ring
• 37 mm filter has polypropylene base
• In-line or open-face
• Stainless steel screen with Viton O-ring
• Has nylon or polyethylene adapters
• In-line or open-face
• Stainless steel base
• Stainless steel or nickel-plated screen
« Screens use Teflon® or Viton O-rings
• In-line or open-face
• Base, support grid, and adapter are PFA Teflon*
• Support grid has Viton O-ring
• In-line
• Teflon* base
Source:
Chow, J. C., "Measurement Methods to Determine Compliance with Ambient far Quality Standards for Suspended Particles,"
/. Air and Waste Manage. Assoc., Vol. 45:320-382,1995.
Page 2.0-8
Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter 10-2
Integrated Sampling Of SPM
Overview
30 microns
9.2 - 30 microns
5.5 - 9.2 microns
3.5 - 5.5 microns
2.0 - 3.3 microns
1.0 - 2.0 microns
0.3 -1.0 microns
0.1 -3.0 microns
Trachea & primary
bronchi
1
Secondary
bronchi
Terminal
bronchi
Alveoli
Alveoli
Figure 1. Depth of respiratory system penetration based on particle size.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.0-9
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Overview
Chapter IO-2
Integrated Sampling of SPM
o
•a
KS
&
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EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-2.1
SAMPLING OF AMBIENT AIR
FOR TOTAL SUSPENDED PARTICULATE
MATTER (SPM) AND PM1O USING
HIGH VOLUME (HV) SAMPLER
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-2.1
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F, McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTF, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTF, NC
• Frank F. McElroy, U.S. EPA, NERL, RTF, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology. '
Author(s)
• William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown,, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
11
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Method IO-2.1
Sampling of Ambient Air for Total Suspended Particulate
Matter (SPM) and PM10 Using High Volume Sampler
TABLE OF CONTENTS
1. Scope 2.1-1
2. Applicable Documents 2.1-3
2.1 ASTM Documents 2.1-3
2.2 Other Documents 2.1-3
3. Summary of Method 2.1-3
4. Significance 2.1-4
5. Definitions '. 2,1-4
6. Apparatus Description 2.1-7
6.1 General Description 2.1-7
6.2 Filter Medium 2.1-7
6.3 Flow Control System 2.1-8
7. Calibration 2.1-9
7.1 Introduction 2.1-9
7.2 Summary of Calibration Procedures . 2.1-10
7.3 Certification of an Orifice Transfer Standard 2.1-10
7.4 Procedure for a Mass-Flow-Controlled (MFC) High Volume Sampler 2.1-13
7.5 Procedure for a Volumetric-Flow-ControUed (VFC) Sampler 2.1-20
7.6 Sampler Calibration Frequency 2.1-26
8. Filters 2.1-26
8.1 Filter Handling 2.1-26
8.2 Visual Filter Inspection 2.1-27
9. Sampling Procedure 2.1-27
9.1 Summary : 2.1-27
9.2 Siting Requirements 2.1-28
9.3 Sampler Installation Procedures 2.1-29
9.4 Sampling Operations 2.1-29
9.5 Sample Validation and Documentation 2.1-36
10. Interferences 2.1-37
11. Calculations, Validations, and Reporting of PM10 Data 2.1-38
12. Records ; 2.1-42
12.1 MFC Sampler 2.1-42
12.2 VFC Sampler 2.1-43
13. Field QC Procedure 2.1-44
13.1 QC Flow-Check Procedure-MFC Sampler 2.1-45
13.2 QC Flow-Check Procedure-VFC Sampler 2.1-48
14. Maintenance 2.1-52
14.1 Maintenance Procedures 2.1-52
14.2 Recommended Maintenance Schedules 2.1-52
14.3 Refurbishment of HV Samplers 2.1-54
15. References 2.1-54
111
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Chapter IO-2
Integrated Sampling of Suspended
Participate Matter (SPM)
Method IO-2.1
SAMPLING OF AMBIENT AIR FOR TOTAL SUSPENDED PARTICULATE
MATTER (SPM) AND PM10 USING HIGH VOLUME (HV) SAMPLER
1. Scope
1.1 Suspended participate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01-100 /*m
and larger. Historically; SPM measurement has concentrated on total suspended particulates (TSP), with
no preference to size selection.
1.2 The U. S. Environmental Protection Agency (EPA) reference method for TSP is codified at 40 CFR
50, Appendix B. This method uses a high-volume sampler (hi-vol) to collect particles with aerodynamic
diameters of approximately 100 /*m or less. The hi-vol samples 40-60 ft^/min of air with the sampling
rate held constant over the sampling period. The high-volume design causes the TSP to be deposited
uniformly across the surface of a filter located downstream of the sampler inlet. The TSP hi-vol can be
used to determine the average ambient TSP concentration over the sampling period, and the collected
material subsequently can be analyzed to determine the identity and quantity of inorganic metals present
in the TSP.
1.3 Research on the health effects of TSP in ambient air has focused increasingly on particles that can
be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10 fan. The
health community generally recognizes that these particles may cause significant adverse health effects.
Recent studies involving particle transport and transformation strongly suggest that atmospheric particles
commonly occur in two distinct modes: the fine (<2.5 pm) mode and the coarse (2.5-10.0 jum) mode.
The fine or accumulation mode (also termed the respirable paniculate matter) is attributed to growth of
particles from the gas phase and subsequent agglomeration, while the coarse mode is made of
mechanically abraded or ground particles. Particles that have grown from the gas phase (either because
of condensation, transformation, or combustion) occur initially as very fine nuclei-0.05 /*m. These
particles tend to grow rapidly to accumulation mode particles around 0.5 jum which are relatively stable
in the air. Because of their initially gaseous origin, particle sizes in this range include inorganic ions such
as sulfate, nitrate, ammonia, combustion-form carbon, organic aerosols, metals, and other combustion
products. Coarse particles, on the other hand, are produced mainly by mechanical forces such as
crushing and abrasion. Coarse particles, therefore, normally consist of finely divided minerals such as
oxides of aluminum, silicon, iron, calcium, and potassium. Coarse particles of soil or dust mostly result
from entrainment by the motion of air or from other mechanical action within their area. Since the size
of these particles is normally > 2,5 /mi, their retention time in the air parcel is shorter than the fine
particle fraction.
1.4 On July 1, 1987, the U. S. Environmental Protection Agency (EPA) promulgated a new size-specific
air quality standard for ambient paniculate matter. This new primary standard applies only to particles
with aerodynamic diameters < 10 micrometers (PM1Q) and replaces the original standard for TSP. To
measure concentrations of these particles, the EPA also promulgated a new federal reference method
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-1
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
(FRM). This method is based on the separation and removal of non-PM^g particles from an air sample,
followed by filtration and gravimetric analysis of PM10 mass on the filter substrate.
1.5 The new primary standard (adopted to protect human health) limits PM1Q concentrations to
150 jig/std. m3 averaged over a 24-h period. These smaller particles are able to reach the lower regions
of the human respiratory tract and, therefore, are responsible for most of the adverse health effects
associated with suspended particulate pollution. The secondary standard, used to assess the impact of
pollution on public welfare, has also been established at 150 jig/std. m3.
1.6 Ambient air SPM measurements are used (among other purposes) to determine whether defined
geographical areas are in attainment or non-attainment with the national ambient air quality standards
(NAAQS) for PM10. These measurements are obtained by the States in their State and local air
monitoring station (SLAMS) networks as required under 40 CFR Part 58. Further, Appendix C of Part
58 requires that the ambient air monitoring methods used in these EPA-required SLAMS networks must
be methods that have been designated by the EPA as either reference or equivalent methods.
1.7 Monitoring methods for particulate matter are designated by the EPA as reference or equivalent
methods under the provisions of 40 CRF Part 53, which was amended in 1987 to add specific
requirements for PMjg methods. Part 53 sets forth functional specifications and other requirements that
reference and equivalent methods for each criteria pollutant must meet and explicit test procedures by
which candidate methods or samplers are to be tested against those specifications. General requirements
and provisions for reference and equivalent methods are also given in Part 53, as are the requirements
for submitting an application to the EPA for a reference or equivalent method determination.
1.8 Several methods are available for measuring SPM in ambient air. As mentioned earlier, the most
commonly used device is the hi-vol sampler, which consists essentially of a blower and a filter, and which
is usually operated in a standard shelter to collect a 24-h sample. The sample is weighed to determine
concentration and may be analyzed chemically. The high volume sampler is considered a reliable
instrument for measuring the mass concentration of TSP in ambient air. When EPA first regulated TSP,
the NAAQS was stated in terms of SPM captured on a filter with aerodynamic particle size of < 100 /*m
as defined by the TSP sampler; therefore, the TSP sampler was used as the reference method.
1.9 Under Part 53 requirements, reference methods for PM1Q must be shown to use the measurement
principle and meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a
PMjn sampler that meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies
a measurement principle based on extracting an air sample from the atmosphere with a powered sampler
that incorporates the inertial separation of PMjQ size range particles followed by the collection of PM^Q
particles on a filter over a 24 h period. The average PM10 concentration for the sample period is
determined by dividing the net weight gain of the filter over the sample period by the total volume of air
sampled, corrected to EPA's standard temperature (25°C) and standard pressure (760 mmHg). Other
specifications for flow rate control and measurement, flow rate measurement device calibration, filter
media characteristics and performance, filter conditioning before and after sampling, filter weighing,
sampler operation, and correction of sample volume to EPA reference temperature and pressure are
prescribed in Appendix J. In addition, sampler performance requirements in Subpart D of Part 53 include
sampling effectiveness (the accuracy of the PM1Q particle size separation capability) at each of the three
wind speeds and at "50% cutpoint" (the primary measure of 10-pi particle size separation). Field tests
Page 2.1-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
for sampling precision and flow rate stability are also specified. In spite of the instrumental nature of
the sampler, this method is basically a manual procedure, and all designated reference methods for
are therefore defined as manual methods.
1.10 This document describes the procedures for sampling SPM in ambient air for both TSP and
based upon active sampling using a high volume air sampler. The ambient particle are collected on
quartz fiber filters. The sampler collects TSP or PMjQ ambient particles depending upon the type of inlet
selected.
2. Applicable Documents
2.1 ASTM Documents
• D4096 Application of the High Volume Sample Method for Collection and Mass Determination of
Airborne Paniculate Matter.
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice for Planning the Sampling of the Ambient Atmosphere.
• D2986 Method for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate)
Smoke Test.
2.2 Other Documents
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA/600/R-94/038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA/600/R-94/038b.
• Reference Method for the Determination of Paniculate Matter in the Atmosphere, 40 CFR 50,
Appendix J.
• Reference Method for the Determination of Suspended Particulates in the Atmosphere (High Volume
Method), 40 CFR 50, Appendix B.
• Reference Method for the Determination of Lead in Suspended Paniculate Matter Collected from
Ambient Air, 40 CRF 50, Appendix G.
• Reference Method for this Determination of Suspended Particulates in the Atmosphere
Method), 40 CFR 50, Appendix J.
3. Summary of Method
3.1 The sampling of a large volume of atmosphere, 1,600-2,400 m3 (57,000-86,000 ft3), with a high-
volume blower, typically at a rate of 1.13-1.70 m3/min (40-60 ft3/min), is described in this method. The
calibration and operation of typical equipment used in this sampling is also described.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-3
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM _ _ _ High Volume
3.2 Air is drawn into the sampler and through a glass fiber or quartz filter by means of a blower, so that
particulate material collects on the filter surface. Without a size-selective inlet, this flow rate allows
suspended particles having diameters less than 100-0.1 /*m to be collected. The collection efficiencies
for particles larger than 20 pm decreases with increasing particle size, and it varies widely with the angle
of the wind with respect to the roof ridge of the sampler shelter. When glass fiber filters are used,
particles 100-0.1 urn or less in diameters are ordinarily collected. With a size-select inlet, particles 10
diameter or less are collected on the quartz filter.
3.3 The upper limit of mass loading is determined by plugging the filter medium with sample material,
which causes a significant decrease in flow rate. For very dusty atmospheres, shorter sampling periods
will be necessary.
3.4 The volume of air sampled is determined by a flow-rate indicator. The instrument flow-rate
indicator is calibrated against a reference orifice meter. The latter is a working standard which, in turn,
has been calibrated against a master flow meter certified by the National Institute of Standards and
Technology (NIST).
3.5 Airborne paniculate matter retained on the filter may be examined or analyzed chemically by a
variety of methods (ICP, ICP/MS, AA, GFAA, and NAA) as delineated in Inorganic Compendium
Methods IO-3.2 through IO-3.7.
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels is essential to proper assessments.
4.2 The high volume sampler is commonly used to collect the airborne particulate component of the
atmosphere. A variety of options available for the sampler provides broad versatility and allows the user
to develop information about the size and quantity of airborne particulate material and, using subsequent
chemical analytical techniques, information about the chemical properties of the particulate matter. The
advent of inductively coupled plasma spectroscopy has improved the speed and performance of metals
analysis in many applications.
5. Definitions
[Note: Definitions used in this document are consistent with those used in ASTM Methods. All pertinent
abbreviations and symbols are defined within this document at point of use.]
5.1 High-Volume Air Sampler (HV). A device for sampling large volumes of an atmosphere for
collecting the contained particulate matter by filtration. Consists of a high-capacity blower, a filter to
collect suspended particles, and a means for measuring the flow rate.
Page 2.1-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
5.2 Working Flow-Rate Standard. A flow-rate measuring device, such as a standard orifice meter,
that has been calibrated against a master flow-rate standard. The working flow-rate standard is used to
calibrate a flow measuring or flow rate indicating instrument,
5.3 Master Flow-Rate Standard. A flow-rate measuring device, such as a standard orifice meter, that
has been calibrated against a primary standard.
5.4 Primary Flow-Rate Standard. A device or means of measuring flow rate based on direct primary
observations such as time and physical dimensions.
5.5 Spirometer. A displacement gasometer consisting of an inverted bell resting upon or sealed by
liquid (or other means) and capable of showing the amount of gas added to or withdrawn from the bell
by the displacement (rise or fall) of the bell.
5.6 Absolute Filter. A filter or filter medium of ultra-high collection efficiency for very small particles
(submicrometer size) so that essentially all particles of interest or of concern are collected. Commonly,
the efficiency is 99.95% or higher for a standard aerosol of 0.3 /im diameter.
5.7 Calibration. The process of comparing a standard or instrument with one of greater accuracy (small
uncertainty) to obtain quantitative estimates of the actual values of the standard being calibrated, the
deviation of the actual value from a nominal value, or the difference between the value indicated by an
instrument and the actual value.
5.8 Differential Pressure Meter. Any flow measuring device that operates by restricting air flow and
measuring the pressure drop across the restriction.
5.9 Emissions. The total of substances discharged into the air from a stack, vent, or other discrete
source.
5.10 Flowmeter. An instrument for measuring the rate of flow of a fluid moving through a pipe or duct
system. The instrument is calibrated to give volume or mass rate of flow.
5.11 Impaction. A forcible contact of particles of matter. A term often used synonymously with
impingement.
5.12 Impactor. A sampling device that employs the principle of impaction (impingement).
5.13 Impingement. The act of bringing matter forcibly in contact. As used in air sampling, refers to
a process for the collection of particulate matter in which the gas being sampled is directed forcibly
against a surface.
5.14 Inhalable Particles. Particles with aerodynamic diameters of < 10 /im that are capable of being
inhaled into the human lung.
5.15 Interference. An undesired positive or negative output caused by a substance other than the one
being measured.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-5
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
5.16 Mass Flowmeter. Device that measures the mass flow rate of air passing a point, usually using
the rate of cooling or heat transfer from a heated probe.
5.17 Matter. The substance of which a physical object is composed,
5.18 Orifice Meter. A flowmeter, employing as the measure of flow rate the difference between the
pressures measured on the upstream and downstream sides of the orifice (that is, the pressure differential
across the orifice) in the conveying pipe or duct.
5.19 Aerodynamic Diameter (a.d.). The diameter of a unit density sphere having the same terminal
settling velocity as the particle in question. Operationally, the size of a particle as measured by an
inertial device.
5.20 Particle. A small discrete mass of solid or liquid matter.
5.21 Particulate. Solids of liquids existing in the form of separate particles.
5.22 Precision. The degree of mutual agreement between individual measurements, namely repeatability
and reproducibility.
5.23 Pressure Gage. The difference in pressure existing within a system and that of the atmosphere.
Zero gage pressure is equal to atmospheric pressure.
5.24 Rotameter. A device, based on the principle of Stake's law, for measuring rate of fluid flow.
It consists of a tapered vertical tube having a circular cross section, and containing a flow that is free to
move in a vertical path to a height dependent upon the rate of fluid flow upward through the tube.
5.25 Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In
air or gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous
isolation of selected components.
5.2(5 Standard. A concept that has been established by authority, custom, or agreement to serve as a
model or rule in the measurement of quantity of the establishment of a practice or procedure.
5.27 Traceability to NIST. Documented procedure by which a standard is related to a more reliable
standard verified by the National Institute of Standards Technology (NIST).
5.28 Uncertainty. An allowance assigned to a measured value to take into account two major
components of error: The systematic error and the random error attributed to the imprecision of the
measurement process.
Page 2.1-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
6. Apparatus Description
6.1 General Description
6.1.1 The essential features of a typical non size-specific TSP high-volume sampler are shown in
Figure 1. The high volume sampler is a compact unit consisting of a protective housing; an electric
motor driven; a high-speed, high-volume blower; a filter holder capable of supporting a 203 x 254-mm
(8 by 10 in.) filter; and a flow-controller for controlling the air-flow rate through the instrument at
39-60 f3/min.
6.1.2 In operation, this traditional TSP sample draws ambient air into the sampler through the air
inlet gap between the cover and the sampler housing walls (see Figure 2). The air inlet is uniform on
all sides of the sampler to provide an effective particle capture air velocity between 20-35 cm/sec, at the
recommended flow rate between 39-60 ft3/min. The gable roof design of the sampler allows the sampled
air to be evenly distributed over the surface of a downstream filter, where TSP is collected.
6.1.3 For PM10 measurement, the traditional gable roof of the TSP sampler is replaced with a an
impactor design size-select inlet, as illustrated in Figure 3. For the impaction design, an air sample
enters a symmetrical (therefore wind-direction insensitive) hood and is deflected upward into a buffer
chamber. The buffer chamber is evacuated at a rate of 68 m3/h (40 cfm) through multiple circular
nozzles. Particles are accelerated as they pass through the nozzles to an impaction chamber (see
Figure 4). Because of their momentum, particles having diameters larger than the inlet's 10-^m cut
design impact the surface of the impaction chamber. Smaller particles rise through the impaction
chamber at speeds slow enough to minimize reentrainment of the impacted particles and then pass through
multiple vent tubes to the high-volume sampler's filter where they are collected.
6.1.4 The second size-select design for PM1Q measurement is the cyclone inlet, as illustrated in
Figure 5. The omnidirectional cyclone used for fractionation in this inlet allows particles to enter from
all angles of approach. An angular velocity component is imparted to the sample air stream and the
particles contained in it by a series of evenly spaced vanes. Larger particle removal occurs in an inner
collection tube. This tube incorporates a "perfect absorber," which is an oil-coated surface to eliminate
particle bounce and reentrainment. The sample flow (with the linremoved smaller particles) then enters
an intermediate tube, where the trajectory is altered to an upward direction. An additional turn is then
made to alter the flow to a downward trajectory to allow the remaining particles (i.e., PM1Q fraction)
to deposit on a filter for subsequent analysis. As with the impaction inlet, control of air velocities in the
cyclonic inlet is critical to maintain the correct particle size cutpoint. Maintaining the correct design
volumetric flow rate through the inlet is important. This design flow rate is specified by the manufacturer
in the instruction manual. For example, a popular cyclonic impaction inlet has a design flow rate of
1.13 nvVmin.
6.2 Filter Medium
6.2.1 Selecting a filtration substrate for time-integrated SPM monitoring must be made with some
knowledge of the expected characteristics and a pre-determined analytical protocol. For any given
standard test method, the appropriate medium will normally be specified.
6.2.2 In high-volume sampling, four types of filter material have been used to capture SPM. They
include cellulose fiber, quartz/glass fiber, mixed fiber and membrane filter types. Selecting a filter
depends upon variables such as background metal content, artifact formation, and affinity for moisture.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-7
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
The basic characteristics of the types of filter material used in high-volume sampling are outlined in
Table 1, while useful filter properties are identified in Table 2. Several characteristics are important in
selection of filter media. They are:
• Particle Sampling Efficiency. Filters should remove more than 99% of SPM from the air drawn
through them, regardless of particle size or flow rate.
• Mechanical Stability. Filters should be strong enough to minimize leaks and wear during handling.
• Chemical Stability. Filters should not chemically react with the trapped SPM.
• Temperature Stability. Filters should retain their porosity and structure during sampling.
* Blank Correction. Filters should not contain high concentrations of target compound analytes.
6.23 Quartz fiber filters are the most commonly used filters for SPM sampling for determining mass
loading. Typical characteristics of quartz fiber filters are (1) a fiber content of high purity quartz, (2) a
binder of below 5% (zero for binderless types), (3) a thickness of approximately 0.5 mm, (4) a surface
with no pinholes, and (5) an allowance of no more than 0.05% of smoke particles to pass through the
filter at a pressure of 100 mm of water with a flow rate of 8.53 m/min (28 ft/min), as determined by a
DOP smoke test (see ASTM Method D2986).
6.2.4 Quartz fiber filters are made from finely spun glass fiber by combining the fiber with an
organic binder and compressing this material in a paper machine. These filters are increasingly used in
air sampling. These filters have the ability to withstand high temperatures (up to 540°C). They are
further typified by high-collection efficiency. In some cases, the organic binder may interfere with
subsequent analysis, so the filter is flash-fired to remove the binder material. This action causes some
loss in tensile strength and usually requires that a backing material be used during sampling. The quartz
filters are nonhydroscopic, thus allowing them to be used in areas where humidity is high. Because they
are glass, they are the filter choice for most corrosive atmospheres. All the filters in this category are
fragile and must be handled with care. Quartz fiber filters, because of the high silicate content, are
extremely difficult to ash by chemicals or heat. Therefore, extraction procedures are performed on these
filters to remove the sample for subsequent chemical analysis. For this reason, flash-fired quartz filters
are the major atmospheric sampling filters.
6.3 Flow Control System
The high-volume sampler employs two basic types of flow control systems. One is a mass-flow-control
(MFC) system; the other is a volumetric-flow-control (VFC) system. Because the calibration and
standard operating procedures differ considerably between these two types of flow-control systems, this
method presents procedures that are control-system-specific. PM10 inlets can be used with either the
MFC and VFC systems.
6.3.1 Mass-flow-control (MFC) system. The flow rate in a MFC system is actively sensed and
controlled at a predetermined set point. Air is pulled through the filter into the intake of a blower and
subsequently exits the sampler through an exit orifice, which facilitates measurement of the flow with a
manometer or pressure recorder. The flow rate is controlled by an electronic mass-flow controller, which
uses a flow sensor installed below the filter holder to monitor the mass flow rate and related electronic
circuitry to control the speed of the motor accordingly to provide a constant sampling rate. The
controlled flow rate can be changed by an adjustment knob on the flow controller.
6.3.2 Volumetric-flow-control (VFC) system. A VFC system maintains a constant volumetric flow
rate through the inlet, rather than a constant mass flow rate as in the MFC system. In a popular
commercial VFC system, a choked-flow venturi is operated such that the air attains sonic velocity in the
throat of the device. In this "choked" mode, the flow rate is unaffected by downstream conditions, such
Page 2.1-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
as motor speed or exit pressure and is a predictable function of upstream conditions, such as the
stagnation pressure ratio and temperature. Thus, the volumetric flow is controlled without any moving
parts or electronic components. In this type of flow control system, no means is provided for adjusting
the controlled flow rate. The controlled flow rate is set by the manufacturer through engineering design
of the venturi.
7. Calibration
7.1 Introduction
[Note: All sampling equipment must be properly calibrated. Calibration is the relationship between an
instrumental output and the input of a known reference standard. The objective of this section is to
provide technically sound flow-rate calibration procedures for the MFC and VFCHV samplers.]
[Note: Consistency of temperature and barometric pressure is required. All temperatures should be
expressed in kelvin (K = °C + 273). All barometric pressures should be expressed in mm Hg. Avoid
calibrating an HV sampler using one set of units and then performing sample calculations using another
set.]
7.1.1 HV sampler inlet. Two types of size-selective inlets available are impaction and cyclonic for
monitoring inhalable particles (< 10 jun). The particle size discrimination characteristics of both the
impaction and cyclonic type inlets depend critically on maintaining certain air velocities within the inlet;
a change in velocity will result in a change in the nominal particle size collected. For this reason, the
flow rate through the inlet must be maintained at a constant value that is as close as possible to the inlet's
design flow rate. The design flow rate for a given sampler is specified in the sampler's instruction
manual. The manual may also provide tolerance limits (or upper and lower limits) within which the
sampler flow must be maintained. If the tolerance is not specified by the manufacturer, it should be
assumed to be ±10%.
7.1.1.1 The symmetrical design of the impaction inlet (see Figure 4) ensures wind-direction
insensitivity. Ambient air that is drawn into the inlet is evacuated from the buffer chamber through nine
acceleration nozzles into the first impaction chamber, where initial particle separation occurs. The air
is then accelerated through an additional 16 jets into a second impaction chamber. The acceleration jets
have critical diameters calculated by the-manufacturer to provide the necessary changes in velocity to
effect correct particle size fractionation within the impaction chambers. The air flow finally exits the inlet
through nine vent tubes onto a sample filter. Because air velocities are critical to maintain the correct
particle size cutpoint within the inlet, maintaining the correct design flow rate through the inlet is
important. This design flow rate is specified by the manufacturer in the instruction manual. For
example, the design flow rate for one popular impaction inlet is 1.13 m^/rnin.
7.1.1.2 The omnidirectional cyclone inlet (see Figure 5) used for fractionation allows particles to
enter from all angles of approach. A angular velocity component is imparted to the sample air stream
and the particles contained in it by a series of evenly spaced vanes. Larger particle removal occurs in
an inner collection tube. This tube incorporates a "perfect absorber," an oil-coated surface to eliminate
particle bounce and reentrainment. The sample flow (with the unremoved smaller particles) then enters
an intermediate tube, where the trajectory is altered to an upward direction. An additional turn is then
made to alter the flow to a downward trajectory to allow the remaining particles (i.e., PM1Q fraction)
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-9
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
ultimately to deposit on a filter for subsequent analysis. As with the impaction inlet, control of air
velocities in the cyclonic inlet is critical to maintain the correct particle size cutpoint. Maintaining the
correct design volumetric flow rate through the inlet is important. This design flow rate is specified by
the manufacturer in the instruction manual. For example, as in the case of the impaction inlet, a popular
cyclonic inlet also has a design flow rate of 1.13 nrVmin.
7.1.2 Total suspended particulate (TSP). As illustrated in Figure 2, particles of less than 100 /*m
are collected at a flow rate of 1.13-1.70 m3/min (40-60 ft3/min) using the conventional high-volume
sampler, without size selection.
7.2 Summary of Calibration Procedures
[Note: During calibration, a closure plate perforated with a number of circular orifices is connected to
the inlet of the sampler. The pressure drop across this orifice plate provides a measure of instrument air
flow rate at any time. This pressure drop may be indicated by a rotameter, manometer, or other
pressure-responsive device traceable to an NIST certified standard.]
7.2.1 A simple and sufficiently accurate method of calibrating is to compare the sampler meter with
an orifice meter (working standard) that has been calibrated against a primary or master standard such
as a Root's meter.
7.2.2 The preferable primary standard is a Roots Meter® of sufficient capacity to allow an accurate
time-volume reading, which would be at least 30 s.
7.2.3 A positive displacement pump or blower may be used as a master flow-rate standard. In this
case, the delivery rate of the master standard must be known accurately and the equipment must be in
sound mechanical condition (no bypass leakage).
7.3 Certification of an Orifice Transfer Standard
[Note,: The following certification procedure is applicable to an orifice transfer standard such as those
that have been used previously in the calibration of both the traditional HV sampler and the PMjQ
samplers. T\vo common types of orifice devices are available: one equipped with a set affixed resistance
plates (e.g., a reference flow [Reff device or a top-hat orifice) and one vith an externally variable
resistance valve. The series of plates normally provided by the orifice manufacturer include an 18-, 13-,
10-, 7-, and 5-hole plate. Unfortunately, the 5-hole plate provides too low a flow rate to be useful for
HV calibration, and other plates may produce flow rates substantially outside the design flow-rate range
of the commercially available HV inlets. One may opt to fabricate or procure a different series of
resistance ranges or use the variable-resistance type orifice device.]
7.3.1 Orifice Calibration Procedure.
7.3.1.1 Assemble the following equipment (see Figure 6):
• Orifice transfer standard (i.e., top-hat orifice, variable orifice, or ReF device) to be calibrated.
• Water or oil manometer with a 0 the 400 mm (0-16") range and minimum scale divisions of
1 mm (0.1"). This manometer should be permanently associated with the orifice transfer
standard.
• Variable voltage transformer, a set of resistance plates, or available flow orifice (see Figure 7).
* Calibrated positive displacement, standard volume meter (such as a Roots Meter®) traceable to
National Institute of Standards and Technology (NIST).
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
(Note: As they are sold, standard volume meters may not be traceable to NIST. Traceability
can be established directly through NIST or indirectly through the meter manufacturer's repair
department. Periodic recertification is not normally required under clean service conditions
unless the meter has been damaged and must be repaired. In general, damage will be indicated
by a substantial (e.g., 50%) increase in the pressure drop across the meter. The meter's
traceability certificate should contain a graph of the pressure drop as a function of flow rate.]
• High-volume air mover (e.g., a blower motor from a HV sampler).
• Accurate stopwatch.
• Mercury manometer, with a 0-200 mm (0-8") range and minimum scale divisions of 1 mm
(0.1").
• Thermometer, capable of accurately measuring temperatures over the range of 0-50°C (273-323
K) to the nearest +1 °C and referenced to an NIST or ASTM thermometer within +2°C at least
annually.
• Barometer, capable of accurately measuring ambient barometric pressure over the range of 500-
800 mm Hg (66-106 kPa) to the nearest mm Hg and reference within ±5 mm Hg of a
barometer of known accuracy at least annually.
• Orifice transfer standard certification worksheet (see Figure 8).
7.3.1.2 Record on the orifice transfer standard certification worksheet the standard volume meter's
serial number; orifice transfer standard's type, model, and serial number; the person performing the
certification; and the date.
7.3.1.3 Observe the barometric pressure and record it as Pa. Read the ambient temperature in
the vicinity of the standard volume meter and record it as Ta (K = °C + 273).
7.3.1.4 Connect the orifice transfer standard to the inlet of the standard volume meter. Connect
the mercury manometer to measure the pressure at the inlet of the standard volume meter. Connect the
orifice (water or oil) manometer to the pressure tap on the orifice transfer standard. Connect a
high-volume air mover to the outlet side of the standard volume meter. Make sure that all gaskets are
present and are in good condition.
7.3.1.5 Check that the standard volume meter table is level and adjust its legs if necessary.
7.3.1.6 Check for leaks by temporarily clamping both manometer lines (to avoid fluid loss) and
blocking the orifice with a large-diameter rubber stopper, wide duct tape, or other suitable means. Start
the high-volume air mover and note any change in the standard volume meter's reading. The reading
should remain constant. If the reading changes, locate any leaks by listening for a whistling sound and/or
retightening all connections, making sure that all gaskets are properly installed.
[Note: Avoid running the sampler for longer than 30 sat a time with the orifice blocked. This precaution
will reduce the chance that the motor will be overheated due to the lack of cooling air. Such overheating
can shorten the motor's lifetime; it can raise temperatures to the point of defeating the electrical
insulation which could result in fire or electric shock to the user.}
7.3.1.7 After satisfactorily completing the leak check, turn off the high-volume air sampler,
unblock the orifice, and unclamp both manometer lines. Zero the water and mercury manometers by
sliding their scales so that their zero lines are even with the bottom of the meniscuses.
7.3.1.8 Turn on the high-volume air sampler. Adjust the variable voltage transformer to achieve
an appropriate flow rate (i.e., within the approximate range of 0.9-1.3 m3/min (32-46 ft3/min)). If
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Method 10-2.1 ChaPter I0-2
Integrated Sampling for SPM High Volume
necessary, use fixed resistance plates or the variable resistance valve to achieve the appropriate flow rate
(see Figure 7). The use of fixed resistance plates is discouraged (but not prohibited) because the leak
check must be repeated each time that a plate is installed.
73.1.9 After setting a flow rate, allow the system to run for at least 1 min to attain a constant
motor speed. Observe the standard volume meter dial reading and simultaneously start the stopwatch.
Error in reading the meter dial can be minimized by starting and stopping the stopwatch on whole number
dial readings (e.g., 4091.00).
7.3.1.10 Record the initial volume that the meter dial indicated when the stopwatch was started.
Maintain this constant flow rate until at least 3 m3 of air have passed through the standard volume meter.
Record the standard volume meter's inlet pressure manometer reading as AHg and the orifice manometer
reading as AH2O. If Afi^O changes significantly during the run, abort the run and start again.
7.3.1.11 When at least 3 m3 of air have passed through the system, note the standard volume
meter reading and simultaneously stop the stopwatch. Record the final volume that the meter dial was
indicating when the stopwatch was stopped. Record the elapsed time ( Time) indicated on the stopwatch.
7.3.1.12 Calculate the volume measured by the standard volume meter ( Vol.) using the following
equation:
A Vol. = Final Volume - Initial Volume
7.3.1.13 Correct this volume to ambient atmosphere pressure.
Va = A Vol. (Pa - A Hg)/Pa
where:
•i
Va = actual volume at ambient barometric pressure, m .
A Vol. = actual volume measured by the standard volume meter, m3.
Pa = ambient barometric pressure during calibration, mm Hg.
A Hg = differential pressure at inlet to volume meter, mm Hg.
7.3.1.14 Calculate the actual volumetric flow rate (m3/min).
Qa = Va/A Time
where:
Qa = actual volumetric flow rate through the orifice, m3/min.
A time = elapsed time, min.
7.3.1.15 Repeat Sections 7.3.1.8 through 7.3.1.14 for at least four additional flow rates within
the approximate range of 0.9-1.3 m3/min (32-46 ft3/min). At least five evenly distributed different flow
rates are required, and at least three flow rates must be in the specified inlet flow-rate interval
(1.02-1.24 nrVmin [36-44 ft3/min]). Better calibration precision may be obtained by running additional
flow rates or repeating the flow rates.
7.3.1.16 For each flow, compute [(A H2O)(Ta/Pa)]1/2, and plot these values against the
corresponding values of Qa. Draw the orifice transfer standard's certification curve. For the model
[(A H2O)(Ta/Pa]1/2 = m (Qa) + b, calculate the linear least squares regression's slope (m), intercept
(b), and correlation coefficient (r) of the certification relationship. Plot the regression line on the same
Page 2.1-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
graph as the calibration data, as illustrated in Figure 9. A certification graph should be readable to
0.02 m3/min.
7.3.1.17 If any calibration point does not fall within ±2% of the line, rerun the point, recalculate,
and replot.
7.3.1.18 For subsequent use of the orifice transfer standard, calculate Qa from the calibration
relationship as:
Qa(orifice) = {[(A H2O)(Ta/Pa)]1/2 - b} {1/m}
where:
Qa(orifice) = actual volumetric flow rate as indicated by the orifice transfer standard, nvVmin
A H2O = pressure drop across the orifice, mm H2O.
Ta = ambient temperature during use, K (K = °C + 273).
b= intercept of the orifice calibration relationship.
m = slope of the orifice calibration relationship.
7.3.2 Orifice Transfer Standard Calibration Frequency. Upon receipt and at 1-yr intervals, the
calibration of the orifice transfer standard should be certified with a standard volume meter (such as a
Roots Meter®) traceable to NIST. An orifice transfer standard should be visually inspected for signs of
damage before each use and should be recalibrated if the inspection reveals any nicks or dents.
7.4 Procedure for a Mass-Flow-ControHed (MFC) High Volume Sampler
The MFC sampler calibration procedure presented in this section relates known flow rates to the pressure
in the exit orifice plenum. The known flow rates are determined by an orifice transfer standard that has
been certified according to the procedure presented in Section 7.3.1. The exit orifice plenum is the area
within the motor housing (below the motor unit) that contains the air flow just before it is exhausted to
the atmosphere through the exit orifice. This exit orifice plenum pressure should be measured with a
25-cm (10") water or oil manometer. Also, each sampler should have its own dedicated manometer,
which can be conveniently mounted to the side of the sampler housing. Other types of pressure
measurement devices may be used provided they have comparable accuracy. The 4" continuous pressure
(flow) recorders of the type often supplied with high volume PM^Q samplers are generally not sufficiently
accurate and are not recommended for quantitative sampler pressure or flow measurements. These flow
recorders should be used only for nonquantitative determination that the flow was approximately constant
and uninterrupted over the sample period. The flow recorder may be connected in parallel with the
manometer or other pressure measuring device, using a tee or "y" tubing connection. For this MFC
calibration procedure, the following conditions are assumed:
• The high volume PM10 sampler is equipped with a mass flow controller to control its sample'flow
rate.
• The sampler flow rate is measured by measuring the exit orifice plenum pressure, using a water
or oil manometer [or, if necessary, a continuous-flow recording device using square-robt-scale
chart paper].
• The transfer standard for the flow-rate calibration is an orifice device equipped with either a series
of resistance plates or an integral variable-resistance valve. The pressure drop across the orifice
is measured by an associated water or oil manometer.
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
[Note: Because flow recorders are still widely used for quantitative flow measurements, the calibration
procedure includes specific instructions for quantitatively calibrating a flow recorder. These flow
recorder instructions are enclosed in brackets [] and should be used only when a manometer or other
pressure measurement device cannot be used.]
7.4.1 Calibration Equipment. .
7.4.1.1 Orifice transfer standard with calibration traceable to NIST (see Section 7.3).
7.4.1.2 An associated water or oil manometer, with a 0-400 mm (0-16") range and an minimum
scale division of 2 mm (0.1")
[Note: Digital manometers may also be used in place of water or oil manometers, especially in
cold/frigate climates. Ensure the battery in the manometer is new before use.]
7.4.1.3 A water or oil manometer, with a 0-400 mm (0-16") range and a minimum scale division
of 2 mm (0.1") for measurement of the sampler exit orifice plenum pressure. This manometer should
be associated with the sampler.
\Note: Manometers used for field calibration may be subject to damage or malfunction and should thus
be checked frequently.]
7.4.1.4 Thermometer, capable of accurately measuring temperature over the range of Or50°C
(273-323 K) to the nearest ±1 °C and referenced to an NIST or ASTM thermometer within ±2 °C at
least annually.
7.4.1.S A portable aneroid barometer (e.g., a climber's or engineer's altimeter) capable of
accurately measuring ambient barometric pressure over the range of 500-800 mm Hg (66-106 kPa) to the
nearest mm Hg and referenced within ±5 mm Hg of a barometer of known accuracy at least annually.
7.4.1.6 Miscellaneous handtools, calibration data sheets or station log book, and 51 mm (2") duct
tape.
7.4.2 Multipoint Flow-Rate Calibration. The procedure presented here is basic and generic, given
the assumptions listed in Section 7.4. More detailed calibration procedures, variations, or alternative
procedures may be presented in the manufacturer's instruction manual. The manual should be reviewed
carefully and the various calibration variations or alternative procedures should be evaluated. In-house
equipment and personnel, procedural simplicity and uniformity, and subsequent data applications should
be considered in establishing the specific, detailed calibration procedure to be implemented.
[Note: Do not attempt to calibrate the MFC sampler under windy conditions. Short-term wind velocity
fluctuations will produce variable pressure readings by the orifice transfer standard's manometer. The
calibration will be less precise because of pressure variations.]
7.4.2.1 Set up the calibration system as recommended by the manufacturer. A typical MFC PM JQ
sampler calibration configuration is illustrated in Figure 10. MFC samplers are calibrated without a filter
or filter cassette installed.
7.4.2.2 Disconnect the motor from the flow controller and plug it directly into a stable line voltage
source (i.e., the sampler's on-off timer, if so equipped, or other source of the line voltage).
Page 2.1-14 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
7.4.2.3 Install the orifice transfer standard and its adapter faceplate on the sampler. Check all
gaskets and replace any questionable ones.
[Note: Tighten the faceplate nuts evenly on alternate comers to properly align and seat the gaskets. The
nuts should be only hand-tightened because too much compression can damage the sealing gasket.]
7.4.2.4 Select the first calibration flow rate and install the appropriate resistance plate or adjust
the variable orifice valve. At least four flow rates are required to define the calibration relationship. For
resistance plate orifices, make sure that the orifice and resistance plate gaskets are in place and the orifice
is not cross-threaded on the faceplate.
7.4.2.5 To leak check, block the orifice with a large-diameter rubber stopper, wide duct tape, or
other suitable means. Seal the pressure port with a rubber cap or similar device. Turn on the sampler.
Gently rock the orifice transfer standard and listen for a whistling sound that would indicate a leak in the
system. A leak-free system will not produce an upscale response in the sampler's exit orifice manometer
or flow recorder. Leaks are usually caused either by a damaged or missing gasket between the orifice
transfer standard and the faceplate or by cross-threading of the orifice transfer standard on the faceplate.
All leaks must be eliminated before proceeding with the calibration. When the system is determined to
be leak-free, turn off the sampler and unblock the orifice.
[Note: Avoid running the sampler for longer than 30 sat a time with the orifice blocked. This precaution
will reduce the chance that the motor will be overheated due to the lack of cooling air. Such overheating
can shorten the motor's lifetime and can raise temperatures to the point of defeating the electrical
insulation, which could result in fire or electric shock to the user.]
7.4.2.6 Inspect the connecting tubing of both manometers for crimps or cracks. Open the
manometer valves (if present) and blow gently through the tubing, watching for the free flow of the fluid.
Adjust the manometers' sliding scales so that their zero lines are at the bottom of the meniscuses.
Connect the orifice transfer standard manometer to the orifice transfer standard. Connect the sampler's
exit orifice manometer [and the continuous-flow recorder, if used] to the exit orifice plenum port. Ensure
that one side of each manometer is open to atmospheric pressure. Make sure that the tubing fits snugly
on the pressure ports and on the manometer.
7.4.2.7 If a continuous flow recorder is to be used quantitatively in lieu of a manometer, record
the site location, sampler S/N, date, and the operator's initials on the blank side of a clean recorder chart.
Make sure the chart has a square-root scale. Open the front door of the sampler and install the clean
recorder chart.
7.4.2.8 Read and record the following parameters on the HV data sheet. An example calibration
data sheet for the MFC sampler is illustrated in Figure 11.
• Date, location, and operator's signature.
• Sampler S/N and model.
• Ambient Pa, mm Hg.
• Ambient temperature (Ta), K (K = °C + 273).
• Orifice S/N and calibration relationship.
[Note: Consistency of temperature and barometric pressure units is required. All temperatures should
be expressed in kelvin (K = °C + 273). Also, all barometric pressures should be expressed in
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-15
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM High Volume
mm Hg. Avoid calibrating a sampler using one set of units and then performing sampler calculations
using another set.]
[Note: Ideally, the temperature of the air in the exit orifice plenum should be measured because it mil
be somewhat higher than ambient temperature. However, an adequate approximation of this temperature
may be obtained by adding 30 K to the ambient temperature. This addition is incorporated in the
calculations given in Section 7.4.3..]
7.4.2.9 Turn on the sampler and allow it to warm up to operating temperature (3-5 min). Then
read and record the orifice transfer standard's manometer deflection, A H2O (in. H2O), and the
corresponding sampler's manometer deflection, A Pex [or flow recorder chart reading, I].
[Note: The sampler inlet may be partially lowered over the orifice transfer standard to act as a draft
shield (if a shield is not otherwise provided). Use a block to provide at least 2" of clearance at the
bottom for airflow and for the manometer tubing.]
7.4.2.10 Install the other resistance plates or adjust the variable orifice value to obtain each of the
other calibration flow rates and repeat Section 7.4.2.9 for each. At least four calibration flow rates are
required.
7.4.2.11 Plot the calibration data on a sheet of graph paper as specified in Section 7.4.3.4.
Mote: The data should be plotted in the field as the calibration is occurring, rather than afterwards back
at the laboratory.]
Repeat Section 7.4.2.9 for any data that are questionable on the plot.
[Note: Running additional calibration points at differing flow rates or repeating the calibration points
at the same flow rates is encouraged to improve the precision of the calibration.]
7.4.2.12 Turn off the sampler and remove the orifice transfer standard.
7.4.2.13 Reconnect the sampler motor to the flow controller.
7.4.2.14 Perform the calibration calculations presented hi the following section. The data
generated will be used to set the mass flow controller (see Section 7.4.4) to a value that will result in
optimal volumetric flow based on the seasonal average temperature and barometric pressure at the
monitoring site.
7.4.3 Calibration Calculations. Gather all calibration data, including the orifice calibration
information and the sampler calibration data sheet (and, if used, the flow recorder chart, which stiould
graphically display the various calibration flow rates).
[Note: These calculations should be done at the time of the calibration, rather than later. This approach
will allow additional calibration points to be taken if questions arise about the data that have already
been obtained.]
7.4.3.1 Verify that the orifice transfer standard calibration relationship is current and traceable
to an acceptable primary standard.
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Chapter IO-2 Method IO_2J
High Volume Integrated Sampling for SPM
7.4.3.2 Calculate and record Qa for each calibration point from the orifice calibration information
using the following equation.
Qa(orifice) = {A H2O(Ta/Pa)]1/2 - b} {1/m} where:
Qa(orifice) = actual volumetric flow rate as indicated by the transfer standard orifice, m3/min
A H2O = pressure drop across the orifice, in. H2O.
Ta = ambient temperature during use, K (K = °C + 273).
Pa = ambient barometric pressure during use, mm Hg.
b = intercept of the orifice calibration relationship.
m = slope of the orifice calibration relationship.
7.4.3.3 Calculate and record the quantity for each calibration point as:
A Pext = [A Pex(Ta+30)/Pa]1/2
where:
A Pext = transformed manometer reading.
A Pex = sampler manometer reading, in. H2O Ta = ambient temperature, K (K = °C +273).
Pa = ambient barometric pressure, mm Hg.
[If a continuous-flow recorder is used quantitatively, calculate and record the quantity [It] as follows:
Pt] = I[Ta+ 30)/Pa]I/2
where:
[It] = transformed flow recorder chart reading.
I = flow recorder chart reading, arbitrary units on square root scale.
[Note: If recorder charts with linear scales are used, substitute (I)l/2 for I in the above equation.]
7.4.3.4 On a sheet of graph paper, plot the calculated Qa(orifice) flow rates on the x-axis and the
transformed sampler manometer response, A Pext [or the transformed flow recorder reading Itl on the
y-axis.
Because determining the sampler's average operational flow rate (Qa) during a sample period depends
on the ambient average temperature and pressure, using a graphic plot of the calibration relationship is
not recommended for subsequent data reduction. This plot is used only to visually assess the calibration
points to see if any should be rerun. Plot the regression line on the same graph paper as the calibration
data. For the regression model y = mx + b, let y +2 A Pext and x = Qa(Orifice) so that the model
is given by:
A Pext = m[Qa(orifice)] + b
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Method 10-2.1 !
Integrated Sampling for SPM _ High Volume
For the flow recorder, the model is:
It = m[Qa(orifice)] + bj
Using a programmable calculator or a'calculation data form, determine the linear regression slop (m),
intercept (b), and correlation coefficient (r) and record them on the data sheet. A five-point calibration
should yield a regression equation with a correlation coefficient of r > 0.990, with no point deviating
more than ±0.04 m3/min from the value predicted by the regression equation. Plot the regression line
on the same graph paper that has the individual calibration points.
7.4.3.5 For subsequent sample periods, the sampler's average actual operational flow rate, Qa,
is calculated from the calibration slope and intercept using the equation.
Qa = {A Pex(Tav+30)/Pav]1/2 - b} {1/m}
where:
tja = the sampler's average actual flow rate, nrVmin.
A Pex = average of initial and final sampler manometer readings (A Pexj + A Pexf), mm Hg.
Tav = average ambient temperature for the sample period, K(K=°C-t-273).
pav = average ambient pressure for the sampling period, mm Hg.
b = intercept of the sampler calibration relationship.
m= slope of the sampler calibration relationship.
[For the flow controller,
TJa" = (I (Tav + 30)/Pav]1/2 - b} {1/m}
where:
I = average flow recorder reading for the sample period.]
mote: If recorder charts with linear scales are used, substitute (I)l/2for (I) in the above equation.]
7.4.4 Mass Flow Controller Adjustment Procedure. The controlled flow rate of an MFC sampler
is adjustable and must be set to the proper design flow rate. The constant mass flow maintained by the
MFC causes the actual volumetric flow rate through the inlet to fluctuate as the ambient temperature and
barometric pressure change at the monitoring site. Normally, the range of these fluctuations is within
the allowable tolerance limits for the inlet. However, the flow-rate set point of the mass flow controller
must be correctly adjusted so that the deviations are "centered" with respect to the seasonal average
temperature and barometric pressure at the site, not the temperature and pressure prevailing at the time
of setting. The correct seasonal volumetric setpoint flow rate (SFR) at Ta and Pa has had the same mass
flow rate as the inlet design volumetric flow rate at Ts and Ps.
[Note; The correct SFR may differ from day to day and may be somewhat higher or lower than the inlet
design flow rate on any particular day.]
Page 2.1-18 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume ^^ Integrated Sampling for SPM
7.4.4.1 Determine the seasonal average temperature (Ts) and seasonal average pressure (Ps) at
the site and record them on the calibration data sheet. (Determination of the number of "seasons," i.e.,
the number of different seasonal average temperatures needed for the year, is left to the discretion of the
operator.)
7.4.4.2 Calculate SFR and record on the calibration data sheet:
SFR = (1.13) (Ps/Pa)(Ta/Ts)
where:
SFR = set-point actual volumetric flow rate for adjustment of the mass flow controller, based on
seasonal average temperature and average pressure at site, nrVmin.
1.13 = inlet design flow rate (as specified by the manufacturer), nrVmin.
Ps, Pa = seasonal average and current ambient barometric pressure at the site, respectively, mm
Hg.
Ts, Ta = seasonal average and current ambient temperature, respectively, K (K = °C + 273).
7.4.4.3 Calculate and record on the sampler's calibration data sheet the sampler set-point
manometer reading [or flow recorder reading] that corresponds to the SFR calculated in Section 7.4.4.2.
SSP = [Pa/(Ta + 30)][m(SFR) +b]2
where:
SSP = sampler set-point manometer reading, in H^O.
Pa = ambient barometric pressure, mm Hg.
Ta = ambient temperature, K (K = °C + 273).
m = slope of the sampler's calibration relationship.
SFR = set-point flow rate from 7.4.4.2, nvVmin.
b = intercept of the sampler's calibration relationship.
[For the flow recorder,
SSP = [m(SFR) + b] [Pa/(Ta+30)]1/2]
7.4.4.4 Visually check to make sure the motor is connected to the mass flow controller and the
manometer is properly connected.
7.4.4.5 Install a clean filter (in a filter cassette) in the sampler according to the manufacturer's
instructions. [If the continuous flow recorder is used quantitatively, install a clean chart and verify that
the recorder is zeroed (i.e., the pen rests on the innermost circle of the chart).]
7.4.4.6 Turn on the sampler and allow it to warm up to operating temperature (3-5 min).
7.4.4.7 Following the manufacturer's instructions, adjust the mass flow controller until the
manometer reading [or flow recorder response] indicates the sampler set point (SSP) as calculated in
Section 7.4.4.3.
7.4.4.8 Verify that the flow controller will maintain this flow rate for at least 10 min. Turn off
the sampler.
7.4.4.9 The sampler can now be prepared for the next sample run day.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-19
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Method 10-2.1 Chapter I0-2
Integrated Sampling for SPM High Volume
7,5 Procedure for a Volumetric-Flow-Controlled (VFC) Sampler
The WC sampler calibration procedure presented in this section relates known flow rates (Qa, as
determined by an orifice transfer standard) to the ratio of the stagnation pressure to the ambient
barometric pressure (Pi/Pa). The stagnation pressure (PI) is the air pressure inside the sampler in the area
just under the filter. VFC samplers have a stagnation pressure tap or port through which the stagnation
pressure can be measured. A VFC sampler may also have an exit orifice below the motor similar to
those in MFC samplers. In this case, the sampler flow rate can be measured and calibrated using the exit
orifice plenum pressure generally described in Section 7.4. However, using the stagnation pressure
generally provides a more accurate indication of sampler flow rate. Additionally, a continuous-flow
recorder may be connected to the exit orifice pressure tap for nonquantitative determination that the flow
rate was constant and uninterrupted over the sample period.
The stagnation pressure should be measured with a 0-1000 mm (0-36") oil, water, or digital manometer.
Also, each sampler should have its own dedicated manometer, which can be conveniently mounted to the
side of the sampler housing. Other types of pressure measurement instruments may be used provided
they have comparable accuracy. However, the 4" continuous pressure (i.e., flow) recorders often
supplied with HV samplers are generally not sufficiently accurate and are not recommended for
quantitative sampler pressure or flow rate measurements.
The VFC sampler's flow control system is a choke-flow venturi. This system must be precisely sized
for a given average annual temperature and pressure because no means is provided for the user to adjust
the operational flow rate. Therefore, the purchasing agency should notify the manufacturer of the
operational location of the sampler; differences in temperature and pressure between the shipping address
and the monitoring site may result in an incorrect operational flow rate. As with the MFC sampler, both
the ambient temperature and barometric pressure readings must be determined or estimated during the
sampling period for the subsequent calculation of total sampler volume in standard volume units.
For this VFC calibration procedure, the following conditions are assumed:
• The VFC sampler uses a choked-flow venturi to control the actual volumetric flow rate.
• The sampler flow rate is measured by measuring the stagnation pressure ratio, and the sampler is
not equipped with a continuous flow recorder. -
• The sampler inlet is designed to operate at a constant actual volumetric flow rate of 1,13 m /min.
• The transfer standard for the flow-rate calibration is an orifice device equipped with either a series
of resistance plates or an integral variable-resistance valve. The pressure drop across the orifice
is measured by an associated water or oil manometer.
• The sampler will be calibrated in actual volumetric flow-rate units (Qa), and the orifice transfer
standard is also calibrated in Qa, as specified in Section 7.3.
7.5.1 Calibration Equipment.
7.5.1.1 Orifice transfer standard with proper calibration traceable to NIST (see Section 7.3).
7.5.1.2 An associated water, oil, or digital manometer, with a 0-400 mm (0-16") range and
minimum scale divisions of 2 mm (0.1").
7.5.13 An oil, water, or digital manometer, with a 0-1000 mm (0-36") range and minimum scale
divisions of 2 mm (0.1") or other pressure measurement device for measurement of the sampler
stagnation pressure. Ideally, this manometer (or other pressure instrument) should be associated with the
sampler.
Page 2.1-20 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
[Note: Manometers used for field calibration may be subject to damage or malfunction and should thus
be checked frequently.]
7.5.1.4 Thermometer, capable of accurately measuring temperature over the range of 0-50°C
(273-323 K) to the nearest ± 1 °C and referenced to an NIST or ASTM thermometer within ±2°C at least
annually.
7.5.1.5 A portable, aneroid barometer (e.g., a climber's or engineer's altimeter) capable of
accurately measuring ambient barometric pressure over the range of 500-800 mm Hg to the nearest
mm Hg and referenced within ±5 mm Hg to a barometer of known accuracy at least annually.
7.5.1.6 Calibration-data sheets or the station log book and 51 mm (2")-wide duct tape.
7.5.1.7 A clean filter.
7.5.2 Multipoint Flow-Rate Calibration Procedure - VFC Sampler. The procedure presented here
is basic and intended to be generic, given the assumptions listed in Section 7.5. More detailed calibration
procedures, variations, or alternative procedures may be presented in the manufacturer's instruction
manual. The manual should be reviewed carefully and that the various calibration variations or
alternative procedures be evaluated. In-house equipment and personnel, procedural simplicity and
uniformity, and subsequent data applications should be considered in establishing the specific, detailed
calibration procedure to be implemented.
[Note: The calibration of some VFC samplers may be affected by changes in line voltage, particularly if
the line voltage is below normal (normal is about 115 V). For this reason, VFC samplers should always
be calibrated at the monitoring site. Further, if the line voltage at the site is low and likely to fluctuate
significantly, a line voltage booster or regulator may be advisable. Also, be sure that replacement blower
motors are of the correct type.]
[Notej_ Do not attempt to calibrate the VFC sampler under windy conditions. Short-term velocity
fluctuations will produce variable pressure readings by the orifice transfer standard's manometer. The
calibration will be less precise because of the pressure variations.]
7.5.2.1 Set up the calibration system as recommended by the manufacturer. A typical VFC
sampler calibration configuration is illustrated in Figure 12. The VFC samplesmanufacturer may specify
that the sampler be calibrated with a filter installed, which generally precludes calibration flow rates
higher than normal operating flow rate. Additional calibration flow rates obtained without a filter may
be appropriate, as discussed in Section 7.5.2.8.
7.5.2.2 Install the orifice transfer standard and its adapter faceplate on the sampler. First inspect
all gaskets and seals and replace any doubtful ones.
[Note± Tighten the faceplate nuts evenly on alternate corners to properly align and uniformly seat the
gaskets. The nuts should be hand-tightened only; too much compression can damage the sealing gasket.]
7.5.2.3 Select a calibration flow rate and install the appropriate resistance plate (or no plate) or
adjust the variable resistance valve. At least four flow rates are required to define the calibration
relationship At least three flow rates should be within the acceptable flow-rate range (i.e.,
1.02-1.24m /min) for the sampler inlet. For resistance plate orifices, make sure the orifice and
resistance plate gaskets are in place and the orifice is not cross-threaded on the faceplate.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-21
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
7.5.2.4 Leak check the system by blocking the orifice with a large-diameter rubber stopper, wide
duct tape, or other suitable means. Seal the pressure port with a rubber cap or similar device. Turn on
the sampler. Gently rock the orifice transfer standard and listen for a whistling sound that would indicate
a leak in the system. Leaks are usually caused either by a damaged or missing gasket between the orifice
transfer standard and the faceplate or by crossthreading of the orifice transfer standard on the faceplate.
All leaks must be eliminated before proceeding with the calibration. When the system is determined to
be leak-free, turn off the sampler and unblock the orifice.
[Note: Avoid running the sampler for longer than 30 sat a time with the orifice blocked. This precaution
mil reduce the chance that the motor will be overheated due to the lack of cooling air. Such overheating
can shorten the motor's lifetime. It can raise temperatures to the point of defeating the electrical
insulation, which could result in fire or electric shock to the user.]
7.5.2.5 Inspect the connecting tubing of the manometers for crimps or cracks. Open the
manometer valves (if present) and blow gently through the tubing, watching for the free flow of the fluid.
Adjust the manometers' sliding scales so that their zero lines are at the bottom of the meniscuses.
Connect the transfer standard manometer to the transfer standard and the sampler stagnation pressure
manometer (or other pressure instrument) to the stagnation pressure port. Ensure that one side of each
manometer is open to atmospheric pressure. Make sure the tubing fits snugly on the pressure ports and
on the manometers.
7.5.2.6 Read and record the following parameters on the VFC Sampler Data Sheet. An example
calibration data sheet for the VFC sampler is illustrated in Figure 13.
• Date, location, and operator's signature.
• Sampler S/N and model.
• Ambient barometric pressure (Pa), mm Hg.
• Ambient temperature (Ta), °C and K (K = °C + 273).
• Orifice S/N and calibration relationship.
[Note: Consistency of temperature and barometric pressure units is required. All temperatures should
be expressed in kelvin (K = °C + 273). Also, all barometric pressures should be expressed in mm Hg.
Avoid calibrating a HV sampler using one set of units and then performing sampler calculations using
another set.}
7.5.2.7 Turn on the sampler and allow it to warm to operating temperature (3-5 rain). Read and
record the orifice transfer standard's manometer reading, H2O, and the corresponding sampler relative
stagnation pressure manometer reading, Pstg, on the data sheet. (Relative stagnation pressure is a
negative pressure [i.g., a vacuum] relative to atmospheric pressure as measured by a manometer with one
leg open to the atmosphere.) Be sure to convert the manometer reading to mm Hg using the following
equation before recording the reading on the calibration data sheet:
mm Hg = 25.4 (in. H^O/lS.d)
[Note: The sampler inlet may be partially lowered over the orifice transfer standard to act as a draft
shield Of a shield is not otherwise provided). Use a block to provide at least 2" of clearance at the
bottom of airflow and for the manometer tubing).]
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Chapter IO-2 Method IQ-2.1
High Volume Integrated Sampling for SPM
7.5.2.8 Install the other resistance plates or adjust the variable orifice value to obtain each of the
other calibration flow rates and repeat Section 7.5.2.7 for each. At least four calibration flow rates are
required with at least three in the acceptable flow-rate range. Difficulties may be encountered in
obtaining flow rates in the acceptable range. Even with modified resistance plates (or with no plates)
installed, it may be impossible to obtain three acceptable flow rates with a filter mounted on the sampler.
Lower flow rate calibration points may be used by extrapolation into the acceptable range without a filter
installed in the sampler. If additional calibration points are obtained without a filter, they should be
examined carefully to make sure they are consistent with the calibration points obtained with a filter (i.e.,
they fall on a smooth curve through all the calibration points).
7.5.2.9 Plot the calibration data on a sheet of graph paper as specified in Section 7.5.3.5 of the
next section. Repeat Section 7.5.2.7 for any data that are questionable on the plot. Running additional
calibration points at differing flow rates or repeating the calibration points at the same flow rates is
encouraged to improve the precision of the calibration.
[Note: The data should be plotted in the field as the calibration is occurring, rather than afterwards back
at the laboratory.]
7.5.2.10 Turn off the sampler and remove the orifice transfer standard.
7.5.2.11 Install a clean filter on the sampler in the normal sampling mode (use a filter cassette if
one is normally used). Turn on the sampler and allow it to warm up to operating temperature.
7.5.2.12 Read the relative stagnation pressure as in Section 7.5.2.7 and record it on the data sheet
in the row for the operational flow rate.
7.5.2.13 Perform the calibration calculations presented in the following sections.
7.5.3 Calibration Calculations. Gather together all the calibration data, including the orifice transfer
standard's calibration information and the sampler calibration data sheet.
[Note: These calculations should be done at the time of the calibration, rather than later. This approach
mil allow additional calibration points to be taken if questions arise about the data that have already
been obtained.]
7.5.3.1 Verify that the orifice transfer standard calibration relationship is current and traceable
to an acceptable primary standard.
7.5.3.2 Calculate the record Qa(orifice) for each calibration point from the orifice calibration
information and the equation.
Qa(orifice) - {[A H2O(Ta/Pa)]1/2 - b} {I/m}
where:
Qa(orifice) = actual volumetric flow rate as indicated by the transfer standard orifice, m3/min.
A H2O = pressure drop across the orifice, in. HoO.
Ta = ambient temperature during use, K (K = °C + 273).
Pa = ambient barometric pressure during use, mm Hg.
b = intercept of the orifice transfer standard's calibration relationship.
m = slope of the orifice transfer standard's calibration relationship.
7.5.3.3 Calculate and record the value of the absolute stagnation pressure ratio, [PI], for each
calibration point:
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
[PI] = Pa - A Pstg
where:
[PI] = absolute stagnation pressure, mm Hg.
Pa = ambient barometric pressure^ mm Hg.
A Pstg = relative stagnation pressure* mm Hg.
7.5.3.4 Calculate and record the stagnation pressure ratio:
Stagnation pressure ratio = Pi/Pa
7.5.3.5 On a sheet of graph paper, plot the calculated orifice transfer standard's flow rates,
Qa(orifice), on the x-axis vs. the corresponding stagnation pressure ratios, Pi/Pa, on the y-axis. Draw
a smooth curve through the plotted data. If necessary, extrapolate the curve to include the acceptable
flow-rate range.
7.5.3.6 If the sampler manufacturer has provided a factory calibration table (i.e., the lookup table)
for the sampler, compare Qa(orifice) for several points on the calibration plot with Qa(sampler)
determined from the factory calibration. Calculate the percentage difference between Qa(orifice) and
Qa(sampler) using the following equation.
% Difference - Qa(sampler) - Qa(orifice) = [100]
Qa(orifice)
If the agreement is within a few (i.e., 2 or 4) percent, the factory calibration is validated and may be used
for sequent sample periods. Proceed to Section 7.5.5.
7.5.3.7 If the agreement is not within a few percentage points, recheck the accuracy of the orifice
transfer standard and recheck the calibration procedure. Look for leaks, manometer reading errors,
incorrect temperature or pressure data, or miscalculations. Also check for abnormally low line voltage
at the site (it should be at least 110 V ac), for the correct blower motor, and for the presence of a gasket
between the motor and the choked-flow venturi. A factory calibration is not likely to be substantially
incorrect, and any discrepancy of more than a few percent is probably due to some problem with the
sampler or with the calibration procedure. However, if no errors or problems with the sampler or with
the calibration can be found, or if no factory calibration is provided by the manufacturer, proceed as
described in Section 7.5.4.
7.5.4 Generation of Calibration Relationship - VFC Sampler.
7.5.4.1 For each calibration point, calculate and record the quantity,
[Pl/Pa)Ta]1/2
where:
Pi/Pa = stagnation pressure ratio from the equation in Section 7.5.3.
Ta = ambient temperature during sampler calibration, K (K = °C + 273).
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
7.5.4.2 For the general linear regression model, y = rax + b, let y = [(Pl/Pa)Ta]^ and let
x = Qa(orifice), such that the model is given by:
[(Pl/Pa)Ta]1/2 = m[Qa(orifice)] + b
Calculate the linear regression slope (m), intercept (b), and correlation coefficient (r).
[Note: Inspect the plotted calibration curve to determine whether any of the calibration points that are
substantially outside of the acceptable flow-rate range need to be eliminated so that they do not result in
an inappropriate linear regression line.] .
7.5.4.3 For subsequent sample periods, the sampler's average actual operating flow rate, Qa, is
calculated from the calibration slope and intercept using the following equation.
Qa(sampler) = {[PT/Pav)Tav]1/2 - b} {1/m}
where:
Qa(sampler) = the sampler's average actual flow rate, m3/min.
PT/Pav = average stagnation pressure ratio for the sampling period.
Tav = average ambient temperature for the sampling period, K (K = °C + 273).
b = intercept of the sampler calibration relationship.
m = slope of the sampler calibration relationship.
/Note: The average value for PI should be calculated from stagnation pressure measurements taken before
and after the sampling period. Pav should be estimated from barometric pressure for the sampling
period. See also Section 9.4 for additional information.]
7.5.4.4 If a calibration (Lookup) table is desired, evaluate the above equation for various
appropriate values of Pi/Pa and Ta and list the corresponding values of Qa(sampler) in tabular form.
7.5.5 Single-Point Operational Elowrate Ventilation. This procedure compares the VFC sampler's
normal operating flow rate to the design flow rate of the inlet (e.g., 1.13 rn^/min).
7.5.5.1 Determine the value of Pi/Pa for the operational flow rate obtained with only the filter
cassette installed (Section 7.5.2.11 and Section 7.5.2.12).
7.5.5.2 Determine the new sampler flow rate, Qa(sampler) from the lookup table that corresponds
to this value of Pi/Pa. Use the manufacturer's calibration table if it has been validated in 7.5.3.6;
otherwise, use the equation in Section 7.5.4.3.
7.5.5.3 Compare Qa(sampler) with the inlet design flow rate (e.g., 1.13 m^/min) using the
following equation:
Design flow rate % difference = Qa(satnpler) ~ L13 x 100
1.13
This design flow rate percentage difference must be less than the allowable flow rate tolerance (i.e., ± 10,
if not otherwise specified by the manufacturer). However, this value should be well within +7 to allow
for some variation with ambient temperature. If this value is not within ±7, recheck the calibration
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-25
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM High Volume
procedure and data for errors. Check the sampler for leaks, bad motor brushes, missing gaskets,
incorrect motor type, or abnormally low line voltage. Because the VFC flow rate is not adjustable, the
VFC manufacturer must be consulted to resolve cases of substantially incorrect VFC flow rates.
7.6 Sampler Calibration Frequency
To ensure accurate measurement calibrate HV samplers upon installation and recalibrate as follows:
7.6.1 At least quarterly or annually (see 40 CFR 58, Appendix A for a description of the quality
assurance requirements);
7.6.2 After any repairs that might affect sampler calibration (e.g., replacing the motor);
7.6.3 After relocation of the sampler to a different site;
7.6.4 If the results of a field flow-check exceed quality control limits (e.g., greater than ±7% from
the sampler's indicated flow rate); or
7.6.S Whenever a field flow-check or performance audit indicates that the sampler is out (or nearly
out) of the acceptable flow-rate range.
[ffote; Multipoint flow-rate calibrations should be distinguished from single-point, quality control flow
checks (see Section 13). The latter are done more frequently than calibrations and are intended to check
if the sampler flow rate, Qa(sampler), or the calibration relationship has changed significantly since the
last calibration.}
8. Filters
8.1 Filter Handling
8.1.1 Filter material may be brittle and subject to shearing and breakage. Laboratory and field
personnel must be aware of these characteristics and handle sample filters with care.
8.1.2 For convenience, filters can be packed in groups of 50 or less in their original containers or
in a box of comparable size. The filters should be separated by a sheet of 8 1/2 x 11" tracing paper.
Filter inventory can be controlled by stacking the filters in numerical order so that the operator will use
the proper filter first. One side of the shipping box can be cut away to allow the operator to remove the
filter easily without damaging the corners.
8.1.3 A filter identification number must be assigned to each filter. Because of difficulty in seeing
the "up" side (i.e., the side with the slightly rougher texture) of the filter, consistency in labeling these
filters will allow the operator easy access to the filter ID number for documentation and cross-referencing
laboratory data forms. This consistency will also eliminate confusion in loading the filter cassettes for
subsequent sampling. If the filter ID number is embossed by the operating agency, gentle pressure must
be used to avoid filter damage, and extreme care must be taken to avoid duplication or missed numbers.
8.1.4 If samples are to be mailed, the field operator should be supplied with reinforced envelopes and
manila folders for protection of the exposed filters during their return to the analytical laboratory. These
manila folders may be printed to serve as sample data sheets.
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
8.2 Visual Filter Inspection
All filters must be visually inspected for defects, and defective filters must be rejected if any are found.
Batches of filters containing numerous defects should be returned to the supplier.
The following are specific defects to look for:
• Pinhole - a small hole appearing as a distinct and obvious bright point of light when examined over
a light table or screen, or as a dark spot when viewed over a black surface.
• Loose material - any extra loose material or dirt particles on the filter that must be brushed off
before the filter is weighed.
• Discoloration - any obvious visible discoloration that might be evidence of a contaminant.
• Filter nonuniformity - any obvious visible nonuniformity in the appearance of the filter when
viewed over a light table or black surface that might indicate gradations in porosity across the face
of the filter.
• Other - a filter with any imperfection not described above, such as irregular surfaces or other
results of poor workmanship.
9. Sampling Procedure
[Note: This section describes routine operation of a monitoring site using an HV sampler and covers an
array of topics, ranging from initial site selection to final data documentation. The procedures herein
are intended to serve as guidelines for developing a monitoring program that will accurately reflect trends
in local or regional air quality. The effectiveness of the monitoring program depends on responsible
day-to-day operation of the monitoring site. The operators who conduct sampling activities offer a unique
perspective on the sampler's performance, and their awareness and attention to detail will salvage data
that may otherwise be lost. Note, however, that "routine" does not mean "unimportant." The site
operator provides cohesiveness in a sampling program.]
9.1 Summary
9.1.1 The PMjQ sampler can be used in a number of ways. Procedure variations may include the
kind of filter medium, the surface area of the filter, prescreening to exclude particles up to a given size,
and the manner of placing and exposing the filter during the test. The procedure most commonly used
will be described here.
9.1.2 Calibrate the sampler as described in the Section 7. Do not make any change or adjustment
on the sampler flow indicator after calibrating. Remove the calibrating orifice. The filters may be
packed into a box with sheets of glassine between the filters, or they may be individually packed in
self-sealing plastic bags for transportation to the field.
9.1.3 Mount the filter sheet in the filter holder taking care not to lose any of the fiber. Clamp it in
place by means provided. Seal into place easier by facing the smooth side into the housing if there is a
difference in texture. If the filter holder is separate from the sampler, mount the holder on the intake
port, making sure that the coupling gasket is in place and that it is tight.
9.1.4 Place the sampler in the position and location called for in the test, which is with the filter face
up, in a horizontal plane, and inside a housing. The dimensions and clearances specified are intended
to provide uniformity in sampling practice.
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM High Volume
9.1.5 Start the sampler motor and record the time and date. Read the flow-rate indicator and record
this reading and the corresponding flow rate as read from the calibration curve. Note also the
temperature and barometric pressure. An electric clock should be connected to the same line as the motor
so as to detect any loss of test time due to power interruption. A continuous record of the sampling flow
rate and sampling time can be obtained by the use of a continuous pressure (or flow rate) recorder.
9.1.6 Allow the sample to run for the specified length of time, which is commonly 24 h, ±1 h.
During this period several readings of flow rate, temperatures, barometric pressure, and time should be
taken if this is feasible. A final set of reading is taken at the end of the test period. If only initial and
final readings are made, assume that change of readings is linear over the period of test. Intermediate
readings will improve the accuracy of volume measurement.
9.1.7 At the end of the sampling period, record all final readings. Remove the filter from the mount
very carefully so as not to lose any of the fiber material or collected paniculate matter. Fold the filter
in half upon itself with the collected material enclosed within. Place the folded filter in a clean tight
envelope and mark it for identification. In some applications it may be desirable to place the used filter
in a tight metal container to prevent any loss or damage to the filter.
9.1.8 In the laboratory remove the filter from its container. Tap the container and knock any loose
fiber or paniculate matter onto the inside surface of the folded filter. Examine the inside surface and,
with a pair of tweezers, remove any accidental objects such as insects.
9.2 Siting Requirements
9.2.1 As with any type of air monitoring study in which sample data are used to draw conclusions
about a general population, the validity of the conclusions depends on the representativeness of the sample
data. Therefore, the primary goal of a monitoring project is to select a site or sites where the collected
paniculate mass is representative of the monitored area.
9.2.2 Basic siting criteria for the placement of high-volume sampler (either TSP or PMjg) are
documented in Table 1. This list is not a complete listing of siting requirements; instead, an outline to
be used by the operating agency to determine a sampler's optimum location. Complete siting criteria are
presented in 40 CFR 58, Appendix E.
9.2.3 Additional factors not specified in the Code of Federal Regulations (CFR) must be considered
in determining where the sampler will be deployed. These factors include accessibility under all weather
conditions, availability of adequate electricity, and security of the monitoring personnel and equipment.
The sampler must be situated where the operator can reach it safely despite adverse weather conditions.
If the sampler is located on a rooftop, care should be taken that the operator's personal safety is not
jeopardized by a slippery roof surface during inclement weather. Consideration also should be given to
the fact that routine operation (i.e., calibrations, filter installation and recovery, flow checks, and audits)
involves transporting supplies and equipment to and from the monitoring site.
9.2.4 To ensure that adequate power is available, consult the manufacturer's instruction manual for
the sampler's minimum voltage and power requirements. Lack of a stable power source can result in the
loss of many samples because of power interruptions.
9.2.5 The security of the sampler itself depends mostly on its location. Rooftop sites with locked
access and ground-level sites with fences are common. In all cases, the security of the operating
personnel as well as the sampler should be considered.
Page 2.1-28 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume ^ Integrated Sampling for SPM
9.3 Sampler Installation Procedures
9.3.1 On receipt of a high-volume sampler (TSP or PM10) from the manufacturer, visually inspect
it and account for all components. Compare the equipment delivered with the enclosed packing slip.
Notify the manufacturer immediately of any missing or damaged equipment.
9.3.2 Perform a laboratory check to determine if the sampler is operational. Turn on the sampler
and observe the vacuum motor performance and shift the recorder response (if so equipped).
9.3.3 Carefully transport the sampler to the field site. If possible, install the sampler in the center
of the site platform. This practice will ensure easy access to the sampler's inlet during maintenance
procedures and will reduce inlet damage if the sampler should topple over.
9.3.4 Following manufacturer's instructions, carefully assemble the base and inlet of the sampler.
The sampler must be bolted down to a secure mounting surface.
9.3.5 Check all tubing and power cords for crimps, cracks, or breaks.
9.3.6 Plug the power cord into a line voltage outlet. If possible, this outlet should be protected by
a ground fault interrupter (GFI) for the operator's safety. The use of waterproof interlocking electrical
connectors is also recommended to ensure operator safety and to avoid shorts or power interruptions.
Do not allow any electrical connections to be submerged during periods of inclement weather.
9.3.7 Turn on the sampler and make sure that it is still working properly. Investigate and correct
any malfunctions before proceeding. Operate the sampler for approximately 30 min to ensure that the
motor brushes are properly seated and that the motor is operating at full performance.
9.3.8 Perform a multipoint flow-rate calibration, as described in Section 7.
9.4 Sampling Operations
9.4.1 General.
9.4.1.1 Operational procedures will vary according to the sampler model and options (e.g., the
types of flow-rate controller and timer) selected for use in the monitoring program. Consult the
instrument manual before putting the sampler into operation. Significant differences exist in the field
operation of the two types of flow-controlling systems and, hence, in the determination of operational
flow rates. The following assumptions are made in this section:
• The flow rate through a sampler that is equipped with a mass-flow controller is indicated by the
exit orifice plenum pressure. This pressure is measured with a manometer (or a flow recorder).
• The flow rate through a sampler that is equipped with a volumetric-flow controller is indicated
by the stagnation pressure. This pressure is measured with a manometer.
• The sampler has been calibrated according to procedure presented in Section 7.
9.4.1.2 The sampler has been calibrated according to procedures presented in Section 7.
9.4.1.3 The average actual flow rate for MFC samplers is calculated by determining the following:
• The average of the initial and final manometer readings of the exit orifice plenum pressure (or
the average flow recorder reading).
• The average ambient temperature (Tav).
• The average ambient barometric pressure (Pav) during the sampling period.
These values are then applied to the sampler's calibration relationship. The 4" pressure flow recorders
often supplied with HV samplers generally are not sufficiently accurate and are not recommended for
quantitative sampler pressure or flow rate measurements. These flow recorders should be used only for
nonquantitative determination that the flow was approximately constant and uninterrupted over the
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-29
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Method 10-2.1 ChaPter I0-2
Integrated Sampling for SPM High Volume
sampling period. The flow recorder may be connected in parallel with the manometer or other pressure
measuring device using a tee or "Y" tubing connector.
[Mote: Because flow recorders are still widely used for quantitative flow rate measurements, the
procedures in this section include specific instructions for the use of a flow recorder. These flow recorder
instructions are enclosed in brackets.]
9.4.1.4 The average actual flow rate for VFC samplers is calculated by determining the following:
• The average of the initial and final relative stagnation pressures (Pstg).
• The average ambient temperature (Tav).
• The average barometric pressure (Pav) during the sampling period and then by applying these
values to the calibration relationship.
/TVbte.- Consistency of temperature and barometric pressure units is required. All temperatures should
be expressed in kelvin (K = °C + 273). Also, all barometric pressures should be expressed in either
mm Hg or kPa (but don't mix the two units). Avoid calibrating a PM1Q sampler using one set of units
and then performing sample calculations using another set.]
9.4.2 Presampling Filter Preparation Procedures.
9.4.2.1 Most high-volume samplers (TSP or PM1Q) have been designed to accept filter cassettes.
Loading these cassettes in the laboratory will minimize damage; however, if extreme care is exercised,
they can be loaded at the site when ambient conditions permit. Wear protective gloves when handling
filters to avoid contaminating the filters with body oils and moisture. Keep the filters in protective folders
or boxes. Never bend or fold unexposed filters. The analytical laboratory (and/or filter manufacturer)
will give each filter an ID number. Because it is extremely difficult to see the "up" side of a quartz filter
(i.e., the side with the slightly rougher texture), the filters should be consistently labeled on one side.
When a filter that has been labeled on its "down" side is folded for transport to the laboratory, its sample
number will be readily accessible for documentation on laboratory log sheets upon arrival at the
laboratory.
9.4.2.2 Following the manufacturer's instructions, carefully load the pre-weighted filter in the
filter cassette. The filter should be centered on the wire screen so that the gasket will form an airtight
seal on the outer edge of the filter when the faceplate is in place. Poorly aligned filters show uneven
white borders after exposure. Care should be taken to ensure that the filter cassette is not excessively
tightened, as the filer may stick or the gasket may be permanently damaged. Check that the gasket is
in good condition and has not deteriorated.
9.4.3 Sampling Procedures—MFC Sampler.
9.4.3.1 Filter Installation Procedure.
9.4.3.1.1 Following the manufacturer's instructions, loosen the nuts that secure the inlet to the
base and gently tilt back the inlet to allow access to the filter support screen.
9.4.3.1.2 Examine the filter support screen. If the screen appears dirty, wipe it clean. If the filter
cassette is equipped with a protective cover, remove it and place the loaded cassette in position on the
sampler support screen. Tighten the thumb nuts to hold the filter cassette securely. Check that the gasket
is in good condition and has not deteriorated.
Caution: Tighten the thumb nuts evenly on alternate corners to properly align and seat the gasket. The
nuts should be only hand-tightened because too much compression can damage the sealing gasket.
Page 2.1-30 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume _ Integrated Sampling for SPM
9.4.3.1.3 If an inlet is being used, lower the sample inlet. Inspect the sample inlet to make sure
that it is resting on the filter cassette and not on the sampler's frame. Secure the sample inlet to the
sampler base.
9.4.3.1.4 Open the front door of the sample and examine the flow recorder. Remove any
moisture inside by wiping it with a clean cloth. Record the sampler S/N, filter ID number, site location,
and sampling data on the back of a clean chart and install the chart in the flow recorder.
/Note: Charts used for PM^Q samplers normally have square-root-function scales; however,
linear-function scales may be used. If charts with linear-function scales are used, Equations in
Section 7.4.3.3 and Section 7.4.3.5 will have to be modified from their current form by replacing I with
(I)112]
[Note: While installing the chart, do not bend the pen arm beyond its limits of travel. Raise the pen head
by pushing on the very top of the pen air (or by using the pen lift). Be sure that the chart tab is centered
on the slotted drive to ensure full 360° rotation in 24 h. Make sure that the chart edges are properly
located beneath the retainers. Lower the pen arm and tap the recorder face lightly to make certain that
the pen is free.]
[Note: During periods of inclement weather, the chart tends to stick to the recorder face. Two charts can
be installed simultaneously to enable the sample (top, annotated) chart to rotate freely.]
9.4.3.1.5 Using a coin or slotted screwdriver, advance the chart and check to see that the pen rests
on zero-the smallest circle diameter. If necessary, adjust the zero set screw while gently tapping on the
side of the flow recorder. If a chart with a linear function scale is used, some positive zero offset may
be desirable to allow for normal variation in the zero readings.
9.4.3.1.6 Turn on the sampler and allow it to equilibrate to operating temperature (3-5 min).
9.4.3.1.7 While the sampler is equilibrating, record the following parameters on the MFC Sampler
Field Data Sheet (see Figure 14):
• Site Location.
• Sample date.
• Filter ID number.
• Sampler model and S/N.
• Operator's initials.
9.4.3.1.8 Inspect the manometer for crimps or cracks in its connecting tubing. Open the valves
and blow gently through the tubing of the manometer while watching for the free flow of the fluid.
Adjust the manometer's sliding scale so that its zero line is at the bottom of the meniscuses.
9.4.3.1.9 Measure the initial exit orifice plenum pressure (Pex) using an oil or water manometer,
with a 0-200-mm (0-8") range and a minimum scale division of 1 mm (0.1"). Record the initial Pex on
the MFC Sampler Field Data Sheet. If Pex is substantially different than for previous samples or
otherwise appears abnormal, carry out a Quality Control (QC) flow check as described in Section 13.1.
9.4.3.1.10 Verify that the flow recorder (if used) is operational and that the pen is inking. Note
the flow recorder reading. If it is substantially different than for previous samples or otherwise appears
abnormal, carry out a QC flow-check as described in Section 13.1.
9.4.3.1.11 Turn the sampler off.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-31
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM High Volume
9.4.3.1.12 Check the time indicated by the time-set pointer on the flow recorder. If it is in error,
rotate the chart clockwise by inserting a screwdriver or coin in the slotted drive in the center of the chart
face until the correct time is indicated.
9.4.3.1.13 Reset the elapsed time meter to 0000 min and the sampler timer for the next run day.
Close the sampler door, taking care not to crimp the vacuum tubing or any power cords. The sampler
is now ready to sample ambient aif.
9.4.3.2 Filter Recovery Procedure. As soon as possible after sampling, the operator should
return to the monitoring site to retrieve the exposed filter. Particle loss or fiteer damage will result if the
filter is left in the sampler for extended periods.
9.4.3.2.1 Turn on the sampler and allow it to equilibrate to operating temperature (3-5 min).
9.4.3.2.2 Measure the final Pex and record it on the MFC Sampler Field Data Sheet.
9.4.3.2.3 Turn off the sampler.
9.4.3.2.4 Open the door of the sampler, remove the flow recorder chart, and examine the recorder
trace. If the trace indicates extensive flow fluctuations, investigate and correct before the next sampling
day.
9.4.3.2.5 Record the following parameters on the MFC Sampler Field Data Sheet:
• Elapsed time of the sampling period, min.
• Average recorder response, arbitrary units.
• Average ambient temperature for the run day (Tav), K (K = °C + 273).
• Average ambient barometric pressure for the run day (Pav), mm Hg or kPa.
[Note: Tav and Pav readings may be recorded or estimated on site or may be obtained from a nearby
U.S. National Weather Service Forecast Office or airport weather station. Barometric pressure readings
obtained from remote sources must be at station pressure (not corrected to sea level), and they may have
to be corrected for differences between the evaluation are not available, seasonal average temperature
(Ts) and barometric pressure (Ps) may be substituted for Tav and Pav, respectively. Care must be taken,
however, that the actual conditions at the site can be reasonably represented by such averages.
Therefore, seasonal values may represent actual values within 20°C and 40 mm Hg.]
The calculations presented in this section assume that the sampler has been calibrated in terms of actual
temperature and barometric pressure and that the substitution of seasonal values is used only to determine
the sampler's operational flow rate during a sample period. Although additional calculations to convert
the sampler's calibration curve to seasonal can be made, the error represented by this method is
negligible.
9.4.3.2.6 Calculate and record the average actual flow rate (as determined by the sampler's
calibration relationship) on the MFC Sampler Field Data Sheet and on the back of the chart. Attach the
chart to the data sheet.
Qa = {[A Pex"(Tav + 30)/Pa]1/2 - b} {I/m}
or for the flow recorder,
Dl = {[I (Tav + 30)/Pa]1/2 - b} {1/m}
Page 2.1-32 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
where:
Qa = average sampler flow rate, actual nnr/min.
Pex = average exit orifice plenum pressure, mm Hg.
I = average flow recorder response, arbitrary units.
Tav = average ambient temperature for the run day, K.
Pav = average ambient pressure for the run day, mm Hg.
b = intercept of the MFC sampler calibration relationship.
m = slope of the MFC sampler calibration relationship.
[Note: If charts with linear-junction scales are used, substitute (I)1/2for L]
9.4.3.2.7 Observe conditions around the monitoring site; note any activities that may affect filter
particle loading (e.g., paving, mowing, fire) and record this information on the MFC Sampler Field Data
Sheet.
9.4.3.2.8 Raise the sampler inlet and remove the filter cassette. Replace the'cassette protective
cover (if so equipped). To avoid particle loss, be careful to keep the cassette as level as possible.
9.4.3.2.9 The sampler may now be readied for the next run day.
9.4.3.2.10 Keeping the filter cassette level, carefully transport it,, the data sheet, and the flow
recorder chart to the laboratory sample custodian.
9.4.4 Sampling Procedures—VFC Sampler.
9.4.4.1 Filter Installation Procedure.
9.4.4.1.1 Following the manufacturer's instructions, loosen the nuts that secure the inlet to the
base and gently tilt back the inlet to allow access to the filter support screen.
9.4.4.1.2 Examine the filter support screen. If the screen appears dirty, wipe it clean. Ifthe filter
cassette is equipped with a protective cover, remove it and place the loaded cassette in position on the
sampler support screen. Tighten the thumb nuts sufficiently to hold the filter cassette securely. Check
that the gasket is in good condition and has not deteriorated.
Caution: Tighten the.thumb nuts evenly on alternate corners to properly align and seat the gasket. The
nuts should be only hand-tightened because too much compression can damage the sealing gasket.
9.4.4.1.3 If an inlet is used, lower the sample inlet and secure it to the sampler base. For
impaction inlets, inspect the sample inlet to make sure that it is resting on the filter cassette and not on
the sampler's frame. Secure the sampler inlet to the sampler base.
9.4.4.1.4 Record the following parameters on the VFC Sampler Field Data Sheet (see Figure 15):
• Site location.
• Sample date.
• Filter ID number.
• Sampler model and S/N.
• Operator's initials.
9.4.4.1.5 Turn on the sampler and allow it to reach a stable operating temperature (3-5 min).
9.4.4.1.6 Bring an oil or water manometer to the side of the sampler. This manometer should
have a range of 0-400 mm (0-16") and a minimum scale division of 1 mm (0.1").
[Note: Be sure to convert the manometer reading to mm Hg using the following equation before recording
the reading on the VFC Sampler Field Data Sheet.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-33
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
mm Hg = (25.4) (in. H2O/13.6)
Inspect the manometer for crimps or cracks in its connecting tubing. Open the valves and blow gently
through the tubing of the manometer, while watching for the free flow of the fluid.
Adjust the manometer's sliding scale so that its zero line is at the bottom of the meniscuses.
9.4.4.1.7 Remove the vacuum cap from the stagnation pressure port located on the side of the
sampler base. Using the connecting tubing, attach one side of the manometer to the port. Leave the
other side of the manometer open to atmospheric pressure. Make sure the tubing snugly fits the port and
the manometer.
9.4.4.1.8 Measure the initial relative stagnation pressure (A Pstg) an«f record this reading on the
VFC Sampler Field Data Sheet.
9.4.4.1.9 Turn off the sampler, disconnect the manometer, and replace the vacuum cap on the
stagnation pressure port.
9.4.4.1.10 Reset the elapsed-time meter to 0000 min and the sampler timer for the next run day.
The sampler is now ready to sample ambient air.
9.4.4.2 Filter Recovery Procedure. As soon as possible after sampling, the operator should
return to the monitoring site to retrieve the exposed filter. Particle loss or filter damage will result if the
filter is left in the sampler for extended periods.
9.4.4.2.1 Turn on the sampler and allow it to warm up to operating temperature (3-5 min).
9.4.4.2.2 While the sampler is equilibrating, record the following parameters on the VFC Sampler
Field Data Sheet:
• Elapsed time of the sampling period, min.
• Average ambient temperature for the run day (Tav), °C and K.
• Average ambient barometric pressure for the run day (Pav), mm Hg.
[Mote: Tav and Pav readings may be recorded or estimated on site or may be obtained from a nearby
U.S. National Weather Service Forecast Office, National Weather Service (NWS) station, or an airport
weather station. Barometric pressure readings obtained from remote sources must be at station pressure
(not corrected to sea level), and they may have to be corrected for differences between the elevation of
the monitoring site and that, of the airport. If Tav and Pav readings are not available, seasonal average
temperature (Ts) and barometric pressure (Ps) can be substituted. Care must be taken, however, that the
actual conditions at the site can be reasonably represented by such averages. Therefore, seasonal values
may represent actual values \vithin 20°C and 40 mm Hg.]
9.4.4.2.3 Inspect the manometer for crimps or cracks in its connecting tubing. Open the valves
and blow gently through the tubing of the manometer, while watching for the free flow of the fluid.
Adjust the manometer sliding scale so that its zero line is at the bottom of the meniscuses.
9.4.4.2.4 Remove the vacuum cap from the stagnation pressure port located on the side of the
sampler base. Using "the connecting tubing, attached one side of the manometer to the port. Make sure
that the tubing snugly fits the port and the manometer. Leave the other side open to atmospheric
pressure.
9.4.4.2.5 Record the final Pstg on the VFC Sampler Field Data Sheet. Turn off the sampler and
replace the vacuum cap.
Page 2.1-34 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
[Note: Be sure to convert the manometer reading to mm Hg using the following equation before recording
the reading on the Sampler Field Data Sheet.]
mm Hg = 25.4 (in. H2O/13.6)
9.4.4.2.6 Calculate the average relative stagnation pressure (APstg) and record it on the data
sheet.
9.4.4.2.7 Calculate the average absolute stagnation pressure (FT) for the sample run day and
record it on the data sheet.
PT = Pav - SPstg
where:
FT = average absolute stagnation pressure, mm Hg.
Pav = average ambient barometric pressure for the run day (not the retrieval day), mm Hg.
APstg = average stagnation pressure drop, mm Hg.
9.4.4.2.8 Calculate and record the average stagnation pressure ratio:
Average stagnation pressure ratio = PI/Pav
where:
PI = average absolute stagnation pressure, mm Hg.
Pav = average ambient barometric pressure on the sample run day, mm Hg.
9.4.4.2.9 Using the manufacturer's lookup table (or an alternate calibration relationship as
described in Section 7.5.4), locate the column and row corresponding to PT/Pav and the Tav value for
the sample run day. Read and record the indicated Qa value.
9.4.4.2.10 Observe conditions around the monitoring site; note any activities that may affect filter
particle loading (paving, mowing, fire) and record this information on the VFC Sampler Field Data Sheet.
9.4.4.2.11 Raise the sampler inlet and remove the filter cassette. Replace the cassette protective
cover (if so equipped). To avoid particle loss, be careful to keep the cassette as level as possible.
9.4.4.2.12 The sampler may now be readied for the next sampling period.
9.4.4.2.13 Keeping the filter cassette level, carefully transport it and the Sampler Field Data Sheet
to the laboratory sample custodian.
9.4.5 Post-Sampling Filter Handling Procedures. If a sample will not be analyzed immediately,
the sample custodian should store the filer within a protective covering. Because filter cassettes often
prove too expensive and unwieldy for storage purposes, the use of a manila folder and a protective
envelope of comparable size to that of the filter is recommended. Laboratory personnel should adhere
to the following procedure:
9.4.5.1 Following the manufacturer's instructions, remove the top frame of the filter cassette.
9.4.5.2 Conduct a secondary check of a sample's validity as presented in "Laboratory Validation
Criteria" (see Section 9.5).
9.4.5.3 Carefully slip a manila folder underneath the edge of the exposed filter. The filter may
stick in the cassette because of overcompression of the filter cassette gasket. Be extremely careful to
avoid damage to the brittle quartz filter.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-35
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Method 10-2.1 ,
Integrated Sampling for SPM _ _ . _ High Volume
9.4.5.4 Center the filter on the folder. If the filter must be touched, do not touch or jar the
deposit. Fold the manila folder lengthwise at the middle with the exposed side of the filter in. If the
collected sample is not centered on the filter (i.e., the unexposed border is not uniform around the filter),
fold it so that only deposit touches deposit. Do not crease the folder-the sample filter may tear. If the
filter shears or breaks, ensure that all pieces of the filter are included within the folder.
9.4.5.5 Insert the folder into the protective envelope.
9.4.5.6 Deliver the filter in its protective folder and envelope, accompanied by the completed data
sheet, to the analytical laboratory.
9.5 Sample Validation and Documentation
9.5.1 Field Validation Criteria. , After each sampling period, calculate the percentage difference
between Qa and the design flow rate (1.13 m3/min) using the following formula:
% Difference = 100
Record this value on a control chart for the field validation of the sampler's actual volumetric flow rate
as is shown in Figure 16.
• Decreases in flow rate during sampling (due to mechanical problems) of more than 10% trom the
initial set point result in sample invalidation. Recalibrate the sampler. A sample flow rate may
also fluctuate due to heavy filter loading. If a high concentration is suspected, the operator should
indicate this on the field data sheet. The laboratory supervisor will make the final decision
regarding the sample's validity.
• Changes in flow-rate calibration of more than 10%, as determined by a field QC flow-rate check
(see Section 13), will invalidate all samples collected back to the last calibration or valid flow
check. Recalibrate the sample.
9.5.2 Laboratory Validation Criteria.
9.5.2.1 Check the filter for signs of air leakage. Leakage may result from a worn or improperly
installed faceplate gasket. A gasket generally deteriorates slowly. The sample custodian should be able
to decide well in advance (by the increased fuzziness of the sample outline) when to change the gasket
before total gasket failure results. If signs of leakage are observed, void the sample, determine the cause,
and instruct the operator to take corrective actions before starting another sampling period.
9.5.2.2 Check the exposed filter for physical damage that may have occurred during or after
sampling. Physical damage after sampling would not invalidate the sample if all pieces of the filter were
put in the folder; however, complete losses of loose particulate after sampling (e.g., loss when folding
the filter) would void the sample. Mark such samples as "void" on the HV data sheet.
9.5.2.3 Check the appearance of the particles. Any changes from normal color may indicate new
emission sources or construction activity in the area. Note any change on the data sheet.
9.5.3 Data Documentation. Recordkeeping is a critical part of the QA program. Careful
documentation of sampling data will salvage samples that may otherwise be lost. The sheer repetition
of recording data may result in errors; however, this cross-referencing between data sheets, log books,
and (for those samplers so equipped) the continuous-flowrecorder charts will allow the operator to
pinpoint discrepancies that may result in a sample's invalidation.
[Note: TKe use of log books at monitoring sites is highly encouraged.]
Page 2.1-36 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
9.5.3.1 Presampling Documentation and Inspection. The following information should be
recorded on the Sampler Field Data Sheet (SFDS), sampler recorder chart (RC), flow-rate control chart
(CC), and in the site log book (LB):
• Site Location.
• Sample Date.
• Filter ID number.
• Sample model and S/N.
• Operator's initials.
9.5.3.2 Post-Sampling Documentation and Inspection. Upon receipt of exposed filters from
the field, the sample custodian should adhere to the following procedures.
9.5.3.2.1 Examine the field data sheet. Determine whether all data needed to verify sample
validity and to calculate mass concentration are provided (e.g., average flow rate, ambient temperature,
barometric pressure, and elapsed time). Void the sample if data are missing or unobtainable from a field
operator or if a sampler malfunction is evident.
9.5.3.2.2 If the exposed filter was packaged for shipment, remove the filter from its protective
envelope and examine the shipping envelope. If sample material has been dislodged from a filter, recover
as much as possible by brushing it from the envelope onto the deposit on the filter with a soft
camel's-hair brush.
9.5.3.2.3 Match the filter ID number with the correct laboratory data/coding form on which the
original balance ID number, filter ID number, filter tare weight, and other information are inscribed.
The sample custodian should group filters according to their recorded balance ID numbers. Initial
separation of filters by balance ID number will decrease the probability of a balance error that could
result from the use of different balances for tare and gross weights.
9.5.3.2.4 Remove the filter from the protective manila folder. Should the filter be retained in its
filter cassette, loosen the nuts on the top and remove the filter. Overtightening the nuts may cause the
filter to adhere to the cassette gasket. Gently remove it by the extreme corners to avoid damage. Inspect
the filters for any damage that may have occurred during sampling. Conduct a secondary check of a
sample's validity (as presented in Section 9.4). If insects are embedded in the sample deposit, remove
them with Teflon®-tipped tweezers and disturb as little of the sample deposit as possible. If more than
10 insects are observed, refer the sample to the supervisor for a decision on acceptance or rejection of
the filter for analysis.
9.5.3.2.5 Place defect-free filters in protective envelopes and forward them to the laboratory for
weighing and analysis. File the data sheets for subsequent mass concentration calculations.
9.5.3.2.6 Place defective filters, with the type of defect(s) listed, in separate clean envelopes.
Label the envelopes and submit them to the laboratory supervisor for final approval of filter validity.
10. Interferences
10.1 Large extraneous objects, such as insects, may be swept into the filter.
10.2 Liquid aerosols, such as oil mists and fog droplets, are retained by the filter. If the amount of
liquid so collected is sizeable, the filter can become wet and its function may be impaired.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-37
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
10.3 Any gaseous or vaporous constituent of the atmosphere under test that is reactive with or absorbed
on the filter will be retained.
10.4 As the filter becomes loaded with collected matter, the sampling rate is reduced. If a significant
drop in flow rate occurs, the average of the initial and final flow rate will not give an accurate estimate
of total flow during the sampling period. The magnitude of such errors will depend on the amount of
reduction of airflow rate and on the variation of the mass concentration of dust with time during the 24-h
sampling period. As an approximate guideline, any sample should be suspect if the final flow rate is less
than one-half the initial rate.
10.5 Power failure or voltage change during the test period will lead to an error, depending on the extent
and time duration of such failure.
10.6 The passive loading of the filter left in place for any time prior to or following a sampling period
can introduce an error. The timely installation and removal of the filter is advisable, or a sampler with
shutters may be used.
10.7 If two or more samplers are used at a given location, they should be placed at least 2- meters apart
so that one sampler will not affect the results of an adjacent sampler.
10.8 Recent wind tunnel studies have shown significant possible sampling errors as a function of sampler
orientation in atmospheres containing high relative concentrations of large particles.
10.9 Metal dusts from motors, especially copper, may significantly contaminant samples under some
conditions.
10.10 Under some conditions, atmospheric SO2 and NOX may interfere. Artifact formation errors are
caused by the retention of sulfur dioxide in the form of sulfate particulate on alkaline filters. Experiments
involving a variety of filters indicate that sulfate loading errors of 0,3-3.0 jig/m3 can be expected with
the use of common glass fiber filters under normal sampling conditions and that larger sulfate errors are
possible under extreme sampling conditions. A neutral or low-alkalinity filter medium will eliminate
excessive artifact formation.
10.11 Guidelines to help prevent post-sampling particle loss are presented in Section 8.
11. Calculations, Validations, and Reporting of TSP and PM10 Data
11.1 Basic Information Used for Calculations
11.1.1 The design flow rate is specified as an actual volumetric flow rate (Qa), measured at existing
conditions of temperature (Ta) and pressure .(Pa). The sampler's operational flow rate should be very
close to the design flow rate. All samplers have some means for measuring the operational flow rate,
and that flow rate measurement system must be calibrated periodically with a certified flow rate transfer
standard. Usually, measurements (or estimates) of ambient temperature and barometric pressure are
required to get an accurate indication of the operational flow rate. To determine the average sampler
Page 2.1-38 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume _ _ Integrated Sampling for SPM
flow rate over a sample period, use the average temperature (Tav) and average barometric pressure (Pav)
over the sample period. However, if average temperature and pressure values (or reasonable estimates)
cannot be obtained for each sample period, seasonal average temperature (Ts) and barometric pressure
(Ps) for the site may be substituted.
[Note: Tav and Pav readings may be recorded on site or estimated from data obtained from a nearby U.S.
National Weather Service Forecast Office, NWS station, or local airport weather station. Barometric
pressure readings obtained from airports or other sources must be at station pressure (i.e., not corrected
to sea level), and they may have to be corrected for differences between the elevation of the monitoring
. site and that of the airport. If individual Tav and Pav readings cannot be obtained for each sample
period and seasonal averages for the site are routinely substituted, care must be taken to ensure that the
actual temperature and barometric pressure at the site are reasonably represented by such averages.
Therefore, seasonal average temperature and pressure values (Ts and Ps)for the site by should be used
only when these values are within 20 K and 40 mm Hg (5 kPa) of the actual average temperature and
barometric pressure (Tav and Pav) for the sample period.]
11.1.2 The calculations presented in this section assume that the sampler has been calibrated in actual
volumetric flow rate units (Qa) and that individual average temperature and barometric pressure values
are used for each sample period. If seasonal average temperature and pressure values for the
site are to be used, Ts may be substituted for Tav, and Ps may be substituted for.
11.1.3 The true or actual flow rate through the sampler inlet must be known and controlled. A
common source or error in a monitoring program is confusion of various air volume flow-rate
measurement units. Although the sampler's operational flow rate must be monitored in terms of actual
volume flow rate units (Qa), sampler flow rates can be corrected to standard volume flow rate units
(Qstd) at EPA standard conditions of temperature (25°C) and pressure (760 mmHg).
• Qa : Actual volumetric air flow rates, measured and expressed at existing conditions of
temperature and pressure and denoted by Qa (Qactual). Typical units are L/min and
m-'/min. Inlet design flow rates for PM^Q samplers are always given in actual volumetric
flow rate units.
• Qstd: Airflow rates that have been corrected to equivalent standard volume flow rates at EPA
standard conditions of temperature and pressure (25°C or 298 K and 760 mm Hg or
101 kPa) and denoted by Qstd (Qstandard). Typical units are std. L/min, and std.
nrVmin. Standard volume flow-rate units are often used by engineers and scientists
because they are equivalent to mass flow units.
11.1.4 The Qa and Qstd measurement units must not be confused or interchanged. The flow-rate
units can be converted as follows, provided the existing temperature and pressure (or in some cases the
average temperature and pressure over a sampling period) are known:
= Ql(Pa/Pstd)(Tstd/Ta)
Qstd = (Pav/Pstd)(Tstd/Tav)
Qa = Qstd(Pstd/Pa)(Ta/Tstd)
where:
•2
Qstd = standard volume flow rate, std nvVmin.
Qa = actual volume flow rate, actual nrVmin.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-39
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_, .. , --. ~ i Chapter IO-2
Method IO-2.1 £ _. ,
Integrated Sampling for SPM High Volume
Pa = ambient barometric pressure, mm Hg.
Pstd = EPA standard barometric pressure, 760 mm Hg.
Tstd = EPA standard temperature, 298 K.
Ta = standard temperature, K (K = °C + 273).
Qstd = average standard volume flow rate for the sample period, std. m /mm.
Qa = average actual volume flow rate for the sample period, m /mm.
Pav = average ambient barometric pressure during the sample period, mm Hg.
Tav = average ambient temperature during the sample period, K.
Inorganic Compendium Method IO-2.4 provides guidance on calculating sample volume corrected to EPA
standard temperature and pressure.
11.2 Flow-Rate Calculations. Because flow control methods (and hence, calibration procedures) vary
among different sampler models, the calculations necessary to determine the average actual flow rate
during a sample run will also differ. The following general procedures are recommended for calculating
the average ambient flow rate of the sampler. In this section, it is assumed that the samplers have been
calibrated according to procedures outlined in Section 7.
/Afo/e.. Consistency in units is required. Adoption of uniform designations of K for temperature and mm
Hg (or kPa) for pressure is recommended in all calculations.]
11.2.1 MFC Sampler.
11.2.1.1 The average actual flow rate for sample period is calculated by determining:
• The average of the initial and final manometer readings (SPSE) [or the average flow recorder
trace];
• The average ambient temperature (Tav); and
• The average ambient barometric pressure (Pav) during the sampling period and applying these
values to the calibration relationship.
11.2.1.2 Each sampler's flow measurement system should be calibrated periodically, and the
calibration should be described by a mathematical expression (e.g., a least-squares linear regression
equation) that indicates the slope and intercept of the calibration relationship. Following the procedure
in Section 7, this expression is in the form of:
IJa = {[F5x"(Tav+ 30)/Pav)]1/2 - b} {1/m}
where:
•2
Qa = the sampler's average actual flow rate for the sample period, nrVmin.
Pex = average of initial and final sampler manometer readings, (A Pexj + A Pexj)/2, in. H2O.
Tav = average barometric pressure for the sample period, K (K = °C + 273).
Pav = average barometric pressure for the sample period, mm Hg.
b = intercept of the sampler calibration relationship.
m = slope of the sampler calibration relationship.
Page 2.1-40 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume _ Integrated Sampling for SPM
For the flow recorder,
Qa = {[I (Tav+30)/Pav]1/2 - b} {1/m}
where:
I = average flow recorder reading for the sample period.
11.2.1.3 The average actual flow rate is then corrected to EPA-standard conditions, calculated as:
= Qa(Pav/Pstd)(Tstd/Tav)
where:
. Qstd = average sampler flow rate corrected to EPA-standard volume flow rate units, std. m^/min.
Qa = average actual sampler flow rate for the sample period, m^/min.
Pstd = standard barometric pressure, 760 mm Hg.
Tstd = standard temperature, 288 K.
11.2.2 VFC Sampler.
11.2.2.1 The average actual flow rate for the sample period is calculated by determining the ratio
of the average absolute stagnation pressure of the average ambient barometric pressure (PT/Pav) and the
ambient average temperature (Tav) for the sampler period.
11.2.2.2 Calculate the value of PI in mm Hg:
PT = Pav -APstg
where:
PI = average absolute stagnation pressure for the sample period, mm Hg .
Pav = average barometric pressure for the sample period, mm Hg.
APstg = average of initial and final relative stagnation pressure readings, mm Hg.
[Note: Be sure to convert a water manometer reading to mm Hg using the following equation before
recording the reading on the data sheet:]
mmHg = 25.4 (A H2O/13.6)
11.2.2.3 Calculate and record the value of the average stagnation pressure ratio.
Average stagnation pressure ratio = (PT/Pav)
11.2.2.4 Use the manufacturer's lookup table (or alternate calibration relationship; see Section 7)
to determine Qa from the average stagnation pressure ratio (PT/Pav) and Tav for the sample period. The
value of Qa is the average volumetric flow rate for the sampler period.
11.2.2.5 The average actual flow rate is then corrected to EPA-standard conditions using the
following equation:
= Qa(Pav/Pstd)(Tstd/Tav)
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-41
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM _ High Volume
where:
TJstH = average sampler flow rate corrected to EPA-standard volume flow rate units, std. m /nun.
?3a = average actual sampler flow rate for the sample period, m /min.
Pstd = standard barometric pressure, 760 mm Hg.
Tstd = standard temperature, 298 K.
11.3 The total standard volume of air sampled is calculated by the following equation:
Vstd =
where: -
Vstd = total volume of air sampled in standard volume units, std m .
average sampler flow rate corrected to EPA-standard conditions, std m Min.
t = total elapsed sampling time, min.
11.4 Percent Difference
11.4.1 After each sampling period, calculate the percentage difference between Qa and the design
flow rate (1.13 nrVmin) using the following formula:
% Difference = 100 Q8'13
Record this value on a control chart for the field validation of the sampler's actual
volumetric flow rate as is shown hi Figure 14,
11.4.2 The following criteria should be used as the basis for determining a sample's
validity:
• Decreases in flow rate during sampling (due to mechanical problems) of more than 10% from the
initial set point cause sample invalidation. A sample flow rate may also fluctuate due to heavy
filter loading. If a high concentration is suspected, the operator should indicate it on the field data
sheet. The laboratory supervisor will make the final decision regarding the.sample's validity.
• Changes in flow-rate calibration of more than 10.% , as determined by a field QC flow-rate check,
will invalidate all samples collected back to the last calibration or valid flow check.
12. Records
12.1 MFC Sampler
Record the following parameters on the MFC Sampler Field Data Sheet (see Figure 14):
Final Pex.
Elapsed time of the sampling period, min.
Average record response, arbitrary units.
Tav for the run day K (K = °C + 273).
Pav for the run day, mm Hg.
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
12.2 VFC Sampler
Record the following parameters on the VFC Sampler Field Data Sheet (see Figure 15):
• Site location.
• Sample date.
• Filter ID number.
• Sampler model and S/N
• Operator's initials.
• Initial Relative Stagnation Pressure ( Pstg).
• Elapsed time of the sampling period, min.
• Tav for the run day Tav, °C and K.
• Pav for the run day Pav, mm Hg.
• Pstg, mm Hg.
• Relative Stagnation Pressure.
• Absolute Stagnation Pressure.
• Qa value (from chart generated hi Section 7.5.4.).
12.3 Tav and Pav readings may be recorded or estimated on site or may be obtained from a nearby U.S.
National Weather Service Forecast Office or airport weather station. Barometric pressure readings
obtained from remote sources must be at station pressure (not corrected to sea level); they may have to be
corrected for differences between elevation of the monitoring site and that of the airport. If Tav and Pav
readings are not available, seasonal average temperature (Ts) and barometric pressure (Ps) may be
substituted for Tav and Pav, respectively. Care must be taken, however, that the actual conditions at the
site can be reasonably represented by such averages. Therefore, seasonal values should represent actual
values within 20°C and 40 mm Hg.
12.4 Observe conditions around the monitoring site; note any activities that may affect filter particle
loading (paving, mowing, fire) and record this information on the VFC Sampler Field Data Sheet.
Document any factors mat may cause a sample's invalidation on the sample data sheet. Forward the data
sheet and the filter to the laboratory supervisor, who will make the final decision regarding the sample's
validity.
12.5 Record the percentage difference between Qa and the design flow rate on Figure 16.
12.6 Recordkeeping is a critical part of the QA program. Careful documentation of sampling data will
salvage samples that may otherwise be lost. The sheer repetition of recording data may result in errors;
however, this cross-referencing between data sheets, log books, and (for those samplers so equipped) the
continuous-flow-recorder charts will allow the operator to pinpoint discrepancies that may result hi a
sample's invalidation.
[Note: The use of log books at monitoring sites is highly encouraged. The following information should
be recorded on the Sampler Field Data Sheet (SFDS), sampler recorder chart (RC), in the site log book
(LB), and on the flow-rate control chart (CC).J
12.6.1 The following information should be recorded by the operator who starts the sample. (The
designation in parentheses indicates where the data must be inscribed):
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
• Site designation and locations (SFDS)(RC)(LB). This information should be recorded in the log
book only once, at the initiation of a monitoring program.
• Sampler model and S/N (SFDS)(RC)(LB). This information needs to be recorded hi the log book
only at the commencement of monitoring, unless there is more than one sampler or a new sampler
has been deployed.
• Filter ID number (SFDS)(RC)(LB).
• Sample date (SFDS)(RC)(LB).
• Initial Pex for MFC or initial A Pstg for VFC (SFDS)(LB).
• Unusual conditions that may affect the results (e.g., subjective evaluation of pollution that day,
construction activity, weather conditions) (SFDS)(LB).
• Operator's initials (SFDS).
• Signature (LB).
12.6.2 The following information should be recorded by the operator who removes the samples.
• Elapsed tune of the sample run (SFDS)(RC)(LB). _
• Final A Pex [or mean I] for MFC or final A Pstg, PI, and Pl/Pav for VFC (DS)(LB)[RC].
• The calculated standard average flow rate (Qstd) hi std mVmin (SFDS)(LB).
• The percentage difference between the actual and design flow rates (CC).
• Average ambient temperature and barometric pressure on the sample run day (SFDS)(LB).
• Seasonal average temperature and pressure, if needed (SFDS/LB). This information needs to be
recorded hi the logbook once, at the change of each season.
• Existing conditions that may affect the results (SFDS)(LB).
• Explanations for voided or questionable samples (SFDS)(LB).
• Operator's initials (SFDS).
• Signature (LB).
13. Field QC Procedure
For HV samplers, a field-calibration check of the operational flow rate is recommended at least once per
month. The purpose of this check is to track the sampler's calibration stability. A control chart (e.g.,
Figure 14) that contains the percentage difference between a sampler's indicated and measured flow rates
should be maintained. This chart is a quick reference of instrument flow-rate drift problems and is useful
for tracking the performance of the sampler. Either the sampler log book or a data sheet must be used to
document flow-check information. This information includes, but is not limited to, instrument and transfer
standard model and serial numbers, ambient temperature and pressure conditions, and collected flow-check
data.
In this section, the following is assumed:
• The flow rate through sampler that is equipped with a mass-flow controller is indicated by the exit
orifice plenum pressure. This pressure is measured with a manometer [or a flow recorder].
• The flow rate through a sampler that is equipped with a volumetric flow controller is indicated by
the stagnation pressure. This pressure is measured with a manometer.
• The acceptable flow-rate fluctuation range is 10% of the design flow rate.
• The transfer standard will be an orifice device equipped with a water or oil manometer.
• The orifice transfer standard's calibration relationship is hi terms of the actual volumetric flow rate
(Qa).
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
13.1 QC Flow-Check Procedure-MFC Sampler. The indicated flow rate (Qa (sampler)) for MFC
samplers is calculated by determining:
• The manometer reading of the exit orifice plenum pressure [or the flow recorder reading],
• The ambient temperature (Ta), and
• The barometric pressure (Pa) during the flow check.
These values are then applied to the sampler's calibration relationship. The 4" pressure (flow) recorders
of the type often supplied with high-volume PMjQ samplers are generally not sufficiently accurate and
are not recommended for quantitative sampler pressure or flow measurements. The flow recorder may
be connected in parallel with the manometer or other pressure measuring device, using a tee or "Y"
tubing connector. An alternate QC flow-check procedure may be presented in the manufacturer's
instruction manual. The manual should be reviewed and the various methods evaluated. Inhouse
equipment and procedural simplicity should be considered in determining which method to use.
[Note: Do not attempt to conduct a flow check of samplers under windy conditions. Short-term wind
velocity fluctuations will produce variable pressure readings by the orifice transfer standard's manometer.
The flow check will be less precise because of the pressure variations.]
13.1.1 Collect the following equipment and transport it to the monitoring station:
[Note: An independent person should perform the QCflow check, with an outside observer present.]
• A water, oil, or digital manometer with a 0-200 mm (0-8") range and a minimum scale division
of 1 mm (0.1") for measuring the sampler's exit orifice plenum pressure. This manometer should
be the same as is used routinely for sampler flow rate measurements.
• An orifice transfer standard and its calibration relationship (different from initial orifice standard).
• An associated water or oil manometer with a 0- to 400-mm (0- to 16") range and a minimum scale
division of 1 mm (0.1") for measuring the orifice transfer standard.
• A thermometer capable of accurately measuring temperature 0-50°C (273-323 K) to the nearest
±1°C and referenced to an NIST or ASTM thermometer within ±2°C at least annually.
• A portable aneroid barometer (e.g., a climber's or engineer's altimeter) capable of accurately
measuring ambient pressure 500-800 mm Hg (66-106 kPa) to the nearest millimeter Hg and
referenced within ±5 mm Hg of a barometer of known accuracy at least annually.
• The sampler's calibration information.
• Spare recorder charts and a clean flow-check filter.
• MFC Sampler Flow-Check Data Sheet or site log book.
13.1.2 Record the site location, sampler S/N, and date on the back of a clean chart and install it in
the flow recorder. While installing the chart, do not bend the pen arm beyond its limits of travel. Raise
the pen head by pushing on the very top of the pen arm (or by using the pen lift) and simultaneously
insert the chart.
13.1.3 Lower the pen arm and tap the recorder face lightly to make certain that the pen can move
freely.
13.1.4 Using a coin or slotted screwdriver, advance the chart and check to see that the pen head rests
on zero (i.e., that smallest diameter circle). If necessary, adjust the zeroset screw while gently tapping
on the side of the recorder. A quarter turn of the set screw usually results in large offsets; adjust the set
screw carefully.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-45
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SFM High Volume
13.1.5 Set up the flow-check system as previously illustrated in Figure 10. MFC samplers are
normally flow-checked with a filter in line (i.e., between the orifice transfer standard and the motor).
Install a clean filter in the sampler. Place the filter directly upon the sampler's filter screen. Do not use
a filter cassette. A flow-check filter should never be used for subsequent sampling because particles
larger than 10 /un can be collected on the filter while the inlet is raised. The sample mass will be biased
as a result of using a filter for both a flow check and subsequent sampling.
13.1.6 Install the orifice transfer standard and its faceplate on the sampler. Do not restrict the flow
rate through the orifice (i.e., by using fixed resistance plates or closing the variable-resistance valve).
Caution: Tighten the faceplate nuts on alternate corners first to eliminate leaks and to ensure even
tiglitening. The nuts should be hand-tightened; too much compression can damage the sealing gasket.
Make sure the orifice transfer standard gasket is in place and the orifice transfer standard is not
cross-threaded on the faceplate.
13.1.7 Connect the orifice manometer to the pressure port of the orifice transfer standard and the
sampler manometer to the sampler's exit orifice plenum. Inspect the manometers' connecting tubings for
crimps and cracks. Open the manometer valves and blow gently through the tubings. Watch for the free
flow of fluid. Adjust the manometers' scales so that their zero lines are at the bottom of the meniscuses.
Make sure that the connecting tubing snugly fits the manometer and the pressure port.
13.1.8 Turn on the sampler and allow it to warm up to operating temperature (3-5 min).
[Note: The sampler inlet may be partially lowered over the orifice transfer standard to act as a draft
shield (if a shield is not otherwise provided). Use a block to provide at least 2" of clearance at the
bottom for airflow and for the manometer tubing.]
13.1.9 Read and record the following parameters on the MFC Sampler Flow-Check Data Sheet:
• Sampler location and date.
• Sampler model and S/N.
• Ambient temperature (Ta), °C and K.
• Ambient barometric pressure (Pa), mm Hg.
• Unusual weather conditions.
• Orifice transfer standard S/N and calibration relationship.
• Operator's signature.
13.1.10 Observe the A K^O across the orifice by reading the manometer deflection. Record the
manometer deflection on the MFC Sampler Flow-Check Data Sheet (see Figure 11).
13.1.11 Measure the exit orifice plenum pressure (A Pex) by reading the manometer deflection.
Record the manometer deflection on the MFC Sampler Flow-Check Data Sheet.
13.1.12 Using a coin or small screwdriver, advance the recorder chart to read the sampler's
corresponding response (I) and record on the data sheet. A gentle tap on the recorder face is often
necessary to ensure that the pen is not sticking to the chart.
13.1.13 Turn off the sampler and remove the orifice transfer standard, but not the filter. Turn on
the sampler and repeat Section 13.1.11 [or Section 13.1.12] to check the flow rate under normal
operating conditions. Turn off the sampler and remove the filter.
13.1.14 Calculate and record Qa(orifice) at actual conditions using the following equation:
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Chapter IO-2 Method IO-2.1
High Volume _ • _ Integrated Sampling for SPM
Qa(orifice) = {[(A H2O)(Ta/Pa)]1/2 - b} {1/m}
where:
Qa(orifice) = actual volumetric flow rate as indicated by the orifice transfer standard, m3/min
A H2O = pressure drop across the orifice, in. f^O.
Ta = ambient temperature, K.
Pa = ambient barometric pressure, mm Hg.
b = intercept of the orifice calibration relationship.
m= slope of the orifice calibration relationship.
13.1.15 Calculate and record the corresponding sampler flow rate at actual conditions using the
following equation:
Qa(sampler) = {A Pex (Ta + 30)/Pa]1/2 - b} {1/m}
or use the following if a flow recorder is being used to measure the exit orifice plenum pressure:
Qa(sampler) = {I(Ta + 30)/Pa]1/2 - b} {1/m}
where:
Qa(sampler) = sampler flow rate, actual m3/min.
A Pex = exit orifice plenum pressure, in. f^O.
Ta = ambient temperature during the flow check, K (K = °C + 273).
Pa = ambient barometric pressure during the flow check, mm Hg.
b = intercept of the MFC sampler calibration relationship.
m = slope of the MFC sampler calibration relationship.
[Note: If charts with linear-junction scales are used, substitute (1)*^ for L]
13.1.16 Using this information and the formulas provided on the MFC Sampler Flow-
Check Data Sheet, calculate the QC check percentage differences.
QC-check % difference = ^(sampler) - Qa(orifice)] {
Qa(orifice) l J
where:
Qa(sampler) is measured with the orifice transfer standard being installed.
Record this value on the MFC Sampler Flow-Check Data Sheet and plot on the QC control chart. If the
sampler flow rate is within 93-107% (±7% difference) of the calculated Qa(orifice) flow rate (in actual
volumetric units), the sampler calibration is acceptable. If these limits are exceeded, investigate and
correct any malfunction. Recalibrate the sampler before sampling is resumed. Differences exceeding
+ 10% may result in the invalidation of all data collected subsequent to the last calibration or valid flow
check. Before invalidating any data, double-check the orifice transfer standard's calibration and all
calculations.
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Method 10-2.1 Chapter IO-2
Integrated Sampling for SPM _ _ _ _ _ High Volume
13.1.17 Calculate the corrected sampler flow rate, Qa(corr. sampler), using the following equation:
• . r« / i YI [(10° ~ % difference)]
Qa(corr. sampler = [Qa(sampler)] 1^ - — - - -
1UU
where:
Qa(sampler) is measured without the orifice transfer standard being installed and where the QC-check
percentage difference was obtained from the equation above.
: Take care to use the correct sign (i.e., positive or negative) for the percent difference.}
13.1.18 Calculate and record on the MFC Sampler Flow-Check Data Sheet the percentage difference
between the inlet's design flow rate and the corrected sampler flow rate as:
_ . _ ~, ,.,..- [Qa(corr. sampler) - 1.13]nnm
Design flow rate % difference = ±-£-i - * - -[100]
[Note; The author assumes in this section that the inlet is designed to operate at a flow rate ofl. 13 actual
m^/min. If the design flow rate percentage difference is less than or equal to ±7%, the sampler
calibration is acceptable. If the difference is greater than ± 7%, investigate potential error sources and
correct any malfunction. Recalibrate the sampler before sampling is resumed. Differences exceeding
±10% may invalidate all data collected subsequent to the last calibration or valid flow check. Before
invalidating any data, double-check the sampler's calibration, the orifice transfer standard's certification,
and all calculations.]
[Note; Deviations from the design flow rate may be caused in part by deviations in the site temperature
and pressure from the seasonal average conditions. Recalculate the optimum set-point flow rate (SFR)
according to Section 7.4.4 to determine if the flow controller should be adjusted.]
13.1.19 Set up the sampler for the next sampling period according to the operating procedure in
Section 9.4.
13.2 QC Flow-Check Procedure-VFC Sampler
The indicated flow rate (Qa (sampler)) for VFC samplers is calculated by determining:
• The relative stagnation pressure (Pstg),
• The ambient temperature (Ta), and
• The barometric pressure (Pa) during the flow check.
These values are then applied to the sampler's calibration relationship. An alternative QC flow-check
procedure may be presented in the manufacturer's instruction manual. The manual should be reviewed
and the various methods evaluated. Inhouse equipment and procedural simplicity should be considered
in determining which method to use.
(Note: Do not attempt to conduct a flow check of samplers under windy conditions. Short-term wind
velocity fluctuations will provide variable pressure readings by the orifice transfer standard's manometer.]
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Chapter IO-2 Method IO-2.1
High Volume _^ Integrated Sampling for SPM
The flow check will be less precise because of the pressure variations.
13.2.1 Collect the following equipment and transport it to the monitoring station:
• An orifice transfer standard and its calibration relationship in actual volumetric flow units (Qa).
• An associated oil, water, or digital manometer, with a 0-400 mm (0-16") range and minimum scale
divisions of 1 mm (0.1").
• An oil, water, or digital manometer, with a 0-400 mm (0-16") range and minimum scale divisions
of 1 mm (0.1") or other pressure measurement device for measurement of the sampler stagnation
pressure. Ideally, this manometer (or other pressure measurement device) should be associated
with the sampler.
[Note: Manometers used for QC flow-checks may be subject to damage or malfunction and thus should
be checked frequently.]
• A thermometer capable of accurately measuring temperature from 0°-50°C (273-323 K) to the
nearest ± 1 °C and referenced to an NIST or ASTM thermometer within 2°C at least annually. To
calculate the orifice flow rates, convert °C to K.
• A portable aneroid barometer (e.g., a climber or engineer's altimeter) capable of accurately
measuring ambient barometric pressure over the range of 500-800 mm Hg to the nearest millimeter
Hg and referenced within 5 mm Hg of a barometer of known accuracy at least annually.
• The sampler's calibration relationship (i.e., lookup table or alternative calibration relationship).
• A clean flow-check filter loaded into a filter cassette.
• A VFC Sampler Flow-Check Data Sheet (see Figure 13) or a site log book.
13.2.2 Set up the flow-check system as previously illustrated in Figure 12. VFC samplers are
normally flow-checked with a loaded filter cassette in line (i.e., between the orifice transfer standard and
the motor). The orifice transfer standard should be installed without fixed resistance plates or with the
adjustable resistance value fully open. A flow-check filter should never be used for subsequent sampling
because particles larger than 10 /*m can be collected on the filter while the inlet is raised. The sample
mass will be biased as a result of using a filter for both a flow check and subsequent sampling.
Caution: Tighten the faceplate nuts on alternate comers first to eliminate leaks and. to ensure even
tightening. The fittings should be hand-tightened; too much compressing can damage the sealing gasket.
Make sure the orifice gasket is in place and the orifice transfer standard is not cross-threaded on the
faceplate.
13.2.3 Turn on the sampler and allow the sampler to warm up to operating temperature (3-5 min).
[Note: The sampler inlet may be partially lowered over the orifice transfer standard to act as a draft
shield (if a shield is not otherwise provided). Use a block to provide at least 2" of clearance at the
bottom for airflow and for the manometer tubing.]
13.2.4 Read and record the following parameters on the VFC Sampler Flow-Check Data Sheet (see
Figure 13):
• Sampler location and date.
• Sampler S/N and model.
• Ambient temperature (Ta), °C and K.
• Ambient barometric pressure (Pa), mm Hg.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-49
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
• Unusual weather conditions.
• Orifice transfer standard S/N and calibration relationship.
• Operator's signature.
13.2.5 Inspect the manometers for crimps or cracks in the connecting tubing. Open the valves and
blow gently through the tubing, watching for the free flow of the fluid.
Adjust the manometers' sliding scales so that the zero lines are at the bottom of the meniscuses.
13.2.6 Connect the orifice manometer to the orifice transfer standard and the sampler manometer to
the sampler stagnation pressure port located on the side of the sampler base. Ensure that one side of each
manometer is open to atmospheric pressure. Be sure that the connecting tubing snugly fits the pressure
ports and the manometers.
13.2.7 Read the pressure drop as indicated by the orifice manometer (A H2O) and record the value
on the VFC Sampler Flow-Check Data Sheet. Read the stagnation pressure drop and record it as A Pstg
(mm Hg) on the data sheet.
(Note: Be sure to convert the manometer reading to mm Hg using the following equation before recording
the reading on the data sheet.]
ram Hg = 25.4(in. H2O/13.6)
13.2.8 Turn off the sampler and remove the orifice transfer standard.
13.2.9 With only a loaded filter cassette in line, turn on the sampler and allow it to warm up to
operating temperature.
13.2.10 Read and record the stagnation pressure drop (A Pstg) for the normal operating flow rate.
Turn off the sampler. Replace the vacuum cap on the stagnation pressure port.
13.2.11 Calculate and record Qa(orifice) flow rate for the flow-check point, as in the equation,
reproduced below:
Qa(orifice) = {[(A H2O)(Ta/Pa)]I/2 - b] P/m]
where:
Qa(orifice) = actual volumetric flow rate as indicated by the transfer standard orifice, m^/min.
A H2O = pressure drop across the orifice, in. H2O.
Ta = ambient temperature, K (K = °C +273).
Pa = ambient barometric pressure, mm Hg.
b = intercept of the orifice calibration relationship.
m = slope of the orifice calibration relationship.
13.2.12 Calculate and record the value of PI (mm Hg) for the measurements, with and without the
orifice installed, according to the following equation:
PI = [Pa- A Pstg ]
where:
PI = stagnation pressure, mm Hg.
Pa = ambient barometric pressure, mm Hg.
A Pstg = stagnation pressure drop, mm Hg.
Page 2.1-50 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
13.2.13 Calculate and record the stagnation pressure ratio for the measurements, with and without
the orifice installed, according to the following equation:
Stagnation pressure ratio = Pi/Pa
where:
PI = stagnation pressure, mm Hg.
Pa = ambient barometric pressure, mm Hg.
13.2.14 Refer to the instrument manufacturer's lookup table (or alternative calibration relationship
as described in Section 7.5.4) and determine the Qa(sampler) flow rates (m^/min) for the measurements
with and without the orifice installed as indicated for the ratio of Pi/Pa and ambient temperature in °C.
Record these values on the VFC sampler flow check data sheet.
13.2.15 Using Qa(orifice) and Qa(sampler) for the measurements with the orifice installed, calculate
the QC-check percentage difference as:
QC-check % difference = ^ampler) - Qa(orifice)]
Qa(orifice)
Record this value on the VFC Sampler Flow-Check Data Sheet and plot it on the control chart for QC
flow checks. If the QC-check percentage difference is less than or equal to ±1%, the sampler calibration
is acceptable. Those differences exceeding ±7% will require recalibration. Differences exceeding
±10% may invalidate all data collected subsequent to the last calibration or valid flow check. Before
invalidating any data, double-check the sampler's calibration, the orifice transfer standard's certification,
and all calibrations.
13.2.16 Using this percentage difference and Qa (sampler) from the measurements without the orifice
installed (i.e., for the normal operating flow rate), calculate the corrected sampler flow rate as:
Qa(corr. sampler = [Qa(samPler)] «"» - % difference)]
Record Qa (corr. sampler) on the VFC Sampler Flow-Check Data Sheet.
13.2.17 Determine the design flow rate percentage difference between the PMjQ sampler inlet design
flow rate (e.g., 1.13 nvVmin) and Qa (corr. sampler) as:
QC-check % difference = ^(sampler) - Qa(orifice)] m
Qa(orifice)
Record this design flow rate percentage difference on the VFC Sampler Flow-Check Data Sheet and plot
it on the control chart for the field validation of flow rates. When plotting this value, use a different
symbol than is normally used for plotting values that are obtained during sampling periods. If the design
flow rate percentage difference is less than or equal to ±7%, the sampler calibration is acceptable. Those
differences exceeding ±7% will require recalibration. Differences exceeding ±10% may invalidate all
data obtained subsequent to the last calibration or valid flow check. Before invalidating any data,
double-check the sampler's calibration, the orifice transfer standard's certification, and all calculations.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-51
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Method IO-2.1 Chapter IO-2
Integrated Sampling for SPM High Volume
14. Maintenance
Maintenance is defined as a program of positive actions aimed toward preventing failure of monitoring
and analytical systems. The overall objective of a routine preventive maintenance program is to increase
measurement system reliability and provide more complete data acquisition. The general maintenance
procedures for HV samplers are outlined in this section. For more complete information on a particular
sampler or on laboratory equipment maintenance, refer to the manufacturer's instruction manual for the
individual instrument. Maintenance activities for the HV sampler are summarized in Table 4. Records
should be maintained for the maintenance schedule of each HV sampler. Files should reflect the history
of maintenance, including all replacement parts, suppliers, costs, expenditures, and in inventory of
on-hand spare equipment for each sampler. Check sheets should be used to record preventive and/or
corrective maintenance activities and the subsequent sampler calibration curve.
14.1 Maintenance Procedures
The HV sampler is comprised of two basic components: the inlet and the flow control system. Because
of the differences between sampler models, refer to the manufacturer's instruction manual for specific
maintenance guidelines and necessary supplies.
14.2 Recommended Maintenance Schedules
14.2.1 MFC Base. The MFC base is equipped with the following items:
14.2.1.1 Connecting tubing and power lines, which must be checked for crimps, cracks, or
obstructions on sample recovery days. Fittings should be inspected periodically for cross-threading and
tightness.
14.2.1.2 A filter screen, which should be inspected on sample recovery days for any impacted
deposits.
14.2.1.3 Filter cassette gaskets, which need to be inspected each time a cassette is loaded. A worn
cassette gasket is characterized on exposed filters by a gradual blending of the boundary between the
collected particulate and the filter border.
14.2.1.4 Motor and housing gaskets, which should be checked at 3-month intervals and replaced
as necessary.
14.2.1.5 Blower motor brushes, which should be replaced before they become worn to the point
that damage may occur. Although motor brushes usually require replacement after 600-1,000 hours of
operation, the optimum replacement interval must be determined by experience. A pumice stone can be
used against the motor's contacts to ensure high conductivity. Change the brushes according to
manufacturer's instructions and perform the operator's field-calibration check as presented in Section 13.
If the sampler's indicated flow rate exceeds the manufacturer-specified design-flow-rate range, adjust the
sampler before the next run day.
To achieve the best performance, new brushes should be properly seated on the motor's commutator
before full voltage is applied to them. After the brushes have been changed, operate the sampler at
50-75% of normal line voltage for approximately 30 min. The motor should return to full performance
after an additional 30-45 min at normal line voltage.
Page 2.1-52 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume Integrated Sampling for SPM
[Note: The motors that are used for HV samplers are higher-current versions of the motors that have been
used for HV total suspended paniculate samplers. The brushes for the two types of motors are different.
Make sure that the correct replacement brushes are used for the maintenance ofHV samplers. If a motor
needs to be replaced, be sure to use the higher-current versions that are needed for HV sampling. When
lower-current motors are installed in HV samplers, the flow rate has been found to vary with changes in
the line voltage.]
14.2.1.6 A flow controller should be replaced if the flow recorder indicates no flow, low flow,
excessive flow, or erratic flow. Minor adjustments can be made to alter sampling flow rates; however,
the controller generally cannot be repaired in the field.
[Note: A flow recorder requires very little maintenance, but does deteriorate with age. Difficulty in
zeroing the recorder and/or significant differences (i.e., greater than 0.3 m?/min) in average flow rates
obtained from consecutive sampling periods usually indicate a faulty recorder. The recorder pens should
be replaced every 30 recording days. In dry climates, a more frequent replacement schedule may be
required.]
14.2.2 VFC Base. The VFC base is equipped with the following items:
14.2.2.1 Power lines, which must be checked for crimps or cracks on sample recovery days.
Fittings should be inspected periodically for cross-threading and tightness.
14.2.2.2 A filter screen at the throat of the choked-flow venturi, which should be inspected on
sample recovery days for any impacted deposits.
14.2,2.3 Filter cassette gaskets, which should be checked each time a filter is installed. A worn
casket gasket is characterized on exposed filters by a gradual blending of the boundary between the
collected particulates and the filter border.
14.2.2.4 Motor and housing gaskets, which should be checked at 3-month intervals and replaced
as necessary.
14.2.2.5 Blower motor brushes, which should be replaced before they become worn to the point
that damage may occur. Although motor brushes usually require replacement after 600-1,000 hours of
operation, the optimum replacement interval must be determined by experience. A pumice stone can be
used against the motor's contacts to ensure high conductivity. Change the brushes according to
manufacturer's instructions, and perform the operator's field-calibration check as presented in Section 13.
If the sampler's indicated flow rate exceeds the manufacturer-specified design flow-rate range, recalibrate
the sampler before the next run day.
To achieve the best performance, new brushes should be seated properly on the motor's commutator
before full voltage is applied to them. After the brushes have been changed, operate the sampler at
50-75 % of normal line voltage for approximately 30 min. The motor should return to full performance
after an additional 30-45 min at normal line voltage.
Caution: Motors that are used for HVPMjQ samplers are higher-current versions of the motors that have
been used for HV total suspended paniculate samplers. The brushes for the two types of motor are
different. Make sure that the correct replacement brushes are used for the maintenance ofHV PMj0
samplers.
14.2.2.6 If a motor needs to be replaced, be sure to use the higher-current versions that are needed
for HV PMj0 sampling. When lower-current motors are installed in HV PM10 samplers, the flow rate
has been found to vary with changes in the line voltage.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-53
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Method 10-2.1 Chapter 10-2
Integrated Sampling for SPM High Volume
14.3 Refurbishment of HV Samplers
If operated in the field for extended periods, HV PM10 samplers may require major repairs or complete
refurbishment. If so, refer to the manufacturer's instrument manual before work is undertaken. A
sampler that has undergone major repairs or refurbishment must be leak-checked and calibrated prior to
sample collection.
15. REFERENCES
1. U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems: Volume II: Ambient Air Specific Methods (Interim Edition),
EPA/600/R-94/038b.
2. U. S. Environmental Protection Agency, Code of Federal Regulations. Title 40, Chapter I,
Subchapter C, Part 50, Appendix J, Office of the Federal Register, Washington, D.C., 1988.
3. U. S. Environmental Protection Agency, Code of Federal Regulations, Title 40, Chapter I,
Subchapter C, Part 53, SubpartD, Office of the Federal Register, Washington, D.C., 1988.
4. Smith, F., P. S. Wohlschlegel, R.S.C. Rogers and D. J. Mulligan, Investigation of Flow Rate
Calibration Procedures Associated with the High Volume Method for Determination of Suspended
Particulates, EPA-600/4-78-047, U. S. Environmental Protection Agency, Research Triangle Park,
NC, 1978.
5. American Gas Association, American National Standard for Rotary-Type Gas Displacement Meters,
ANSI Standard No. B109.3, AGA Catalog No. X68606, Arlington, VA, 1986.
6. Koch, R. C. and H. E. Rector, Optimum Network Design and Site Exposure Criteria for Paniculate
Matter, EPA-450/4-87-009, U.S. Environmental Protection Agency, Research Triangle Park, NC,
1987.
7. Coutant, R. W. "Effect of Environmental Variables on Collection of Atmospheric Sulfate,"
Environmental Science and Technology, Vol. 11 (9):873-878, September 1977.
8. American Society for Testing and Materials, "Standard Method for Evaluation of Air Assay Media
by the Monodisperse OOP (Dioctyl Phthalate) Smoke Test," ASTM Standard No. D2986-71(79) in
Annual Book of ASTM Standards. Volume 11.03-Atmospheric Analysis: Occupational Health and
Safety, Philadelphia, PA 1988.
9. Harrell, R.M., Measuring the Alkalinity of Hi-vol Air Filters, EMSL/RTP-SOP-QAD534,
U. S. Environmental Protection Agency, Atmospheric Research and Exposure Assessment
Laboratory, Quality Assurance Division, Research Triangle Park, NC, 27711, October 1985.
10. "Reference Method for the Determination of Suspended Particulates in the Atmospheric (High
Volume Method)," Federal Register, Vol. 36(84), April 30, 1971.
Page 2.1-54 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.1
High Volume ^^ Integrated Sampling for SPM
11. American Public Health Association, "Tentative Method of Analysis for Suspended Particulate
Matter in the Atmosphere: (High Volume Method)," Methods of Air Sampling and Analysis,
Inter-society Committee, pp. 365-372, Washington, D.C.., 1972.
12. McKee, H. C., et al, "Collaborative Testing of Methods to Measure Air Pollutants, I, The
High-Volume Method for Suspended Particulate Matter," Journal of the Air Pollution Control
Association, Vol. 22(5):342-347, 1972.
13. "Ambient Air Quality Monitoring," 40 CFR 58, Federal Register, Vol. 44(9)2, 2755827604.
14. Benson, Levins, Massucco, Sparrow, and Valentine, "Development of a High Purity Filter for High
Temperature Particulate Sampling and Analysis," Journal of the Air Pollution Control Association,
Vol.25(3):274-277, 1975.
15. Smith, J.H., and Surprenant, N.F., "Properties of Various Filtering Media for Atmospheric Dust
Sampling," Proceedings ASTM, Vol. 55, 1955.
16. Wedding, J. B., McFarland A. R., and Cermak, J. E., "Large Particle Collection Characteristics
of Ambient Aerosol Samplers," Environmental Science and Technology, Vol. 11:387-390, 1977.
17. Fennelly, P. F., "The Origin and Influence of Airborne Particulates," American Scientist,
Vol. 64:46-56, 1976.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.1-55
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
TABLE 1. BASIC CHARACTERISTICS OF SOME COMMON FILTER MATERIAL
QUARTZ FIBER FILTER
(Glass Spun with Organic Binder)
Whatman QMA Filter
• Maximum temperature of up to 540 °C
• High Collection Efficiency
• Non-hydroscopic
• Good for Corrosive Atmospheres
• Fragile
• Lowest background metals content
CELLULOSE FIBER FILTER
;!|Celhilose Pulp)
"s"
Whatman # 41/MSA
• Low Ash
• Maximum Temperature of 150°C
• High Affinity for Water
• Enhanced Artifact Formation for SOJ and NO3
• Good for X-Ray/Neutron Activation Analysis
• Low Metal Content
MEMBRANE FILTER
(Dry Gel of Cellulose Esters)
Whatman #41
• Fragile, Therefore Requires Support Pad
• High Pressure Drop
• Low Residue when Ashed
Page 2.1-56 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
TABLE 2. SUMMARY OF USEFUL FILTER PROPERTIES
Filter and Filter
Composition
Teflon® (Membrane)
(CF2)n(2^m Pore Size)
Cellulose (Whatman 41)
(C6Hio05)n
Glass Fiber
(Whatman GF/C)
"Quartz" Gelman
Microquartz
Polycarbonate (Nuclepore)
C15H14+CO3 C0-3/00 Pore Size
Cellulose Acetate/Nitrate
Millipore(C9Hj3O7)n(1.21 jun
Pore Size)
Density
mg/cm
0.5
8.7
5.16
6.51
0.8
5.0
PH
Neutral
Neutral
(Reacts with HNO3)
Basic pH - 9
pH - 7
Neutral
Neutral
(Reacts with HNO3)
: Filter Efficiency %
99.95
58% at
0.3 fj.m
99.0
98.5
93.9
99.6
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.1-57
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
TABLE 3. MINIMUM HIGH VOLUME SAMPLER SITING CRITERIA
Scale
Micro
Middle, neighbor-
hood, urban, and
regional scale
Height above
ground,
meters
2 to 7
2 to 15
Distance from
supporting structure,
meters
Vertical
>2
>2
Horizontal*
Other spacing criteria
1.
2.
Should be >20 meters from
trees.
Distance from sampler to
obstacle, such buildings,
must be twice the height and
the obstacle protrudes above
the sampler.
Must have unrestricted
airflow 270 degrees around
the sampler inlet.
No furnace or incineration
flues should be nearby.'1
5. Spacing from roads varies
with traffic (see 40 CFR 58r
Appendix E).
Sampler inlet is at least 2 m
but not greater than 4 m
from any collocated PM10
sampler. (See 40 CFR 58,
Appendix A.)
4.
6.
aWhen inlet is located on rooftop, this separation distance is in reference to walls, parapets, or
penthouses located on the roof.
^Distance depends on the height of furnace or incineration flues, type of fuel or waste burned,
and quality of fuel (sulfur, ash, or lead content). This is to avoid undue influences from minor
pollutant sources.
Page 2.1-58
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
TABLE 4. EXAMPLE OF ROUTINE MAINTENANCE ACTIVITIES
FOR HIGH VOLUME SAMPLERS
Equipment
Sampler inlet
Sampler base
Power lines
Filter screen and throat
Gaskets
Brushes
Motor
Flow controller
Recording device
Tubing, fittings
Frequency and/or
method
Dismantle and clean at
manufacturer-specified
internals
Check for crimps or
cracks
Visually check on
sample-recovery days
At 3-mo intervals,
inspect all gaskets in the
sampler
Replace after 600-
1 ,000 h of operation
Replace if needed
Check when flowrate
changes are evident
Inspection with
experiencing difficulty
in zeroing, or when
large changes in flow
rates occur
Visually inspect on
sample-recovery days
Acceptance limits :;
No obvious particulate
deposits or damage
No obvious damage
No obvious deposits;
clean with wire brush
No leaks; no
compression damage
evident
Stable flow rate
Correct model must be
used
Stable flow rate
throughout sample run
Recorder stays zeroed;
chart advances; pen inks
No crimps, cracks, or
obstructions; no
crossthreading
Action if requirements
are hot met
Clean, replace damaged
equipment before
sampling
Replace as necessary
Clean
Replace as necessary
Replace as necessary
Obtain correct model
Replace or repair if
possible
Replace or repair if
possible
Replace as necessary.
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Page 2,1-59
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
Figure 1. Hi-vol sampler with shelter.
Page 2.1-60
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
Hi Volume Sampler in Shelter
Figure 2. Inlet to EPA approved high volume sampler.
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Compendium of Methods for Inorganic Air Pollutants
Page 2.1-61
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
Hfgh Volume
Buffer Chamber
Acceleration Nozzles
Vent Tubes
Impaction Chambe
Motor
Shelter
Air Flow
Flowrate Recorder
Flow Controller Probe
Flow Controller
Figure 3. High-volume sampler with mass flow controller and impactor design size select inlet.
Page 2.1-62 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
Buffer
Chamber
Air Flow
Acceleration Nozzle
Impaction
Chamber
Acceleration Nozzle
Impaction
Chamber
Vent Tubes
Filter Cassette
Filter
Filter Support Screen
Motor Inlet
Figure 4. Schematic diagram of an impaction inlet, for size select sampling for particulate matter
January 1997
Compendium of Methods for Inorganic Air Pollutants
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
Maintenance Access Port
Perfect
Absorber
No-Bounce
Surface
Vanes
Vanes
Assembly
Base
Insect
Screen
Housing-Deflector
Spacing
Protective
Housing
Aerodynamic Inlet
Pathway
Aerodynamic Flow
Detector
Outer Tube
Figure 5. Schematic diagram of a cyclonic inlet for size select sampling for particulate matter.
Page 2.1-64
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
Mercury
manometer
High volume
sampler motor
Thermometer
Barometer
Flow rate
transfer standard
Filter
adapter
Positive displacement
standard volume
meter (Roots® meter)
Figure 6. Flow rate transfer standard calibration setup.
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Page 2.1-65
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
Static
Pressure
Tap
(a) Orifice transfer standard with resistance plates
Static
Pressure :
Tap
Gasket Resistance plates
Resistance
adjustment knob
(b) Variable resistance orifice transfer standard
Figure 7. Typical orifice-type flow rate transfer standards.
Page 2.1-66
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
ORIFICE TRANSFER STANDARD CERTIFICATION WORKSHEET
Date: Roots meter S/N: Ta: K
Operator: Orifice S/N: Pa: mm Hg
Plate or
Volts AC
initial
Volume
Final Volume
A Vol.
ATime (min)
^Hg (mm)
AH2O (in.)
DATA TABULATION
Vstd
(x-axis)
Ostd
fy-ax/s>
UH20(Pa/Ta)]%<
m B
b «
r a
Va
(x-axis)
Qa
(y-axis)
UH20 (Ta/Pa)}'A
m *
b *
r m
CALCULATIONS
Vstd « A Vbl KPa - JHg)/7BOl (298/Ta)' Va « ^Vd [(Pa - .iHg}/Pal
Qstd » Vstd/^Time' Qa « Va/JiTime
y * mx + b y « mx + b
For subsequent flow rate calculations: • '
Ostd - lUHaOfPa/Ta)]'7* - b! 11/mj • Qa - i[±H2O tfaJPa)]*2 ~ t>! M/™!
•NOTE: For PMlO monitoring, a calibration curve corrected to standard conditions is optional.
Figure 8. Example orifice transfer standard certification worksheet.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.1-67
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
as
CT>
CM
Qstc|,stdm%min
Figure 9. Typical calibration curve for a flow rate transfer standard.
Page 2.1-68
Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
18
13
10
Cabinet
Support
Rod
Inlet
Face Plate
Least
Resistance
Calibrated Orifice
Resistance Plates
Most
Resistance
Shut-off Valves
Tygon Tubing
Gasket
Orifice Adaptor ', .„..„/ Resistance
Plate
Gasket
Attach
Faceplate Here
3E
Manometer
0-20" Oil
or Water
Filter Support Screen
Base
Figure 10. Typical calibration set-up for a mass flow controller (MFC).
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
MFC SAMPLER CALIBRATION DATA SHEET
j
1
1
1
1
(
Station Loca
Sampler Mo
3-\
Hal
S/N
mm Wri Ta ®C
?*i» mmHq T«* °C '"
jrince o/i't
Drifice calibration relations
Plate
Number
Total AH2O
(In.)
Data Tfmo
Operator _
K, Unusual conditions: _
K, ("seasonal average Ta and Pa>
Orifice Calibration Date —
X-Axfe =
Qa (orifice) flow rate*
(m3/mln)
t> - •"«
Y-Ax
Sampler APex (in. H20) Sampler
lor 1 for flow recorders! lor rt for flow
is =
APext"
recorders]0
"•Qa « (KAHzO) era/Pa)]1A - b} {1/m}
bAPext - tAPexOa + SOI/Pa)]1*
clt « HI ICTa + 30)/Pa]% if a flow recorder is used
Sampler Calibration Relationship (Qa on x-axis; APext or [It] on y-axis):
APext - mtQa (Orifice)] + b or It - mlQa(Orifice)] + b
m _ H - f -
For subsequent calculat
Qa « {[mean APex CTai
or Qa « {mean HCTav + C
Set point flow rate (SFR)
SFR - 1.13 (Ps/Pa) (Ta/Ts)
on of sampler flow rate:
/ + 30)/Pav]1/4 - b} {1/m}
JO)/Pavl1A - b} {1/m>
Samoler set noiht /SSPV
SSP « iPa/CTa + 30)1 [m(SFR) + bF
or SSP « lPa/(Ta + 30)P (m(SFR) + b] for flow
recorders
Figure 11. Example MFC sampler calibration data sheet.
Page 2.1-70
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
0-16 in. H2O Manometer
r
Resistance Plates
18 13 10 7 5
0-16 in. \r\2Q Manometer
•»• -r
AP
Calibration Orifice
Orifice Adaptor Plate
Filter Paper
Cartridge/Cassette
Stagnation
Pressure
Tap
Figure 12. Calibration of a typical volumetric flow controller (VFC).
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.1-71
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
MFC SAMPLER CALIBRATION DATA SHEET
Station Location .
Sampler Model __
Pa mm Hg, Ta
Orifice S/N
Orifice Calibration Relationship: m
Date
Time
S/N
°C
Operator
. K, Unusual Conditions
Orifice Calibration Date
b «
Plate
No.
AH20
On.)
Operational Flow Rate
amm Hg «
bQa (orifice
c% Differe
Sampler C
D Look
D New
APstg
(mm Hg)a
Pi— Pa— APsta
(mm Hg)
25.4 (in. H2O/13.6)
») « 1/m {[(AH20) CTa/Pa)]* - b}
Qa (sampler) - Qa (orifice) rinnj
Qa (orifice) J
allbratlon Relationship
up Table Validated (i.e., % difference < 4)
calibration relationship:
P1/Pa
(mm Hg)
Qa
(Orifice)
Qa (orifice)
flow rateb
(m3/mln)
Qa (orifice)
[Taj*
Qa (sampler)
(Lookup Table)
Difference0
[Taj
*
m
For subsequent calculation of sampler flow rate:
Qa - {[P1/Pa - blfTaJ^} {1/m}
Operational Flow Rate m3/min
Figure 13. Example VFC sampler calibration data sheet.
Page 2.1-72
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
MFC SAMPLER FIELD DATA SHEET
Station
Location Date SAROAD*
Sampler Model S/N
Filter ID No. Pav mm Hg. Tav °C
Sampler Manometer Readings Flow Recorder Readings
Initial APex in. H^O Mean 1
Final APex in. H«O
Mean APex in. H^O
Sampler Calibration Relationship: m «= , b « r =
Oa m3/min Elapsed Time
Qa « {[mean APex (Tav + SO/Pav)1'4 - b} {1/m}
Qa - {mean I {(Tav + 30)/Pav]'A - b} {1/m} for flow recorders
Operator
Comments:
K
min
Laboratory Calculations:
exTri std m3/min Gross weight (Wg)
Q5td - Qa (Pav/Pstfl) (Tstdrrav) Tare weight (Wt)
3 Net Weight (Wn)
Vstd stdm3 s
\A-td (Otd) (cInDi-cd time) PM10 Concentration
PM10 Concentration « (Wn) (106)/Vstd
g
g
g
/ig/std m3
Figure 14. Example MFC sampler field data sheet.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.1-73
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Method IO-2.1
Integrated Sampling for SPM
Chapter IO-2
High Volume
VFC SAMPLER FIELD DATA SHEET
Station
Location
Date.
SAROAD*
Sampler Model
Filter ID No.
S/N
Pav
. mm Hg, Tav
.K
Relative Stagnation Pressure Readings
Initial APstg_ mm H9
Final APstg • rnm Hg
Average APstg « rnrn Hg
Absolute Stagnation Pressure
Pi
Pi
. mm Hg
Pav - Average APstg
Average Stagnation Pressure Ratio (Pl/Pav)
Average Flow/rate (Qa)'.
•Obtained from manufacturer's lookup table (or
from alternate calibration relationship)
. m3/min Elapsed Time
.mm
Operator
Comments:
Laboratory Calculations:
Qstd '
Qstd - 51 (Pav/Pstd) (Tstd/Tav)
Vstd
Vstd - (Qstd) (Elapsed Time)
. Std m3/min
stdm3
Gross Weight (Wg) '
Tare Weight (Wt)
Net Weight (Wn) !
PM10 Concentration
PM10 Concentration - (Wn) (106)/Vstd
• 9
.9
.9
. /tg/std m3
Figure 15. Example VFC sampler field data sheet.
Page 2.1-74
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
High Volume
Method IO-2.1
Integrated Sampling for SPM
+15
+10
'ra
DC
o
-------
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-2.2
SAMPLING AMBIENT AIR FOR
PM1Q USING A GRASEBY
DICHOTOMOUS SAMPLER
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-2.2
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of die U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERT), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), bodi hi the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by die
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTF, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTF, NC
• Frank F. McElroy, U.S. EPA, NERL, RTF, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., Midwest Research Institute, Gary, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
-------
Method IO-2.2
Sampling of Ambient Air for PM10
Using a Graseby Dichotomous Sampler
TABLE OF CONTENTS
Page
1. Scope 2.2-1
2. Applicable Documents 2.2-2
2.1 ASTM Documents 2.2-2
2.2 Other Documents 2.2-2
3. Summary of Method 2.2-2
4. Significance 2.2-3
5. Definitions 2.2-3
6. Apparatus Description 2.2-5
6.1 General Description 2.2-5
6.2 Flow System 2.2-5
6.3 Control Panel 2.2-6
7. Apparatus Listing 2.2-6
8. Initial Calibration of Dichotomous Sampler Using a Mass Flow Controller 2.2-7
8.1 Scope 2.2-7
8.2 Significance 2.2-7
8.3 Summary of Calibrations 2.2-8
8.4 Calibration Procedure 2.2-8
9. Sampling Procedure 4 2.2-9
10. Interferences 2 2-10
11. Calculations And Record Keeping 2.2-10
12. Performance Criteria and QA 2.2-11
12.1 Flow Rates ' . 2^2-11
12.2 Filter Quality 2.2-11
13. Field Flow Calibration Check of Dichotomous Samplers 2.2-11
13.1 Scope 2.2-11
13.2 Significance 2.2-12
13.3 Flow Check Procedures 2.2-12
14. Routine Maintenance 2.2-13
14.1 Sampling Module 2.2-13
14.2 Control Module 2.2-13
14.3 Refurbishment Procedures 2.2-15
15. References 2.2-17
111
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Chapter IO-2
INTEGRATED SAMPLING OF SUSPENDED
PARTICULATE MATTER (SPM)
Method IO-2.2
SAMPLING OF AMBIENT AIR FOR PM10
USING A GRASEBY DICHOTOMOUS SAMPLER
1. Scope
1.1 Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01-100 /an
and larger. Historically, SPM measurement has concentrated on total suspended particulates (TSP), with
no preference to size selection.
1.2 The U. S. Environmental Protection Agency (EPA) reference method for TSP is codified at 40 CFR
50, Appendix B. This method uses a high-volume sampler (hi-vol) to collect particles with aerodynamic
diameters of approximately 100 jim or less. The hi-vol samples 40 and 60 ftVmin of air with the
sampling rate held constant over the sampling period. The high-volume design causes the TSP to be
deposited uniformly across the surface of a filter located downstream of the sampler inlet. The TSP hi-
vol can be used to determine the average ambient TSP concentration over the sampling period, and the
collected material subsequently can be analyzed to determine the identity and quantity of inorganic metals
present in the TSP.
1.3 Research on the health effects of TSP in ambient air has focused increasingly on particles that can
be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10 /an (PM JQ).
Researchers generally recognize that these particles may cause significant, adverse health effects. Recent
studies involving particle transport and transformation strongly suggest that atmospheric particles
commonly occur in two distinct modes: the fine (<2.5/an) mode and the coarse (2.5-10.0 pan) mode.
The fine or accumulation mode (also termed the respirable particulate matter) is attributed to growth of
particles from the gas phase and subsequent agglomeration, while the coarse mode is made of
mechanically abraded or ground particles. Particles that have grown from the gas phase (either because
of condensation, transformation, or combustion) occur initially as very fine nuclei-0.05 /tin. These
particles tend to grow rapidly to accumulation mode particles around 0.5 /an, which are relatively stable
in the air. Because of their initially gaseous origin, particle sizes in this range include inorganic ions such
as sulfate, nitrate, ammonia, combustion-form carbon, organic aerosols, metals, and other combustion
products. Coarse particles, on the other hand, are produced mainly by mechanical forces such as
crushing and abrasion. Coarse particles, therefore, normally consist of finely divided minerals such as
oxides of aluminum, silicon, iron, calcium, and potassium. Coarse particles, of soil or dust mostly result
from entrainment by the motion of air or from other mechanical action within their area. Since the size
of these particles is normally >2.5 /an, their retention time in the air parcel is shorter than the fine
particle fraction.
1.4 The procedure for sampling ambient air particulate matter using dichotomous samplers is described
in this compendium method. The dichotomous sampler collects inhalable particles (i.e., particles
< 10 /an) and separates them by size, into coarse (2.5-10 /an) particles and fine (<2.5 /an) particles.
The particles are collected on ring-mounted 37-mm diameter, Teflon® filters.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-1
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Method 10-2.2 .™
Dichotomous Sampler Integrated Sampling for SPM
2. Applicable Documents
2.1 ASTM Documents
• D4096 Application of the High Volume Sample Method for Collection and Mass Determination of
Airborne Particulate Matter.
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice for Planning the Sampling of the Ambient Atmosphere.
• D2986 Method for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate)
Smoke Test.
2.2 Other Documents
• STP598 Calibration in Air Monitoring.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94/038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b. -
• "Reference Method for the Determination of Particulate Matter in the Atmosphere, 40 CFR 50,
Appendix!. „„
• "Reference Method for the Determination of Suspended Particulates in the Atmosphere (High
Volume Method)," 40 CFR 50, Appendix B.
• EPA Project Summary Document (1).
». EPA Laboratory Standard Operating Procedures (2).
• Scientific Publications of Ambient Air Studies (3-9).
3. Summary of Method
3.1 Particles < 10 ;im are collected via a 10 pm inlet and separated into fine (<2.5 /im) and coarse
(2.5-10 /an) fractions by a virtual impactor.
3.2 The particles enter the 10 jim inlet at a flow rate of 17.6 L/min. Constant air flow through the
system is maintained by a series of rotameters.
3.3 In recent literature of ambient air particulate sampling and elemental analysis, the duration of
sampling ranges from 12-24 h depending upon experimental design and amount of ambient particulate
present.
3.4 The particles are collected on 37 mm diameter Teflon® filters. The filters should be free of pinholes
and have a pore size of less than 2 /un.
Page 2.2-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
3.5 The filters are transported from the sampling site to the laboratory in the Lexan® dichotomous filter
holders. Once at the laboratory, they are analyzed by neutron activation analysis or X-ray fluorescence
spectroscopy.
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state, and local governments are based on these data.
4.2 Inhalable ambient air paniculate matter (<10 /mi) can be collected on Teflon® filters by active
sampling using a dichotomous sampler. The dichotomous sampler collects particles in two size ranges:
fine (<2.5 /xm) and coarse (2.5-10 pm). The trace element concentrations of each fraction can be
determined using a nondestructive energy dispersive X-ray fluorescence spectrometer (Inorganic
Compendium Method IO-3.3) or neutron activation analysis (Inorganic Compendium Method IO-3.7).
5. Definitions
/Note: Definitions used in this document are consistent with those used in ASTM. Methods. All pertinent
abbreviations and symbols are defined within this document at point of use.]
5.1 Aerodynamic Diameter (a.d.). The diameter of a unit density sphere having the same terminal
settling velocity as the particle in question. Operationally, the size of a particle as measured by an
inertial device.
5.2 Aerosol. A dispersion of solid or liquid particles in gaseous media.
5.3 Ambient. Surrounding on all sides.
5.4 Calibration. The process of comparing a standard or instrument with one of greater accuracy
(smaller uncertainty) to obtain quantitative estimates of the actual values of the standard being calibrated,
the deviation of the actual value from a nominal value, or the difference between the value indicated by
an instrument and the actual value.
5.5 10 ftm Dichotomous Sampler. An inertial sizing device that collects suspended inhalable particles
(< 10 /an) and separates them into coarse (2.5-10 pm) and fine (<2.5 /im) particle-size fractions.
5.6 Differential Pressure Meter. Any flow measuring device that operates by restricting air flow and
measuring the pressure drop across the restriction.
5.7 Emissions. The total of substances discharged into the air from a stack, vent, or other discrete
source.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-3
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Method IO-2.2 Chapter IO-2
Dichotomous Sampler _ - __ _ Integrated Sampling for SPM
5.8 Filter. A porous medium for collecting partlculate matter.
5.9 Flowmeter. An instrument for measuring the rate of flow of a fluid moving through a pipe or duct
system. The instrument is calibrated to give volume or mass rate of flow.
5.10 Gas Meter. An instrument for measuring the quantity of a gas passing through the meter.
5.11 Impaction. A forcible contact of particles of matter. A term often used synonymously with
impingement.
5.12 Impactor. A sampling device that employs the principle of impaction (impingement).
5.13 Impingement. The act of bringing matter forcibly in contact. As used in air sampling, refers to
a process for the collection of paniculate matter in which the gas being sampled is directed forcibly
against a surface.
5.14 Inhalable Particles. Particles with aerodynamic diameters of < 10 /tin that are capable of being
inhaled into the human lung.
5.15 Interference. An undesired positive or negative output caused by a substance other than the one
being measured.
5.16 Mass Flowmeter. Device that measures the mass flow rate of air passing a point, usually using
the rate of cooling or heat transfer from a heated probe.
5.17 Matter. The substance of which a physical object is composed.
5.18 Orifice Meter. A flowmeter, employing as the measure of flow rate the difference between the
pressures measured on the upstream and downstream sides of the orifice (that is, the pressure differential
across the orifice) in the conveying pipe or duct.
5.19 Particle. A small discrete mass of solid or liquid matter.
5.20 Particulate. Solids or liquids existing in the form of separate particles.
5.21 ppb— a unit of measure of the concentration of gases in air expressed as parts of the gas per billion
) parts of the air-gas mixture, normally both by volume.
5.22 Precision. The degree of mutual agreement between individual measurements, namely repeatability
and reproducibility.
5.23 Pressure Gage. The difference in pressure existing within a system and that of the atmosphere.
Zero gage pressure is equal to atmospheric pressure.
Page 2.2-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
5.24 Rotameter. A device, based on the principle of Stake's law, for measuring rate of fluid flow.
It consists of a tapered vertical tube having a circular cross section, and containing a float that is free to
move in a vertical path to a height dependent upon the rate of fluid flow upward through the tube.
5.25 Sampling. A process consisting of the withdrawal or isolation of a fractional part of a whole. In
air or gas analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous
isolation of selected components.
5.26 Standard. A concept that has been established by authority, custom, or agreement to serve as a
model or rule in the measurement of quantity or the establishment of a practice or procedure.
5.27 Traceability to NIST. Documented procedure by which a standard is related to a more reliable
standard verified by the National Institute of Standards Technology (NIST).
5.28 Uncertainty. An allowance assigned to a measured value to take into account two major
components of error: The systematic error and the random error attributed to the imprecision of the
measurement process.
5.29 Virtual Impaction. Impaction of particles on stagnant air rather than a solid plate. A virtual
sampler is one in which particle size separation is accomplished by impaction into an air stream of
differing velocity rather than onto an impaction surface.
6. Apparatus Description
6.1 General Description
The dichotomous sampler described throughout this method is the Graseby Dichotomous Sampler, 500
Technology Court, Smyrna, GA 30082 (800) 241-6898. This sampler is a low-flow rate (16.7 L/min)
sampler that divides the air stream passing the 10 urn inlet into two portions that are filtered separately.
The samplers cut the 0- to 10-jim total sampler into 0- to 2.5-/mi (fine) and 2.5- to 10-jtm (coarse)
fractions that are collected on separate 37-mm diameter Teflon® filters. The sampler (see Figure 1)
consists of two modules: the sampling module and the flow control module. Specifications for the
Graseby Dichotomous Model 244 sampler are given in Table 1.
6.2 Flow System
Particle-laden air passing through the fractionating inlet of the dichotomous sampler is forced to take a
sharp turn upon entry. Because of their greater mass (inertia), most large particles (>30 /mi) cannot
make this turn into the cap and continue to move in their original direction. The impactor-type aerosol
inlet of the dichotomous sampler is illustrated in Figure 2. In an inlet designed for a 10-/mi separation,
particles > 10 /mi in diameter do not make the turn into the internal inlet. The Graseby dichotomous
sampler currently samples particles in the range of < 10 /mi. The application of the design in
dichotomous samplers to divide the aerosol into a coarse fraction (2.5-10 /*m) and a fine fraction
(<2.5 /mi) by means of the virtual impactor technique is illustrated in Figure 3. After passing through
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-5
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Method 10-2.2 Chapter IO-2
Dichotomoiis Sampler Integrated Sampling for SPM
the inlet, the air containing inhalable particles is forced to pass through an acceleration jet and then
around a lower jet having a lower velocity air flow. Most of the fine particles do not follow the
high-velocity flow stream (15.0 L/min) and are captured on the fine particle filter. This particular design
is called "virtual impaction" because the particles impact on a slowly pumped (1.67 L/min) void rather
than on a solid plate. The coarse-particle flow, 1.67 L/min, is controlled by its flow selector valve,
which feeds into the inlet of the pump. The coarse and fine flows are relatively constant except for small
decreases that can occur during sampling.
6.3 Control Panel
The control panel is behind a weathertight door and contains vacuum gauge, rotameters, elapsed time
meter, and timer. The control module for the dichotomous sampler is illustrated in Figure 4. The
junctions of the various displays and controls are described below.
6.3.1 Flow Control and Measurement. Flow control valves and rotameters are provided for setting
the total- and coarse-particle flow rates. Vacuum gauges, measure the pressure drop across the filters
collecting the fine and coarse particles.
6.3.2 Timer. The sampler is equipped with a 7-day mechanical timer. The timer is divided into
seven segments, each representing a day of the week. Each day segment is marked with the hours of the
day. An "on" and an "off1 tripper are positioned to the desired day of week and time of day for sampler
operation.
6.3.3 Elapsed Time Meter. The elapsed time meter indicates the total time that the sampler has
actually operated.
7. Apparatus Listing
Mote: The following list of equipment is specific for the Graseby Dichotomous Model 244 Dichotomous
Sampler, (equipped with the Graseby PM]0 inlet, Graseby, 500 Technology Court, Smyrna, GA 30082
(800) 241-6898.]
7.1 Sampling Module
7.1.1 Graseby PM10 Fractionating Inlet. Separates particles of > 10 fim and prevents them from
entering the system, Graseby, 500 Technology Court, Smyrna, GA 30082 (800) 241-6898.
7.1.2 Dichotomous Sampler Module. Separates particles into a coarse fraction (2.5-10 pm) and
a fine fraction (<2.5 /un) Graseby, 500 Technology Court, Smyrna, GA 30082 (800) 241-6898
7.1.3 Vacuum Pump. Diaphragm type 1/4 hp, best source.
7.1.4 Vacuum Gauge. ±10% accuracy, best source.
7.1.5 Rotameter. ±1.5% accuracy at 1 m3/hr flow rate, best source.
7.1.6 Elapsed Time Indicator.
7.1.7 Timer. Mechanical, 7-day, double pole, double throw. Accuracy ± 15 min per 24 h, best
source.
7.1.8 Filters. 37 mm Teflon®, 2 /*m pore size, ring-mounted, best source.
7.1.9 Interconnecting Tubing. 10 m long, 3/8" o.d. for fine-particle flow, 1/4" o.d. for
coarse-particle flow, best source.
Page 2.2-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
7.1.10 Filter Holders. Circular, Polyolefm or Lexan®, 1.750" o.d. , best source.
7.2 Calibration Modular (see Figure 5)
7.2.1 Transfer Standards. Mass flowmeter, dry gas meter, or other flow-measuring devices
traceable to NIST and capable of accurately (±2% at the 95% confidence level) measuring flows over
the ranges of 0-20 L/min and 0-5 L/min, best source.
7.2.2 Barometric Pressure Gauge. A barometer capable of measuring barometric pressure to the
nearest 5 mm Hg (0.5" H2O), best source.
7.2.3 Timer. Timer (if dry gas meter is used as flow measuring device) capable of measuring 0.1 s
for time intervals of 30 s up to several minutes, best source.
7.2.4 Filters. A set of filters identical to those used to collect samples in the field, best source.
7.2.5 Miscellaneous. An adapter to connect the orifice device to the inlet of the sampler; flexible
tubing to connect the ports of the orifice device to the ports of the manometer and the inlet of the sampler
to the mass flowmeter.
8. Initial Calibration of Dichotomous Sampler Using a Mass Flow Controller
8.1 Scope
Dichotomous samplers are calibrated using flow measurement devices (mass flowmeters and dry test
meters) that have been referenced to a positive displacement volume standard traceable to the National
Institute of Standards and Technology (NIST).
8.2 Significance
8.2.1 Each sampler and each field calibration check orifice device is calibrated for a specific site.
The average site barometric pressure is calculated from the site elevation or based on measured values.
Calibration data for both sampler rotameters and calibration check orifice devices are calculated from the
seasonal average site barometric pressure and temperature for the period during which the sampler is
operating.
, 8.2.2 Flow rate calibrations are expressed in terms of volumetric flow rates at ambient conditions
because the sampler's cutpoints depend on a fixed actual flow rate, not a fixed flow at standard
conditions.
8.2.3 The sampler's rotameter calibration must be within 10% of the total flow rate indicated by the
calibration flow check orifice.
8.2.4 Calibrations of the sampler rotameters and the field calibration check device are traceable to
the NIST via the following procedure. Primary standards such as bubble flowmeters, spirometers, and
frictionless pistons certified by NIST are used to calibrate the mass flowmeter and dry gas meter as
transfer standards that, in turn, are used to calibrate the sampler's rotameters and the field calibration
check device. Records of all calibrations should be kept on file.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-7
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Method IO-2.2 Chapter IO-2
Dichotomous Sampler Integrated Sampling for SPM
8.3 Summary of Calibrations
Each dichotomous sampler's rotameters must be calibrated before being shipped to the field. A Field
Flow Check Orifice is calibrated and shipped with the sampler(s) for performing calibration checks in
the field. Sampler rotameter calibrations are performed when the sampler's calibration is out of
specification.
8.4 Calibration Procedure
The sampling system is set up in its normal operation configuration with a calibrated flow measuring
device connected in place of the fractionating inlet to the sampling module (see Figure 5). Clean filters
should be installed in the sampling module, and all front panel toggle switches on the control module
should be switched off.
8.4.1 Turn on the sampler and mass flowmeter (if used) and allow them to warm up to operating
temperature (about 5 mm). Fully open the control valves for both rotameters (counterclockwise).
8.4.2 Fill in pertinent information on the Dichotomous Transfer Standard Calibration Form (see
Figure 6). Leak the check system according to Section 14.3.3.1.
8.4.3 Close the control valve on the coarse rotameter. Ensure that the throttle valve on the inlet
arrangement is fully open.
8.4.4 Adjust the flow rate through the total rotameter to the first rotameter ball setting as observed
from the Dichotomous Flow Orifice Calibration Curve (see Figure 6) by using the manometer reading
on the x-axis. Observe the flow rate from the mass flowmeter (or dry gas meter) and record next to the
rotameter setting under the total rotameter section of the data sheet.
[Note: The mass flo\vmeter or dry gas meter may have correction factors supplied with them. Multiply
the mass flowmeter reading by the correction factor and record as "corrected flow. "Ifa dry gas meter
is used, the volume of air passing through the meter must be timed. The volume of air through the meter
divided by the time required yields the flow rate. Correct this flow rate to standard conditions (25 °C and
760 mm Hg). Enter this volume as corrected flow.]
8.4.5 Repeat Section 8.4.4 for each additional total rotameter point listed on the data sheet.
8.4.6 Reset the flow rate through the total rotameter to 16.7 L/min using the current calibration table
and turn the sampler off.
8.4.7 Disconnect the 3/8-in. o.d. tubing from the fine particle side of the filter holder and install a
plug fitting on the holder.
8.4.8 Turn the sampler on and adjust the flow through the coarse rotameter to the first rotameter
setting listed on the Dichotomous Transfer Standard Calibration Form, Figure 7. Record the
corresponding flow rate as measured by the mass flow meter or dry gas meter.
8.4.9 Repeat Section 8.4.8 for each coarse rotameter setting listed on the data sheet.
8.4.10 Reset the flow rate through the coarse rotameter to 1.67 L/min using the current calibration
table and turn the sampler off.
8.4.11 Remove the plug fitting installed in Section 8.4.7 and re-connect the 3/8-in. o.d. tubing to
the filter holder.
8.4.12 Develop calibration tables for the total and coarse rotameters by linear regression and maintain
with the sampler for future reference.
Page 2.2-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
9. Sampling Procedure
9.1 Ensure that the sampling module is clean and free of paniculate deposition on its inner surfaces.
Ensure the bug screen is clean as documented in Section 14.
9.2 Loosen the knurled filter holder ring nut for the coarse paniculate flow and lower the filter holder.
The coarse paniculate filter holder has 1/4" o.d. tubing and is aligned with the center of the virtual
impactor head and aerosol inlet. Remove a Lexan® filter cassette containing a preweighted filter from
its plastic container and install it on the support screen in the filter holder. The lower half of the cassette
(the side having the shortest distance to the filter surface) goes on the screen. Ensure that the filter holder
O-ring is in place. Raise the filter holder into place and tighten the knurled ring nut. Mark "COARSE"
or "C" on the plastic container from which the filter cassette was removed.
9.3 Loosen the knurled filter holder ring nut for the fine paniculate flow and lower the filter holder.
The fine paniculate filter holder has 3/8" o.d. tubing and is offset from the center line of the virtual
impactor head and aerosol inlet. Remove a preweighted filter cassette from its plastic container and
install it on the support screen. Ensure that the filter holder O-Ring is in place. Raise the filter holder
into place and tighten the knurled ring nut. Mark "FINE" or "F" on the plastic container from which
the filter cassette was removed.
9.4 Open the front cover to the closure of the control module. The latch is opened by turning the knob
counterclockwise and released by turning the indicator one-quarter turn counterclockwise; it is locked by
reversing this process.
9.5 Turn the mechanical timer switch to "off."
9.6 Connect the main power cord to line voltage. Leak check the system as illustrated in
Section 14.3.3.1.
9.7 Ensure that the flow selector valve on the bottom of the total rotameter is open.
9.8 Turn the mechanical timer switch to "on."
9.9 Set the total flow rate by adjusting the flow control valve to a reading on the total rotameter that will
give an ambient flow rate of 0.0167 m3/min (17.6 L/min), as determine by a previous calibration of the
sampler. Record the rotameter set point on the project data sheet. The vacuum gauge will read
approximately 1-2" Hg for a 2-3 fim pore size Teflon® filter. The flow control valve will require only
slight adjustment between sampling periods.
9.10 Set the coarse flow rate by adjusting the flow control valve to a reading on the coarse rotameter
that will give an ambient flow rate of 0.00167 m3/min (1.67 L/min), as determined by a previous
calibration of the sampler. Record the rotameter set point on the Dichotomous Field Test Data Sheet (see
Figure 8). The vacuum gauge will read approximately zero. The flow control valve will require only
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-9
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Method 10-2.2 ™
Dichotomous Sampler Integrated Sampling for SPM
minor adjustment between samples. A Coarse Rotameter Calibration Table should be developed for each
sample based upon most recent calibration curves.
9.11 Turn the mechanical timer switch to "off." Set the correct time by rotating the dial until the correct
day and time of day appear at the red pointer. Position the "on" tripper to the day and time of day that
the unit is to begin sampling. Position the "off1 tripper to the day and time of day that the unit is to stop
sampling. Reset the elapsed time indicator to 0000.00 min by pressing the reset button. Close the front
cover of the control module. The unit is ready to sample.
9.12 After the sampling period is over, turn the sampler on and allow it to run approximately 5 min.
Record the final total and coarse rotameter readings on the Dichtomous Field Test Data Sheet. Turn the
sampler off.
9.13 Remove the exposed filter cassette from the coarse flow filter holder and return it to the plastic
container from which it originally came. Record the filter number on the Dichotomous Field Test Data
Sheet.
9.14 Remove the exposed filter cassette from the fine flow filter holder and return it to the plastic
container from which it originally came. Record the filter number on the Dichotomous Field Test Data
Sheet.
9.15 Ship both filters, along with a chain-of-custody, back to the laboratory for gravimetric and
elemental analysis.
10. Interferences
The dichotomous sampler should only be operated at the flow rate mentioned in Section 6.2 otherwise
particle size fractionation will be inaccurate.
11. Calculations And Record Keeping
11.1 Information pertaining to the identification of the filters and the operation of the sampler should
be recorded on the Dichotomous Field Test Data Sheet. Pertinent information that should be recorded
on any data sheet is as follows:
• Sampling site.
• Sampler identification number. ,
• Coarse rotameter reading that provides an ambient flow of 0.00167 m /min.
• Total rotameter reading that provides a flow of 0.0167 m3/min.
• Date of sampling.
• Coarse filter identification.
• Fine filter identification.
* Coarse rotameter reading at the end of sampling.
Page 2.2-10 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
• Total rotameter reading at the end of sampling.
• Time of sampler operation.
• Comments about sampler and sample period.
11.2 Information should be recorded in a diary format in an instrument logbook. This log should
indicate the time and nature of maintenance, periods when samplers are out of service and the reason,
dates of field calibration flow checks and QC checks, and unusual occurrences such as power outages,
dates of sampler replacements, and operating personnel changes. This log will be used to help identify
unusual trends or patterns that may be site-, operator-, or sampler-induced.
11.3 The following data are obtained by calculations of the collected values acquired in Section 9.
11.3.1 Average Coarse Rotameter Reading. This reading is determined by adding the beginning
coarse rotameter reading to the final coarse rotameter reading and dividing by 2. Look up the coarse
rotameter reading on the Coarse Rotameter Calibration Table for the corresponding standard flow rate
(in rcr/min)i
11.3.2 Average Total Rotameter Reading. This reading is determined by adding the beginning total
rotameter reading to the final total rotameter reading and dividing by 2. Look up the average total
rotameter reading on the Total Rotameter Calibration Table for the corresponding standard flow rate (in
m^/min).
11.3.3 Fine Average Flow. Subtract the coarse flow rate from the average total flow rate.
11.3.4 Percent Error. Subtract the orifice flow rate (m^/min) from the total sampler flow rate
(m3/min) and divide by the orifice flow rate (nr'/min).
11.3.5 QC Flowcheck. Add 100 to the percent error to obtain the QC flowcheck percent.
12. Performance Criteria and QA ,
12.1 Flow Rates
12.1.1 Decreases in flow rate during sampling of > 10% from the initial setpoint will require that
the unit be checked for performance.
12.1.2 Changes in flow rate calibration of > 10%, as determined by a field calibration check, will
require that the unit be checked for performance and recalibrated.
12.2 Filter Quality
Any filter that is obviously damaged (i.e., torn or frayed) should be voided.
13. Field Flow Calibration Check of Dichotomous Samplers
13.1 Scope
During routine operation of a dichotomous sampler, a flow calibration check should be performed
periodically to assure sample accuracy and equipment performance. The check is made by installing an
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-11
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Method 10-2.2 Chapter IO-2
Didiotomous Sampler Integrated Sampling for SPM
orifice device (calibrated over the operating range of the total rotameter) on the inlet to the sampler, as
illustrated in Figure 5, without the mass flow controller.
13.2 Significance
Changes in flow rate calibration of > 10%, as determined by a field calibration check, will require that
the sampler unit be checked for performance and recalibrated.
13.3 Flow Check Procedures.
133.1 Apparatus Listings. The following equipment is required for a field calibration check:
• Calibrated orifice (see Figure 5).
• Audit orifice calibration table or developed curve.
• Dichotomous sampler total and coarse rotameter calibration tables.
• Water or red oil manometer calibrated in inches of water (range should be 0-16" H2O).
13.3.2 Procedure.
13.3.2.1 Install clean filters in the sampling module as described in .the operating procedure.
13.3.2.2 Remove the inlet to the sampling module and install the flow check orifice. Connect the
tubing from the manometer to the ports on the orifice. Open fully both ports on the manometer and align
the zero on the scale with the water or oil level in the manometer.
13.3.2.3 Turn on the sampler and allow it to warm up to operating temperature (approximately
5 min).
13.3.2.4 Open both total and coarse flow control valves fully counterclockwise. Adjust both the
total and coarse rotameters to their respective seasonal setpoints that will provide a total flow of
0.0167 m3/min (16.7 L/min) and a coarse flow of 0.00167 m3/min (1.67 L/min). Use the total and
coarse (ambient) rotameter calibration tables. Record the total rotameter reading and the corresponding
flow rate (0.0167 m3/min) on the Dichotomous Flow Check Data Sheet (see Figure 9).
13.3.2.5 Record the orifice serial number and its calibration date on the Dichotomous Flow Check
Data Sheet. Observe and record the manometer reading. Find the manometer reading on the orifice
calibration table and record the corresponding ambient flow rate in cubic meters per minute (m /min).
13.3.2.6 Turn off the sampler, remove the orifice device, and replace the inlet to the sampling
module.
13.3.2.7 Remove the flow check filters from the sampling module.
13.3.3 Calculations. Calculate the percent error by using the information above in the formulas
provided on the Dichotomous Flow Check Data Sheet. Calculate the value on the Flow Check Data
Sheet.
133.4 Performance Criteria and QA. If the calculated quality control (QC) Check % is within
± 10% of the 0.0167 m3/min total flow rate, the sampler is operating properly. A calculated QC Check
% not within ±10% of the 0.0167 nrVmin total flow rate indicates that there is a leak or other
malfunction. The sampler must be examined, tested, and, if necessary, recalibrated.
Page 2.2-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
14. Routine Maintenance
[Note: Step-by-step instruction for maintaining and repairing the sampler are provided in this procedure.
Information for disassembling, cleaning, replacing, and repairing each component of the sampler is
provided.]
14.1 Sampling Module
14.1.1 All parts are sealed with O-rings. Internal particulate deposits accumulate primarily on the
outer and inner surfaces of the tip of the receiver tube in the virtual impactor head. The receiver tube
should be inspected periodically for such particulate deposits and cleaned as required. The receiver tube
should be cleaned every 3-4 months. The remaining inner surfaces should be cleaned every 6-12 months.
Cleaning should be done with alcohol or water using a camel's-hair brush. Disassembly and internal
cleaning should normally not be attempted in the field.
14.1.2 The diametral O-rings in the aerosol inlet and the flow-splitting chamber should be
conditioned periodically with vacuum grease (see Figure 2).
14.1.3 The bug screen in the aerosol inlet should be cleaned periodically during the summer months.
A diametral O-ring in the aerosol inlet acts as the seal.
14.1.4 Sampler connector tubing should be examined periodically and replaced as necessary (see
Figure 3).
14.1.5 Recalibration is required if the unit is disassembled for cleaning or if a field flow check
reveals that the unit is out of limits. Clean the sampling module as follows:
14.1.5.1 Dismantle and clean the 10-jim inlet assembly by removing four Phillips head screws and
wiping out the interior with the cleaner and paper towels. Allow the unit to dry, then carefully
reassemble.
14.1.5.2 Dismantle and clean the main sample head by following these steps:
• Mark each assembly point of the sample inlet with pen or pencil to provide "match marks" during
reassembly.
• Disassemble the unit, taking care to retain all O-rings and miscellaneous parts.
[Note: Many of the assembly screws may appear frozen, in which case pliers or penetrating oil may be
required.]
• Clean all interior surfaces with the general-purpose cleaner, paying particular attention to small
openings and crevices. Cotton swabs or a small brush are helpful in these areas. Completely dry
all components.
• Reassemble the unit in accordance with the previously scribed match marks. Take particular care
to ensure that all O-ring seals are properly seated and that all screws are uniformly tight.
14.2 Control Module
[Warning: Unplug the line power cord from its receptacle before removing the front panel of the Graseby
Model 244 control module enclosure.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-13
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Method 10-2.2 Chapter IO-2
DJchotomous Sampler Integrated Sampling for SPM
14.2.1 FUter Elements. After approximately 12-24 months of sampling, the vacuum pump jar filters
for the coarse and fine particle flows may need replacement. In normal operation, air entering these jars
is filtered by the two 17-mm membrane filters in the sampling module. Hence, jar filter replacement is
infrequent. To replace these filters, unplug the line power cord and remove the front panel of the control
module by removing the 6 screws. The filter jar from the coarse-particle flow is the small jar
(approximately 2.5" dia. x 3" long) in the upper left side of the enclosure. Unscrew the jar, remove the
old filter element, and replace with a new element. Tighten the jar very tightly when installing, to avoid
leaks. The fine-particle filter jar is behind the coarse-particle filter jar. It is approximately 3" dia. x 5"
long and is the one closest to the bulkhead fitting on the side of the enclosure.
14.2.2 Vacuum Pump. The diaphragm of the vacuum pump should be replaced routinely at 1-yr
intervals or if sampler vacuum is suddenly reduced and a leak check indicates there are no leaks in the
system. To replace the diaphragm, unplug the line voltage and remove the front panel (see Figure 4).
Remove the finned head of the pump by removing the 6 head screws. Remove the four diaphragm plate
hold-down screws and change the diaphragm. To reassemble, reverse the procedure, making sure that
the screw clearance cavity in the plate is lined up under the intake valve screw heads and that all head
screws are tightened evenly. Clean the control module as follows (see Figure 4):
14.2.2.1 Ensure that power is disconnected from the unit. If compressed air is available, open the
unit and blow out loose dust and dirt.
14.2.2.2 Wipe down all surfaces with the general-purpose cleaner and towels. Make note of any
obvious problems in the unit and take action to correct them before completion of cleaning.
14.2.2.3 Check rotameters for cleanliness. If they are dirty or contain water, they must be
removed and cleaned. (If water is found, the interior of the vacuum pump may be damaged. It will have
to be opened for inspection and possible repair.) Rotameters are cleaned by the following steps:
• Remove the tubing from the total rotameter output port and any other connected tubing that
may prove too inflexible to allow removal of the rotameters.
• Remove the four screws securing the rotameter assembly to the front panel.
• Slip the assembly back from the front panel to gain access to the alien screws in the tops of
the rotameters. Remove the protective covers from each rotameter.
• While holding the glass rotameter with one hand, loosen the large alien screws just enough to
allow removal of the unit. Repeat for each unit.
• Clean the two rotameters with the cleaner, followed by a thorough rinsing in distilled water.
CTo properly clean the unit, remove the float and its retainers. The retainers are easily
removed with the aid of a wire hook fashioned from a paper clip.)
• Allow the tubes to dry thoroughly. Then reassemble.
14.2.2.4 Remove and clean all filter jars (check each for possible cracks and replace if necessary).
Clean or replace all dirty filter elements.
14.2.2.5 Clean the fan's blades and housing. Observe the housing for any dirt buildup that could
cause the fan to lock up.
14.2.2.6 Clean exterior surfaces of the unit, ensuring that all cooling vents are open. Check all
mounting brackets to ensure that they are tight and in good repair.
14.2.2.7 When all cleaning operations and necessary repairs are completed, close the module and
reconnect the sample module to allow performance of leak and calibration checks.
Page 2.2-14 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
14.3 Refurbishment Procedures
Step-by-step instruction for refurbishing samplers that may have been operated in the field for extended
periods are described in this procedure. Information is provided for disassembling, cleaning, replacing,
and repairing each component of the sampler.
14.3.1 Control Module.
14.3.1.1 Using a general household cleaner, clean all exterior surfaces of the module (see
Figure 4). Observe the general condition of the cabinet and hardware items. Any damaged or missing
components must be replaced before the unit is returned to service.
14.3.1.2 Open the front door of the unit and clean the interior surfaces. Examine the front panel
for the presence of water in the rotameters. (If any water is present, the vacuum pump must be inspected
for interior water damage.)
14.3.1.3 Using a combination of cleaner and compressed air, clean all interior surfaces of the unit.
Remove, clean, and replace all filter jars and media. Replace any damaged components.
14.3.1.4 Remove and clean both rotameters by removing the 4 bracket screws, disconnecting
necessary tubing, and pulling the assembly free. Remove each glass tube by loosening the alien screw
at the end of each rotameter. Remove the white stops and ball floats from the glass rotameters. Flush
out the rotameters with distilled water; then swab them out with a soft tissue and set aside to dry
thoroughly before reinstallation.
Caution: Be sure to check the cooling fan. It tends to collect dust, and. if the buildup is sufficient, the
blades will bind and subsequently destroy the fan. Screens are available to filter out this dust and should
be installed if possible during the refurbishment process.
14.3.1.5 Check all electrical wiring and connections. Replace any frayed or damaged components.
Caution: If water was initially observed in the rotameters, check the vacuum pump for water damage by
removing the cylinder head and valve plate and removing any moisture or corrosion.
14.3.1.6 Reassemble rotameters (only if they are completely dry) and reinstall them in the unit.
Make a final check of all plumbing to ensure that reconnections have been made properly and that all
fittings are tight.
14.3.1.7 Temporarily secure the front panel of the module and perform a brief operational check
as follows:
• Connect power to the unit and manually turn on sampler.
• Advance flow control valves and observe rotameters for smooth operation throughout their
range.
Caution: If the sampler is equipped with a filter overload switch, it must be turned off or disabled (by
removing one of the relay coil wires) before a leak or performance test can be done.
• Leak-test the unit by capping off the tubing inlet ports and observing the vacuum gauges for a
maximum reading.
• Once a maximum has occurred, turn off the sampler and observe the rate of decrease in vacuum
readings. A slow, gradual decrease requiring 60 s or more to reach a minimum is the mark of
a good system. A rapid decline indicates a leakage problem that should be investigated.
[Note: Filter jars are often leakage areas, and some pumps tend to leak. A leaky pump can be identified
by plugging the output port immediately after turning off power to the unit. If the rate of decline is
slowed, then the system is acceptable.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-15
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Method 10-2.2 Chapter IO-2
Dicholomous Sampler Integrated Sampling for SPM
14.3.2 Sample Module. This assembly initially should be inspected for any damaged or missing
components. Attention should be given to all hardware items at this point; penetrating oil may need to
be applied to selected hardware to disassemble the units for cleaning. Actual disassembly and cleaning
should proceed as follows:
14.3.2.1 Disassemble the unit as shown into various subassemblies.
14.3.2.2 Using general-purpose household cleaner, clean all interior surfaces, paying special
attention to the various small nozzles and openings in the various components. Rinse with distilled water
and dry thoroughly.
14.3.2.3 Inspect all seals in the unit and replace any questionable ones. Pay special attention to
those that seal the filer cassettes.
14.3.2.4 Reassemble the module, using stainless steel hardware to replace all defective screws.
14.3.2.5 Disassemble and clean the 10-/«n inlet. To disassemble the inlet, unscrew the 3"
diameter outer-tube containing the impaction chamber. Clean all interior surfaces. Inspect and replace
the O-ring seal, if necessary, and reassemble the unit. The precipitation trap should be removed and
cleaned at the same time.
14.3.3 Operational Tests. The following procedure provides tests to determine if the.sampler is
ready for field operation. The sampling system should be set up in its normal operating configuration
with a calibrated flow measuring device connected in place of the inlet hat (see Figure 5). Clean filters
should be inserted in the sample module, and all front panels toggle switches on the control module
should be switched off. Required environmental data should be recorded on the data sheet and, before
actual calibration, the following preliminary system tests should be performed.
14.3.3.1 System Leak Test. Open both rotameters (counterclockwise). Apply power to the
sampler and, after the unit reaches full flow, close the throttle valve on the sample inlet tube. Once a
maximum indication on the total vacuum gauge is observed, shut off power to the unit, record the
maximum reading on the data sheet, and observe the vacuum gauges' rate of decline.
[Note: Leak-free systems should indicate a vacuum of 23" Hg or more, and the rate of decline to 0
indication should require 60 s or more. If these conditions are not met and the control module was
successfully leak-tested previously, a leak exists either in the interconnecting tubing or the sample
module.]
14.3.3.2 Pump Performance Check. With conditions as in the system leak test, open the throttle
valve and apply power to the unit. Once stable flow is achieved, adjust the valve to give an actual flow
through the system of 16.7 L/min (0.0167 nrVmin). Observe and record on the maintenance sheet the
indicated total vacuum gauge indication.
[Note: A good pump should give an indication of 17.25" Hg or more. Readings lower than this value
indicate possible pump diaphragm or reed valve problems, which should be checked at this time.]
14.3.3.3 Filter Overload Test. If this option is present (identified by a relay mounted on back
of the clock timer and a black plastic transducer plumbed into the total vacuum gauge), it should be tested
by opening the inlet throttle valve and switching the device on. With the sampler energized, slowly close
off the throttle valve while observing the total vacuum gauge. The overload feature should shut down
the system when approximately 15" of vacuum is reached.
Page 2.2-16 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.2
Integrated Sampling for SPM Dichotomous Sampler
15. References
1. Dzubay, T.G., Development and Evaluation of Composite Receptor Methods, EPA Project Summary,
EPA-600/3-88-026, U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711,
September 1988.
2. Inhalable Paniculate Network Operations and Quality Assurance Manual, Office of Research and
Development, Environmental Monitoring Systems Lab, U.S. Environmental Protection Agency, Research
Triangle Park, NC, 27711, May 1980.
3. Bevington, P.R, Data Reduction and Error Analysis for the Physical Sciences, McGraw-Hill Book
Co., New York, NY.
4. Dzubay, T.G., "Chemical Element Balance Method Applied to Dichotomous Sampler Data," Annals
of the New York Academy of Sciences, 1980.
5. Goulding, F.S., and Jaklevic, J.M., Fabrication of Monitoring System for Determining Mass and
Composition of Aerosol as a Function of Time, U. S. Environmental Protection Agency, Research
Triangle Park, NC, 27711, EPA 650/2-75-041, June 1975.
6. Hodges, M.G., and Wright, E.W., Intercomparison of High-Volume, PM]0, and Dichotomous
Paniculate Matter Samplers at a Site with Low Paniculate Matter Concentrations, Environmental Science
and Engineering, Inc., Gainesville, FL, September 1987.
7. NIST Standard Reference Materials Catalog, National Institute of Standards and Technology,
Publ. 260, U.S. Department of Commerce, Washington, DC, p. 64, June 1986.
8. Operating Procedure for the Sierra Series 244E Dichotomous Sampler Equipped with the Andersen
Andersen Model 246B PM10 Inlet, Environmental Monitoring Systems Lab, Office of Research and
Development, U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711, May 1980.
9. Stevens, R.K., and Dzubay, T.G., "Dichotomous Sampler - A Practical Approach to Aerosol
Fractionation and Collection," EPA 600/2-78-112, Environmental Monitoring Systems Lab, Office of
Research and Development, U. S. Environmental Protection Agency, Research Triangle Park NC 27711
June 1978.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.2-17
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Method IO-2.2
Dichotomous Sampler
Chapter IO-2
Integrated Sampling for SPM
TABLE 1. SPECIFICATIONS FOR THE GRASEBY MODEL 244
DICHOTOMOUS SAMPLER
Item
Collection efficiency
Internal losses
Flow rates
Flowmeters
Concentration ratio
Vacuum pump
Timer
Elapsed time indicator
Filter media
Filter holder
Interconnecting tubing
Aerosol inlet
Power required
Overall dimensions
Net weight
Total shipping weight
Specifications
Mass median diameter at 50% collection efficiency
for equivalent spherical particles at 1 g/cnr' is
2.5 jtm
Maximum value over range of 0-20 /un is < 1-2%
and occurs at 2.5 /on. Average loss for all particles
is <1%.
Total flow: 1 m3/h, or 16.7 L/min;
Fine-particle flow: 0.9 nv*/h., or 15.0 L/min;
Coarse-particle flow: 0.1 m^, or 1.67 L/min.
Precision rotameters, +.1.5% accuracy at above
flows.
10:1.
Diaphragm type, split phase motor, 1/4 hp.
Mechanical, 7-day, double pole, double throw,
120 volt, 60 Hz. Accuracy: .+ 15 min in 24 h.
9999.99 min; resettable.
37-mm membrane or glass fiber; Teflon® membrane
media recommended.
Circular, polyolefin, 1.750" o.d.
10 m long; 3/8" o.d. for fine-particle flow; 1/4" o.d.
for coarse-particle flow.
10 jrni nominal cutpoint over approximately
0-20km/h wind speed range; includes bug screen.
115 V a.c. .±15%, 50-60 Hz, 200 W.
Control module: 16" H x 11" W x 22" L; sampling
module: 40" H x 25.63" diam. tripod base bolt
circle.
Control module: 50 Ib; sampling module: 15 Ib.
85 Ib.
Page 2.2-18
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-2
Integrated Sampling for SPM
Method IO-2.2
Dichotomous Sampler
n
I I
INLET HEAD
FINE FLOW
(2.5
0 0
Coarse
Flow
Roatometer
Total
Flow
Roatometer
Figure 1. Graseby Model 244 dichotomous sampler.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.2-19
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Method IO-2.2
Dichotomous Sampler
Chapter IO-2
Integrated Sampling for SPM
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.2
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Compendium of Methods for Inorganic Air Pollutants
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Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2
Integrated Sampling for SPM
Method IO-2.2
Dichotomous Sampler
DICHOTOMOUS TRANSFER STANDARD CALIBRATION FORM
Mass flowmeter S/N:
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January 1997
Figure 7. Dichotomous transfer standard calibration form.
Compendium of Methods for Inorganic Air Pollutants
Page 2.2-25
-------
Method IO-2.2
Dichotomous Sampler
Chapter 1O-2
Integrated Sampling for SPM
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Chapter IO-2
Integrated Sampling for SPM
Method IO-2.2
Dichotomous Sampler
Location:
Date: _
Dichotomous Flow Check Data Sheet
Atmospheric pressure:
Temperature:
_ Operator:
mm Hg, in. Hg
:, °F
Sampler EPA Number:
Dickson/ratameter reading(s)
A Coarse rotameter:
B Fine rotameter:
C Total rotameter:
D Dickson recorder:
Total sampler flow rate: (1)
Orifice serial number:
Orifice manometer reading:
Orifice flow rate: (2)
Sampler flow rates m^/min
A Coarse rotameter:
B Fine rotameter:
C Total rotameter:
D Dickson recorder:
m3/min (A + B, C, or D)
Calibration date:
inches HoO
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Calculations
Percent error t1>"(2> X 100 = (3)
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Figure 9. Dichotomous Flow Check Data Sheet.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 2.2-27
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-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-2.3
SAMPLING OF AMBIENT AIR FOR PM1O
CONCENTRATION USING THE
RUPPRECHT AND PATASHNICK (R&P)
LOW VOLUME PARTISOL® SAMPLER
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method 10-2.3
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
James L. Cheney, Corps of Engineers, Omaha, NB
Michael F. Davis, U.S. EPA, Region 7, KC, KS
Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
William A. McClenny, U.S. EPA, NERL, RTP, NC
Frank F. McElroy, U.S. EPA, NERL, RTP, NC
William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• Erich Rupprecht, Rupprecht and Patashnick, Albany, NY
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S, Army Corps of Engineers, Omaha, NB
• Neil Olsen, Utah Department of Health, Salt Lake City, UT
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
u
-------
age
Method IO-2.3
Sampling of Ambient Air for PM1Q Concentration
Using the Rupprecht and Patashnick (R&P)
Low Volume Partisol® Sampler
Using Low Volume Partisol® Sampler
TABLE OF CONTENTS
1- Scope 2.3-1
2. Applicable Documents 2.3-3
2.1 ASTM Documents 2.3-3
2.2 Other Documents 2.3-3
3. Summary 23-3
4. Significance 2 3-4
5. Definitions 2 3-4
6. Apparatus Description 2.3-6
6.1 General Description 2.3-6
6.2 Flow System 2.3-7
6.3 Microprocessor-Enabled Functions 2.3-8
7- Filters 2.3-10
7.1 Filter Media 2 3-10
7.2 Filter Handling and Inspection 2.3-11
7.3 Initial 47 mm Filter Equilibration 2.3-11
7.4 Initial 47 mm Filter Weighing . 2.3-11
7.5 Filter Exchange 2 3-12
7.6 Post-Collection Equilibration 2.3-12
7.7 Post-Collection Weighing 2.3-13
7.8 Computation of Mass Concentration 2.3-13
8. Routine Maintenance 2.3-14
9- Audit ;......".".".".".".'.'.' 2^3-14
9.1 Temperature Audit of the Partisol® Sampler 2.3-14
9.2 Pressure Audit of the Partisol® Sampler 2.3-14
9.3 Leak Check of the Partisol® Sampler 2^3-15
9.4 Flow Audit of the Partisol® Sampler 2.3-16
10. Calibration of the Partisol® Sampler 2.3-16
10.1 Interface Board Calibration 2.3-17
10.2 Analog Input Calibration 2.3-17
10.3 Temperature Calibration 2 3-18
10.4 Pressure Calibration 2.3-19
10.5 Flow Calibration 2 3-19
11. Operation Procedure 2^3-20
12. Interferences 2 3-22
13. Performance Criteria and QA . 2 3-22
14. Records 2 3-22
15. References 2 3-22
111
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Chapter IO-2
INTEGRATED SAMPLING OF SUSPENDED
PARTICIPATE MATTER (SPM)
Method IO-2.3
Sampling of Ambient Air for PM1Q Concentration
Using the Rupprecht and Patashnick (R&P)
Low Volume Partisol® Sampler
1. Scope
1.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels is essential to proper assessment.
1.2 Suspended paniculate matter (SPM) in air generally is a complex multi-phase system of all airborne
solid and low-vapor pressure liquid particles having aerodynamic particle sizes from below 0.01-100 /zm
and larger. Historically, SPM measurement has concentrated on total suspended particulates (TSP), with
no preference to size selection.
1.3 The U. S. Environmental Protection Agency (EPA) reference method for TSP is codified at 40 CFR
50, Appendix B. This method uses a high-volume sampler (hi-vol) to collect particles with aerodynamic
diameters of approximately 100 [im or less. The hi-vol samples 40 and 60 ftrVmin of air with the
sampling rate held constant over the sampling period. The high-volume design causes the TSP to be
deposited uniformly across the surface of a filter located downstream of the sampler inlet. The TSP high
volume can be used to determine the average ambient TSP concentration over the sampling period, and
the collected material subsequently can be analyzed to determine the identity and quantity of inorganic
metals present in the TSP.
1.4 Research on the health effects of TSP in ambient air has focused increasingly on those particles that
can be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10 pm.
Researchers generally recognize that these particles may cause significant, adverse health effects.
1.5 On July 1, 1987, the U. S. Environmental Protection Agency (EPA) promulgated a new size-specific
air quality standard for ambient paniculate matter. This new primary standard applies only to particles
with aerodynamic diameters <10 micrometers (PM^) and replaces the original rules for TSP. To
measure concentrations of these particles, the EPA also promulgated a new federal reference method
(FRM). This method is based on the fractionation of non-PMjQ particles from their size distribution,
followed by filtration and gravimetric analysis of PMjQ mass on the filter substrate.
1.6 The new primary standard (adopted to protect human health) limits PMjQ concentrations to
150 /ig/m3 during a 24-h period. These smaller particles are able to reach the lower regions of the
human respiratory tract and, thus, are responsible for most of the adverse health effects associated with
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-1
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Method 10-2.3 Chapter IO-2
R&P Fartisol® Sampler Integrated Sampling for SPM
suspended participate pollution. The secondary standard, used to assess the impact of pollution on public
welfare, has also been established at 150 jig/m .
1.7 Monitoring methods for particulate matter are designated by the EPA as reference or equivalent
methods under the provisions of 40 CFR Part 53, which was amended in 1987 to add specific
requirements for PM10 methods. Part 53 sets forth functional specifications and other requirements that
reference and equivalent methods for each criteria pollutant must meet, along with explicit test procedures
by which candidate methods or samplers are to be tested against those specifications. General
requirements and provisions for reference and equivalent methods are also given in Part 53, as are the
requirements for submitting an application to the EPA for a reference or equivalent method determination.
1.8 Under the Part 53 requirements, reference methods for PM10 must use the measurement principle
and meet other specifications set forth in 40 CFR 50, Appendix J. They must also include a PM10
sampler that meets the requirements specified in Subpart D of 40 CFR 53. Appendix J specifies a
measurement principle based on extracting an air sample from the atmosphere with a powered sampler
that incorporates inertial separation of the PM10 size range particles followed by collection of the PM10
particles on a filter over a 24-h period. The average PM1Q concentration for the sample period is
determined by dividing the net weight gain of the filter over the sample period by the total volume of air
sampled. Other specifications are prescribed in Appendix J for flow rate control and measurement, flow
rate measurement device calibration, filter media characteristics and performance, filter conditioning
before and after sampling, filter weighing, sampler operation, and correction of sample volume to EPA
reference temperature and pressure. In addition, sampler performance requirements in Subpart D of
Part 53 include sampling effectiveness (the accuracy of the PM10 particle size separation capability) at
each of three wind speeds and "50 percent cutpoint" (the primary measure of 10-micron particle size
separation). Field tests for sampling precision and flow rate stability are also specified. In spite of the
instrumental nature of the sampler, this method is basically a manual procedure, and all designated
reference methods for PM^Q are therefore defined as manual methods.
1.9 The procedures for sampling SPM in ambient air for PM10 based upon active sampling using a
low-volume (16.7 L/min flow rate) air sampler are described in this compendium method. The ambient
particle are collected on Teflon®-coated glass or Teflon® filters. The sampler collects PM10 ambient
particles. The sampler can be adapted with a 2.5nm size-select inlet for the determination of fine
particulate concentration.
1.10 The Partisol® air sampler, fitted with either a PM10 or PM2 5 inlet, can be used with other types
of particulate collection hardware such as filter packs and polyurethane foam (PUF) samplers.
Page 2.3-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
2. Applicable Documents
2.1 ASTM Documents
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice for Planning the Sampling of the Ambient Atmosphere.
2.2 Other Documents
• STP598 Calibration in Air Monitoring
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94-038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94-038b.
• Reference Method for the Determination of Paniculate Matter in the Atmosphere, Code of Federal
Regulations, 40 CFR 50, Appendix J.
• Reference Method for the Determination of Suspended Particulates in the Atmosphere (High Volume
Method), 40 CFR 50, Appendix B.
• Operations Manual, Partisol® Model 2000 Air Sampler, Ruppecht and Patashnick, Albany, NY.
3. Summary
3.1 The Ruppecht and Patashnick (R&P) Low-Volume Partisol® Air Sampler is a
microprocessor-controlled manual sampler with a unique set of features that make it a suitable platform
for measuring particulate concentration, acid aerosol, and other constituents found in the atmosphere.
When equipped with a PM^Q inlet and operated in its most basic mode, the hardware performs the same
function as traditional high-volume PMjQ samplers. For source apportionment or traffic studies, the
device can be set up to sample by wind velocity and/or direction or by tune of day.
3.2 Ambient air is drawn through a low flow (16.7 L/min) PMjQ or PM2 5 inlet where particle size
selection takes place.
3.3 The particulate-laden air is then directed through a collection filter composed of either quartz,
Teflon®-coated glass, or Teflon® where the particulate matter is collected.
3.4 A mass flow control system maintains the sample flow through the system at the prescribed
volumetric flow using information from sensors that measure the ambient temperature (°C) and ambient
pressure (atmospheres). A piston pump creates a vacuum to draw the sample stream through the inlet,
filter, and mass flow controller.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-3
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Method IO-2.3 Chapter IO-2
R&P Partisol® Sampler ^_ Integrated Sampling for SPM
3.5 A microelectronics system provides the user with menu-driven programming and diagnostic and data
storage capabilities.
3.6 The sample filter is conditioned and weighed both before and after sample collection to determine
the amount of mass collected during the sampling period, which is 24 h for EPA reporting purposes. As
is the case with all filter-based manual samplers, proper filter handling is an important element in
computing valid mass concentration results.
4. Significance
4.1 Particulate concentration is a criteria pollutant for which the EPA has set health-related standards.
In addition, a number of recently published studies point to a link between the concentration of particulate
matter and human health-related indicators. In attempting to lower the overall concentration of particulate
matter, agencies and private organizations use the conditional sampling capabilities of the Partisol®
Sampler to help identify sources.
4.2 The airborne particulate collected on the 47 mm filter in the Partisol® Sampler may be subjected to
a number of post-collection chemical analytical techniques to ascertain the composition of the material
caught by the filter. Such techniques include X-ray fluorescence (XRF) spectrometry, graphite furnace
atomic absorption (GFAA), inductively coupled plasma/mass spectroscopy (ICP/MS), PIXE, and others.
The type of filter media should be compatible with the analytical method used.
4.3 To determine the concentration levels of polynuclear aromatic hydrocarbons (PAH's), dioxins,
polychlorinated biphenyls (PCB's), polychlorinated naphthalenes (PCN's) and pesticides in ambient air,
the standard 47 mm filter holder/exchange mechanism can be replaced with a PUF sampler. An optional,
multi-stage filter pack can be used to collect particulate, nitric acid, and other airborne constituents. An
optional annular denuder system can be used to collect acid aerosols.
4.4 The hub and satellite configuration of the Partisol® Sampler makes it possible to perform conditional
particulate measurements by time of day, wind direction, analog input or serial input. These modes of
operation are in addition to the sampler's basic 24-h, midnight-to-midnight sampling program. The added
capabilities listed above are important to individuals who would like to determine the sources of ambient
particulate.
5. Definitions
(Note: Definitions used in this document are consistent with ASTM Methods. All pertinent abbreviations
and symbols are defined \vithin this document at point of use.]
5.1 Absolute Filter. A filter or filter medium of ultra-high collection efficiency that collects very small
particles (submicrometer size) with an efficiency of 99.95% or higher for a standard aerosol of 0.3 jim
diameter.
Page 2.3-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
5.2 Aerodynamic Diameter. The diameter of a unit density sphere having the same terminal settling
velocity as the particle in question. Operationally, the size of a particle as measured by an inertial device.
5.3 Aerosol. A dispersion of solid or liquid particles in gaseous media.
5.4 Ambient. Surrounding on all sides.
5.5 Calibration. The process of comparing a standard or instrument with one of greater accuracy
(smaller uncertainty) to obtain quantitative estimates of the actual values of the standard being calibrated,
the deviation of the actual value from a nominal value, or the difference between the value indicated by
an instrument and the actual value.
5.6 Differential Pressure Meter. Any flow measuring device that operates by restricting air flow and
measuring the pressure drop across the restriction.
5.7 Filter. A porous medium for collecting paniculate matter.
5.8 Flow Meter. An instrument for measuring the rate of a fluid moving through a pipe or duct system.
The instrument is calibrated to give volume or mass of flow.
5.9 Impaction. A forcible contact of particles of matter. A term used synonymously with impingement.
5.10 Impactor. A sampling device that employs the principle of impaction (impingement).
5.11 Inhalable Particles. Particles with aerodynamic diameters of < 10 jum that are capable of being
inhaled into the human lung.
5.12 Interference. An undesired positive or negative output caused by a substance other than the one
being measured.
5.13 Mass Flow Meter. A device that measures the flow rate of air passing a point, usually using the
rate of cooling or heat transfer from a heated probe.
5.14 Matter. The substance of which a physical object is composed.
5.15 Particulate. Solids or liquids existing in the form of separate particles.
5.16 Precision. The degree of mutual agreement between individual measurements, namely repeatability
and reproducibility.
5.17 Sampling. A process of withdrawing or isolating a fractional part of a whole. In air or gas
analysis, the separation of a portion of an ambient atmosphere with or without the simultaneous isolation
of selected components.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-5
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Method IO-2.3 Chapter IO-2
R&P Partisol"' Sampler Integrated Sampling for SEM
5.18 Standard. A concept established by authority, custom, or agreement to serve as a model or rule
in the measurement of quantity or the establishment of a practice or procedure.
5.19 Traceability to NIST. A documented procedure by which a standard is related to a more reliable
standard verified by the National Institute of Standards and Technology (NIST).
5.20 Uncertainty. Any allowance assigned to a measured value to take into account two major
components of error: the systematic error and the random error attributed to the imprecision of the
measurement process.
5.21 Virtual Impaction. Impaction of particles on stagnant air rather than a solid plate.
5.22 Virtual Impactor. Sampler in which particle size separation is accomplished by impaction into
an air stream of differing velocity rather than onto an impaction surface.
6. Apparatus Description
6.1 General Description
6.1.1 The R&P Low-Volume Partisol® sampling system may be composed of either a hub unit
operating alone or a hub unit connected to as many as three satellite units (see Figure 1). The hub unit
contains not only the sample inlet (PM10 or PM2 5) and 47 mm filter exchange mechanism found in the
satellite units, but also a microprocessor with internal data storage, an active flow control system, and
a pump. The satellite units are connected to the hub by flow lines that are activated by solenoid valves
contained in the hub. Only one unit (either hub or satellite) can be active at any particular time. The
user programs the system using menu-driven software to determine the conditions under which the hub
or satellite units are active.
6.1.2 In its simplest form, the Partisol® Sampler is set up to collect particulate matter (PM10 or
PM2 5) on a standard 47 mm filter disk for 24-h periods stretching from midnight to midnight. As with
other manual sampling devices, the filters used in this procedure are conditioned and weighed before
exposure, and then conditioned and weighed again after use to determine the mass of particulate collected
during the 24-h exposure time. The Partisol® hardware stores the data relevant to each 24-h collection
period in its internal data logger for viewing and/or retrieval after the fact. Such information includes
the total volume (in terms of standard temperature and pressure), total collection time, average
temperature, and average pressure during the collection period.
6.1.3 In addition to the sampler's basic 24-h midnight-to-midnight operating cycle, the hardware can
also be operated manually. If the system is purchased with an optional advanced EPROM (electrically
programmable read only memory) module, four additional advanced programming modes are available:
to indicate time, meteorology, analog input from a data logger, and digital input.
6.1.4 Internal diagnostics determine whether any status conditions are present. These conditions are
displayed on the main screen of the sampler and are stored in the internal memory of the hardware for
later retrieval.
Page 2.3-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
6.1.5 An analog output channel (0-5 VDC) can be set up to operate in one of two different modes:
(1) to indicate which flow channel is currently in use and whether any status conditions are present; and
(2) to indicate output changes in relation to the flow rate currently passing through the sampler.
6.1.6 Ambient temperature and pressure sensors maintain the flow through the sample inlet at the
proper volumetric flow rate. The total flow volume for each collection filter is reported in mass terms
according to the standard temperature and pressure entered by the user in the Setup Screen.
6.1.7 RS-232 communication capabilities allow for data retrieval into a personal computer or
remotely through a modem. The selection of which sampling station is currently active can be controlled
optionally through a digital transmission through the RS-232 connection to the Partisol® Sampler.
6.2 Flow System
6.2.1 The system flow schematic (see Figure 2) provides an overview of the hardware's flow and
electronic connections, and depicts a PMjQ inlet on the hub unit as well as on three satellite units. The
satellite units are connected to the hub through 10 m (20 m available optionally) flow lines that are
controlled by solenoid valves in the hub unit. Only one sampling station (hub or satellite) is active at any
given time. The system's solenoid valves are controlled by the embedded microprocessor in accordance
with the sampling program defined by the user.
6.2.2 After the sample flow passes through the 47 mm filter or other installed collection hardware,
it passes through the solenoid valve and an in-line filter that protects the mass flow sensor. The sampler
measures the current atmospheric pressure (atmospheres) and ambient temperature (°C) to adjust the
reading from the mass flow sensor so that the proper volumetric flow rate is maintained. While the
vacuum pump constantly operates at full capacity, a servo valve allows varying rates of flow to enter the
system so that the sample flow is maintained at its volumetric set point. The accumulator minimizes
pulsation caused by the vacuum pump, while the manual shut-off valves and vacuum gauge are used in
audit and calibration procedures.
6.2.3 The Partisol® maintains a constant volumetric flow rate through the hub and satellite units at
the set point entered by the user, while reporting flow volumes (m3) in mass terms based upon standard
temperature and pressure. The flow rate used must be appropriate for the inlets being used in the
Partisol® system. The PM1Q, PM2 5 and TSP inlets available from R&P operate at a flow rate of 16.7
L/min (1 m3/h).
6.2.4 The sampling hardware determines the ambient temperature and pressure for flow rate
calculations in one of two different ways: (1) the temperature and pressure transducers measure the
current ambient temperature (°C) and ambient pressure (atmospheres); or (2) if the sampler is installed
in an indoor location where outdoor air is being sampled, the user can override the automatic temperature
and pressure measurements by entering seasonal averages for temperature and pressure in the software.
6.2.5 The Partisol® Sampler displays in its Setup Screen the standard temperature (°C) and standard
pressure (atmospheres) in which flow volumes are computed for regulatory reporting purposes. These
values may be changed by the user. By default, the standard temperature is 25 °C and the standard
pressure is 1 atmosphere.
6.2.6 The mass flow meter in the sampler is calibrated at a temperature of 0°C and a pressure of 1
atmosphere (1013.2 millibars or 760 mm Hg). For the device to sample at the correct volumetric flow
rate, it uses the measured (or entered) average temperature and pressure. Using this information, the
microprocessor calculates the correct mass flow set point (Flow RategTp) using the following formula:
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-7
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Method IO-2.3 Chapter IO-2
R&P Partisol® Sampler _ Integrated Sampling for SFM
where:
Flow RateSTp = Control set point of the mass flow meter (equivalent flow at 0°C and 1
atmosphere).
Flow RateVol = Volumetric flow rate set point (L/min) as entered by the user in the Setup Screen
of the sampler. This value is 16.7 L/min (1 m3/h) for most applications.
Ave Temp «= The current temperature (°C) as measured by the temperature transducer mounted
on the sample tube of the hub unit or the value entered for average temperature
by the user in the Setup Screen.
Ave Pres = The current pressure (atmospheres) as measured by the pressure transducer in the
hub unit, or the value entered for average pressure by the user in the Setup
Screen.
6.2.7 Mass concentration data reported to the EPA must be referenced to standard cubic meters of
air based on a standard temperature of 25 °C and standard pressure of 1 atmosphere. For the instrument
to report mass flow volumes according to this standard, the user must ensure that the standard
temperature and standard pressure parameters in the Setup Screen are set at their default values of 25 °C
and 1 atmosphere, respectively.
The flow rates referenced internally by the instrument to 0°C are converted to EPA standard
conditions (25°C and 760 mmHg) using the following computation:
„ , _7 . „ Std Temp+273.15 ,, 1 Atm
Volume^ - Volume^ X - - X
This VoIumeEpA is the value displayed and stored by the Partisol® Sampler. This feature saves the user
from having to make the conversion manually, as must be done with conventional high-volume samplers.
6.3 Microprocessor-Enabled Functions
6.3.1 The operation of the Partisol® Sampler is controlled by an embedded microprocessor equipped
with a battery-backed, real-time clock and internal storage capability. The operator uses a display and
keypad to interact with the system. The software allows the user to view the data, program the
instrument, and set operating parameters (see Figure 3). The following is a brief description of the
screens in the sampler.
6.3.1.1 The Title Screen appears when the user first turns on the sampler and contains the name
of the instrument and software revision number.
6.3.1.2 The Main Screen displays the operating statistics for each installed unit on a separate line,
including the volume of air drawn through each sampling station and the elapsed time that the unit was
operating. In most programming modes, the Main Screen also allows the user to enter the conditions
Page 2.3-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
under which each sampling station is to be active. This screen also displays the presence of any status
conditions currently detected by the sampler.
6.3.1.3 The Programming Screen is present in the Meteorological and Time programming modes
and allows the user to enter the conditions under which each sampling station is to be active.
6.3.1.4 The Statistics Screen displays the current operating condition of the sampler, including
the flow rate, ambient temperature and pressure, the status of serial and analog inputs, and the software
version number.
6.3.1.5 The Setup Screen contains the basic configuration of the sampler, including the number
of sampling stations, current programming mode, flow rate set point, type of analog output, current time
and date, and standard and average temperatures and pressures.
6.3.1.6 The Filter Data Screen allows the user to scroll forward and backward through time to
view the operating data corresponding to each filter exposed in the Partisol® Sampler. Data stored for
each filter include the station number, time and date of first and last exposures, programming mode,
volume and elapsed time during which the filter was exposed, average temperature, and average pressure.
6.3.1.7 The Interval Data Screen allows the user to scroll forward and backward through time
to view half-hour summaries of the sampler's operation. Data stored for each 30 min period of operation
include the length of time during which each sampling station was active, the average temperature and
pressure, as well as the minimum, average, and maximum flow rate.
6.3.1.8 The RS232 Setup Screen allows the user to configure the Partisol® Sampler for two-way
serial communication and includes the baud rate and data transmission protocol.
6.3.1.9 The Calibration Screen displays the values necessary for the user to perform audits and
calibrations on the Partisol® Sampler.
6.3.1.10 The Diagnostics Screen displays the current state of the system's analog inputs and
outputs and its digital outputs.
6.3.2 Programming Modes
The Partisol® Sampler can operate in a number of programming modes.
6.3.2.1 The Basic mode supports sample collection from midnight to midnight.
6.3.2.2 In the Manual mode, the user selects the currently active sampling station through direct
keypad entry.
6.3.2.3 In the Time mode, the operation of the sampling stations is controlled according to time
and date ranges entered by the user. This feature is included in the advanced EPROM.
6.3.2.4 In the Meteorology mode, the sampling stations is controlled by wind velocity and/or
direction criteria entered by the user. This feature is included in the advanced EPROM and requires a
compatible wind vane/anemometer to measure wind direction and velocity.
6.3.2.5 The Analog Input mode enables control of the sampler through an externally-generated
analog input. This feature is included in the advanced EPROM.
6.3.2.6 The Serial Input mode allows the user to control the operation of the Partisol® Sampler
through a two-way RS232 link. This feature is included in the advanced EPROM.
6.3.3 Status Conditions
The current status condition is displayed on the Main Screen of the Partisol® Sampler and is stored as
part of the 30-min Interval Data. The following status definitions indicate the present condition of the
sampler.
6.3.3.1 The "OK" condition means there are no current status conditions.
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Method 10-2.3 Chapter IO-2
R&P Partisol® Sampler Integrated Sampling for SPM
6.3.3.2 The "F" (Flow) condition occurs whenever the current volumetric flow rate varies more
than 7% from the set point for the volumetric flow rate entered in the Setup Screen.
6.3.3.3 The "T" (Ambient Temperature) condition ensures that the ambient temperature sensor
located on the sample tube of the hub unit measures correctly. This status occurs whenever the ambient
temperature indicated by the temperature sensor is less than -40°C or greater than 60°C.
6.3.3.4 The "P" (Pressure Transducer) condition ensures that the ambient pressure sensor located
in the hub unit measures correctly. This conditions occurs whenever the ambient pressure indicated by
the pressure sensor is less than 0.4 atmospheres.
6.3.3.5 The "I" (Instrument Temperature) condition reacts to the internal temperature of the
Partisol® Sampler as measured on one of its electronics boards. This diagnostic determines whether the
temperature of the system electronics is approaching the operational limits; it is activated whenever the
instrument temperature is less than 5°C or greater than 60°C.
6.3.3.6 The "S" (Serial Communication) condition indicates that a failure has occurred in the
sampler's RS232 interface.
6.3.3.7 The "E" (Electrical Outage) condition indicates that an interruption has occurred in the
supply of main power.
6.3.3.8 The "K" (Relay Control Hardware) condition indicates that a fault has occurred in the
digital input/output section of the system electronics.
7. Filters
This section covers the initial inspection of 47 mm filters used in the Partisol® system, as well as the
equilibration and weighing before use. Further, the procedure for filter insertion and removal is
described along with the means by which post-collection equilibration and weighing occur and the
computations involved in determining the mass concentration. Follow the guidelines described in this
section closely to ensure data quality.
7.1 Filter Media
A number of different media are available in the standard 47 mm size for use with the Partisol® Sampler.
They are:
• Pallflex TX40 Filters.
• Teflon® Filters.
* Quartz Fiber Filters.
These media are currently acceptable for use in EPA equivalent and reference PM10 instrumentation.
All are suitable for particulate mass measurement; however, one type of media may be preferable to
others depending upon the type of post-collection chemical speciation desired. Filter media may be used
for EPA PM10 reporting purposes as long as the material meets the collection efficiency, integrity, and
alkalinity requirements of 40 CFR Part 50 Appendix J. Further, materials must have relatively low
pressure drop characteristics so that the sampler can maintain the 16.7 L/min flow rate required for the
during an entire 24-h sampling period.
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
7.2 Filter Handling and Inspection
Take deliberate care when handling and transporting sample filters. Quartz fiber filters are very brittle,
while other type of material are susceptible to tearing.
Mote: Keep filters dean and never touch filters with fingers. Filters should be stored and transported
in petri dishes. Only non-serrated forceps should be used to handle the 47 mm filters used with the
sampler.]
Inspect each filter visually for integrity before use. Check for pinholes, chaff or flashing, loose material,
discoloration, and non-uniformity.
7.3 Initial 47 mm Filter Equilibration
[Note: Use a petri dishes to storae and transport the filters.]
7.3.1 Place a label on the cover of each petri dish and number each dish.
7.3.2 Place the petri dish cover under the bottom half of the dish.
7.3.3 Place each inspected filter into a separate petri dish.
7.3.4 Record the filter number, relative humidity, temperature, date, and time at the beginning of
equilibration.
7.3.5 Equilibrate each filter for at least 24 h under the following conditions:
7.3.5.1 The equilibration room must be held at a constant relative humidity of <50%.
7.3.5.2 The equilibration room must be held at a constant temperature between 15 and 35°C with
a variability of no more than ±3°C.
7.4 Initial 47 mm Filter Weighing
7.4.1 Ensure that each filter has been equilibrated for at least 24 h before weighing.
7.4.2 Filters must be weighed on a semi-micro balance with a minimum resolution of 0.01 mg.
Ensure that the balance has been turned on at least 1 h before performing any weighings.
7.4.3 Weigh each filter at least once (three times recommended) and record the mass in grams. The
average mass reading is the initial filter weight, Wj.
7.4.4 Immediately place each weighed filter into an open filter cassette and then close the filter
cassette by snapping its top part onto the bottom. Ensure that the cassette is properly sealed by one of
the following methods:
7.4.4.1 While holding the bottom part of the filter cassette in one hand, rotate the top of the
cassette approximately 1/8 of a turn while applying pressure.
7.4.4.2 Hold the closed cassette in both hands with your thumb on the top and forefinger on the
bottom. Rotate the entire cassette completely while applying pressure with your thumb and forefinger.
7.4.5 Place the filter cassette with its 47 mm filter installed into a petri dish and place the cover over
the petri dish.
7.4.6 Document the relative humidity, temperature, date, and time of the initial weighing.
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Method IO-2.3 Chapter IO-2
R&P Partisol® Sampler Integrated Sampling for SPM
7.4.7 Verify the "zero" reading of the semi-micro balance between each filter weighing.
7.4.8 Filters are transported to the sampling site in their petri dishes.
7.5 Filter Exchange
[Note: With the exception of the Basic programming mode, the sampler must be in the "Stop" operating
mode before filters are exchanged. Press when in the Main Screen to toggle between
the "Run" and "Stop" operating modes. When in the Basic programming mode, leave the sampler in the
"Run" operating mode, but be careful not to exchange the filter in the currently-operating sampling
station. The active unit is displayed on the second line of the Main Screen as "Curr. "]
7.5.1 For each sampling station where a filter is being exchanged, record the valid and total exposure
times and the standard volume (V§TD) displayed on the Main Screen.
7.5.2 Lift the handle of the filter exchange mechanism in the hub or satellite unit into its upward
position to expose the area in which the filter cassette is installed.
7.5.3 If a filter is currently installed in the sampling unit, remove the filter cassette with its filter and
place it immediately into its uniquely-numbered petri dish. A groove in the filter holding mechanism
allows the user to gain better access to the filter cassette for removal.
7.5.4 Take the new filter cassette with its unused filter installed out of its petri dish and place it into
the filter holding well of the filter exchange mechanism. The enclosure of the sampling station serves
as a good storage location for the petri dish currently in use.
7.5.5 Close the filter exchange mechanism.
7.5.6 If the Partisol® Sampler is being operated in its Basic programming mode, use the soft function
keys in the Edit Mode to define the sampling program for the newly-installed 47 mm filters. Make sure
that the hardware remains in the "Run" operating mode so that the newly-defined sampling program is
executed; press if the sampler is currently in the "Stop" operating mode.
7.5.7 If the unit is in any other programming mode besides the Basic mode, use the soft function
keys in the Edit mode to define the sampling program for the newly-installed 47 mm filters. Then, return
the sampler to the "Run" operating mode by pressing in the Main Screen to execute the
newly-defined sampling program.
7.6 Post-Collection Equilibration
7.6.1 Examine the filter for defects that may have occurred during sampling and for evidence of
leaks in the filter cassette. Leaks manifest themselves as pronounced radial streaks that extend beyond
the exposed area of the filter.
7.6.2 Carefully remove the 47 mm filter from the filter cassette and set the filter in its petri dish.
The cassette can then be used to hold other filters once it has been cleaned.
7.6.3 Place the petri dish cover under the bottom half of the dish.
7.6.4 Place a paper towel over the open petri dish during equilibration.
7.6.5 Record the filter number, relative humidity, temperature, date, and time at the beginning of
this post-collection equilibration.
7.6.6 Equilibrate each filter for at least 24 h under the following conditions:
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM _ R&P Partisol® Sampler
7.6.6.1 The equilibration room must be held at a constant relative humidity, <50%, with a
variability of no more than ±5%.
7.6.6.2 The equilibration room must be held at a constant temperature, between 15-35°C, with a
variability of no more than ±3°C.
7.7 Post-Collection Weighing
7.7.1 Ensure that the filter has been equilibrated for at least 24 h before weighing.
7.7.2 Filters must be weighed on a semi-micro balance with a minimum resolution of 0.01 mg.
Ensure that the balance has been turned on for at least 1 h before performing any weighings.
7.7.3 Remove the filter from its petri dish.
7.7.4 Weigh each filter at least once (three times recommended) and record the mass in grams. The
average mass reading is the final filter weight, Wf.
7.7.5 Return the filter to its petri dish and store for archival purposes.
7.7.6 Document the relative humidity, temperature, date, and time of the post-collection weighing.
7.7.7 The "zero" reading of the semi-micro balance should be verified between each filter weighing.
7.7.8 Determine the net mass filter loading (AW) by subtracting the average initial filter weight
[Wj (g)] from the final filter weight [Wf (g)]. Ensure that the figures used in this computation are
obtained for the same filter and balance.
7.8 Computation of Mass Concentration
Compute the average mass concentration, C (jiglror), corrected to standard temperature and pressure
(25°C and 710 mm Hg), of PM1Q, PM2 5 or TSP during the sampling period of each filter by using the
following formula with the information assembled above:
where:
C = average mass concentration, /tg/m , corrected to standard temperature any
pressure (25°C and 710 mm Hg).
AW = the net change in the mass (g) of the 47 mm filter between the initial weighing
and the post collection weighing, as computed in Section 7.4 through 7.7.
10" = Conversion factor from grams (g) to micrograms 0*g).
= the volume (nr*) drawn through the filter, corrected to standard temperature and
pressure, as recorded in Section 6.2.7.
For 24-h PM^Q measurement averages to be valid for EPA reporting purposes, the "Valid Time"
recorded in the Filter Data storage area must be at least 23 h. The "Total Time" is the length of time
during which the sample stream flows through a filter, and the "Valid Time" is the length of time during
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Method 10-2.3 Chapter IO-2
R&P PartisoF Sampler Integrated Sampling for SPM
which the status condition is "OK." Therefore, the "Valid Time" is always less than or equal to the
"Total Time."
8. Routine Maintenance
The routine maintenance of the Partisol® Sampler consists of the following procedures.
8.1 Inspect filter cassettes for contamination after every use. Wipe with a clean dry cloth as required.
8.2 Inspect the seals that rest against the filter cassette in the hub and satellite units every time a filter
is exchanged. Wipe with a clean dry cloth as required. Replace if worn or damaged.
8.3 Clean each PM10 inlet after every 14 days of inlet usage. The PM10 inlet must be cleaned with the
corresponding sampling station is not operating.
8.4 Exchange the large in-line filter in the hub unit every 6 months of system operation. Turn the
sampler off to replace the large in-line filter.
8.5 Check the voltage level of the batteries on the main computer board of the hub unit every 6 months.
9. Audit
This section describes the means by which the ambient temperature, ambient pressure, and sample flow
rate measured by the hub unit are audited. In addition, this part describes the procedure for performing
a leak check of the hub and satellite units. The audit should be performed every 3 months of continuous
operation. Individual monitoring organizations may, however, abide by different standards.
9.1 Temperature Audit of the Partisol® Sampler
9.1.1 Press when in the Setup Screen to access the Calibration Screen (see Figure 4).
9.1.2 Determine the current temperature (°C) at the ambient temperature sensor positioned on the
sample tube of the hub using an external thermometer, [°C = 5/9 x (°F - 32)].
9.1.3 Verify that the value for temperature displayed in the "Calc" column of the Calibration Screen
is within ±2°C of the measured temperature. If this is not the case, perform the temperature calibration
procedure described hi Section 10.3.
9.2 Pressure Audit of the Partisol® Sampler
9.2.1 Press when in the Setup Screen to access the Calibration Screen (see Figure 4).
9.2.2 Determine the current ambient station pressure in atmospheres (absolute pressure, not corrected
to sea level).
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
• To convert from mm Hg at 0°C to atmospheres, multiply by 0.001316.
• To convert from millibars to atmospheres, multiply by 0.000987.
• To convert from inches Hg at 32°F to atmospheres, multiply by 0.03342.
9.2.3 Verify that the value for pressure displayed in the "Calc" column of the Calibration Screen is
within ±0.02 atmospheres of the measured ambient pressure. If not, perform the pressure calibration
procedure described in Section 10.4.
9.3 Leak Check of the Partisol® Sampler
[Note: To ensure leak tightness, a filter cassette containing a new 47 mm filter must be installed in each
sampling station tested.]
9.3.1 Return the Partisol® sampler to the Main Screen.
9.3.2 The device must be in the "Stop" operating mode to perform a leak test. If the hardware is
currently in the "Run" operating mode, as shown in the upper right-hand corner of the Main Screen,
press to enter the "Stop" operating mode.
9.3.3 Display the Calibration Screen (see Figure 4) by pressing and then when in the Main Screen.
9.3.4 Carefully remove the size-selective inlet from sampling station being checked.
9.3.5 Install the optional Flow Audit Adapter supplied with the sampler on the end of the sample tube
of the sampling station being checked.
9.3.6 Turn on the pump by pressing ( j when in the Calibration
Screen.
9.3.7 Press either , , , or , depending upon
which sampling station is currently being checked.
9.3.8 Shut off the valve on the Flow Audit Adapter.
9.3.9 Shut off the flow to the flow controller assembly by turning the manual valve located on the
manifold in the hub (marked in Figure 5).
9.3.10 Record the reading on the vacuum gauge in the hub.
9.3.11 Shut off the flow to the pump by turning the other manual valve located on the manifold in
the hub (marked in Figure 6).
9.3.12 Record the reading on the vacuum gauge 10 s after the pump valve is closed. This reading
should not drop below half of the original reading during this 10 s period. If this is not the case, trace
the internal (and external) flow paths to identify problems in tubing or connections.
9.3.13 Open the flow controller valve and pump valve that were closed in Sections 9.3.9 and 9.3.11
above.
9.3.14 Open the valve of the Flow Audit Adapter and remove this hardware from the sampling
station being checked. Replace the size-selective inlet.
9.3.15 Perform Sections 9.3.5 through 9.3.14 for each sampling station in the Partisol® system.
9.3.16 Return to the Main Screen by pressing twice.
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Method 10-2.3 Chapter IO-2
R&P Partisol® Sampler Integrated Sampling for SPM
9.4 Flow Audit of the Partisol® Sampler
(Note: Perform the temperature audit, pressure audit, and leak check described above before executing
the flow audit procedure below.]
9.4.1 Return the Partisol® sampler to the Main Screen.
9.4.2 The device must be in the "Stop" operating mode to perform a flow audit. If the hardware is
currently in the "Run" operating mode, as shown in the upper right-hand corner of the Main Screen,
press to enter the "Stop" operating mode.
9.4.3 Install a filter cassette containing a 47 mm filter into the filter holder of the hub unit. This
filter will be thrown away at the end of this flow audit.
9.4.4 Display the Calibration Screen (see Figure 4) by pressing and then when in the Main Screen.
9.4.S Carefully remove the size-selective inlet from the hub.
9.4.6 Install the Flow Audit Adapter provided with the sampler on the end of the sample tube of the
hub.
9.4.7 Attach a volumetric flow meter to the Flow Audit Adapter. R&P offers such a flow meter as
part number 10-001742-0120 for 120 VAC and 10-001742-0240 for 240 VAC (see Figure 7).
9.4.8 Turn on the pump by pressing (< SHIFT > ); then press
.
9.4.9 Use the (continuously decrease flow), (maintain current
flow rate), and (continuously increase flow) keys to display the flow rate in the "Calc"
column of the Calibration Screen at approximately 16.7 L/min. As the servo valve in the hub closes and
opens to increase and decrease the sample flow rate, the potentiometer value, "Pot," changes. This figure
generally should not drop below 0.5 VDC or exceed 4.5 VDC.
9.4.10 Determine the flow in units of actual L/min using the external flow meter and verify that it
matches the value displayeihfor flow in the "Calc" column of the Calibration Screen to within ±7%.
If this is not the case, perform the flow calibration procedure described in Section 10.
9.4.11 Return to the Main Screen by pressing twice.
9.4.12 Restore the sampling hardware to its original state by removing the flow metering hardware
and re-installing the size selective inlet on the sample tube of the hub. Remove the filter cassette from
this sampling station and throw away the filter installed in it.
10. Calibration of the Partisol® Sampler
[Note: This section contains instructions for performing an interface board, temperature, pressure, and
flow calibration of the Partisol9 Air Sampler. The temperature and pressure calibrations must be done
before the flow calibration.]
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
10.1 Interface Board Calibration
/Note: The interface electronics board is located on the bottom panel of the area behind the keypad in
the hub unit (labeled in Figures 8 and 9).]
10.1.1 Locate the two red test points on the front section of the interface board. These two test
points are labeled "+6V" and " + 10V."
10.1.2 Locate the black ground test point labeled "GND" between the two large black capacitors.
10.1.3 Ensure that the sampler is turned on and that the display backlight is on. The backlight must
be on during the +6 V calibration. If the backlight is off, press any key on the keypad to turn it on.
10.1.4 Place the positive lead of a multimeter on the +6 V test point.
10.1.5 Place the ground lead on the ground test point.
10.1.6 Locate R21 on the on the rear section of the interface board. R21 is a horizontal pot, and
its designation "R21" is silk-screened on the board.
10.1.7 Tweak R21 until the multimeter reads 6.00 VDC ± 0.05 V.
10.1.8 Place the positive lead of the multimeter on the +10 V test point.
10.1.9 Locate R44 on the rear section of the interface board. R44 is a blue vertical pot, and its
designation "R44" is silk-screened on the board.
10.1.10 Tweak R44 until the multimeter reads 10.000 VDC ± 0.002 V.
10.2 Analog Input Calibration
(Note: The following procedure must be performed after the interface board calibration and before the
temperature, pressure, and flow calibrations.]
10.2.1 Return the Partisol® sampler to the Main Screen.
10.2.2 The device must be in the "Stop" operating mode to perform an analog input calibration. If
the hardware is currently in the "Run" operating mode, as shown in the upper right-hand corner of the
Main Screen, press to enter the "Stop" operating mode.
10.2.3 Press and then when in the Main Screen to access the
Calibration Screen (see Figure 4).
10.2.4 Plug the six-pin end of the Analog Input Calibration Cable supplied with the sampler (part
number 51-002604) into the socket labeled "ANEMOMETER" on the back of the Partisol® hub unit.
10.2.5 Plug the four-pin end of the Analog Input Calibration Cable into the socket labeled "USER
OUTPUT" on the back of the Partisol® hub unit.
10.2.6 Attach the positive lead from a multimeter with four-digit resolution to the green test point
labeled "PWM1" on the interface board. Attach the ground lead to the ground test point (see Figure 10).
10.2.7 Use the arrow key to position the cursor so that it is in the location labeled "A/O."
10.2.8 Press < Enter > to enter the Edit Mode. Type in a number between 0.050 and 0.150 volts
and press < Enter >.
10.2.9 Observe the number displayed in the row labeled "A/I" in the column labeled "Calc." Ensure
that this number does not vary more than ±0.005 volts after watching it for 5 s. If this number is not
stable, choose a new number for "A/O" between 0.050 and 0.150 volts.
10.2.10 Read the voltage displayed on the multimeter.
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Method IO-2.3 Chapter IO-2
R&p Partisol® Sampler Integrated Sampling for SPM
10.2.11 Use the arrow keys to position the cursor so that it is in the row labeled "A/I" and the
column labeled "Act."
10.2.12 Press Edit to enter the Edit Mode. Type the voltage read from the multimeter (to three digit
accuracy, i.e., O.xxx) in this position and press . To calculate the "Offset."
10.2.13 Ensure that the number now displayed in the row labeled "A/I" and the column labeled
"Calc" matches the number displayed on the multimeter within ±0.005 volts.
10.2.14 Use the arrow key to position the cursor so that it is in the location labeled "A/O."
10.2.15 Press to enter the Edit Mode. Type in a number between 4.800 and 4.900
volts and press < Enter >.
10.2.16 Observe the number displayed in the row labeled "A/I" in the column labeled "Calc."
Ensure that this number does not vary more than ±0.005 volts after watching it for 5 s. If this number
is not stable, choose a new number for "A/O" between 4.800 and 4.900 volts.
10.2.17 Read the voltage displayed on the multimeter.
10.2.18 Use the arrow keys to position the cursor so that it is in the row labeled "A/I" and the
column labeled "Act."
10.2.19 Press to enter the Edit Mode. Type the voltage read from the multimeter (to three
digit accuracy, i.e., O.xxx) in this position and press to calculate the "Span."
10.2.20 Ensure that the number now displayed in the row labeled "A/I" and the column labeled
"Calc" matches the number displayed on the multimeter within ±0.005 volts.
10.2.21 Remove the multimeter leads from the interface board and the-Analog Input Calibration
Cable from the back of the Partisol® hub.
10.2.22 After completing the analog input calibration, perform the temperature, pressure, and flow
calibrations.
[Note: If the instrument has been reset and you have recorded the value of "Offset" and "Span" for the
flow, you may enter these numbers directly when in the Edit Mode.]
10.3 Temperature Calibration
10.3.1 Return the Partisol® sampler to the Main Screen.
10.3.2 The device must be in the "Stop" operating mode to perform a temperature calibration. If
the hardware is currently in the "Run" operating mode, as shown in the upper right-hand corner of the
Main Screen, press to enter the "Stop" operating mode.
10.3.3 Press and when in the Main Screen to access the Calibration
Screen (see Figure 4).
10.3.4 Determine the current temperature (°C) at the ambient temperature sensor positioned on the
sample tube of the hub using an external thermometer, [°C = 5/9 x (°F - 32)].
10.3.5 Press to enter the Edit Mode and move the cursor to the "Act" (actual) column
in the row labeled "Temp."
10.3.6 Enter the current ambient temperature (°C) and press < ENTER> to leave the Edit Mode.
Use the key to enter negative temperatures when in the Edit Mode.
10.3.7 Upon receiving the actual temperature, the system's microprocessor automatically computes
"Span" for the ambient temperature. Note this number for future reference.
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Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
[Note: If the instrument has been reset and you have recorded the value of "Span" for the ambient
temperature, you may enter it directly in the "Span" column when in the Edit Mode.]
10.4 Pressure Calibration
10.4.1 Return the Partisol® sampler to the Main Screen.
10.4.2 The device must be in the "Stop" operating mode to perform a pressure calibration. If the
hardware is currently in the "Run" operating mode, as shown in the upper right-hand corner of the Main
Screen, press to enter the "Stop" operating mode.
10.4.3 Press and when in the Main Screen to access the Calibration
Screen (see Figure 4).
10.4.4 Determine the current ambient station pressure in atmospheres (absolute pressure, not
corrected to sea level).
• To convert from mm Hg at 0°C to atmospheres, multiply by 0.001316.
• To convert from millibars to atmospheres, multiply by 0.000987.
• To convert from inches Hg at 32°F to atmospheres, multiply by 0.03342.
10.4.5 Press to enter the Edit Mode and move the cursor to the "Act" (actual) column
in the row labeled "Pres."
10.4.6 Enter the current ambient pressure (atmospheres) and press < ENTER > to leave the Edit
Mode.
10.4.7 Upon receiving the actual pressure, the system's microprocessor automatically computes
"Span" for the ambient pressure. Note this number for future reference.
[Note: If the instrument has been reset and you have recorded the value of "Span" for the ambient
pressure, you may enter it directly in the "Span" column when in the Edit Mode.]
10.5 Flow Calibration
[Note: The temperature and pressure calibrations described above must be performed before undertaking
the flow calibration. In addition, the leak check discussed in Section 9.3 must also be undertaken before
the flow calibration executed.]
10.5.1 Return the Partisol® sampler to the Main Screen.
10.5.2 The device must be in the "Stop" operating mode to perform a flow calibration. If the
hardware is currently in the "Run" operating mode, as shown in the upper right-hand corner of the Main
Screen, press to enter the "Stop" operating mode.
10.5.3 Carefully remove the size-selective inlet from the hub.
10.5.4 Install a filter cassette containing a 47 mm filter into the filter holder of the hub unit. This
filter will be thrown away at the end of this flow calibration.
10.5.5 Display the Calibration Screen (see Figure 4) by pressing and then when in the Main Screen.
10.5.6 Install the Flow Audit Adapter with its valve open on the end of the sample tube of the hub.
10.5.7 Attach a volumetric flow meter to the Flow Audit Adapter (see Figure 7).
10.5.8 Leave the pump turned off. If it is currently on, press to turn it off.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-19
-------
Method IO-2.3 Chapter IO-2
R&P Partisol® Sampler Integrated Sampling for SPM
10.5.9 Press to enter the Edit Mode and move the cursor to the "Act" (actual) column
in the row labeled "Flow."
10.5.10 Enter a zero in this position and press < ENTER > to leave the Edit Mode. This procedure
causes the microprocessor to compute "Offset," which is the zero offset for the mass flow sensor. Note
this number for future reference.
10.5.11 Turn on the pump by pressing and then press to cause the
sample flow to pass through the sample tube of the hub.
10.5.12 Use the (continuously decrease flow), (maintain current
flow rate), and (continuously increase flow) keys so that the flow rate in the "Calc"
column of the Calibration Screen is approximately 16.7 L/min. As the servo valve in the hub closes and
opens to increase and decrease the sample flow rate, the potentiometer value, "Pot," changes. This figure
should generally not drop below 0.5 VDC or exceed 4.5 VDC.
10.5.13 Determine the flow in actual L/min using the external flow meter.
10.5.14 Press to enter the Edit Mode and move the cursor to the "Act" (actual) column
in the row labeled "Flow."
10.5.15 Enter the flow determined by the external flow meter and press < ENTER > to leave the
Edit Mode. This procedure causes the microprocessor to compute "Span," which is the span offset for
the mass flow sensor. Note this number for future reference.
[Note: If the instrument has been reset and you have recorded the value of "Offset" and "Span" for the
flow, you may enter these numbers directly when in the Edit Mode.]
10.5.16 Return to the Main Screen by pressing twice.
10.5.17 Restore the sampling hardware to its original state by removing the flow metering hardware
and re-installing the size selective inlet on the sample tube of the hub. Remove the filter cassettes from
the hub and satellite units, and throw away the filters installed in them.
11. Operation Procedure
The Basic programming mode is the default setting of the Partisol® Sampler, which allows the user to
collect samples for 24-h periods from midnight to midnight on each 47 mm filter in the sampling stations
of the Partisol® system. The hardware is set for this mode when it is turned on for the first time.
Information concerning the sampler's other programming modes may be found in the operating manual.
[Note: Do not attempt operation of the Partisol® Sampler until the hardware is installed according to
the instructions in the operating manual. Also refer to the operating manual regarding the entry of
appropriate system parameters in the Setup Screen before setting up the software for sampling in the Basic
programming mode.]
11.1 The user defines the sampling program (i.e., during which 24-h periods the Partisol® hardware
samples) in the Main Screen (see Figure 11). If the sampler is not currently in the Main Screen, press
until this display appears.
Page 2.3-20 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
11.2 The right-most column of the screen labeled "Date" contains the only editable information. The
user enters the dates in this field during which 24-h samples are to be collected in the hub. and satellite
units.
11.3 Follow the procedure below with the Main Screen displayed on the sampler to set up a Basic
sampling program. If the sampler is currently in the "Run" operating mode, do not switch to the "Stop"
operating mode. Leave the device in its current operating mode when executing the steps below.
11.3.1 Exchange the 47 mm collection filters in all sampling stations whose filter status, as shown
in the "Stat" column of the Main Screen, is "DONE." If the sampler is being operated for the first time
or at a new location, install new filters in each of the system's sampling stations. These filter exchanges
and/or installations must be done in accordance with the instructions in Section 7.
11.3.2 Press to enter the Edit Mode and change the sampling dates shown in the "Date"
column of the Main Screen. The cursor changes from an underline shape to a large square shape when
the hardware enters the Edit Mode.
11.3.3 Press when in the Edit Mode to set a range of sequential dates automatically
across sampling stations beginning with the next full 24-h period. This command affects all sampling
stations except for the currently active one (if any), as indicated by •"ON" in the "Stats" column.
Alternatively, press < F2: Today +1 > when in the Edit Mode to assign tomorrow's date to the sampling
station on the current line. Perform this action on each line that is to receive a new date, using the cursor
keys to move from one date line to another.
11.3.4 Press the arrow keys to move from line to line, and among the day and month areas of each
date field on the Main Screen. Press , , , and to
increment and decrement the values of the day and month areas of each date. The days and months also
may be entered directly from the keypad.
[Note: If is pressed after making a change to afield in the Edit Mode, the sampler returns
to the View Data Mode. Press again to return to the Edit Mode, if wished. Note that using
the cursor keys after each edit (not ) enables the user to remain in the Edit Mode until all
desired values have been changed.]
[Note: The system does not allow the user to change the sampling date of a sampling station that is
currently active.]
11.3.5 Leave the Edit Mode by pressing < ENTER> to retain the changes made above. To cancel
these edits, press and perform the above steps again.
11.3.6 If the Model 2000 sampler is currently in the "Stop" operating mode, as indicated in the upper
right-hand corner of the Main Screen, press when in the View Data Mode to put the
sampler into the "Run" operating mode. Do not change operating modes if the hardware is already in
the "Run" operating mode.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-21
-------
H TO 2 ^ Chapter IO-2
R&PPartisoF Sampler Integrated Sampling for SPM
12. Interferences
To ensure a proper size cut point when using the R&P PM10 inlet, the Partisol® Sampler should only be
operated at a volumetric flow rate of 16.7 L/min. The procedure for auditing the flow is described in
Section 9 4 while Section 10.5 contains the steps involved in a full calibration of the flow. A status
condition MF" appears when the instrument determines that the flow rate is not within 7% of its set point
(see Section 6).
13. Performance Criteria and QA
The detailed steps required for filter handling and inspection, conditioning, weighing, and installation is
described in Section 7. The Partisol® Sampler contains extensive diagnostics that monitor its operation
(see Section 6), indicating whether the hardware is operating within its required bounds. Section 9
contains the procedures necessary to perform a field audit of the sampler.
The most important factors to observe in the assurance of quality data are filter quality and its seating
in the filter cassette, the correctness of the flow rate, and the leak tightness of the system.
14. Records
A Filter Log is recommended to record the data relevant to the conditioning, weighing, and exposure of
the filter as well as the computation of PM10 concentration averages (see Figure 12). Individual users
may want to develop their own documentation to track audits (see Section 9) and calibrations (see
Section 10).
15. References
1 Patashnick, H., and G. Rupprecht, "A New Real Time Aerosol Mass Monitoring Instrument:. The
TEOM®," Proc.: Advances in Paniculate Sampling and Measurement, EPA-600/9-80-004, Daytpna
Beach, FL, 1979.
2. Wang, J. C. F., Patashnick, H., and G. Rupprecht, "New Real Time Isokinetic Dust Mass
Monitoring System," J. Air Pollution Control Assn., 30(9): 1018, 1980.
3. Wang, J. C. F., et al., "Real-Time Total Mass Analysis of Particulates in the Stack of an Industrial
Power Plant," /. Air Pollution Control Assn., 33(12): 1172, 1983.
4. Patashnick, H., Rupprecht, G., and D. W. Schuerman, "Energy Source for Comet Outbursts,"
Nature, 250(5464), July 1974.
Page 2.3-22 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter 10-2 Method IO-2.3
Integrated Sampling for SPM R&P Partisol® Sampler
5. Hidy, G. M., and J. R. Brock, "An Assessment of the Global Sources of Tropospheric Aerosols,"
Proceedings of the Int. Clean Air Congr. 2nd, pp. 1088-1097, 1970.
. 6. Hidy, G. M., and J. R. Brock, The Dynamics of AerocolloidalSystems, Pereamon Press New York
NY, 1970.
7. Lee, R. E., Jr., and S. Goranson, "A National Air Surveillance Cascade Impactor Network:
Variations in Size of Airborne Paniculate Matter Over Three-Year Period," Environ. Sci. Technol
10:1022, 1976.
8. Appel, B. R., Hoffer, E. M., Kothny, E. L., Wall, S. M., Haik, M., and R. M. Knights, "Diurnal
and Spatial Variations of Organic Aerosol Constituents in the Los Angeles Basin," Proceedings:
Carbonaceous Particles in the Atmosphere, March 20-22, 1978. T. Nonokov, ed., Lawrence
Berkeley Laboratory, University of California, LBL-9037, pp. 84-90, 1979.
9. Nagda, N. L., Rector, H. E., and M. D. Koontz, Guidelines for Monitoring Indoor Air Quality,
Hemisphere Publishing Corporation, New York, NY, 1987.
10. 40 CFR, Part 58, Appendix A, B.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-23
-------
Method IO-2.3 .
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SPM
Figure 1. Partisol® Air Sampler, with Satellite on Left and Hub on Right.
Page 2.3-24
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
PM-10 INLET
STATIONS
SAMPLE
FILTER
MAIN HUB
MASS
FLOW
SENSOR
BAROMETRIC
PRESSURE
TRANSDUCER
i r
I i
I
AMBIENT
TEMPERATURE
TRANSDUCER
GAUGE
MANUAL ZERO VALVE
SHUTOFF
VALVES
o
INLET FILTER
ACCUMULATOR
VACUUM PUMP
. AIR FLOW LINES
ELECTRICAL LINES
Figure 2. Partisol® Flow Schematic.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-25
-------
Method IO-2.3
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SPM
Stats Screen
RS232 Setup
Screen
i
Title Screen
;
Main Screen
Setup Screen
Calibration
Screen
MET
TIME
,
Programming
Screen
Filter Data
Screen ;
Diagnostics
Screen >
. Interval Data !
* Screen ;
Figure 3. Hierarchy -of Screens.
Page 2.3-26 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
BASIC Calibration STOP
Calc Act Offset Span
A/I: 1.003 0.000 0.0000 1.0000
Temp: 27.9 0.0 1.0000
Pres: 0.998 0.000 1.0000
Flow: 16.7 0.0 0.0000 1.0000
A/0: 1.00 Pot: 3. 752 Flow Adj: Hold HI
Edit
Hubl
Sat2
Sat3
Sat4
>
Soft Function Kevs In View Data Mode
Edit
PuiapOff
Hubl
PumpOn
Sat2
DecrFlw
Sat3
HoldFlw
Sat4
IncrFlw
>
<
Soft Function K«vs jn. Edit Mod.e
—
+/-
-
4-
-M-
Bksp
>
<
Unshlfted
Shifted
Unshffted
Shifted
Figure 4. Calibration Screen.
January 1997 Compendium of Methods for Inorganic Air Pollutants
Page 2.3-27
-------
Method IO-2.3
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SPM
CC-V.A.'' • ''f-'-* J-'1"' --
Page 2.3-28
Figure 5. Flow control manual valve (A) shown in its closed position.
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
Figure 6. Pump manual valve (A) shown in its closed position.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-29
-------
Method IO-2.3
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SPM
Figure 7. Flow meter (A) attached to flow audit adapter (B).
Page 2.3-30 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
-
/ +S.SV REFERENCE. /
MOTOBA—
MOTOBB
CONNECTS TO FLOW
CONTROL VALVB ASSEMBLY
(POO. POO AND PBO)
CONNECTS TO HEATERS
CONNECTS TO TRANSFORMER
VOLTAGE SELECT SWITCH
120/Z40VAC
LINE yOLTASE INPUT
"'i'V ' Pia
a 2. av ,-----., , ^
i — i 11 : L . i *
KS3 VPEG1 lO"*82 MO
PZO [• 1 VBEB3 *M4 .,
1 ' F1^ r= — i pai
, . . «— ' » <
| f!2 | pgT BOTCKP
"• ? *TEMP1 Q HFS» »
U-4 GKO»
QvcS
+VCC
pr
'~~~N\ i *"
1 1 ( THt ) 1
' ' ^ ' CONNECTS TO OlSt
LCD 8 IAS j
CONNECTS TO KEYP
*6V«
1 SMI 1 SND 9 :OUT» ourjf wri" dim
V_y r>| OOOOOOOO
: tut i tun tun cmr
« »IW
r ' r j r ; r i r j r
; PIO |P3i ;PB! ;p7i ;PB; JPO! 'p^
' ' J • J • J ' ' • J '
CNOSP09
•4OOIR«
PM419
• PRESS
P17
PTt
P1B
"LAY
PIS
AD (P7O)
AMS
TEUP
i
i
PI
PUMP HUB SAT* SAT2 SAT3 FAN AMBIENT
TEMPERATURE
SENSOR
CONNECTS TO 08 ON CPU
WNALOQ TO OIOITAL CONVEHTEB)
CONNECTS TO J7 ON CPU
CONNECTS TO OS ON CPU
STATUS LIGHT DIRECTORY
-vr^^
OUTO
OUT1
OOT2
OUT3
OUT4
OUTS
OUTB
OOT7
ON
ON
ON
ON
OFF
ON
ON
OFF
*v»
IF
If
IF
IF
If
•IF
IF
IF
.,_..
HUB VALVE IS ... .
SATt VALVE IS ...
SAT2 VALVE IS ...
SAT3 VALVE IS ...
PUMP IS
FAN IS
LCD BACK LIGHT IS
HEATERS ABC
ON
ON
ON
ON
ON
ON
ON
ON
Figure 8, Layout of Interface Board.
January 1997 Compendium of Methods for Inorganic Air Pollutants
Page 2.3-31
-------
Method IO-2.3
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SFM
Figure 9. Interface Board (A).
Page 2.3-32
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
/'STATUS cooe\
\I. R, P, T, FJ
/ AOJUST BS3 TO SET /-
MOTOP.A
MOTORS
CONNECTS TO FLOW
CONTROL VALVE ASSEMBLY
(POO. PBO AND POO)
CONNECTS TO TRANSFORMER
120/Z40VAC
LINE VOLTASE INPUT
/^O^E^E./-! J *%« «^
P1B
VPEC 1 VRC&2
R33 ^C" I"*** WNDOine
1 1 j 1 ^__^_^ 'j' PI4M1 9
L_J ^ • PRESS
f12 1 POT. "TEW
U-4 6ND* *"Tt
r— , s~\ -n
/ \ +VCC
P21 1 C3° )pt«W P16
v^/x r
1 1 ( THt ) 1
1 ' v ' CONNECTS TO DISPLAY
P3 [ Ct | LCD BIAS ("^
\ y • • i
1 ' V /CONKECTS TO KEYPAD (P7OI
^~~—^^'9
v_x r>i°ooo\Do'oo
-------
Method IO-2.3
R&P Partisol® Sampler
Chapter IO-2
Integrated Sampling for SFM
BASIC Partisol Main Screen RUN
16:21 03~Oct-93 Curr:2 Status :Ok
Stat Std Vol Valid Total Date
HI; DONE 24.143 24:00. 24:00 02-Oct
S2t ON 16.342 16:21 16:21 03-Oct
S3: OFF 0.000 0:00 0:00 04-Oct
S4:
Edit
Stats
Storage
Run/stp
Setup
Soft Function Kevs In View Dqta.MotfS
Edit
Stats
Storage
Run/Stp
Setup
Soft Function Kevs |n_6dft M-P***
Daily
—
Today+1
-
4-
+
++
•M-
Bksp
Bksp
>
<
•
Unshifted
Shifted
Unshifted
Shifted
Figure 11. Main screen, basic programming mode.
Page 2.3-34
Compendium of Methods for Inorganic Mr Pollutants January 1997
-------
Chapter IO-2
Integrated Sampling for SPM
Method IO-2.3
R&P Partisol® Sampler
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January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.3-35
-------
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-2.4
CALCULATIONS
FOR
STANDARD VOLUME
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-2.4
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were me project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• WilliamT. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
11
-------
Method IO-2.4
Calculating Standard Volume
TABLE OF CONTENTS
Page
1. Introduction
2.4-1
2. Calculation of Volume to STP 2.4-1
3. Federal Register Citation 2.4-1
in
-------
-------
Chapter IO-2
INTEGRATED SAMPLING OF SPM IN AMBIENT AIR
Method IO-2.4
CALCULATING STANDARD VOLUME
1. Introduction
1.1 Most atmospheric sampling techniques use a sampling train whereby air containing the pollutant of
interest enters the train and passes through a sample collection device.
1.2 The weight of the pollutant collected is compared to the volume of air drawn through the train to
extrapolate the concentration of the pollutant in the ambient air. The concentration is usually expressed
in terms of fig/m, corrected to EPA's standard temperature and pressure (STP).
2. Calculation of Volume to STP
2.1 To compare gas sampling data collected by various agencies and organizations from around the
country, EPA has specified that all gas volumes must be corrected to a set of predetermined standard
conditions. For atmospheric or ambient sampling, these conditions are 25°C or 298K and 760 mm Hg.
2.2 The equation used to correct sample volumes (V) to EPA standard volume (V) conditions is:
vstd =
Vstd= (Vs)(Patn/760 mm Hg)(298 K/Tatm)
Vstd - (VsXO-^atn/W
where:
Vst(j = volume of gas sampled, corrected to EPA's standard pressure (760 mm Hg) and standard
temperature (25 °C), m3.
Vs = volume of gas sampled at atmospheric pressure (Patm) and temperature (Tatm), m3.
Tstd - EPA standard temperature (25 °C), 273 + 25 = 298 K.
Pstd = EPA standard pressure, 760 mmHg.
Tatm = averaSe atmospheric temperature during sampling (°C), 273 + 25 = 298K.
Patm = averaSe atmospheric pressure during sampling, mmHg.
0.39 = 298 K/760 mm Hg
3. Federal Register Citation
3.1 The full text of EPA's specifications for correcting volumes to STP can be found in 40 CFR, Part
50, Appendix B.
3.2 All sample volumes must be corrected to STP.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 2.4-1
-------
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Chapter IO-3
CHEMICAL SPECIES ANALYSIS OF
FILTER-COLLECTED SUSPENDED
PARTICULATE MATTER
OVERVIEW
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
-------
Chapter IO-3 -
CHEMICAL SPECIES ANALYSIS OF FILTER-COLLECTED
SUSPENDED PARTICIPATE MATTER (SPM)
OVERVIEW
As discussed in Chapter IO-2, the EPA's approach toward regulating and monitoring SPM in ambient
air has evolved over time. Initially, the EPA was concerned about total concentrations of SPM and lead
(Pb); recently, however, interest has focused on smaller particles as well as other types and quantities of
various inorganic components of SPM. A comprehensive discussion of the various approved methods
and technology used for time-integrated sampling of SPM are presented in Chapter IO-2. These methods
principally include:
• High volume samplers for collecting TSP (total suspended particulate with aerodynamic diameters
less than 100 pm) and PM10 (particulate matter with aerodynamic diameters less than 10 jim); and
• Low volume samplers for collection PM10 utilizing dichotomous and Partisol® samplers.
Chapter IO-3 contains the options available for identifying and quantifying the inorganic compounds in
SPM. This overview is intended to introduce these analytical options and provide information to help
guide the selection of options appropriate to the particular task at hand.
Two methods of sample preparation for quantitative analysis of chemical species in SPM are described
in Compendium Method IO-3.1, These methods include hot acid extraction and microwave digestion.
Both methods are described in detail in Section IO-3.1. Selecting an appropriate method will depend
upon the type of analytical technique used.
Chapter IO-3 includes six options for the quantitative analysis of inorganic compounds in PM.
These options are:
Method Analytical Technique ; V
Method IO-3.2 Flame and graphite furnace atomic absorption spectroscopy (FAA/GFAA)
Method IO-3.3 X-Ray fluorescence spectroscopy (XRF)
Method IO-3.4 Inductively coupled plasma atomic emission spectroscopy (TCP)
Method IO-3.5 Inductively coupled plasma/mass spectroscopy (ICP/MS)
Method IO-3.6 Proton induced X-Ray emission spectroscopy (PIXE)
Method IO-3.7 Neutron activation Analysis (NAA)
These options are described in detail in Methods IO-3.2 through IO-3:7. A brief summary of each of
the techniques is provided below.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.0-1
-------
Chapter IO-3
Analysis of SPM Overview
Method IQ-3.2
Atomic Absorption Spectroscopy (FAA and GFAA)
The two atomic absorption analysis options included in Compendium Method IO-3.2, FAA and
GFAA, are similar in that the measurement principle for these two options is the same. However, they
differ in how the sample is introduced into the instrument. Both types of atomic absorption Spectroscopy
involve irradiating the sample with light of a single wavelength and measuring how much of the input
light is absorbed. Each element absorbs light at a characteristic wavelength; therefore, analysis for each
element requires a different light source, and only one element can be determined at a time. In FAA,
the sample is atomized and introduced into the optical beam using a flame, typically air/acetylene or
nitrous oxide/acetylene. In GFAA, a graphite furnace electrothermal atomizer is used. These analytical
techniques are destructive and require that the sample be extracted or digested for introduction into the
system in solution. The detection limit of GFAA is typically about two orders of magnitude better than
FAA. High-volume samplers (hi-vols) are typically used for sampling when FAA or GFAA analysis is
planned, as documented in Figure 1.
Method IO-3.3
X-ray Fluorescence Spectroscopv fXRF)
In XRF analysis, the sample is irradiated with a beam of x-rays, and the elements in the sample emit
X-rays at characteristic wavelengths. The wavelengths that are detected indicate which elements are
present, and the quantity of each element is determined from the intensity of the X-rays at each
characteristic wavelength. X-ray fluorescence spectrometry can be used for all elements with atomic
weights from 11 (sodium) to 92 (uranium), and multiple elements can be determined simultaneously.
This analysis technique is nondestructive and requires minimal sample preparation-the filter is inserted
directly into the instrument for analysis. This technology is relatively inexpensive; however, the detection
limit is higher than other analysis techniques. As indicated in Figure 1, analysis by XRF typically
involves collection of SPM by dichotomous sampler or the Partisol® sampler.
Method IO-3.4
Inductively Coupled Plasma Atomic Emission Spectroscopy flCP)
In ICP analysis, the sample is excited using an argon plasma "torch." When the excited atoms return
to their normal state, each element emits a characteristic wavelength of light. The wavelengths detected
and their intensities indicate the presence and amounts of particular elements. Up to 48 elements can be
determined simultaneously. As with FAA and GFAA, the SPM sample must be extracted and digested
for ICP analysis, and the material introduced into the instrument is destroyed during analysis. An ICP
instrument is more costly than FAA or GFAA instruments. The ICP detection limit for many elements
is equal to or somewhat better than that for FAA. (With particular elements, however, one or the other
analysis technique is very superior to the other.) The GFAA detection limit is better than that for ICP
for most elements. As indicated in Figure 1, hi-vols are typically used for sampling when ICP analysis
is planned.
Page 3.0-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Overview Analysis of SPM
Method IO-3.5
Inductively Coupled Plasma/Mass Spectroscopv (ICP/MS)
Analysis by ICP/MS also uses argon plasma torch to generate elemental ions for separation and
identification by mass spectrometry (MS). This analysis technique allows many more than 60 elements
to be determined simultaneously, and even the isotopes of an element can be determined. For ICP/MS
analysis, the SPM sample must be extracted or digested, and the analysis is destructive. An ICP/MS
instrument is the most costly of those included hi this Chapter, and its detection limit is the lowest.
Sampling is typically conducted using hi-vols when ICP/MS analysis is planned, as shown in Figure 1.
Method IO-3.6
Proton Induced X-ray Emission Spectroscopv (FIXE)
PIXE analysis is very similar to XRF analysis hi that the sample is irradiated by a high energy
source, in this case high energy protons, to remove inner shell electrons. Fluorescent x-ray photons are
detected using the same detection methods as XRF. Analysis by PIXE also typically involves collecting
SPM by dichotomous sampler, or by Partisol® sampler.
Method IO-3.7
Neutron Activation Analysis (NAA)
In NAA analysis, the sample and an appropriate standard are exposed to a high neutron thermal flux
in a nuclear reactor or accelerator. The sample elements are transformed into radioactive isotopes that
emit gamma rays. The distribution or spectrum of energy of the gamma rays can be measured to
determine the specific isotopes present. The intensity of the gamma rays can also be measured and is
proportional to the amounts of elements present. NAA is a simultaneous, multi-element method and does
not generally require significant sample preparation. It is highly sensitive, though it does not quantify
elements such as silicon, nickel, cobalt, and lead. NAA is a non-destructive technique and does not
require the addition of any foreign materials for irradiation; thus, the problem of reagent introduced
contaminates is avoided. Analysis by NAA is compatible with sampling by dichotomous sampler,
Partisol® sampler and continuous PMjQ sampler.
Comparative Selection Criteria
Some of the analytical techniques listed above typically are used only with particular sampling
methods. The relationships between sampling technologies and compatible analytical techniques is
illustrated in Figure 1. Furthermore, the type of filter medium used to capture the sample is a factor in
the choice of analytical technique and vice-versa.
Most importantly, the choice of analytical method will depend on the inorganic compounds of interest
and the detection limits desired. A relative comparison of the ranges of detection limits that are typical
for the various techniques is provided in Figure 2. Table 1 contains a more detailed summary of the
species measured and the respective minimum detection limits associated with analytical options discussed
in this Chapter.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.0-3
-------
Chapter IO-3
Analysis of SPM Overview
Some of the advantages and disadvantages associated with the analytical options presented in
Compendium Method IO-3 are summarized in Figure 3. While factors such as element specificity and
sensitivity are critically important, considerations such as cost and throughput (the number of samples
and number of elements to be determined per sample) are also important. A comparison of the typical
throughput for the analytical options in Compendium Method IO-3 is provided in Figure 4.
Unfortunately, no one analytical method can address all data quality objectives for a particular ambient
air monitoring program. Each method has its own attributes, specificities, advantages, and disadvantages,
as previously discussed. However, Compendium Method IO-3 attempts to encompass into one chapter
the various analytical options, in a step-by-step methodology, to facilitate accurate and reliable data for
SPM and metal concentration in the ambient air.
Page 3.0-4 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Overview
Chapter IO-3
Analysis of SPM
Determination
Average TSP
Concentration
Average PM10
Concentration
Average PM10
Concentration
<2.5um and > 2.5 urn
Sampling
Methodology
Hi-VoI
Sampler
(Reference Method
TSP or PM-io)
(Chapter IO-2)
Instantaneous
Concentration' "
Analytical
Methodology
Flame Atomic
Absorption (FAA)
Low Volume Sampler
— Dichotomous
~ Partisol®
(Chapter IO-2)
Continuous
PMio Sampler
(Chapter IO-1)
Graphite
Furnace Atomic
Absorption (GFAA)
Inductively
Coupled Argon
Plasma Spectroscopy
(ICP)
Inductively
Coupled Plasma
Spectroscopy
(ICP/MS)
Proton Induced
" X-ray Emission
Spectroscopy
(PIXE)
X-Ray
Fluorescence
(XRF)
Neutron
Activation
Analysis
(NAA)
Figure 1. Relationship between Chapter IO-1 and IO-2 sampling technologies
and Chapter IO-3 analytical techniques.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.0-5
-------
Chapter IO-3
Analysis of SPM
Overview
NEUTRON ACTIVATION ANALYSIS
ICP/MS
GFAA
ICP EMISSION
0.01 0.1
PIXE
FLAME AA
X-RAY FLUORESCENCE
1
10
100 1000
NANOGRAMS / m 3(ng/m 3)
Figure 2. Typical detection limits for Chapter IO-3 analytical options.
Page 3.0-6
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Overview
Chapter IO-3
Analysis of SPM
ADVANTAGE
DISADVANTAGE
FLAME AA
GFAA
ICP
ICP / MS
PIXE
XRF
NAA
• easy to use
• extensive applications
• low detection limits
1 well documented applications
> lower detection limits than
Flame AA
• multi-element
• high sample throughput
• well documented applications
• intermediate operator skill
• linear range over 5 orders of
magnitude
• multi-elements
• low concentrations
• isotopic analysis
• intermediate operator skills
• multielement
• non-destructive
• minimal sample preparation
multielement
non-destructive
minimal sample preparation
• multielement
• non-destructive
• minimal sample preparation
• % to ppb range
• high sample throughput
• well documented applications
• higher concentration
• sample dissolution required
• one (1) element at a time
limited working range sample
low sample throughput
one element at a time
more operator skill
• more expensive (~ 120K)
• sample dissolution is required
• other elements can interfere
• most expensive (~250K)
• limited documented applications
• standard/sample must match
closely (matrix)
• matrix offsets and background
impurities may be a problem
> standard/sample must match
closely (matrix)
' matrix offsets and background
impurities may be a problem
' some elemental interferences
• standard sample matrix
corrections
• required access to research
nuclear reactor
Figure 3. Advantages/disadvantages associated with analytical options in Chapter IO-3.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.0-7
-------
Chapter IO-3
Analysis of SPM
Overview
HI(
/
CO
\
LO
3H
i
NC.
P
W
i
FLAME AA
GFAA
r«A/ -^
XRF
or
PIXE
NUMRFR
ICP EMISSION
ICP / MS
or
NAA
— te» wirsw
OF ANALYSES
Figure 4. Throughput of analytical options in Chapter IO-3.
Page 3.0-8
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Overview
Chapter IO-3
Analysis of SPM
Table 1. Minimum Detection Limits (ng/m3) of Air Filter Samples
For Different Chapter IO-3 Analytical Methodsa>b
Species
Ag
Al
As
Au
Ba
Be
Br
Ca
Cd
Ce
Cl
Co
Cr
Cs
Cu
Eu
Fe
Ga
Hf
Hg
I
In
K
La
Mg
Mn
Mo
Na
Ni
P
Pb
Pd
Rb
S
Sb
Analytical Technique
•:"•'. NAA- -
0.12
24
0.2
NA
6
NA
0.4
94
4
0.06
5
0.02
0.2
0.03
30
0.006
4
0.5
0.01
NA
1
0.006
24
0.05
300
0.12
NA
2
NA
NA
NA
NA
6
6,000
0.06
XRF
6
5
0.8
2
25
NA
0.5
2
6
NA
5
0.4
1
NA
0.5
NA
0.7
0.9
NA
I
NA
6
3
30
NA
0.8
1
NA
0.4
3
1
5
0.5
2
9
PIXE
NA
12
1
NA
NA
NA
1
4
NA
NA
8
NA
2
NA
1
NA
3
1
NA
NA
NA
NA
5
NA
20
2
5
60
1
8
3
NA
2
8
NA
Flamfr
AAS
4
30
100
21
8
2
NA
1
1
NA
NA
6
2
NA
4
21
4
52
2,000
500
NA
31
2
2,000
0.3
1
31
0.2
5
100,000
10
10
NA
NA
31
Graphite
Furnace
AAS
0.005
0.01
0.2
0.1
0.04
0.05
NA
0.05
0.003
NA
NA
0.02
0.01
NA
0.02
NA
0.02
NA
NA
21
NA
NA
0.02
NA
0.004
0.01
0.02
<0.05
0.1
40
0.05
NA
NA
NA
0.2
TCP
1
20
50
2.1
0.05
0.06
NA
0.04
0.4
52
NA
1
2
NA
0.3
0.08
0.5
42
16
26
NA
63
NA
10
0.02
0.1
5
NA
2.
50
10
42
NA
10
31
ICP/MS
1.01
1.01
1.10
NA
NA
0.02
NA
NA
0.02
NA
NA
0.01
0.01
NA
0.01
NA
0.01
'NA
NA
NA
NA
NA
NA
NA
0.02
0.02
0.02
NA
0.02
NA
0.01
NA
NA
NA
0.01
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.0-9
-------
Chapter IO-3
Analysis of SPM
Overview
Table 1. Minimum Detection Limits (ng/m3) of Air Filter Samples
For Different Chapter IO-3 Methods (cont).
Species
Sc
Se
SI
Sm
Sn
Sr
Ta
Th
Ti
TI
U
V
W
Y
Zn
Zr
Cl
NH4
N03
so4
Elemental
Carbon
Organic
Carbon
Analytical Technique
*
NAA
0.001
0.06
NA
0.01
NA
18
0.02
0.01
65
NA
NA
0.6
0.2
NA
3
NA
NA
NA
NA
NA
NA
NA
XRF
NA
0.6
3
NA
8
0.5
NA
NA
2
1
1
1
NA
0.6
0.5
0.8
NA
NA
NA
NA
NA
NA
a Minimum detection limit is three times
density.
PIXE
NA
1
9
NA
NA
2
NA
NA
3
NA
NA
3
NA
NA
1
3
NA
NA
NA
NA
NA
NA
Flame
AAS
50
100
85
2,000
31
4
2,000
NA
95
21
25,000
52
1,000
300
1
1,000
NA
NA
NA
NA
NA
NA
Graphite
Furnace ,
AAS
NA
0.5
0.1
NA
0.2
0.2
NA
NA
NA
0.1
NA
0.2
NA
NA
0.001
NA
NA
NA
NA
NA
NA
NA
ICP
0.06
25
3
52
21
0.03
26
63
0,3
42
21
0.7
31
0.1
1
0.6
NA
NA
NA
NA
NA
' NA
ICP/MS
NA
1.10
NA
NA
0.01
NA
NA
NA
0.01
0.01
0.01
0.01
0.01
0.01
0.01
NA
NA
NA
NA ,
NA
NA
the standard deviation of the blank for a filter of 1 mb/cm2 areal
ICP = Inductively Coupled Plasma Emission Spectroscopy.
AAS = Atomic Absorption Spectrophotometry.
PIXE = Proton Induced X-ray Emissions.
XRF = X-ray Fluorescence.
NAA = Instrumental Neutron Activation Analysis.
k Chow, J. C., "Measurement Methods to Determine Compliance with Ambient Air Quality Standards for
Suspended Particles,11 /. Air and Waste Manage. Assoc., Vol. 45:
320-382, 1995
Page 3.0-10 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.1
SELECTION, PREPARATION
AND EXTRACTION OF
FILTER MATERIAL
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-3.1
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-G3-0315, WA No. 2-10,
by Midwest Research Institute (MSI), as a subcontractor to Eastern Research Group, Inc. (ERG), and
under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning, Center
for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure Research
Laboratory (NERL), both in the EPA Office of Research and Development, were the project officers
responsible for overseeing the preparation of this method. Other support was provided by the following
members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, MB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in the
preparation and review of this methodology. • ,
Author(s)
Avie Mainey, Midwest Research Institute, Kansas City, MO
William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
David Brant, National Research Center for Coal and Energy, Morgantown, WV
John Glass, SC Department of Health and Environmental Control, Columbia, SC
Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
Dewayne Ehman, Texas Natural Resource Conservation Committee, Austin, TX
Gary Wester, Midwest Research Institute, Kansas City, MO
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
11
-------
Method IO-3.1
Selection, Preparation and Extraction of
Filter Material
TABLE OF CONTENTS
1. Scope 3.1-1
2. Applicable Documents 3.1-1
2.1 ASTM Documents 3.1-1
2.2 Other Documents 3.1-2
3. Apparatus 3.1-2
3.1 Equipment For Gravimetric Analysis 3.1-2
3.2 Microwave Digestion Apparatus and Materials 3.1-2
3.3 Hot Acid Extraction Apparatus and Materials 3.1-3
4. Filter Medium Selection 3.1-4
4.1 Introduction 3.1-4
4.2 Visual Filter Inspection 3.1-5
5. Gravimetric Determination 3.1-6
5.1 Introduction 3.1-6
5.2 High Volume Filter Weighing Procedure ! 3.1-6
5.3 Dichotomous Filter Weighing Procedure 3.1-8
5.4 Transport of Filters 3.1-9
6. Extraction of Glass Fiber Filters in Preparation for Metal Analysis . . . 3.1-10
6.1 Introduction 3.1-10
6.2 Microwave Extraction Procedure 3.1-10
6.3 Hot Acid Extraction Procedure 3.1-14
111
-------
-------
Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF
FILTER-COLLECTED SUSPENDED PARTICULATE MATTER (SPM)
Method IO-3.1
SELECTION, PREPARATION AND EXTRACTION OF
FILTER MATERIAL
1. Scope
1.1 This methodology consists of (1) filter media selection, (2) numbering and pre-field tare weighing
quartz fiber and dichotomous ambient air filters, (3) post-field final weighing, and (4) subsequent
microwave or hot acid extraction for metal analysis by ICP, AA, ICP/MS or GFAA.
1.2 Pre-field filters are conditioned in a room of constant humidity and temperature and are
gravimetrically tared. After air samples have been collected, the filters are returned to the laboratory and
conditioned as before and weighed. The final filter weight minus the tare weight is calculated. The
procedure for the weighing of filters is based on 40 CFR 50, Appendix B, entitled "Reference Method
for the Determination of Suspended Matter in the Atmosphere (High-Volume Method)."
1.3 After the post-field filter final weights have been obtained, the filter is subsampled by cutting a filter
strip consisting of one-ninth of the overall filter and digested using a microwave or hot acid extraction
technique; these extracts are then analyzed by one of many analytical techniques. The results are
multiplied by a factor of 9 to obtain the actual total ng of each metal found on the entire 8" x 10" filter.
Based upon the analysis of a blank filter, background metal concentration may be subtracted from the
total metal concentration to get a net value. Therefore, the analytical results represent the total fig found
on the 8" x 10" filter but do not represent the volume of air sampled.
1.4 Sectioning the filter for extraction is based on 40 CFR 50, Appendix B entitled "Determination of
Lead in Suspended Particle Matter Collected From Ambient Air." The procedure for the microwave
extraction is based on a method developed by EPA entitled Microwave Extraction of Glass-Fiber Filters,
as identified in Section 2.2. This procedure has been modified for extracting quartz fiber filters.
2. Applicable Documents
2.1 ASTM Documents
• D4096 Application of the High Volume Sample Method for Collection and Mass Determination
of Airborne Particle Matter.
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice for Planning the Sampling of the Ambient Atmosphere.
• D2986 Method for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Phthalate)
Smoke Test.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-1
-------
Method 10-3.1 Chapter 10-3
Filter Material Chemical Analysis
2.2 Other Documents
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94/038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b.
• Reference Method for the Determination of Paniculate Matter in the Atmosphere, Code of Federal
Regulations (40 CFR 50, Appendix J).
• Reference Method for the Determination of Suspended Particulates in the Atmosphere (High
Volume Method), Code of Federal Regulations (40 CFR 50, Appendix B).
* Reference Method for the Determination of Lead in Suspended Paniculate Matter Collected from
Ambient Air, Federal Register 43 (194): 46258-46261.
• U. S. Environmental Protection Agency, Microwave Extraction of Glass Fiber Filters, Method
Research and Development Division, RTP, NC 1989.
3. Apparatus
3.1 Equipment For Gravimetric Analysis
3.1.1 Controlled Temperature. Temperature between 15 and 30°C with less than ±2°C variation
during equilibration period.
3.1.2 Controlled Humidity. Less than 50% relative humidity, constant within ±5%
3.1.3 Analytical Balance. Sensitive to 0.1 mg, with weighing chamber designed to accepted an
unfolded 20.3 x 25.4 cm (8" x 10") filter.
3.1.4 Area Light Source. Similar to X-ray film viewer to backlight filters for visual inspection.
3.1.5 Numbering Device. Capable of printing identification numbers on the filters before they are
placed in the filter conditioning environment if not numbered by the supplier.
3.1.6 Hygrothermograph. Capable of recording temperature and relative humidity in the weighing
room.
3.2 Microwave Digestion Apparatus and Materials
3.2.1 Microwave Digestive System and Capping Station. With programmable power settings up
to 600 watts, best source.
[Note: Commercial kitchen or home-use microwave should NOT be used for digesting samples. The oven
cavity must be corrosion resistant and well ventilated. All electronics must be protected against corrosion
for safe operation.]
3.2.2 PEA Teflon® Digestion Vessels. Capable of withstanding pressures of up to 120 psi. Pressure
ventime vessels capable of controlled pressure relief at pressures exceeding 120 psi (60-120 mL capacity),
best source.
3.2.3 Teflon® PFA Overflow Vessel. Double ported (60-120 mL capacity), best source.
Page 3.1-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
3.2.4 Rotating Table. Uniform exposure of samples within the oven.
3.2.5 Volumetric Glassware. 50-100 mL capacity (Class A borosilicate).
3.2.6 Bottles, Linear Polyethylene or Polypropylene with Leakproof Caps, for Storing Samples.
Teflon® bottles for storing multielement standards (500 mL, 125 mL, and 30 mL), best source.
3.2.7 Centrifuge Tubes. Oak Ridge polysulfone tubes with screw caps of polypropylene, 30 mL.
3.2.8 Nylon or Teflon® 0.45 /tg Syringe Filters. Acrodisc® No. 4438 or equivalent and syringes
for rapid nonmetals contributing filtering.
3.2.9 Sterile Polypropylene Tubes with Screw Caps of Polypropylene, 15 mL Capacity. Best
source.
3.2.10 Pipette. Automatic dispensing with an accuracy of setting 0.1 mL or better and repeatability
of 20 [j.L, Grumman Automatic Dispensing Pipette, Model ADP-30DT or equivalent.
3.2.11 Particle Mask. 3M, No. 8500, to be worn while cutting and handling glass-fiber filters.
3.2.12 Template.Aid in sectioning the glass fiber filter. Federal Register 43 (194): 46258-46261.
3.2.13 Pizza Cutter, Thin Wheel. Clean razor blade (< 1 mm).
3.2.14 Vortex Mixer. VWR2 variable speed or equivalent.
3.2.15 Hydrochloric Acid. Baker Instra-Analyzed, concentrated (36.5%-38%/12.3 M) or
equivalent, for preparing samples.
3.2.16 Nitric Acid. Baker Instra-Analyzed, concentrated (70% 16M) or equivalent, for preparing
samples.
3.2.17 ASTM Type II Water. ASTM D193.
3.3 Hot Acid Extraction Apparatus and Materials
3.3.1 Thermolyne Model 2200 Hot-Plate or Equivalent.
[Note: Temperature of the extracts may be monitored by the use of a beaker containing a thermometer
and similar reagents as the samples.]
3.3.2 Volumetric Glassware. 50-100 mL capacity (Class A borosilicate).
3.3.3 Bottles, Linear Polyethylene or Polypropylene with Leakproof Caps, for Storing Samples.
Teflon® bottles for storing multielement standards (500 mL, 125 mL, and 30 mL).
3.3.4 Centrifuge Tubes. Polypropylene or Oak Ridge polysulfone tubes with screw caps of
polypropylene, 30 mL (Nalgene 3119-0050/3115-0030 or equivalent).
3.3.5 Nylon or Teflon® 0.45 pug Syringe Filters. Acrodisc® No. 4438 or equivalent and syringes
for rapid nonmetals contributing filtering.
3.3.6 Sterile Polypropylene Tubes with Screw Caps of Polypropylene, 15 mL capacity. Falcon
Model No. 2099 or equivalent.
3.3.7 Pipette. Automatic dispensing with an accuracy of setting 0.1 mL or better and repeatability
of 20 fj.L. (Grumman Automatic Dispensing Pipette, Model ADP-30DT or equivalent).
3.3.8 Particle Mask. 3M, No. 8500. To be worn while cutting and handling glass-fiber filters.
3.3.9 Vortex Mixer. VWR2 variable speed or equivalent.
3.3.10 Hydrochloric Acid. Baker Instra-Analyzed, concentrated (36.5%-38%/12.3 M) or
equivalent, for preparing samples.
3.3.11 Nitric Acid. Baker Instra-Analyzed, concentrated (70% 16M) or equivalent, for preparing
samples.
3.3.12 ASTM Type H Water. ASTM D193.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-3
-------
Method 10-3.1 ^ Chapter 10-3
Filter Material Chemical Analysis
4. Filter Medium Selection
4.1 Introduction
4.1.1 In general, the filter medium depends on the purpose of the test. For any given standard test
method, the appropriate medium will be specified. However, it is important to be aware of certain filter
characteristics that can affect selection and use.
4.1.2 Selecting a filtration substrate for time-integrated SPM monitoring must be made with some
knowledge of the expected characteristics and a pre-determined analytical protocol. For any given
standard test method, the appropriate medium will normally be specified.
4.1.3 In high-volume sampling, four types of filter material to capture SPM are commonly used.
They include cellulose fiber, quartz/glass fiber, mixed fiber, and membrane filter types. Selecting a filter
depends upon variables such as background metal content, artifact formation, and affinity for moisture.
The basic characteristics of the types of filter material used in high volume are outlined in Table 1
sampling. Useful filter properties are described in Table 2. Several characteristics are important in the
selection of filter media. They are: '
• Particle Sampling Efficiency. Filters should remove more than 99 % of SPM drawn through them,
regardless of particle size or flow rates.
• Mechanical Stability. Filters should be strong enough to minimize leaks during sampling and
wear during handling.
• Chemical Stability. Filters should not chemically react with the trapped SPM.
• Temperature Stability. Filters should retain their porosity and structure during sampling.
• Blank Correction. Filters should not contain high concentrations of target compound analytes.
Quartz fiber filter medium is most widely used for determining mass loading. Weight stability with
respect to moisture is an attractive feature. Quartz fiber filters provide high efficiency and collect
airborne particles of practically every size and description. Typical characteristics of quartz fiber filters
are (1) a fiber content of high purity quartz, (2) a binder of below 5% (zero for binderless types), (3) a
thickness of approximately 0.5 mm, (4) a surface with no pinholes, and (5) an allowance of no more than
0 05% of smoke particles to pass through the filter at a pressure of 100mm of water with a flow rate of
8.53 m/min (28 ft/min), as determined by ASTM-D2986, Method for Evaluation of Air Assay Media by
the Monodisperse DOP (Dioctyl Phthalate) Smoke Test.
Paniculate matter collected on quartz fiber filters can be analyzed for many constituents. If chemical
analysis is anticipated, binderless filters should be used. Glass is a commercial product generally
containing test-contaminating materials; therefore, appropriate background corrections should be made.
Background concentration of various metals associated with different grades of quartz fiber filters are
documented in Table 3.
4.1.4 Silica fiber filters are used when it may be required or desirable to use a mineral fiber filter,
which may later be extracted by strong reagents. These fibers are usually made by leaching glass fibers
with strong mineral acids followed by washing with deionized water. The fibers are rather weak but can
be formed into filter sheets using little or no binder. These filters have been recently developed and are
commercially available.
4.1.5 For some purposes, airborne particles may be collected on cellulose fiber filters. Cellulose
low-ash filters are especially useful when the filter is to be destroyed by ignition or chemical digestion.
Page 3.1-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
However, these filters have higher flow resistance (lower sampling rate) and have been reported to have
much poorer collection efficiency than the glass fiber media. Furthermore, cellulose is very sensitive to
moisture conditions, and even with very careful conditioning before and after sampling, accurately
weighing the collected particles is difficult. The filter should be enclosed in a lightweight metal can with
a tight lid and weighed.
4.1.6 As documented in the 40 CFR Part 58, Appendices A and B, identify the filter specifications
when used as part of the Federal Reference Method for Paniculate Matter in Ambient Air. These
specifications include (1) a quartz-fiber, nonhydroscopic filter, (2) a size of approximately 8" x 10", (3)
an exposure area of approximately 63 in.2, (4) a 99% collection efficiency as measured by ASTM-2986
(DOP test) for particles 0.3 /tin diameter, (5) a pressure drop range of 42-54 mm Hg at a flow rate of
1.5 m^/min through the nominal exposed area, (6) a pH of 6 to 10, and (7) a maximum weight integrity
of 2.4 mg.
4.2 Visual Filter Inspection
4.2.1 After purchased, all filters must be visually inspected for defects, and defective filters must be
rejected if any are found. Batches of filters containing numerous defects should be returned to the
supplier.
4.2.2 The following are specific defects to look for:
4.2.2.1 Pinhole. A small hole appearing as a distinct and obvious bright point of light when
examined over a light table or screen, or as a dark spot when viewed over a black surface.
4.2.2.2 Loose material. Any extra loose material or dirt particles on the filter that must be
brushed off before the filter is weighed.
4.2.2.3 Discoloration. Any obvious visible discoloration that might be evidence of a contaminant.
4.2.2.4 Filter nonuniformity. Any obvious visible nonuniformity in the appearance of the filter
when viewed over a light table or black surface that might indicate gradations in porosity across the face
of the filter.
4.2.2.5 Other. A filter with any imperfection not described above, such as irregular surfaces or
other results of poor workmanship.
4.2.3 Visually inspect each filter in front of an area light and observe for any specific defects listed
above.
4.2.4 Use a renumbering stamp to code the filter on its noncollection side with a 7-digit code before
tare weighing. The noncollection side of the filter is designated by the manufacturer printed number and
by a mesh texture. The number code might be as follows:
Example: Filter Number Code = 9622001
First 2 digits = yr, such as 96 for 1996
Third digit = project, such as 2
Fourth digit = filter type, such as 2 for 8" x 10" quartz fiber, Whatman QMA type
Last 3 digits = filter number, such as 001 .
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-5
-------
Method IO-3.1 Chapter IO-3
niter Material Chemical Analysis
5. Gravimetric Determination
5.1 Introduction
5.1.1 The filter is weighed (after moisture equilibration) before and after use to determine the net
weight (mass) gain. The total volume of air sampled corrected to EPA standard conditions (25 °C,
760 mm Hg) is determined from the measured flow rate and the sampling time. The concentration of
TSP matter in the ambient air is computed as the mass of collected particles divided by the volume of
air sampled (corrected to standard conditions) and expressed in jtg/std nor (see Inorganic Compendium
Method IO-2.4). For samples collected at temperatures and pressures significantly different than standard
conditions, the corrected concentrations may differ substantially from actual concentrations /tg/m ,
particularly at high elevations. The actual particulate matter concentration can be calculated from the
corrected concentration using the actual temperature and pressure during the sampling period.
5.1.2 Verify that the weighing room conditions are within the limits. Filter equilibrium and weighing
should be performed under controlled atmospheric conditions—a temperature of 25± 10°C and a relative
humidity <50% (normally 50±5% humidity).
5.1.3 Use the results from the motorized psychrometer to verify the temperature and relative
humidity indicated by the hygrothermograph. Record the psychrometer values on the strip chart, along
with the date, time, and your initials.
(Note: For traceability purposes, document your initials and full name in the front of the weighing room
notebook,]
5.1.4 Record the room equilibration data on the Weighing Room Atmospheric Condition Form (see
Table 4).
5.2 High Volume Filter Weighing Procedure
5.2.1 Filter Handling Procedure.
5.2.1.1 Filters should only be handled with finger cots or vinyl (nonpowdered) gloves. This
procedure applies to filter handling in the field as well as in the weigh room.
5.2.1.2 Avoid using metal tweezers since the filters later will be used for metals analysis. When
handling filter with gloved fingers or with any type of tweezers, avoid touching the sampled area.
5.2.2 Initial Weighing of High Volume Filter.
5.2.2.1 Upon receipt of new high volume filters (8" x 10" quartz fiber), take them to the climate
controlled room, remove the paper and plastic envelope (wearing clean plastic gloves), place each on edge
in a clean metal file rack, and cover with clean white paper towels.
5.2.2.2 Allow the filters to equilibrate in the metal file rack in the weighing room atmosphere for
at least 24 h. Humidity and temperature must be within Federal Reference method specification,
0.e., <50% and 15-35°C, respectively).
5.2.2.3 Zero the high volume balance before weighing.
5.2.2.4 Manually calibrate the balance. However, checks against NIST traceable weights (Class S)
should be conducted before the daily weighing. If the difference between the traceable weights is more
than 0.5 mg, do not use the balance until it has been repaired.
Page 3.1-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
5.2.2.5 Record the results on the Weighing Balance Check Form (see Table 5).
5.2.2.6 Check the balance at least once during every 4 h of weighing. If the difference limit is
exceeded, stop, place the balance .on a repair list, and reweigh any filters processed from the last
acceptable check on a balance that is within the limits.
5.2.2.7 Weigh each filter and record filter numbers and tare weights on the Filter Weighing Form
(see Table 6).
5.2.2.8 Return the weighed filters to the plastic and paper envelopes.
5.2.2.9 Weigh filters in lots of approximately 100, if possible. After every fifth weighing, recheck
the zero of the balance. The balance response should be ± 1 mg from 0. All differences should be
corrected. Any difference exceeding 1 mg requires reweighing the previous five filters. Any filter
weight outside the normal range of 3.5-5.0 g requires immediate investigation.
5.2.2.10 A second analyst should reweigh 100%. If the difference between the weights are less
than 1.0 mg, the results are acceptable.
5.2.2.11 If the difference is greater than this limit, wait another 24 h and reweigh them.
5.2.2.12 If the results are still outside acceptable limits, wait another 24 h and reweigh them again.
Then report the last reweigh values as the pre-field tare weights.
5.2.3 Final Weighing of High Volume Filter.
5.2.3.1 Exposed filters should be logged into the laboratory computer and received in individual
manila folders, with computer printed identification labels affixed. No exposed filter should be touched
until this label is affixed.
5.2.3.2 Condition all filters in the manner specified by the Federal Reference Method, as
documented in Sections 5.1.2 and 5.2.2.
5.2.3.3 Weigh all filters according to the Tare Weighing Procedure in Section 5.2.2. Record final
weights on the Filter Weighing Form (see Table 6).
5.2.3.4 For filters not to be analyzed, put an asterisk in the space preceding the four-letter code.
Leave this space blank for samples to be analyzed. Sign and date the forms.
5.2.3.5 Archive asterisked high volume filters.
5.2.3.6 Have a second analyst reweigh 10% of the filter and verify that the weights have not
changed.
• If the difference between the weights are less than 2.0 mg, the results are acceptable. Use the
results from the first weighing.
• If the difference is greater than this limit, reweigh 100% of that lot and use the last reweigh
weight. Calculate and report the particulate matter concentrations as:
(Wf - W;) x 106
SPM = U ll
Vstd
where:
SPM = mass concentration of suspended particulate matter (TSP or PMjQ>, /tg/std nA
Wj = initial weight of clean filter, g.
Wf = final weight of exposed filter, g.
Vstd = air vomme sampled, converted to standard conditions (25CC and 760 mm Hg), std m3.
10" = conversion of g to /tg.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-7
-------
Method IO-3.1 Chapter IO-3
Filter Material Chemical Analysis
5.3 Dichotomous Filter Weighing Procedure
53.1 Initial Weighing of Dichotomous Filters.
5.3.1.1 Fabric filters, 37-mm in diameter, with a circumferential plastic reinforcing ring are
usually supplied in small boxes. Open the boxes in the climate-controlled room under conditions suitable
for high volume weighing. Cover with a clean label paper towel and allow to equilibrate for 24 h.
5.3.1.2 Weigh filters on a Mettler microbalance; each balance is identified by a balance number.
5.3.1.3 Assign each balance a block of 7-digit sample numbers to be used sequentially. Assign
a sample number to each filter when it is tared.
[Note; Inaccuracies in this aspect of the procedure mil cause irremedial sample loss.]
5.3.1.4 Turn on the balance and allow it to warmup for at least 15 min. If the balance is used
daily, leave it on at all times.
5.3.1.5 Set the range knob to 10 mg with the automatic tare turned off. Turn the release lever to
" 1" and zero the balance using the tare adjusting knob.
5.3.1.6 To calibrate, turn the 10 mg tare knob to "C" and adjust the fine and coarse calibrating
screws for a reading of 10.000 ± 0.002. Return the release level to "0" and the 10 mg tare knob to "0."
5.3.1.7 Using clean nonserrated tweezers that will not damage the filter, remove the filter from
the Lexan jig and place it on the weighing pan. Turn the release lever to "1" and dial in tare weights
until a reading between 0.000 and 7.000 is obtained. Allow the reading to stabilize (which may require
2 to 4 min). Record the reading and the dialed-in tare weight. Return the release lever to "0" and remove
the filter from the weighing pan.
IWote: Do not use metal tweezers.}
5.3.1.8 Place a white label on a clean 50-mm diameter plastic petri dish (tight fitting lit type).
5.3.1.9 Assign a sample number to each filter (from those assigned to that balance), taking
extreme care to avoid duplication or missed numbers.
5.3.1.10 Record the assigned sample number on the petri dish label, leaving sufficient room for
one more letter to be written following the number. Do not record the balance number on this label.
5.3.1.11 Record the balance number, the assigned sample number, the dialed-in tare weight, and
the digital-displayed tare weight on the sample form. Number each sheet of the form sequentially in the
upper right-hand corner. Write "Tare Weight, Dichot Filters" on the top of each sheet. When bound,
these forms may serve as the laboratory notebook.
5.3.1.12 Place the weighed filter in its numbered petri dish for future use.
5.3.2 Final Weighing of Dichotomous Filter.
5.3.2.1 Filters should be returned from the field with a computer printed label affixed to the petri
dish. The label should contain a five-character identification code that is different from the original
sample number, a balance ID, the balance tare, and other information. All filters should be accompanied
by extra labels. Some will have the words "To Be Analyzed" on the labels. The filter in each petri dish
should rest in a Lexan jig.
5.3.2.2 Each filter on the balance on which its tare weight was obtained. In the climate-controlled
room, group the filters according to recorded balance numbers. Open the petri dishes, making certain
that lids are placed under the bottoms and that no mixup occurs. Cover with a clean white label paper
towel and allow to equilibrate.
Page 3.1-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
5.3.2.3 Repeat Section 5.3.1.7 of the dichotomous filter tare weighing procedure.
5.3.2.4 Perform "Standard Filter" quality control check to assure validity of reweighing.
5.3.2.5 Using clean, nonserrated tweezers that will not. damage the filter, remove the filter from
the Lexan jig and place it on the weighing pan. Dial in the tare weight recorded on the information label
and turn the release lever to"l."
5.3.2.6 If the dichotomous filter is not to be analyzed, use the tweezers to place it in a small
glassine envelope to which one of the extra labels has been affixed. Place an asterisk before the
five-character code on the form. Deliver these filters to the filter bank for archiving.
5.3.2.7 If the filter is to be analyzed, use tweezers to carefully put it back into the petri dish.
Place the petri dish carefully in a box.
5.3.2.8 Place a label on a sheet of 8 1/2" x 11" paper for either NAA or XRF analysis. Indicate
the page number and balance number on each list. Keep the samples in the box in an order
corresponding with the lists.
5.3.2.9 Without jostling the box, deliver it, the two lists, and the original Field Test Data Sheets
with two copies of each to the sample custodian who will initial the original forms and return them upon
receipt.
5.3.2.10 Calculate and report the particulate matter concentration for both fine and coarse samples
utilizing the following equation:
' (Wf - Wj) x 106
vstd
where:
•2
PM = mass concentration of particulate matter (TSP, fine or coarse friction), /xg/std m .
Wj = initial weight of clean filter, g.
Wf — final weight of exposed filter, g.
Vgtcj = air volume sampled, converted to standard conditions, std nr (see Inorganic
Compendium Method IO-2.4).
10" = conversion of g to ng.
5.4 Transport of Filters
5.4.1 After collecting samples, transport the filters to the laboratory, taking care to minimize
contamination and loss of the sample. Glass fiber filters should be transported or shipped in a shipping
envelope. Cover the exposed surface of the membrane filters with an unexposed filter and seal the filter
in plastic filter holders.
5.4.2 Assign numbers to the filters and log them into the data record form, ensuring that any
necessary sampling information is included (Untreated filter samples may be stored indefinitely.)
5.4.3 Provide one blank sample with every 10 actual samples. No air is drawn through the blank
filter, but it is subjected to the same handling and shipping manipulations as the actual samples.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-9
-------
Method IO-3.1 Chapter JO-3
Filter Material Chemical Analysis
6. Extraction of Glass Fiber Filters in Preparation for Metal Analysis
6.1 Introduction
This section describes a microwave-extraction procedure to extract inorganics from the paniculate quartz
glass-fiber filter. Following microwave extraction, target analytes are analyzed by ICP, ICP/MS, AA,
or GFAA.
6.1.1 Ambient air quartz fiber filters should be received folded in half lengthwise with the paniculate
material inward and enclosed in protective envelopes. Store these protective envelopes approximately
15°-30°C until analysis.
6.1.2 The maximum sample holding times is usually 180 days. Analyze the samples within 180 days,
even if these times are less than the maximum data submission times allowed.
6.2 Microwave Extraction Procedure
6.2.1 Filter Cutting Procedure.
6.2.1.1 Cut a 1" x 8" strip from the 8" x 10" filter using a template (see Figure 1) and cutting
tool (see Figure 2) as described in the Federal Reference Method for lead. Use a laboratory microwave
extraction system to extract the metals with either a hydrochloric/nitric acid solutions (for ICP and FAA)
on a nitric acid solution (for ICP/MS and GPAA). After cooling, mix the digestate and use Acrodisc®
syringe filters to remove any insoluble material. Microwave extraction is used to prepare samples for
ICP, ICP/MS, AA, or GFAA.
6.2.1.2 Prior to use, acid wash the plexiglass filter template, the polysulfone centrifuge tubes and
caps, and all other laboratory equipment that will come into contact with the filter samples to prevent
contamination.
6.2.1.3 Using vinyl gloves, place the acid-cleaned filter template and cover inside a balance hood
for cutting quartz fiber filters.
6.2.1.4 Wipe plexiglass template base, cover, and cutting blade with a clean, dry Kinwipe to
prevent sample cross-contamination.
6.2.1.5 Unfold the 8" x 10" quartz filter to be sectioned and carefully place sampled side up
(numbered side down) within the plexiglass template filter margins.
6.2.1.6 Carefully (without disturbing sampled area of filter) place the grooved cover, notch side
down, within the margins of the base template. Use a clear cutting blade to cut a 1" x 8" strip.
6.2.1.7 Using gloved fingers, accordion-fold or tightly roll the filter strip and transfer on edge
to an acid cleaned polysulfonte tube, labeled with wax pencil. DO NOT use barcodes or tape in
microwave.
6.2.1.8 Clean filter template between samples with dry Kinwipes. (Change gloves between
samples to prevent cross-contamination.)
6.2.1.9 Duplicate sample frequency is normally 1 per 20 field samples (see Table 7). Prepare a
sample filter duplicate by moving the template cover to a second portion of the field collected filter. Cut
an additional filter strip by moving the template cover to a second section of the filter and repeat
Sections 6.2.1.6 through 6.2.1.8 above using a separate polysulfone tube.
Page 3.1-10 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
6.2.1.10 Select a field collected filter for matrix spiking. In addition to the filter strip cut for
determining metals, section a second portion of the filter, and fortify (spike) with target metals.
6.2.1.11 Prepare matrix spike samples at a frequency of 1 per 20 field samples or a minimum of
1 per extraction day (see Table 7). Move the template to a second section of the filter and repeat Sections
6.2.1.6 - 6.2.1.8, using a separate polysulfone tube and spike as shown in Table 7.
6.2.2 Microwave Calibration Procedure. Calibration of the microwave unit is a critical step prior
to its use. In order that absolute power settings may be interchanged from one microwave unit to
another, the actual delivered power must be determined, which allows the analyst to relate power in Watts
to the partial power setting of the unit (% Power).
Calibration of a laboratory microwave unit (see Figure 3) depends on the type of electronic system
used by the manufacturer. If the unit has a precise and accurate linear relationship between the output
power and the scale used in controlling the microwave unit, the calibration can be a three-point
calibration in the range of 50% to 100% power. If the unit does not prove linear (± 10 W) using the
three-point technique, a multiple-point calibration is necessary. A bracketed calibration range of the
digesting power to be used is recommended for determining the calibration points. If the unit power
calibration needs multiple-point calibration, the point where the linearity begins must be identified. For
example, a calibration at 100, 99, 98, 97, 95, 90, 80, 70, 60, and 50% paver settings can be applied
and the data plotted. The nonlinear portion of the calibration curve can be excluded or restricted. Each
percent is equivalent to approximately 5.5-6.5 W and becomes the smallest unit of power that can be
controlled. If 20-40 W are contained from 99-100%, that portion of the microwave calibration is not
controllable by 3-7 times that of the linear portion of the control scale and will prevent duplication of
precise power conditions specified in that portion of the power scale.
6.2.3 Microwave Power Evaluation. The equation in the following section evaluates the power
available for heating in a microwave cavity. The variables are determined by measuring the temperature
rise in 1 kilogram of water exposed to electromagnetic radiation for a fixed period of time. The
following procedure is used for evaluating each calibration point, represented as % power output for each
microwave.
6.2.3.1 Measure and record a 1 kilogram (l,OOQg ±0.1 g) sample of room temperature
(23°±2°C) distilled water in a thick-walled microwave transparent (Teflon®) beaker for each calibration
point.
6.2.3.2 Measure and record the initial temperature of the water, (Tj), to within 0.1 °C. The
starting temperature should be between 22 and 26°C.
6.2.3.3 Place the Teflon® beaker in microwave and irradiate at full power (100% point) for 2 min
(120 s). Each calibration point (i.e., 100%, 50% or multi-points) requires a separate clean beaker
containing water at room temperature.
6.2.3.4 Remove beaker from the microwave and measure and record the maximum final
temperature (Tf) to 0.1 °C, within 30 s of the end of irradiation. This process should be done while
stirring continuously (an electronic stirrer using a large stir bar works best).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-11
-------
Method IO-3.1 Chapter IO-3
Filter Material _ Chemical Analysis
Calculate the microwave power according to the following formula:
K x C x M x AT
Power =
t
K x C x M
= 34.87
t
Power = 34.87 x AT
where:
o
Power = The apparent power absorbed by the sample, watts (W = joule-s" ).
K = The conversion factor for thermochemical calories-s"1 to W = 4.184.
Cp = The heat capacity, thermal capacity, or specific heat (cal-g~ - C'1 = 1.0 for water).
M = The mass of the sample, grams.
AT = Tf-Tj, °C.
t = Time, s.
6.2.3.5 Derive an equation for the linear portion of the calibration range and determine the
equivalent value in watts of the arbitrary setting scale. Use the actual power in watts to determine the
appropriate setting of the particular microwave unit being used. Each microwave unit will have its own
(96 power) setting that corresponds to the actual power (in wattage) delivered to the samples.
6.2.3.6 An initial multipoint power evaluation should be performed for each microwave unit. If
linear, the calibration should be checked on a regular basis, using the 3-point calibration verification
routine. A single point verification may be appropriate when utilizing a single power output for
digestion. If any part of the power source to the microwave has been serviced or altered, the entire
calibration must be reevaluated.
6.2.4 Cleaning Procedure for PFA Vessels. All digestion vessels must be acid cleaned and rinsed
with reagent water prior to use to prevent contamination.
6.2.4.1 Wash each PFA vessel with deionized detergent and rinse with reagent water.
6.2.4.2 Add 10 mL concentrated HNO3 to each of 12 vessels, cap, and place in microwave.
6.2.4.3 Heat vessels at 100% power in microwave for 10 min as recommended by CEM
(microwave manufacturer). Rinse the vessels with copious amounts of deionized, distilled water prior
to use for any analyses under this contract. If only 6 vessels are to be cleaned, 70% power may be
utilized, which corresponds to approximately 5% per vessel.
6.2.5 Digestion Procedure for Microwave Extraction For Ambient Filter Samples.
6.2.5.1 Prepare extracting acid (2.06 M HC1, 0.89 M HNO3). In a 1-L volumetric flask, combine
in order and mix 500 mL of deionized, distilled water, 55.5 mL of concentrated (70%/16 M) redistilled
spectrographic-grade nitric acid, and 167.5 mL of ACS reagent-grade concentrated hydrochloric acid
(12.3 M). Cool and dilute to 1-L with deionized, distilled water.
{Note: Nitric and hydrochloric acid fumes are toxic. Prepare in a well-ventilated fume hood. Mixing
results in an exothermic reaction. Stir slowly.]
Page 3.1-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
6.2.5.2 Prepare nitric acid (3 M HNOg) for use with GFAA analysis. In a 1-L volumetric flask,
combine in order and mix 500 mL of deionized distilled water and 192 mL of concentrated nitric acid.
Slowly dilute to 1 L.
6.2.5.3 Using vinyl gloves or plastic forceps, retrieve the filter strip from Section 6.2.1 and place
on its edge in a labeled centrifuge tube. Using the plastic forceps, crush the filter strip down into the
lower portion of the centrifuge tube to ensure acid volume will cover entire filter.
/Note: A breathing mask and vinyl gloves are required for safety of personnel handling dry glass-fiber
filters. The breathing mask prevents the inhalation of minute glass shards and paniculate material. The
gloves protect the skin from the same materials and also prevent contamination of the sample by skin
secretions. A recommended alternate to the use of a breathing mask would be performing cutting and
transfer operations involving sample filters in a laminar flow hood, if available.]
[Note: More than one strip from a filter should be extracted to ensure adequate sample volume for
sample and QC sample analysis. Blank filter samples should be extracted and analyzed, and digestion
blanks should be run to ensure low levels of metals in the reagents used.]
6.2.5A Using a pieset calibrated automatic dispensing pipette or:.Tlass A glass pipette, add
10.0 mL of extracting acid for ICP and ICP/MS analysis or 10 mL of 3 M nitric acid for AA/GFAA
analysis. The acid should cover the strip completely. The sequence of adding the filter strip and acid
to the centrifuge tube may be reversed, if more convenient, without affecting the results. Place the
centrifuge tube in a Teflon® PFA vessel containing 31 mL of deionized water. Continue this process for
a total of 12 samples to maximize microwave capacity.
6.2.5.5 Place the PFA vessel caps with the pressure release valves on the vessels hand-tight and
tighten using the capping station to a constant torque of 12 ft-lb. Weigh and record the capped vessel
assembly to the nearest 0.01 g. Place the vessels in the microwave carousel. Connect each sample vessel
to the overflow vessel using the Teflon® PFA connecting tubes (see Figure 3).
6.2.5.6 Place the carousel containing the 12 vessels onto the turntable of the microwave unit. Any
vessels containing 10 mL of acid solution for analytical blank purposes are counted as sample vessels.
Irradiate the sample vessels at 486 W (power output) for 23 min. (Based on the calibration of the
microwave as previously described). If fewer than 12 samples are to be digested, adjust the microwave
system by reducing the power so that equivalent digesting power is delivered to the smaller sample batch.
Generally, each vessel represents approximately 5% power. Therefore, a reduction in W would be
reduced by 30% if only 6 vessels are digested. This reduction is only approximate, and each microwave
unit will produce a different level of power output.
6.2.5.7 At the end of the microwave program, allow the pressure to dissipate (venting may be
utilized with caution), then remove the carousel containing the vessels and cool in tap water for 10 min.
Using the capping station uncap the microwave vessels, remove the labeled centrifuge tubes containing
samples and discard the water in the PFA vessels.
6.2.5.8 Using a calibrated automatic dispensing pipette or a Class A glass pipette, add 10 mL of
deionized distilled water to each centrifuge tube. Cap the centrifuge tube tightly and vortex (mix) the
contents thoroughly. Using a nylon or teflon syringe pull-up a volume of sample from the centrifuge
tube, place Acrodisc filter on syringe and dispense into a prelabeled sterile 15 mL centrifuge tube.
Continue until centrifuge tube contains 10 to 15 mL of filtered digestate.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-13
-------
Method IO-3.1 Chapter IO-3
Filter Material _ Chemical Analysis
6.2.5.9 The matrix is 0.45 M nitric acid and 1.03 M hydrochloric acid for ICP analysis. The
filtered sample in the falcon tube is now ready for analysis. Store for subsequent analysis by one or more
of the Inorganic Compendium methods.
6.3 Hot Acid Extraction Procedure
6.3.1 Introduction. A hot extraction procedure to solubilize metals from the glass-fiber filter for
subsequent analysis by ICP, ICP/MS, AA, or GFAA is described in this method. Nitric acid or a acid
extraction solution is used to extract the metals from the quartz filter on a hot-plate.
6.3.2 Summary of Method.
6.3.2.1 Use the hot-acid extraction procedure as an alternate when microwave technology is not
available.
6.3.2.2 Cut a 1" x 8" strip from the 8" x 10" filter as described in Federal Reference Method for
lead. The inorganics are extracted from the filter strip by a hydrochloric/nitric acid solution or nitric acid
only (to allow for GFAA analysis) using a hot acid extraction procedure. After cooling, pour the
digestate rinses to a volumetric flask and dilute to volume. Filter to remove any insoluble material.
6.3.3 Hot Acid Extraction Procedure.
6.3.3.1 Using vinyl gloves or plastic forceps, retrieve the strip from Section 6.2.1 and place it in
a labeled 150 mL Griffin beaker. Place the filter strip down into the lower portion of the beaker to
ensure acid volume will cover entire filter.
More than one strip from a filter should be extracted to ensure adequate sample volume for
sample and QC sample analysis. Blank filter samples should be extracted and analyzed and digestion
blanks should be run to ensure low levels of metals in the reagents used.]
6.3.3.2 Using a preset calibrated automatic dispensing pipette or Class A glass pipette, add
15.0 mL of extracting acid (see Section 6.2.5) for ICP or ICP/MS analysis or 15 mL of 3M nitric acid
for AA/GFAA analysis.
[Note: The acid should cover the strip completely.]
6.3.3.3 Place beaker on the hot-plate, contained in a fume hood, and reflax gently while covered
with a watch glass for 30 min. Do not allow sample to dry.
[Caution: Nitric acid fumes are toxic. Remove the beakers from the hot-plate and allow to cool.]
6.3.3.4 Rinse the beaker walls and wash with reagent water. Decant rinsings and extract into a
Class A 100 mL volumetric flask. Add approximately 40 mL reagent water to the remaining filter
material in the beaker and allow to stand for at least 30 min. Rinse sidewalls and filter and transfer the
contents of the beaker quantitatively to the volumetric flask. This critical step must not be deleted; it
allows the acid to diffuse from the filter into the rinse.
6.3.3.5 Fill volumetric to approximately 85 mL with reagent water, cap, and mix thoroughly.
Allow to stand approximately 5 min, then dilute to 100 mL final volume with reagent water.
6.3.3.6 Using a nylon or Teflon® syringe, pull-up a volume of sample from the centrifuge tube,
place disc filter on syringe, and dispense into a prelabeled sterile 15 mL centrifuge tube. Continue until
centrifuge tube contains 10 to 15 mL of filtered digestate.
Page 3.1-14 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.1
Chemical Analysis Filter Material
6.3.3.7 The matrix is 0.45 M nitric acid, 1.03 M hydrochloric acid for ICP or ICP/MS analysis,
or 1.5 M nitric acid for AA/GFAA analysis and deionized, distilled water. The filtered sample contained
in the falcon tube is now ready for analysis by one or more of the Inorganic Compendium methods.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.1-15
-------
Method 10-3.1 Chapter IO-3
Filter Material Chemical Analysis
TABLE 1. CHARACTERISTICS OF FILTER MEDIUM
Cellulose Fiber (Cellulose Pulp)
Low ash
Maximum temperature of 150 °C
High affinity for water _
Enhances artifact formation for SP^f and NO~3
Good for x-ray/neutron activation analysis
Low metal content
Quartz Fiber (Quartz spun with/without organic binder)
Maximum temperature up to 540 °C
High collection efficiency
Non-hydroscopic
Good for corrosive atmospheres
Very fragile however
Difficult to ash; good with extraction
Synthetic Fiber (Teflon® and Nylon®)
Collection efficiency >99% for 0.01 p particles
Low artifact formation
Low impurities
Excellent for X-ray analysis
Excellent for determining total mass due to non-hydroscopic nature
Nylon fiber good for HNO3 collection
Membrane Fiber (Dry gel of cellulose esters)
• Fragile; requires support pad during sampling
• High pressure drop
• Low residue when ashed
Page 3.1-16 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.1
Filter Material
TABLE 2. SUMMARY OF USEFUL PHYSICAL PROPERTIES OF VARIOUS FILTER
MEDIUMS
Filter and Filter Composition
Teflon® (Membrane)
(CF2)n(2 jim Pore Size)
Cellulose (Whatman 41)
(C6H1005)n
Glass Fiber (Whatman GF/C)
"Quartz" Gelman
Microquartz
Polycarbonate (Nuclepore)
C15H14 + C03 (0.3 foa.
Pore Size)
Cellulose Acetate/Nitrate
Millipore (C9H13O7)n
(1.21 nm Pore Size)
Density,
mg/cm^
0.5
8.7
5.16
6.51
0.8
5.0
PH
Neutral
Neutral
(Reacts with HNO3)
Basic pH - 9
pH -7
Neutral
Neutral
(Reacts with HNO3)
Filter Efficiency %
99.95
58% at 0.3 pm
99.0
98.5
93.9
99.6
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.1-17
-------
Method IO-3.1
Filter Material
Chapter IO-3
Chemical Analysis
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Page 3.1-18 Compendium of Methods for Inorganic Air Pollutants January 1991
-------
Chapter IO-3
Chemical Analysis
Method IO-3.1
Filter Material
TABLE 4. WEIGHING ROOM ATMOSPHERIC CONDITION FORM
Equilibrium Period
Begin
Date
Begin
Time
End
Date
End
Time
Temperature Limits = 15 °C
to35°C
Max-
Min
Avg
Limits
met?
Relative Humidity Limits =
<50%
Max-
Min
Avg
Limits
met?
Name
TABLE 5. WEIGHING BALANCE CHECK FORM
Date
Time
Balance
Type
Balance
ID
Class S
Weights
Serial No.
or ID
mg
Class S
; weight
Balance
weight
Difference
Limit =
0.5 mg
Limits
met?
Name
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.1-19
-------
Method IO-3.1
Filter Material
Chapter IO-3
Chemical Analysis
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Page 3.1-20
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.1
Filter Material
TABLE 7. QUALITY CONTROL SAMPLES
Type
Method Blank
QMA Filter Lot Blank
Filter Duplicate
Matrix Spikeb
LC Blank0
LCSd
Frequency
1 per 24 samples
1 per filter lot change
1 per 20 samples
1 per 20s samples
1 per extraction day
1 per extraction day
Contains
I"x8" filter-
strip
No
Yes
Yes
Yes
No
No
Volume of Multimetal
Stock Standard21
Containing reagents only, to evaluate
background contributions from
reagents.
Analyzed prior to, use of new filter
lot.
This is a second I"x8" filter strip cut
from a single field sample.
0.2 mL
Entire NIST traceable filter.
Entire NIST traceable filter.
level.
These multimetal stock standards can be acquired from Spex Industries, Inc., or equivalent.
°The matrix spike (MS) is a I"x8". strip cut from a field sample filter and spiked at a target .
'TTie Lab Control (LC) Blank is a manufactured filter blank certified below NIST traceable detection
limits.
The Lab Control Sample (LCS) is a manufactured filter reference material certified at NIST traceable
levels.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.1-21
-------
Method IO-3.1
Filter Material
Chapter IO-3
Chemical Analysis
MANILA FILE FOLDER-TO PREVENT
FILTER FROM STICKING TO PLASTIC
/"
HO,/_ 23cm
WIDTH OF 1y«n //
GROOVE 1 cm -z£ X/ ^ " GLASS FIBER FILTER
FOLDED (LENGTHWISE) IN HALF " ,
/T V^'^^^^^a*^ : '. - -2.5 cm "'
ALL GROOVES
2 mm DEEP
RIGID PLASTIC
PIZZA CUTTER
25 mm (1") WIDE
WIDTH OF GROOVE
6mm
Figure 1. Templates for cutting filters.
fage 3.1-22 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.1
Filter Material
STRIPS FOR
OTHER ANALYSES
3/4" X 8" STRIP FOR
LEAD ANALYSIS
Figure 2. Diagram of filter cutting procedure.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.1-23
-------
Method IO-3.1
Filter Material
Chapter IO-3
Chemical Analysis
MICROWAVE EXTRACTION
Pressure
monitor
MDS
unit
DIGESTION VESSEL
ASSEMBLY
Pressure monitoring
vesel assembly
Venting nut
1
j— Vent tubing
Vessel cap
Relief valve
Vessel body
Figure 3. Microwave digestion system.
Page 3.1-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
EPA/625/R-96/OlOa
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.2
DETERMINATION OF METALS
IN AMBIENT PARTICIPATE MATTER
USING ATOMIC ABSORPTION (AA)
SPECTROMETRY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-3.2
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-10,
by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG), and
under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning, Center
for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure Research
Laboratory (NERL), both hi the EPA Office of Research and Development, were the project officers
responsible for overseeing the preparation of this method. Other support was provided by the following
members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McEIroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in the
preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
• David Brant, National Research Center for CoaL and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• Jim Cheney, U.S. Army Corps of Engineers, Omaha, NB
• Eric Prestbo, Frontier GeoScience, Seattle, WA
• Anne M. Falke, Frontier GeoScience, Seattle WA
• Gary Wester, Midwest Research Institute, Kansas City, MO
• Margaret Zimmerman, Texas Natural Resource Conservation Commission, Austin, TX
• Doug Duckworth, Martin Marietta Energy Systems, Inc., Oak Ridge, TN
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade names or commercial products does
11
-------
Method IO-3.2
Determination of Metals in Ambient
Particulate Matter Using Atomic Absorption (AA) Spectrometry
TABLE OF CONTENTS
Page
1. Scope
3.2-1
2. Applicable Documents . . . 3.2-2
2.1 ASTM Standards . 3.2-2
2.2 Other Documents 3.2-2
3. Summary of Method 3.2-2
3.1 Collection of Sample 3.2-2
3.2 Sample Extraction 3.2-2
3.3 Sample Analysis 3.2-3
4. Significance . 3.2-3
5. Definitions 3.2-3
6. Interferences 3.2-4
7. Apparatus 3.2-5
7.1 Glassware 3.2-5
7.2 Analysis Equipment 3.2-5
8. Reagents 3.2-6
8.1 Nitric Acid (HNO3) Concentrated 3.2-6
8.2 Hydrochloric Acid (HC1) Concentrated , 3.2-6
8.3 Water 3.2-6
8.4 Standard stock solutions (1,000 ^g/mL) 3.2-6
8.5 Working Standards 3.2-7
8.6 lonization and Chemical Interference Suppressants 3.2-8
9. Determination of Background Concentration of Metals in Filters . ; 3.2-8
10. Analysis 3.2-8
10.1 Receiving of Sample From Extraction Laboratory 3.2-8
10.2 Flame Procedure 3.2-9
10.3 Furnace Procedure 3.2-10
10.4 Method of Standard Additions 3.2-11
10.5 Background Correction Methods 3.2-11
11. Spectrometer Calibration Curve 3.2-12
12. Calculations 3.2-13
12.1 Sample Air Volume 3.2-13
12.2 Metal Concentration 3.2-14
13. Maintenance 3.2-15
14. Quality Assurance (QA) and Performance Criteria 3.2-16
14.1 QA Program 3.2-16
14.2 Performance Criteria . 3.2-17
15. Method Safety 3.2-.18
16. References . 3.2-19
-------
-------
Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF FILTER COLLECTED SPM
Method IO-3.2
DETERMINATION OF METALS IN AMBIENT
PARTICULATE MATTER USING ATOMIC ABSORPTION (AA),SPECTROMETRY
1. Scope
1.1 Suspended paniculate matter (SPM) in air generally is a complex multi-phase system of all airborne
solid and low vapor pressure liquid particles having aerodynamic particle sizes from below 0.01-100 /*m
and larger. Historically, SPM measurement has concentrated on total suspended particulates (TSP), with
no preference to size selection.
1.2 Research on the health effects of TSP in ambient air has focused increasingly on particles that can
be inhaled into the respiratory system, i.e., particles of aerodynamic diameter less than 10 pm.
Researchers generally.recognize that these particles may cause significant, adverse health effects. Recent
studies involving particle transport and transformation strongly suggest that atmospheric particles
commonly occur in two distinct modes: the fine (<2.5 jun) mode and the coarse (2.5 to 10.0 fim) mode.
The fine or accumulation mode (also termed the respirable paniculate matter) is attributed to growth of
particles from the gas phase and subsequent agglomeration, while the coarse mode is made of
mechanically abraded or ground particles. Because of their initially gaseous origin, particle sizes in this
range include inorganic ions such as sulfate, nitrate, ammonia, combustion-form carbon, organic aerosols,
metals, and other combustion products. Coarse particles, on the other hand, are produced mainly by
mechanical forces such as crushing and abrasion. Coarse particles of soil or dust result primarily from
entrainment by the motion of air or from other mechanical action within their area. Since the size of
these particles is normally >2.5 fim, their retention time in the air parcel is shorter than the fine particle
fraction.
1.3 Several methods are available for measuring SPM in ambient air. The most commonly used device
is the high volume (hi-vol) sampler, which consists essentially of a blower and a filter, and which is
usually operated in a standard shelter to collect a 24-h sample. The sample is weighed to determine
concentration and is usually analyzed chemically. The hi-vol is considered a reliable instrument for
measuring the weight of TSP in ambient air.
1.4 The procedures for determining toxic metals in paniculate matter in ambient air is described in this
method. The method is based on active sampling with a high-volume sampler. Analysis is done by
atomic absorption spectrometry. This method describes both flame atomic absorption (FAA) spectroscopy
and graphite furnace atomic absorption (GFAA) spectroscopy. Of the two methods, the detection limit
for GFAA is about two orders of magnitude better than FAA.
1.5 The trace metal to be detected is dissociated from its chemical bonds by flame or in a furnace and
is put into an unexcited or "ground" state. The metal is then capable of absorbing radiation at discrete
lines of narrow bandwidth. A hollow cathode or electrode less discharge lamp for the determined metal
provides a source of the characteristic radiation energy for that particular metal. The absorption of this
characteristic energy by the atoms of interest in the flame or furnace is measured and is related to the
concentration of the metal in the aspirated sample.
January 1997 Compendium of Methods for Inorganic Air Pollutants . Page 3.2-1
-------
Method IO-3.2 Chapter IO-3
AA Methodology ' Chemical Analysis
1.6 The sensitivity, detection limit, and optimum working range for each metal detected by this
methodology are given in Table 1.
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definition of'Terms Related to Atmospheric Sampling and Analysis.
• D1357 Planning the Sampling of the Ambient Atmosphere.
• D4185-83 Standard Test Methods for Metals in Workplace Atmosphere by Atomic Absorption
Spectrophotometry.
2.2 Other Documents
• Federal Regulations (1,2).
* Laboratory and Ambient Air Documents (3-14).
3. Summary of Method
3.1 Collection of Sample
3.1.1 Particulate matter from ambient air may be collected on glass fiber filters using a high-volume
sampler. The high-volume sampler must be capable of sampling at an average flow rate of 1.70 mr/min
(60 ft^/min). Constant air flow is maintained by a mass flow controller iver a 24-h period.
3.1.2 Air is drawn into a covered housing and through a filter by means of a high-flow rate blower
at a flow rate [1.13 to 1.70 m^/min. (40 to 60 frVmin)] that allows suspended particles having diameters
< 100 ;tm (Stokes equivalent diameter) to pass to the filter surface. Particles 100-0.1 /*m diameter are
ordinarily collected on glass fiber filters. The mass concentration (jj.g/nr) of suspended particulates in
the ambient air is computed by measuring the mass of collected particulates and the volume of air
sampled. After the mass is measured, the filter is ready for extraction to determine metal concentration.
3.2 Sample Extraction
3.2.1 Samples collected on glass fiber filters may be extracted by ultrasonication using a mixture of
room temperature nitric acid (HNC^) and hydrochloric acid (HC1). Strips are cut from the filters,
HNOg/HCl solution is added, and samples are ultrasonicated for 30 min.
3.2.2 Other extraction techniques use a hot nitric acid (HNOg) procedure. Strips are cut from the
filters and gently boiled in 3 M HNO^ for 30 min. This procedure can be hazardous since nitric acid
fumes are toxic. This procedure should be conducted in a well-ventilated fume hood.
3.2.3 The preferred method of extraction is by microwave extraction. In operation, a 1" x 8" strip
is cut from the 8" x 10" filter as described in the Federal Reference Method for Lead. The metals are
extracted from the filter strip by a hydrochloric/nitric acid solution or by a nitric acid solution only (to
allow for GFAA analysis) using a laboratory microwave digestion system. After cooling, the digestate
is mixed and filtered with Acrodisc syrine filters to remove any insoluble material. Microwave extraction
Page 3.2-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.2
Chemical Analysis AA Methodology
is used to prepare samples for inductively coupled plasma (TCP) spectroscopy or FAA analysis using the
hydrochlorice/nitric acid solution and for GFAA using the nitric acid solution.
3.3 Sample Analysis
3.3.1 The trace element concentrations in each sample are determined by atomic absorption
spectrometry. This technique operates by measuring energy changes in the atomic state of the analyte.
As illustrated in Figure 1, the sample is vaporized and dissociates into its elements in the gaseous state.
The element being measured is aspirated into a flame or injected into a graphite furnace and atomized.
The atoms in the unionized or "ground" state absorb energy, become excited, and advance to a higher
energy level.
3.3.2 A light beam containing the corresponding wavelength of the energy required to raise the atoms
of the analyte from the ground state to the excited state is directed through the flame or furnace. This
wavelength is observed by a monochromator and a detector that measures the amount of light absorbed
by the element, hence the number of atoms in the ground state in the flame or furnace. A hollow cathode
or electrode less discharge lamp for the element being determined provides a source of that metal's
particular absorption wavelength.
3.3.3 The data output from the spectrometer can be recorded on a strip chart recorder or processed
by computer. Determination of metal concentrations is performed from prepared calibration curves or
read directly from the instrument.
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Exposure to metal containing paniculate can cause adverse health effects. For example, high levels of
lead in the body can cause motor nerve paralysis, anaemia, and, in children, inhibition of the nervous
system's development. High cadmium levels can cause cardiovascular problems and bone thinning.
Effects of long-term exposure to subacute levels of toxic metals in air pollution is, as yet, not well
known.
4.2 Atomic absorption spectrophotometry is capable of quantitatively determining most metals at levels
that are required by federal, state, and local regulatory agencies. Sensitivity and detection limits may
vary from instrument to instrument.
5. Definitions
/Note: Definitions used in this document are consistent with ASTM methods. All pertinent abbreviations
and symbols are defined within this document at point of use.]
5.1 Analysis Spike Sample. An analytical sample taken through the analytical preparation method and
then spiked prior to analysis.
5.2 Analyte. The element or icon an analysis seeks to determine; the element of interest.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.2-3
-------
Method IO-3.2 Chapter IO-3
AA Methodology Chemical Analysis
5.3 Analytical Preparation. An analytical sample taken through the analytical preparation method.
Also referred to as preparation or sample preparation.
5.4 Analytical Preparation Method. A method (digestion, dilution, extraction, fushion, etc.) used to
dissolve or otherwise release the analyte(s) of interest from its matrix and provide a final solution
containing the analyte which is suitable for instrumental or other analysis methods.
5.5 Analytical Sample. Any solution or media introduced into an instrument on which an analysis is
performed excluding instrument calibration, initial calibration verificatin, initial calibration blank,
continuing calibration verification and continuing calibration blank.
5.6 Calibration. The establishment of an analytical curve based on the absorbance, emission intensity,
or other measured characteristic of known standards. Calibration procedures differ for the various
methods included in this SOW. Refer to the method of interest for a definition specific to that method.
5.7 Calibration Standards. A series of known standard solutions used by the analyst for calibration
of the instrument (i.e., preparation of the analytical curve). The solutions are not subject to the
preparation method but contain the same matrix as the sample preparations to be analyzed.
5.8 Field Blank. Any sample submitted from the field identified as a blank.
5.9 Field Sample. A portion of material received to be analyzed that is contained in a single or multiple
containers and identified by a unique EPA Sample Number.
5.10 Flame Atomic Absorption (AA). Atomic absorption which utilizes flame for excitation.
5.11 Graphite Furnace Atomic Absorption (GFAA). Atomic absorption which utilizes a graphite cell
for excitation.
6. Interferences
6.1 In atomic absorption (AA) spectrometry, interferences, though less common than in other analytical
methods, can occur. In flame atomic absorption analysis of some elements, the type and temperature of
the flame used is critical; with improper conditions, chemical and ionization interferences can occur. In
furnace atomic absorption analysis, the advantages of enhanced sensitivity may be offset by the fact that
interference is also more of a problem. The categories of interference are discussed below.
6.1.1 Background or nonspecific absorption can occur from particles produced in the flame that can
scatter light and produce an apparent absorption signal. Light scattering may be encountered when
solutions of high salt content are being analyzed. They are most severe when measurements are made
at shorter wavelengths (for example, below about 250 nm). Background absorption may also occur as
the result of the formation of various molecular species that can absorb light. The background absorption
can be accounted for by using background correction techniques as discussed in Section 11.5.
6.1.2 Spectral interferences are interferences that result when an atom different from the one being
measured absorbs a portion of the radiation. Such interferences are extremely rare in AA. In some
cases, multi-element hollow cathode lamps may cause a spectral interference by having closely adjacent
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emission lines from two different elements. In general, the use of multi-element hollow cathode lamps
is discouraged.
6.1.3 lonization interference occurs when easily ionized atoms are being measured. The degree to
which such atoms are ionized is dependent upon the atomic concentration and the presence of other easily
ionized atoms. This interference can be controlled by the addition of a high concentration of another
easily ionized element that will buffer the electron concentration in the flame. The addition of sodium
or potassium to the standards and samples is frequently used as an ionization suppressant.
6.1.4 Chemical interferences occur in AA when species present in the sample cause variations in the
degree to which atoms are formed in the flame, or when different valence states of a single element have
different absorption characteristics. Such interferences may be controlled by adjusting the sample matrix
or by the method of standard additions. For example, calcium phosphate does not dissociate completely
in the flame. Lanthanum may be added to bind the phosphate and allow the calcium to be ionized.
6.1.5 Physical interferences may result if the physical properties of the samples vary significantly.
Changes in viscosity and surface tension can affect the sample aspiration rate and, thus, cause erroneous
results. Sample dilution, the method of standard additions, or both, are used to correct such
interferences. High concentrations of silica in the sample can cause aspiration problems. If large
amounts of silica are extracted from the samples, they should be allowed to stand for several hours and
centrifuged or filtered to remove the silica. The matrix components of the sample should match those
of the standards. Any reagent added during extraction should be added to the standards.
6.2 Matching the matrix of the samples to the matrix of the standards minimizes interference. The
method of standard additions in Section 11.4 and the use of background correction techniques in Section
11.5 should identify and correct for interference.
6.3 The known interferences and correction methods for each metal are indicated in Table 2.
7. Apparatus
7.1 Glassware
[Note: All glassware should be Class A borosilicate glass and should be cleaned with laboratory
detergent, rinsed, soaked for 4 h in a 20% (w/w) HNO^, and rinsed several times with distilled water.]
7.1.1 Beakers. Borosilicate glass, including 30 mL, 125 mL, 150 mL Phillips or Griffin.
7.1.2 Volumetric flasks. 10 mL, 100 mL, 1 L.
7.1.3 Pipettes. Volumetric, including 1, 2, 4, 8, 15, 30, 50 mL.
7.1.4 Additional glassware. As required depending on dilution required to obtain concentrations
above the detection limit, in the response range.
7.2 Analysis Equipment
7.2.1 Atomic Absorption Spectrometer. Eequipped with air/acetylene and nitrous oxide/acetylene
burner heads or graphite furnace.
7.2.2 Hollow cathode or electrode less discharge lamp. For each element to be determined.
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7.2.3 Acetylene gas and regulator. Cylinder of acetylene equipped with two gauge, two stage
pressure reducing regulator with hose connections.
7.2.4 Nitrous oxide gas and regulator. Cylinder of nitrous oxide equipped with 2 two gauge,
two-stage pressure reducing regulator with hose connections.
7.2.5 Heating tape and rheostat. May be required to heat second stage of nitrous oxide gas cylinder
regulator and hose to prevent freeze-up of line.
7.2.6 Air supply. Clean, dry compressed air with a two-stage regulator.
7.2.7 Parafilm M sealing film. A pliable, self-sealing, moisture-proof, thermoplastic sheet material,
substantially colorless is recommended for use in sealing the acidified sample beakers. Commercially
available Parafilm M satisfies this requirement.
8. Reagents
8.1 Nitric Acid (HNO3) Concentrated. ACS reagent grade HNO3 and commercially available
redistilled HNO3 which have sufficiently low metal concentrations.
8.2 Hydrochloric Acid (HC1) Concentrated. ACS reagent grade.
8.3 Water. ASTM Type II (ASTM D193) or equivalent. The same source or batch of distilled,
deionized water must be used for all purposes in the analysis.
8.4 Standard stock solutions (1,000 Aig/mL)
[Note: For each metal that is to be determined, standards of known quality and concentration must either
be made or acquired commercially. These solutions are stable for 1 yr when stored in polyethylene
bottles, except as noted. Instructions for laboratory preparation are described below.]
[Note: Nitric acid fumes are toxic. Prepare in a well-ventilated fume hood]
8.4.1 Stock Aluminum Solution. Dissolve 1.00 g of aluminum wire in a minimum volume of
1 4- 1 HC1. Dilute to volume in a 1-L flask with distilled water.
8.4.2 Stock Barium Solution. Dissolve 1.779 g of barium chloride (BaC122H2O) in water. Dilute
to volume in a 1-L flask with distilled water.
8.4.3 Stock Bismuth Solution. Dissolve 1.000 g of bismuth metal in a minimum volume of 6 N
HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.4 Stock Cadmium Solution. Dissolve 1.000 g of cadmium metal in a minimum volume of 6 N
HCI. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.5 Stock Calcium Solution. To 2.497 g of primary standard calcium carbonate (CaCO3), add
50 mL of distilled water. Add drop wise a minimum volume of HCI (approximately 10 mL) to dissolve
the CACO3. Dilute to volume in a 1-L flask with distilled water.
8.4.6 Stock Chromium Solution. Dissolve 3.735 g of potassium chromate (K2CrO4) in distilled
water. Dilute to volume in a 1-L flask with distilled water.
8.4.7 Stock Cobalt Solution. Dissolve 1.000 g of cobalt metal in a minimum volume of 1 + 1 HCI.
Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
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8.4.8 Stock Copper Solution. Dissolve 1.000 g of copper metal in a minimum volume of 6 N
HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNOo.
8.4.9 Stock Indium Solution. Dissolve 1.000 g of indium metal in a minimum volume of
1 + 1 HC1. Addition of a few drops of HNO3 and mild heating will aid in dissolving the metal. Dilute
to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.10 Stock Iron Solution. Dissolve 1.000 g of iron wire in 50 mL of 6 N HNOs. Dilute to
volume in a 1-L flask with 2% (v/v) HNO3.
8.4.11 Stock Lead Solution. Dissolve 1.598 g of lead nitrate (Pb(NO3)2) in 2% (v/v) HNOo.
Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.12 Stock Lithium Solution. Dissolve 5.324 g of lithium carbonate (LI2COo) in a minimum
volume of 6 N HC1. Dilute to volume in a 1-L flask with distilled water.
8.4.13 Stock Magnesium Solution. Dissolve 1.000 g of magnesium ribbon in a minimum .volume
of 6 N HC1. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.14 Stock Manganese Solution. Dissolve 1.000 g of manganese metal in a minimum volume of
6 N HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.15 Stock Nickel Solution. Dissolve 1.000 g of nickel metal in a minimum volume of 6 N
HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.16 Stock Potassium Solution. Dissolve 1.907 g of potassium chloride (KC1) in distilled water.
Dilute to volume in a 1-L flask with distilled water.
8.4.17 Stock Rubidium Solution. Dissolve 1.415 g of rubidium chloride (RBC1) in distilled water.
Dilute to volume in a 1-L flask with distilled water.
8.4.18 Stock Silver Solution. Dissolve 1.575 g of silver nitrate (AgNO3) in 100 mL of distilled
water. Dilute to volume in a 1-L volumetric flask with 2% (v/v) HNO3. The silver nitrate solution will
deteriorate in light and must be stored in an amber bottle away from direct light. New stock silver
solution shall be prepared every few months.
8.4.19 Stock Sodium Solution. Dissolve 2.542 g of sodium chloride (NaCl) in distilled water.
Dilute to volume in a 1-L flask with distilled water.
8.4.20 Stock Strontium Solution. Dissolve 2.415 g of strontium nitrate (Sr(NO3)2) in distilled
water. Dilute to volume in a 1-L flask with distilled water.
8.4.21 Stock Thallium Solution. Dissolve 1.303 g of thallium nitrate (TINO3) in a 10% (v/v)
HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.22 Stock Vanadium Solution. Dissolve 1.000 g of vanadium metal in a minimum volume of
6 N HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.4.23 Stock Zinc Solution. Dissolve 1.000 g of zinc metal in a minimum volume of 6 N HNO?.
Dilute to volume in a 1-L flask with 2% (v/v) HNO3.
8.5 Working Standards
8.5.1 Working Standards. Working standards are prepared by appropriate single or multiple
dilutions of the standard solutions listed in Section 8.4. Mixed standards should be prepared with any
chemical incompatibilities in mind. For those metals in Table 2 that indicate chemical or ionization
interferences, the final dilution shall contain 2% (v/v) of the 50-mg/mL cesium and lanthanum solutions.
8.5.2 Match Matrices. To match the standard and sample matrices, the final dilution should contain
10% (v/v) HNO3 or whatever acid mixture is used to prepare the sample. When using those atomic
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absorption spectrometers equipped with concentration read-out, follow the manufacturer's suggestions as
to the spacing of the standard concentrations over the range of interest.
8.6 lonization and Chemical Interference Suppressants
8.6.1 Cesium Solution (50 mg/mL). Dissolve 73.40 g of cesium nitrate (CsNOg) in distilled water.
When stored in a polyethylene bottle, this solution is stable for at least 1 yr.
8.6.2 Lanthanum Solution (50 mg/mL). Dissolve 156.32 g of lanthanum nitrate (LaCNOg^'eE^O)
in a 2% (v/v) HNO3. Dilute to volume in a 1-L flask with 2% (v/v) HNO3. When stored in a
polyethylene bottle, this solution is stable for at least 1 yr.
9. Determination of Background Concentration of Metals in Filters
9.1 Use glass fiber filters to collect paniculate matter with the high volume sampler. High quality filters
with reproductible properties must be used in sampling for metals in ambient air. Analyze 5% of the
total number of filters for the presence of specific metals, prior to sample collection, to verify
reproductibility and low background metal concentrations.
9.2 Cut one 1" x 8" strip from each filter. Extract and analyze all strips separately, according to the
directions given as delineated in Inorganic Compendium Method IO-3.1.
9.3 Calculate the total metal in each filter as:
FD = PS metal/mL x (40 mL/strip) x (9)
where:
Fjj = Amount of metal per 27 square in. of filter, ^g.
/ig metal/mL = metal concentration determine from Section 11.2.
40 mL/strip = total sample volume from microwave extraction procedure.
9 = 464.52 cm2/51.61 cm2.
9.4 Calculate the mean, Fm, of the values and the relative standard deviation (standard deviation/mean
x 100). If the relative standard deviation is high enough so that, in the analyst's opinion, subtraction of
Fm may result in a significant error in the jtg metal/mr, the batch should be rejected.
9.5 For acceptable metal/batches, use the value of Fm to correct all metal/analyses of particulate matter
collected using that batch of filters. If the analyses are below the Method Detection Limit (MDL) from
Table 1, no correction is necessary.
10. Analysis
10.1 Receiving of Sample From Extraction Laboratory
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10.1.1 The sample should be received by the atomic absorption spectroscopist in a 15-mL volumetric
flask from the extraction procedure outlined in Inorganic Compendium Method IO-3.1.
10.1.2 If more than one metal is to be determined in the. sample, dilution to a volume larger than
10 mL may be required. In such cases, maintain the acid, ionization buffer, and releasing agent
concentrations by increasing proportionally the amount added. The amount of dilution permitted will
depend upon the number and concentration of metals being determined.
10.1.3 The 10-mL solution may be analyzed directly for any elements of very low concentration in
the sample. Aliquots of this solution may be then diluted to an appropriate volume for the other elements
of interest present at higher concentrations. Approximately 2 mL of solution are required for each
element being determined.
10.1.4 Filter blanks must be subject to the entire extraction and analytical procedure and processed
as described.
10.1.5 Some relatively rare chemical forms of some of the elements listed in Table 2 may not be
dissolved by the procedures stated in this method. If such chemical forms are suspected, results of their
procedure should be compared to results of a non-destructive technique, which does not require sample
dissolution, such as X-ray fluorescence.
10.1.6 Because of the differences between makes and models of atomic absorption spectrometers,
formulating detailed instructions applicable to every instrument is difficult. Consequently, the user should
follow manufacturer's operating instructions.
10.2 Flame Procedure
10.2.1 Set the atomic absorption spectrometer for the standard conditions as follows: choose the
correct hollow cathode lamp or electrode less discharge lamp, install, and align in the instrument; position
the monochromator at the value recommended by the manufacturer; select the proper monochromator slit
width; set the light source current according to the manufacturer's recommendation; light the flame and
regulate the flow of fuel and oxidant; adjust the burner for maximum absorption and stability; and balance
the meter.
10.2.2 If using a chart recorder, set the chart speed at 8-15 cm/min and turn on the power, servo,
and chart drive switches. Adjust the chart pen to the 5 % division line. Also adjust instrument span using
highest calibration standard. While aspirating the standard sample, span instrument to desired response.
10.2.3 Run a series of standards of the metal of interest and construct a calibration curve as in
Section 12.3. Set the curve corrector of a direct reading instrument to read the proper concentration.
10.2.4 To evaluate the contribution to the absorbance from the filters and reagents used, blank
samples must be analyzed. Usually blanks will be provided with each set of samples. Subject the blank
to the entire analysis procedure. The absorbance obtained from the aspiration of the blank solution is
subtracted from the sample absorbance.
10.2.5 The sample can be analyzed from the centrifuge tube or an appropriate amount of sample
decanted into a sample analysis tube. In either case, care should be taken not to disturb the settled solids.
At least the minimum sample volume required by the instrument should be available for each aspiration.
10.2.6 Aspirate samples, standards, and blank into the flame and record the absorbance. Aspirate
distilled water after each sample or standard. If using a recorder, wait for response to stabilize before
recording absorbance.
10.2.7 To the extent possible, all determinations should be based on replicate analyses.
10.2.8 Determine the average absorbance value for each known concentration and correct all
absorbance values by subtracting the blank absorbance value. Determine the metal concentration in /*g
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metal/mL from the calibration curve as presented in Section 12.3 or by direct reading from the
instrument.
10.2.8.1 Dilute samples that exceed the calibration range by taking an aliquot of the sample and
diluting the sample to a known volume with a solution of the same acid concentration and ionization and
chemical suppressants as the calibration standards and reanalyzed.
10.2.8.2 Check for drift of the zero point resulting from possible nebulizer clogging, especially
when dealing with samples of low absorbance.
10.2.8.3 Aspirate a mid-range standard with sufficient frequency (once every 10 samples, after
every 5 full MSAs or every 2 hr) to verify the continuing accuracy of the calibration curve.
10.3 Furnace Procedure
10.3.1 In graphite furnace atomic absorption, only a few micro liters of the sample are placed in the
furnace. Within seconds or fractions of a second, the sample is atomized. Graphite furnace analysis is
more sensitive for trace element determination than the flame detection limit because it requires a smaller
sample volume. As a general rule, samples that can be analyzed by flame or furnace may be more
conveniently run with flame since flame atomic absorption is faster, simpler, and has fewer interference
problems.
10.3.2 When some samples are atomized, they may absorb or scatter light causing sample absorbance
to be greater than it should be, necessitating background correction. If some sample remains unburned,
memory effects can occur. Blank burns should be run, and the graphite furnace should be cleaned by
running at full power at intervals during determination series.
10.3.3 Inject a measured /iL aliquot of sample into the furnace and atomize. If the concentration
found is greater than the highest standard, the sample should be diluted in the same acid matrix and
reanalyzed. Multiple injections can improve accuracy and help detect furnace pipetting errors.
10.3.4 To verify the absence of interference, follow the serial dilution procedure given below.
10.3.4.1 Withdraw 2 equal aliquots from the sample. Add a known amount of analyte to one of
the aliquots and dilute both to the same predetermined volume. (The dilution volume should be based
on the analysis of the undiluted sample. Preferably, the dilution should be 1:4. Keep in mind that the
diluted value should be at least 5 times the instrument detection limit. Under no circumstances should
the dilution be less than 1:1.)
10.3.4.2 Analyze the diluted aliquots and compare the unspiked results, multiplied by the dilution
factor, to the original determination. Agreement of the results (within 10%) indicates the absence of
interference. Comparison of the actual signal from the spike with the expected response from the analyte
in an aqueous standard should help confirm the finding from the dilution analysis.
10.3.5 Run a mid level check standard and a blank standard after every 10 sample injections, after
5 full MSAs, or at 2-hr intervals. Standards are run in part to monitor the life and performance of the
graphite tube. Lack of reproducibility or significant change in the signal fa. the standard indicates that
the tube should be replaced. Tube life depends on sample matrix and atomization temperature. A
conservative estimate of tube life is about 50 firings. A pyrolytic coating will extend that estimated life
by a factor of three.
10.3.6 To determine the metal concentration by direct aspiration and furnace, read the metal value
in ligfL from the calibration curve or directly from the read-out of the instrument.
10.3.7 If sample dilution was required, calculate the final concentration using the following formula:
[j.g/L metal in sample = A x (C + B) / C
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Chapter IO-3 Method IO-3.2
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where:
A = fig/L of metal in diluted aliquot from calibration curve.
B = Acid blank matrix used for dilution, mL.
C = Sample aliquot, mL.
10.4 Method of Standard Additions
10.4.1 If chemical interferences are suspected, the method of standard additions may be used to
evaluate them; and if deemed desirable, the method may be used to make an accurate determination of
metal concentration in the presence of an interference.
10.4.2 Take three identical portions from a sample. Dilute the first portion to a known volume with
the solvent used in the standard solutions. Add known but different amounts of the metal of interest to
the second and third portions. The additions and dilutions should be kept as small as possible by using
micro liter pipets.
10.4.3 Aspirate each portion and measure the absorbance. Plot the absorbance values (Y-axis) against
metal concentration (X-axis). Consider the first portion concentration to be 0 and that of the others as
the known amount added to each. Draw the curve through these points; it should be a straight line. The
metal concentration in the unknown is measured as the distance from the origin along the X-axis in the
negative direction using the same concentration scale factor.
10.4.4 Compare the values obtained for the same samples by direct comparison to the calibration
curve. If the values are the same, no chemical interferences are present, and subsequent analyses can
be made by direct comparison to the standard working curve.
10.4.5 If the slope of the spiked sample curve is not parallel to the original calibration curve, an
interference may be present. Standard additions may allow metal concentration to be determined in the
presence of interference by using the standard addition curve as the calibration. This method can give
incorrect values if the interferant does not associate with the additions to the same extent as in the original
analyte.
10.5 Background Correction Methods
10.5.1 Spurious absorption, absorption not due to the atoms of the metal being determined, can be
caused by the presence of small particles in the resonance beam, the presence of radicals or molecular
species resulting from components of the prepared sample, or from combustion reactions of the flame
itself. The effects of background absorption and scatter are an increase in the absorption signal and in
the noise component of the signal. The final results may be considerably higher than the true value and
a loss of sensitivity because of the increased noise. Various correction systems exist as indicated in the
following sections.
10.5.2 The deuterium arc automatic correction system operates by rapidly alternating light from a
deuterium arc and the hollow cathode tube through the sample. The light from the arc is essentially
unabsorbed by the element, but absorbed by the background. The difference is the element's actual
absorbance. Most deuterium arc systems correct up to 0.5 absorbance (about 70% absorption) at
wavelengths as high as that of copper (324.7 nm). Improved optical designs can extend this performance.
10.5.3 The Zeeman effect automatic correction system operates by placing the light source or
atomizer between the poles of a strong magnet, thus splitting the spectral line emitted or absorbed by the
atoms of interest into a central TT component having the original wavelength and two sideband a
components, which are shifted in wavelength. The components are polarized in different planes relative
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to the magnetic field. Various magnet and polarizer configurations are employed in various instrument
designs, all ultimately allowing subtraction of the a signal from the TT signal to produce background
correction. The Zeeman system, though expensive, overcomes some weaknesses inherent in the
deuterium arc system.
10.5.4 The Smith-Hieftje automatic correction system operates on the principle of self-reversal : when
excessive current is passed through a hollow cathode lamp, the emission line is broadened and absorbance
from the analyte is reduced. Correction is accomplished by comparing low current absorption where the
sample and the background absorb light to a brief pulse of much higher current causing self-reversal and
greatly reducing the sample's absorption, while background absorption remains proportional. The
background correction is determined by the difference between the two signals. The Smith-Hieftje system
also overcomes some weaknesses inherent in the deuterium arc system and is comparable to the Zeeman
system.
10.S.5 For atomic absorption spectrometers without automatic background correction devices,
background correction can be accomplished by using a deuterium continuum lamp.
10.5.5.1 Measure the absorbance of a sample and a suitable standard in the usual manner.
10.5.5.2 Remove the hollow cathode lamp and replace with the continuum lamp; without changing
the flame conditions or any other parameters, adjust the output of the amplifier to read 0 absorbance.
10.5.5.3 Measure the absorbance of the same sample and standardaoid subtract the continuum
lamp values from the hollow cathode lamp values to get an absorbance value free of background
absorbance interference.
11. Spectrometer Calibration Curve
Calibration is one of the most important factors in maintaining good quality data. Equipment
must be calibrated regularly, when first purchased, after maintenance, and whenever audit checks indicate
greater than acceptable deviation.]
11.1 The analytical application of atomic absorption, like other analytical methods, has a lower detection
limit, which is specific for each individual instrument. Therefore, calibration curves must be constructed
using not only standard solutions, but also standard conditions for each individual instrument. The
standard conditions include instrumental parameters, burner gas flames, and aspiration rates. In routine
sample analysis, several standards must be run with each set of samples so that the operating parameters
are exactly the same for sample and standard. Standard procedures for analysis are supplied with most
commercially available atomic absorption instruments. Standard curves must be constructed for each
element, and standards must be analyzed each time a set of samples are run. The standard curves should
list all parameters of the instrument, as well as sample preparation methods.
11.2 Prepare standard solutions from the solutions listed in Sections 8.4 andaS.5 to bracket the estimated
concentration of the metal in the samples. Select at least three standards (plus the reagent blank) to cover
the linear range indicated by the instrument manufacturer's instructions. Aspirate the standards into the
flame and record the absorbance. Repeat until good agreement is obtained between replicates. Prepare
a calibration graph by plotting absorbance (y-axis) versus the metal concentration in jig metal/mL
(x-axis). Calculate the best fit straight line for the data points by the method of least squares (in
Section 12.3.3), and draw it in. Use the best fit line or its equation to obtain the metal concentration in
the samples to be analyzed.
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11.3 Calculate the calibration line by the least squares regression procedure as follows:
y = mx + c
where:
m = n[E x y) Ex(Ey)] / [n(Ex2) - (Ex)2].
c = y - mx.
n = number of points used to fit the curve.
y = arithmetic mean of the y-coordinates for n points.
x = arithmetic mean of the x-coordinates for n points.
Exy = the sum of the products of the x-coordinate times the y-coordinate for the n points.
Ex = the sum of the x-coordinates of n points.
Ey = the sum of the y-coordinates of n points.
ry
Ex^ = the sum of the squares of the x-coordinates of n points.
f\
(Ex)z = the square of the sum of the x-coordinates of n points.
11.4 To determine stability of the calibration curve, analyze a control standard and reagent blank sample
before the first sample, after every subsequent 10th sample, and after the last sample. Vary the control
standard concentration by alternating, in run sequence, a value less than 1 jig metal/mL and a value
between 1 and 10 /ig metal/mL. If either standard deviates by more than 5% from the value predicted
by the calibration curve, take corrective action and repeat the previous 10 analyses.
12. Calculations
12.1 Sample Air Volume
At standard temperature and pressure (STP) [25°C and 760 mm Hg] for sample air volume rotameter,
use the following equation:
V = [(Qj + Of) / 2] t
where:
V = air volume sampled, m .
Qj = initial air flow rate, m^/min at STP.
Qf = final air flow rate, nvVmin at STP.
t = sampling period (elapsed time), min.
For samplers equipped with flow recorders:
V = Qt
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where:
Q = average sampling rate, m3/min at STP.
12.2 Metal Concentration
12.2.1 Estimation of Metal of Interest Concentration of the Blank Filter. For testing large
batches of filters (>500 filters), select at random 20 to 30 filters from a given batch. For small batches
(<500 filters) a lesser number of filters may be taken. Cut a 2.5 x 20.3 cm (1" x 8") strip from each
filter. Analyze all strips separately.
12.2.2 Calculate total metal of interest in each filter as:
Fb = /J.g metal/mL x (40 mL/strip) x (9)
where:
Fu = amount of metal per 465 square cm (72 square in.) of blank filter, /ig.
/ig metal/mL = metal concentration determined from Section 11.2.
40/strip = total sample volume from microwave extraction procedure.
9 = 464.52 cm2/51.61 cm2.
12.2.3 Calculate the mean, Fm, and the relative standard deviation (100 x standard deviation/mean).
nv
Fm = 2 Fu: / n
where:
Fm = average amount of metal per 72 in/ of filter,
Fb| = amount of metal per 72 in.2 for each filter, jug
n = number of blank filters analyzed.
12.2.4 The standard deviation (SD) of the analyses for the blank filters is given by equation
SD = [S(Fbi-Fm)2/n-l]^
The relative standard deviation (RSD) is given by the following equation:
RSD = 100SD/Fm
If the relative standard deviation is high enough so that in the analyst's opinion subtraction of Fm the
mean may result in a significant error in the fig metal/m3, the batch shouldl-e rejected. Por acceptable
batches, use the value of Fm to correct all analyses (Section 13.1.2.2) collected using that batch of filters.
If Fm is below the lower detectable limit (LDL), no correction is necessary.
12.2.5 Calculation of Metal of Interest Concentration of the Exposed Filter. Metal concentration
in the air sample can be calculated from data tabulated on data record form (Figure 2) as follows:
Page 3.2-14 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.2
Chemical Analysis AA Methodology
C = [(fig metal/mL x (40 mL/strip)(9) - Fm]/ Vgtd
where:
C = concentration, fig metal/std. m-*.
fig metal/mL = metal concentration determined from Section 11.
40 mL/strip = total sample volume,
_ . [Useable filter area, 20 cm x 23 cm (8" x 9")]
[Exposed area of one strip, 2.5 cm x 20 cm (1" x 8")]
Fm = average concentration of blank filters, ng.
Vst(j = air volume pulled through filter, std. nA
13. Maintenance
13.1 Scheduled maintenance of the sampling equipment and the atomic absorption spectrophotometer will
reduce downtime and remedial maintenance. The major maintenance checks are summarized in Table 3.
Record all maintenance activities in a maintenance log book. Normally, two to three remedial
maintenance activities are required per year. Major maintenance and calibration should be done by
service engineers or qualified operators. The following general maintenance procedures should be carried
out only after consulting the manufacturer's manual.
13.2 Light Source
13.2.1 When problems are suspected with a light source, check the hollow cathode lamp or electrode
less discharge lamp mounting bracket and lamp connection. Make sure the instrument is plugged in,
turned on, and warmed up. If line voltages are low, operate the power supply from a variac that is set
to give maximum voltage. Lamp current meter fluctuation can be reduced by using a constant voltage
sine wave transformer.
13.2.2 As the lamp is used, a loss of the element from the hollow cathode source occurs. Some
lamps will evolve hydrogen, which will contaminate the element's spectrum and reduce sensitivity and
calibration linearity. Hydrogen contamination may be reversed by running the lamp with reversed
polarity at a few mill amperes for several minutes.
13.3 No Absorbance Response
Make sure that the lamp is lighted, properly aligned, and that the wavelength, slit, and range controls are
properly adjusted. If the meter cannot be zeroed, adjust the level of the burner head to avoid intercepting
the light beam and clean the lamp and window, or meter cover windows, with a diluted solution of a mild
detergent; rinse several times with distilled water. Dirty windows or lenses are a major problem when
operating the instrument below 2300 A° (230 nm).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.2-15
-------
Method IO-3.2 Chapter IO-3
AA Methodology Chemical Analysis
13.4 Readout Noisy, Flame On
Check the lamp current setting, fuel, and oxidizer flow rates; the leviner to make sure it is draining
properly; the nebulizer for corrosion around the tip; the adjustment of the nebulizer capillary; the burner
head (it may need cleaning with razor blade); the acetylene cylinder pressure; the air pressure; and the
air line filter.
13.5 Poor Sensitivity (Within 50% of That Suggested in the Analytical Method Book)
Check the sensitivity obtainable for several other elements to ascertain that the low sensitivity is not due
to the lamp used. Check the slit width, wavelength, range setting, burner alignment, adjustment of the
nebulizer capillary, and fuel/oxidant flow rate ratio to ascertain that it is optimized for the element to be
analyzed. Make sure that the lamp current is not above the recommended value. Check the lamp
alignment and the concentration of the standard solution used. All other maintenance problems, such as
cleaning of mirrors or gratings, should be discussed with the manufacturer or service representative.
14. Quality Assurance (QA) and Performance Criteria
14.1 QA Program
14.1.1 To achieve quality data, two essential considerations are necessary: the measurement process
must be in a state of statistical control at the time of the measurement and the systematic errors, when
combined with the random variation (errors of measurement), must result in an acceptable level of
uncertainty. To produce good quality data, perform quality control checks and independent audits of the
measurement process, document these data, and use materials, instruments, and measurement procedures
that can be traced to an appropriate standard of reference. Repeat measurements of standard reference
samples (primary, secondary, and/or working standards) aid in establishing a condition of process control.
The working calibration standards should be traceable to standards of higher accuracy.
Several other procedures are usually necessary to ensure that the instrument is providing good quality
data. These procedures are documented in the EPA Contract Laboratory Program (CLP) Methods.
Following the initial instrument calibration with a calibration blank and at least three calibration (standard
reference) samples, a calibration verification sample is prepared at the midpoint of the calibration curve
from certified stock solutions. The use of additional calibration standards and blanks during the sample
analyses were discussed in Section 11. In addition to the standard and blank samples, laboratory control
spike samples, matrix spike samples, and duplicate spike samples are prepared and analyzed with most
sample batches. A summary of the quality control procedures for GFAA is provided in Table 4.
Depending upon the specific requirements of the client, some of these procedures may be deleted, or
additional procedures may be initiated to comply with specific analysis requirements.
14.1.2 The user should develop, implement, and maintain a quality assurance program to ensure that
the sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted on a regularly scheduled basis and should be part of
the quality assurance program. The manufacturer's instruction manual should be followed and included
in the QA program. Additional QA measures (e.g., troubleshooting) as well as further guidance in
maintaining the sampling system are provided by the manufacturer.
Page 3.2-16 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.2
Chemical Analysis AA Methodology
14.1.2.1 Consult the latest copy of the Quality Assurance Handbook for Air Pollution Measurement
Systems to determine the level of acceptance of zero and span errors.
14.1.2.2 For detailed guidance in setting up a quality assurance program, refer to the EPA Quality
Assurance Handbook and the Code of Federal Regulations.
14.1.3 Sampling Qualify Assurance
14.1.3.1 Select a site with the highest expected geometric mean concentrations.
14.1.3.2 Locate two high-volume samplers within 4 m of each other, but at least 2 m apart, to
preclude air flow interference.
14.1.3.3 Identify one of the two samplers at the time of installation as the sampler for normal
routine monitoring; identify the other as the duplicate sampler.
14.1.3.4 Be sure that the calibration, sampling, and analysis are the same for the collocated
sampler as for all other samplers in the network.
14.1.3.5 Operate the collocated sampler whenever the routine sampler is operated.
14.1.3.6 Use the differences in the concentrations (jtg metal/std. m^) between the routine and
duplicate samplers to calculate precision.
14.1.4 Analysis Quality Assurance
14.1.4.1 Perform a linearity test on the atomic absorption spectrometer employing a series of
standard metal solutions. This procedure should be done at regular intervals and when the analyst
suspects erroneous readings. Refer to Table 3 and manufacturer's instructions for details on
instrument performance checkout.
14.1.4.2 Obtain Standard Reference Materials (SRM) from National Institute Bureau of
Standards Technology and EPA reference standards. Analyze these standards at regular intervals
along with samples and record accuracy.
14.1.5 Standard Operating Procedures (SOPs)
14.1.5.1 SOPs should be generated by the users to describe and document the following
activities in their laboratory:
• assembly, calibration, leak check, and operation of the specific sampling system and
equipment used;
• preparation, storage, shipment, and handling of the sampler system;
• purchase, certification, and transport of standard reference materials; and
• all aspects of data recording and processing, including lists of computer hardware and
software used.
14.1.5.2 Provide specific instructions in the SOPs that are available and understood by the
personnel conducting the monitoring work.
. 14.2 Performance Criteria
The sensitivity, detection limit, and optimum working range for each metal are given in Table 1. The
values for the sensitivity and detection limits are instrument-dependent and may vary from instrument
to instrument.
14.2.1 The sensitivity is defined as that concentration of a given element that will absorb 1 % of
the incident radiation (0.0044 absorbance units) when aspirated into the flame. The atomic absorption
sensitivity for an element can be calculated using the absorbance of a know concentration and solving
the equation below.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.2-17
-------
Method IO-3.2 Chapter IO-3
AA Methodology Chemical Analysis
cone of std / measured abs = sensitivity / 0.0044
therefore:
sensitivity = (cone of std x 0.0044) / measured abs .
14.2.2 The detection limit is defined as that concentration of a given element that produces a
signal-to-noise ratio of 2, which is the lowest limit of concentration that can be distinguished from
zero.
[J^ote: The blank signal is defined as that signal that results from all added reagents and a clean filter
that has been extracted exactly as the samples.]
14.2.3 The working range for an analytical precision better than 3 % is generally defined as those
sample concentrations that will absorb 10%-70% of the incident radiation (0.05-0.52 absorbance units.)
15. Method Safety
15.1 This procedure may involve hazardous materials, operations, and equipment. This method does
not purport to address all of the safety problems associated with its use. The user must establish
appropriate safety and he^th practices and determine the applicability of regulatory limitations prior to
the implementation of this procedure. This requirement should be part of the user's SOP manual.
15.2 Hazards to personnel exist in the operation of the atomic absorption spectrometer. Atomic
absorption units are potentially dangerous when using a nitrous oxide/acetylene flame. Do not operate
these unit until the manufacturer's instruction manual has been read and completely understood. Follow
all safety instructions in the manual and the safety requirements pertaining to the handling, storage, and
use of compressed gases.
15.3 Hazards to personnel exist in all operations in which hot, concentrated mineral acids are used.
The appropriate laboratory procedures for working with reagents of this nature should be observed.
Ultrasonic extraction using room temperature acids reduces this hazard.
15.4 Many of the metals that can be determined by atomic absorption are health hazards (for example,
cadmium, arsenic, beryllium, mercury) and must be handled in a manner consistent with the danger they
present.
15.5 The instrument exhaust gases contain the combustion products of the flame as well as metal vapor
from the sample. Both the combustion products and the metal vapor are definite personnel hazards. The
instrument combustion gases should be mechanically exhausted from the laboratory.
Page 3.2-18 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.2
Chemical Analysis AA Methodology
16. References
1. Code of Federal Regulations, Vol. 40, Part 58, Appendix A, B.
2. "Reference Method for Lead," Code of Federal Regulations, Vol.43(194), Appendix G, October 5,
1978.
3. Methods of Air Sampling and Analysis, Second Edition, Ed. M. Kate, APHA Intersociety
Committee, 1977.
4. Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds in Ambient
Air, EPA-600/4-83-027, U. S. Environmental Protection Agency, Research Triangle Park, NC,
1983.
5. Harper, S., et al., "Simplex Optimization of Multielement Ultrasonic Extraction of Atmospheric
Particulates," Analytical Chemistry, Vol.55(9), August 1983.
6. Kahn, H.L., et al., "Background Correction in AAS," American Laboratory, November 1982.
7. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II - Ambient Air
Specific Methods (Interim Edition), EPA 600/R-94/038b.
8. Air Pollution, W. Strauss and S. J. Main Waring, Edward Arnold (Publishers) LTD, London,
England, 1984.
9. . Slavin W., Atomic Absorption Spectroscopy, Interscience Publishers, New York, NY, 1968.
10. Ramirez Munoz, J., Atomic Absorption Spectroscopy, Elsevier Publishing Company, New York,
NY, 1968.
11. Smith, G. F., Wet Chemical Oxidation of Organic Compositions, G. Frederick Smith Chemical
Company, Columbus, OH, 1965.
12. "Some Fundamentals of Analytical Chemistry," ASTM Special Technical Publication 564,
Philadelphia, PA, 1973.
13. Willard, H. H., and Rulf, C. L., "Decomposition and Dissolution of Samples: Inorganic," Treatise
on Analytical Chemistry, Part 1, Vol. 2, Eds. Kotthoff, I.M. and Elving, P.J, Interscience, New
York, NY, 1961.
14. Laboratory Manual Physical/Chemical Methods, SW-846 Third Edition, U. S. Environmental
Protection Agency, Washington, DC, 1986.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.2-19
-------
Method IO-3.2
AA Methodology
Chapter IO-3
Chemical Analysis
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Chapter IO-3
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Method XO-3.2
AA Methodology
Chapter IO-3
Chemical Analysis
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Page 3.2-22
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.2
AA Methodology
QC
procedure
Initial
calibration
ICV
ICB
CCV
CCB
Method blank
LCS
MSD
Matrix spike (MS)
Serial dilution
Post-digestion spike
Sample dilution
TABLE 4. GFAA QUALITY CONTROL SUMMARY
Typical frequency
Acceptance
criteria
Action* if outside criteria
At the beginning of the analysis
Immediately after initial
calibration
Immediately after the ICV
Analyzed before the first sample,
after every 10 samples or 5 full
MS As, and at the end of the run
Analyzed following each CCV
Linear correlation
coefficient 5: 0.995
90%-110% of the actual
concentration
See Section 9.3 < RDL
80%-120% of the actual
concentration
See Section 9.5 < RDL
1 per 20 samples, a minimum of See Section 9.7 < RDL
1 per batch
1 per 20 samples, a minimum of
1 per batch
80%-120% recovery, with the
exception of Sb
1 per 10 samples per matrix type RPD < 20%
1 per 10 sample per matrix type Percent recovery of 75%-125%
1 per matrix type, if MS/MSD
criterion fails and if needed
1 per matrix type, if MS/MSD
criterion fails and if needed
Dilute sample beneath the upper
calibration limit, minimizing the
dilution factor
10% Difference
%R = 85%-115%
As needed
Legend of Abbreviations (alphabetical order):
CCB = Continuing Calibration Blank
CCV = Continuing Calibration Verification
ICB = Initial Calibration Blank
ICV = Initial Calibration Verification.
LCS = Laboratory Control Spike
MSD = Matrix Spike Duplicate
Terminate analysis and restart
the run with initial calibration
Terminate analysis, recalibrate,
and restart the run
Terminate analysis, recalibrate,
and restart the run
Terminate analysis, recalibrate,
and reanalyze samples from last
acceptable CCV
Terminate analysis, recalibrate,
and reanalyze samples from last
acceptable CCB
Identify affected analytes in
analysis report
Qualify results in analysis report
Report and qualify results in
analysis report
Perform appropriate interference
tests
Analysis by method of standard
addition (MSA)
Analysis by MSA recommended
Not applicable
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.2-23
-------
Method IO-3.2
AA Methodology
Chapter IO-3
Chemical Analysis
Digital Readout
Photo Multiplier
Hollow Cathode
Lamp
-k— -i—
Flame
Figure 1. Schematic of atomic absorption.
Page 3.2-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.2
AA Methodology
MANILA FILE FOLDER-TO PREVENT
FILTER FROM STICKING TO PLASTIC
WIDTH OF 12.7cm
GROOVE 1 cm
RIGID PLASTIC
GLASS FIBER FILTER
FOLDED (LENGTHWISE) IN HALF
• 2.5 cm
ALL GROOVES
2 mm DEEP
25 mm (1") WIDE
PIZZA CUTTER
WIDTH OF GROOVE
6mm
Figure 2. Schematic of filter cutting apparatus.
January 1997
Compendium of Methods for Inorganic Mr Pollutants
Page 3.2-25
-------
-------
EPA/625/R-96;010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.3
DETERMINATION OF METALS
IN AMBIENT PARTICULATE
MATTER USING
X-RAY FLUORESCENCE (XRF)
SPECTROSCOPY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method 10-3.3
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA
No. 2-10, by Midwest Research Institute (MRI)*, as a subcontractor to Eastern Research Group, Inc.
(ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A.
Manning, Center for Environmental Research Information (CERI), and Frank F. McElroy, National
Exposure Research Laboratory (NERL), both in the EPA Office of Research and Development, were
the project officers responsible for overseeing the preparation of this method. Other support was
provided by the following members of the Compendia Workgroup:
James L. Cheney, Corps of Engineers, Omaha, NB
Michael F. Davis, U.S. EPA, Region 7, KC, KS
Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
William A. McClenny, U.S. EPA, NERL, RTP, NC
Frank F. McElroy, U.S. EPA, NERL, RTP, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• Bob Kellog, ManTech, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, $C
• Roy Bennet, U.S. EPA, RTP, NC
• Charles Lewis, EPA, RTP, NC
• Ray Lovett, West Virginia University, Morgantown, WV
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. 'Mention of trade names of commercial
products does not constitute endorsement or recommendation for use.
ii
-------
Method IO-3.3
Determination of Metals in Ambient Particulate Matter Using
X-Ray Fluorescence (XRF) Spectroscopy
TABLE OE CONTENTS
Page
1. Scope 3.3-1
2. Applicable Documents 3.3-2
2.1 ASTM Documents 3.3-2
2.2 U.Si Government Documents 3.3-2
2.3 Other Documents 3.3.3
3. Summary of Method 3.3-3
4. Significance 3.3-3
5. Definitions 3.3-4
6. Description of Spectrometer. 3.3.5
7. Caveats 3.3-6
8. Sample Preparation 3.3-7
9. Spectral Acquisition and Processing 3.3-7
10. Data Reporting 3 3_g
11. Calibration 3 3.9
12. Detection Limits 3.3-10
13. Quality Control 3.3-10
14. Precision and Accuracy 3.3-11
15. References 3.3-11
111
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Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF FILTER-COLLECTED SPM
Method IO-3.3
DETERMINATION OF METALS IN AMBIENT PARTICULATE MATTER USING
X-RAY FLUORESCENCE (XRF) SPECTROSCOPY
1. Scope
1.1 During a span of more than 2 decades, the U. S. Environmental Protection Agency (EPA) has
developed and applied x-ray fluorescence (XRF) to the analysis of ambient and source aerosols using both
energy and wavelength dispersive spectrometers. Inorganic Compendium Method IO-3.3 briefly describes
the agency's experience with XRF and informs the reader of its capability in elemental aerosol analysis
and attempts to give a brief account of what is involved in its application. The procedures described have
been hi a continual state of evolution beginning with those in use on a special purpose spectrometer
designed by Lawrence Berkeley Laboratory (LBL) and eventually applied to a commercially available
instrument manufactured by Kevex. It is for the Kevex spectrometer to which this method applies.
1.2 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by Federal, state, and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels is essential to proper assessments.
1.3 Suspended paniculate matter (SPM) in air generally is considered to consist of a complex multi-phase
system consisting of all airborne solid and low vapor pressure, liquified particles having aerodynamic
particle sizes ranging from below 0.01 microns to 100 (0.01 pm to 100 jim) microns and larger.
Historically, measurement of SPM has concentrated on total suspended particulates (TSP) with no
preference to size selection.
1.4 The most commonly used device for sampling TSP in ambient air is the high-volume sampler, which
consists essentially of a blower and a filter, and which is usually operated in a standard shelter to collect
a 24-hour sample. The sample is weighed to determine concentration of TSP and is usually analyzed
chemically to determine concentration of various inorganic compounds. When EPA first regulated TSP,
the National Ambient Air Quality Standard (NAAQS) was stated in terms of SPM with aerodynamic
particle size of < 100 ^m captured on a filter as defined by the high-volume TSP sampler. Therefore,
the high-volume TSP sampler was the reference method. The method is codified in 40 CFR 50,
Appendix B.
1.5 More recently, research on the health effects of TSP in ambient air has focused increasingly on
particles that can be inhaled into the respiratory system, i.e., particles of aerodynamic diameter of
< 10 jim. These particles are referred to as PMjQ. It is now generally recognized that, except for toxic
materials, it is this PM10 fraction of the total paniculate loading that is of major significance in health
effects. Therefore, the primary NAAQS for SPM is now stated in terms of PM10 rather than TSP. The
reference method for PMjQ is codified in 40 CFR 50, Appendix! and specifies a measurement principle
based on extracting an ambient air sample with a powered sampler that incorporates inertia! separation
of PM1Q size range particles and collection of these particles on a filter for a 24-hour period. Again,
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-1
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Method 10-3.3 Chapter 10-3
X-Ray Analysis Chemical Analysis
the sample is weighed to determine concentration of PM10 and is usually analyzed chemically to
determine concentration of various inorganic compounds.
1.6 Further research now strongly suggests that atmospheric particles commonly occur in two distinct
modes, the fine (<2.5 ^m) mode and the coarse (2.5 to 10.0 jam) mode. The fine or accumulation mode
(also termed the respirable particles) is attributed to growth of particles from the gas phase and
subsequent agglomerization, whereas the coarse mode is made up of mechanically abraded or ground
particles. Because of their initially gaseous origin, the fine range of particle sizes includes inorganic ions
such as sulfate, nitrate, and ammonium as well as combustion-form carbon, organic aerosols, metals, and
other combustion products. Coarse particles, on the other hand, normally consist of finely divided
minerals such as oxides of aluminum, silicon, iron, calcium, and potassium. Samplers which separate
SPM into two size fractions of 0-2.5 fim and 2.5-10 p.m are called dichotomous samplers.
1.7 Airborne particulate materials retained on a sampling filter, whether TSP, PM10 or dichotomous size
fractions, may be examined by a variety of analytical methods. This method describes the procedures
for XRF analysis as the analytical technique. The XRF method provides analytical procedures for
determining concentration in ng/m3 for 44 elements that might be captured on typical filter materials used
in fine particle or dichotomous sampling devices. With the sample as a thin layer of particles matrix
effects substantially disappear so.the method is applicable to elemental analysis of a broad range of
particulate material. The method applies to energy dispersive XRF analysis of ambient aerosols sampled
with fine particle (<2.5 /im) samplers, dichotomous and VAPS (versatile air pollution sampler) samplers
with a 10 pm upper cut point and PMjQ samples.
1.8 X-ray fluorescence spectroscopy should be used by a scientist with a minimum training of 5 years
in energy dispersive X-ray fluorescence analysis of atmospheric aerosols and its associated data
processing. The scientist should also have an advanced degree in the physical sciences.
2. Applicable Documents
2.1 ASTM Documents
• D4096 Application of High Volume Sample Method For Collection and Mass Determination of
Airborne Particulate Matter.
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice For Planning the Sampling of the Ambient Atmosphere.
2.2 U.S. Government Documents
• U.S. Environmental Protection Agency, Quality Assurance Handbook for AirPollution Measure-
ment Systems, Volume I: A Field Guide for Environmental Quality Assurance, EPA-600/R-94/038a.
• U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution Measure-
ment Systems, Volume II: Ambient Air Specific Methods (Interim Edition), EPA-600/R-94/038b.
Page 3.3-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.3
Chemical Analysis X-Ray Analysis
• "Reference Method for the Determination of Particulate Matter in the Atmosphere," Code of
Federal Regulations, 40 CFR 50, Appendix B.
• "Reference Method for the Determination of Particulate Matter in the Atmosphere
Method)," Code of Federal Regulations, 40 CFR 50, Appendix J.
• " 1978 Reference Method for the Determination of Lead in Suspended Particulate Matter Collected
From Ambient Air." Federal Register 43 (194):46262-3.
• Test Methods for Evaluating Solid Waste, Method 9022, EPA Laboratory Manual, Vol. 1-A,
SW-846.
2.3 Other Documents
• Kevex XRF TOOLBOX II Reference Manual
• Kevex 771-EDX Spectrometer User's Guide and Tutorial
3. Summary of Method
The method described is x-ray fluorescence applied to PMjQ, fine (<2.5 fim) and coarse (2.5-10 jim)
aerosols particles captured on membrane filters for research purposes in source apportionment. The
samplers which collect these particles are designed to separate particles on their inertial flow
characteristics producing size ranges which simplify x-ray analysis. The instrument is a commercially
available Kevex EDX-771 energy dispersive x-ray spectrometer which utilizes secondary excitation from
selectable targets or fluorescers and is calibrated with thin metal foils and salts for 44 chemical elements.
Spectra are acquired by menu-driven procedures and stored for off-line processing. Spectral
deconvolution is accomplished by a least squares algorithm which fits stored pure element library spectra
and background to the sample spectrum under analysis. X-ray attenuation corrections are tailored to the
fine particle layer and the discrete coarse particle fraction. Spectral interferences are corrected by a
subtractive coefficient determined during calibration. The detection limits are determined by propagation
of errors in which the magnitude of error from all measured quantities is calculated or estimated as
appropriate. Data are reported in ng/nr* for all samples. Comprehensive quality control measures are
taken to provide data on a broad range of parameters, excitation conditions and elements.
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state and local governments are based on these data.
4.2 Inhalable ambient air particulate matter (< 10 jtm) can be collected on Teflon® filters by sampling
with a dichotomous sampler and analyzed for specific metals by X-ray fluorescence. The dichotomous
sampler collects particles in two size ranges - fine (< 2.5 /tm) and coarse (2.5-10 ^m). The trace element
concentrations of each fraction are determined using the nondestructive energy dispersive X-ray
fluorescence spectrometer.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-3
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Method 10-3.3 Chapter IO-3
X-Ray Analysis Chemical Analysis
4.3 The detectability and sensitivity of specific elements may vary from instrument to instrument
depending upon X-ray generator frequency, multichannel analyzer sensitivity, sample interferences, etc.
5. Definitions
{Note: Definitions used in this document are consistent with ASTM Methods. All pertinent abbreviations
and symbols are defined within this document at point of use.]
5.1 Accuracy. The agreement between an experimentally determined value and the accepted reference
value.
5.2 Attenuation. Reduction of amplitude or change in wave form due to energy dissipation or distance
with time.
5.3 Calibration. The process of comparing a standard or instrument with one of greater accuracy
(smaller uncertainty) for the purpose of obtaining quantitative estimates of the actual values of the
standard being calibrated, the deviation of the actual value from a nominal value, or the difference
between the value indicated by an, instrument and the actual value.
5.4 10 /im Dichotomous Sampler. An inertia! sizing device that collects suspended inhalable particles
(< 10 /«n) and separates them into coarse (2.5-10 /am) and fine (<2.5 jtm) particle-size fractions.
5.5 Emissions. The total of substances discharged into the air from a stack, vent, or other discrete
source.
5.6 Filter. A porous medium for collecting particulate matter.
5.7 Fluorescent X-Rays (Fluorescent Analysis). Characteristic X-rays excited by radiation of
wavelength shorter than the corresponding absorption edge.
5.8 Inhalable Particles. Particles with aerodynamic diameters of < 10 /tin which are capable of being
inhaled into the human lung.
5.9 Interference. An undesired positive or negative output caused by a substance other than the one
being measured.
5.10 Precision. The degree of mutual agreement between individual measurements, namely repeatability
and reproducibility.
5.11 Standard. A concept that has been established by authority, custom, or agreement to serve as a
model or rule in the measurement of quantity or the establishment of a practice or procedure.
5.12 Traceability to NBS. A documented procedure by which a standard is related to a more reliable
standard verifled'by the National Institute of Standards Technology (MIST).
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r,", - Method 10-3.3
Chemical Analyse X-Ray Analysis
5.13 Uncertainty. An allowance assigned to a measured value to take into account two major
components of error: (1) the systematic error, and (2) the random error attributed to the imprecision of
the measurement process.
5.14 Chi-square. A statistic which is a function of the sum of squares of the differences of the fitted
and measured spectrum.
5.15 Fluorescer. A secondary target excited by the x-ray source and in turn excites the sample.
5.16 FWHM. Full width at half maximum, a measure of spectral resolution.
5.17 NIST. National Institute of Standards and Technology.
5.18 Shape. The actual shape of a background corrected pulse height spectrum for an element.
5.19 SRMs. Standard reference materials.
5.20 Teflo®. Trade name of a Teflon filter.
5.21 Unknown. A sample submitted for analysis whose elemental concentration is not known.
5.22 XRF. X-ray fluorescence.
6. Description of Spectrometer
The x-ray analyzer is a Kevex EDX-771 energy dispersive spectrometer with a 200 watt rhodium
target tube as an excitation source. The machine has multiple modes of excitation including direct
filtered direct, and secondary which utilizes up to 7 targets or fluorescers. To minimize radiation damage
to delicate aerosol samples only the secondary mode is used. Table 1 provides a listing of the fluorescers
and the elements which they excite associated with energy dispersive spectrometers. Analysis
atmospheres are selectable with choices of helium, vacuum or air; helium is used for all targets except
Gd where air is employed because it gives a lower background. The detector is cryogenically cooled
lithium-drifted silicon with a 5 /mi Be window and a resolution of 158 eV at Fe IT and comes with two
manually changeable collimators. A 16 position rotating wheel accommodates the samples and provides
sample changing. F
The machine is operated by procedure files (or programs) written in Kevex's proprietary Job Control
Language (JCL) which runs in a Windows 3.1 environment and provides setting of the analytical
conditions and data acquisition. Using the JCL language, procedures have been written in-house to
perform all the functions necessary to acquire spectra and to assign to them file names in a structured
manner to facilitate future spectral processing. These procedures are invoked in menu form
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-5
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Method IO-3.3 Chapter IO-3
X-Ray Analysis Chemical Analysis
7. Caveats
7.1 The type of samplers mentioned in Section 1.7 must be operated in accordance with Inorganic
Compendium Method IO-2.2 Sampling for Suspended Particulate Matter in Ambient Air Using a
Dichotomous Sampler, or severe errors in x-ray analysis may occur. For example, errors in flow rate
will not only give erroneous volumes but will cause a more serious condition of altering the cut points
upon which the coarse particle x-ray attenuations are based. If samples are intended for x-ray analysis
then the sampling protocol must conform to the constraints inherent within this method. Furthermore,
the type of filter on which the sample is collected is very important. In general, thin membrane filters
(Teflo* and Nuclepore*) are required so that the background is low and penetration of particles into the
matrix of the filter is small. Thick depth filters such as quartz or glass fiber not only have high
background but also allow particles to penetrate into the matrix of the filter - a condition which the
spectral processing program cannot accommodate.
7.2 Some internal contaminations consisting of Sn, Ni, Cu and Fe are present which sometimes appear
in blanks. Routine analysis of blanks with samples will give the magnitude of the correction necessary
to compensate for this.
7.3 In general the elements analyzed by the Gd fluorescer have higher detection limits than the other
fluorescers (see Table 2). The reason for this is due to limitations in the upper voltage limit of the x-ray
tube power supply and the use of rhodium instead of a heavier element such as tungsten as a target
material for the x-ray tube. As a secondary consequence of this, there are also higher detection limits
for many of the elements below chromium because they overlap the elements analyzed by Gd.
7.4 An inherent problem with a helium atmosphere is the diffusion of He through the detector window
causing detector degradation and necessitating replacement. A lifetime of 3 to 4 years is expected.
7.5 Due to an x-ray leak around the anode area of the x-ray tube the head must be shielded with
additional lead cladding to prevent unwanted excitation of internal parts. This leak posed no threat to
personnel but caused high background when operating at the maximum voltage. The additional shielding
proved very effective at improving detection limits.
7.6 Experience with wavelength dispersive spectrometers (WDXRF) has shown good agreement with
energy dispersive instruments (EDXRF) over a broad range of elements. In spite of this agreement and
the simpler spectral processing requirements of wavelength machines the preference remains with energy
dispersive equipment for a variety of reasons. The very low power tubes in EDXRF machines leaves
the sample intact and unaffected whereas in WDXRF the high power excitation embrittles the filter itself
after 15 - 30 min exposure raising the possibility of altering particle morphology. This is a concern if
electron microscopy is considered. Also, the vacuum environment, necessary for WDXRF, causes loss
of some volatile materials.
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Chapter IO-3 Method IO-3.3
Chemical Analysis X-Ray Analysis
8. Sample Preparation
8.1 Sample preparation begins with the correct operation of the samplers employed. Inorganic
Compendium Method IO-2.2, Sampling for Suspended Participate Matter in Ambient Air Using a
Dichotomous Sampler, covering the option of the samplers in the field and subsequent collection of
ambient air particles on 37-mm Teflon® filter for XRF analysis. One of the greatest advantages of
analyzing aerosols by XRF is that the sample can, in theory, be collected in a manner most advantageous
to XRF by sampling for a duration that produces an ideal mass loading on the filter. An approximate
maximum target mass is about 100 ^g/cm2 although much less is often collected in many environments.
8.2 The types of filters used for aerosol sampling are 37-mm or 47-mm Teflo® with a pore size of
2 microns and, if electron microscopy is planned for the coarse fraction, then a 0.6 micron pore size
Nuclepore® filter is used. The sample should be collected on the side of the Teflo® filter with the
supporting ring to maintain the proper distance between the sample and detector during analysis. A
properly collected sample will be a uniform deposit over the entire collection area of at least 25mm in
diameter. Samples which are not uniformly deposited over the whole collection area are not
quantitatively analyzable.
8.3 All filter samples received for analysis are removed with tweezers from their container and are
checked for any invalidating conditions such as holes, tears, or a non-uniform deposit which would
prevent quantitative analysis. If such a condition is found the sample is noted as invalid on the XRF data
entry form; data from such samples are not reported. Teflo® filters are easily handled because of the
supporting ring, however, Nuclepore® filters must have a supporting ring applied to them (after
gravimetric assay) to help maintain their flatness and to securely hold them in the frame. The sample
is then placed in a custom-designed commercially available two-part sample frame which snaps together
holding the filter securely in place.
9. Spectral Acquisition and Processing
9.1 Spectra are acquired in sets of 15 samples each. Up to 7 spectra are acquired for each sample
depending on how many secondary excitation targets are selected. Utilizing all seven fluorescers requires
approximately 4 hours machine time for 44 elements analyzed plus atmospheric argon.
9.2 Elemental intensities are determined by spectral deconvolution with a least squares algorithm which
utilizes experimentally determined elemental shape functions instead of the mathematical Gaussian
function. This approach has been successfully implemented for many years on an earlier machine and
is described in Section 15, Citation 10. Since the spectral shape is not a pure Gaussian the experimental
shapes are a more realistic representation of a spectrum. In addition to this library of elemental shape
spectra there is also a background shape spectrum for each of the types of filters. It is assumed that the
background on an unknown sample is due to the filter and not to the sample. (This is one of the reasons
for avoiding heavily loaded filters.) The least squares algorithm synthesizes the spectrum of the sample
under analysis by taking a linear combination of all the elemental shapes spectra and the background
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-7
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Method IO-3.3 Chapter IO-3
X-Ray Analysis _ Chemical Analysis
shape spectrum. The coefficients on the linear combination of elemental shapes and background spectra
are scaling factors determined by minimizing chi-square thus producing the best fit possible by least
square minimization. Values of the chi-square statistic are calculated for each sample and fluorescer to
give an indication of the quality of the fit.
9.3 X-ray attenuation corrections are performed as described in Section 15, Criterion 10 and are briefly
described here. The mass absorption coefficients for the layer of fine particles is based on a typical
composition of ambient aerosol particles so the actual x-ray attenuations on a given sample are simply
a function of the mass loading. Coarse particle attenuations are more complex in that they are based on
x-ray attenuation by spherical particles with compositions of common crustal minerals with various size
distributions. An average attenuation and uncertainty for each coarse particle element is based on this
broad range of crustal minerals and is therefore a one-time calculation giving an attenuation factor useable
for all subsequent coarse (2.5-10 /im) particle analyses. This treatment assumes low coarse particle
loading so that the particles do not shadow one another - yet another reason for assuring that the sample
mass loading is not too high. Attenuation corrections on PM^Q particles are deduced from elemental
concentration data from samples taken with collocated PM^Q and dichotomous samplers.
9.4 The need for interference corrections arises from overlaps that are not deconvoluted by the least
squares algorithm. This can best be illustrated by an example: Barium and titanium are analyzed by the
gadolinium and iron fluorescers, respectively. The barium L x-rays overlap with the K x-rays of titanium
and require an interference correction because the elements analyzed by gadolinium do not include
titanium. The interference correction technique is described by Gilfrich in Section 15, Criterion 29. The
interference coefficient, determined during calibration, represents the fraction of the concentration of an
affecting element (barium in the present example) which must be subtracted from the concentration of
the affected element concentration (titanium) to compensate for the interference.
9.5 When samples are collected by the dichotomous or other samplers using virtual impaction, an
additional correction must be employed because these type of samplers do not perfectly separate the fine
and coarse particles. Due to virtual impaction requirements, about 10% of the fine particle mass is
deposited on the coarse filter. Therefore, the attenuation corrections used for the particles on the coarse
filter "over-correct" the attenuation because of these residual fines on the coarse filter. These effects are
compensated for by the flow fraction correction.
10. Data Reporting
The two most important data output files are an ASCII file which contains a recapitulation of the field
data and the final sample concentrations in ng/m^ and a Lotus file with only the sample data. An
example printout of a fine/coarse sample pah: is shown in Table 3.
The uncertainty reported with each concentration is a la (68% confidence level) uncertainty and is
determined by propagating the errors given in Section 12. Elements with concentrations below 3 times
the uncertainty are flagged with an asterisk (*) on the printed record. If the true elemental concentration
is zero then the fitting procedure implies that negative and positive results are equally probable.
Therefore, negative numbers may be reported.
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Chapter IO-3 Method IO-3.3
Chemical Analysis X-Ray Analysis
11. Calibration
11.1 Calibration is performed only when a change in fluorescers or x-ray tubes or detector is made or
a serious malfunction occurs requiring significant repairs. Calibration establishes the elemental sensitivity
factors and the magnitude of the interference or overlap coefficients. It takes approximately 2 weeks to
complete a calibration.
11.2 Thin film standards are used for calibration because they most closely resemble the layer of
particles on a filter. There are two types of calibration standards in use. One type consists of thin films
deposited on Nuclepore substrates (Micromatter Co., Eastsound, WA). These standards are available for
almost all the elements analyzed ranging in atomic number from 11 (Na) to 82 (Pb) with deposit masses
gravimetrically determined to ± 5 %. Another type consists of polymer films that contain known amounts
of two elements in the form of organo-metallic compounds dissolved in a polymer and are not
commercially available but their preparation is described in Section 15, Citation 9. These standards have
been prepared for elements with atomic numbers above 21 (titanium and heavier). The same set of
standards is used every time the spectrometer is calibrated. The standards are sufficiently durable to last
many years, however occasionally one must be replaced due to accidents in handling. Approximately
200 calibration standards for 44 elements are in use (see Table 4.) and the acquisition of their spectra
requires several days.
11.3 The background files which are used for background fitting are created at calibration time. Thirty
clean Teflo® and Nuclepore® blanks are kept sealed in a plastic bag and are used exclusively for
background measurement. After acquiring spectra for all 7 fluorescers the spectra are added together to
produce a single spectrum for each fluorescer. Options are available to omit a spectrum from the sum
if one shows a contamination. It is these summed spectra that are fitted to the background during spectral
processing.
11.4 The shapes standards are thin film standards consisting of ultra pure elemental materials for the
purpose of determining the physical shape of the pulse height spectrum. For this purpose it is not
necessary for the concentration of the standard to be known - only that it be pure. A slight contaminant
in the region of interest in a shape standard can have serious effect on the ability of the least squares
fitting algorithm to fit the shapes to the unknown. For this reason the Se and elemental As standards,
whose compounds are volatile, are kept in separate plastic bags in a freezer to prevent contamination of
other standards; the Au standard, which will slowly amalgamate with atmospheric Hg, is kept in a
desiccator. The shape standards are acquired for sufficiently long times to provide a large number of
counts in the peaks of interest. It is these elemental shapes spectra that are fitted to the peaks in an
unknown sample during spectral processing.
11.5 The spectra from the calibration standards are deconvoluted to get elemental intensities as described
in Section 9.2. Using these intensities and the elemental concentration in the standards the sensitivities
are determined by a polynomial fit using a model based on the fundamentals of the x-ray physics process
as well as measurements on the calibration standards. This approach allows the calculation of sensitivities
for elements for which there are poor or no standards such as volatile ones like Se and elemental As as
well as improving on elements with good standards.
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Method IO-3.3 Chapter IO-3
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11.6 The overlap coefficients are determined during calibration and represent the extent of interference
that exists between overlapping spectral peaks. During calibration an affecting element (barium, to
continue with the example of Section 9.4) is measured both at the analyte line peak for barium and at the
titanium peak. The coefficient is expressed as the ratio of the concentration of the affected element
(titanium) to the concentration of the affecting element (barium). All elements requiring overlap
coefficient determination are calculated in this manner.
12. Detection Limits
The detection limits are determined by propagation of errors. The sources of random error which
are considered are: calibration uncertainty (± 5%); long term system stability (± 5%); peak and
background counting statistics; uncertainty in attenuation corrections; uncertainty in overlap corrections;
uncertainty in flow rate; and uncertainty in coarse fraction due to flow fraction correction (paired samples
only). Table 2 outlines typical Iff (68% confidence level) detection limits on a Teflo® blank for fine
particles and a Nuclepore® blank for coarse (2.5 /im-10 /j.m) particles. These detection limits are defined
in terms of the uncertainty in the blank. This ignores the effect of other elements which generally is
small except for the light elements (potassium and lower) where overlapping spectral lines will increase
the detection limit.
(Note: Tlie difference in the detection limits between the two filters in Table 2 is due more to the
difference in sensitivity to fine and coarse particles and less to the difference in filter material]
Higher confidence levels may be chosen for the detection limits by multiplying the Iff limits by 2 for a
2ff (or 95% level) or by 3 for 3ff (or 99.7% level). To convert the detection limits to more useful units
one can use the typical deposit areas for 37mm and 47mm diameter filters of 6.5 cm2 and 12.0 cm2
respectively.
13. Quality Control
13.1 A comprehensive quality control program is in effect consisting of many measured parameters
covering all measurement conditions and automatically produces control charts for all such measurements.
All plotted data are normalized to the mean to give a rapid assessment of relative change.
13.2 Run-time quality control gives an indication of instrument performance at the time of data
acquisition by measurements on stable qualitative standards. The parameters which are measured and
their significance are: peak areas (monitors change in sensitivity), background areas (monitors
contamination or background changes), centroid (monitors gain and zero adjustment to insure that spectra
are assigned the correct channel), and FWHM, (monitors degradation of the detector resolution). These
four parameters are measured for elements ranging from sodium to lead and include atmospheric argon.
An example of plots of run-time QC data and illustrated in Figures 1 through 4 and Table 5, for the
target and tolerance values for the parameters measured.
13.3 In addition to the run-time quality control procedure the analysis results of Standard Reference
Materials SRM1833 and SRM1832 are included in the data reports. These results provide an overall
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Chapter IO-3 Method IO-3.3
Chemical Analysis X-Ray Analysis
check of the spectral processing program for the elements which are certified in the standards. The sole
purpose of the SRMs is to provide a quality control measure; the standards are not used for calibration.
Typical results of these SRMs are documented in Tables 6 and 7, and plotted in Figure 5.
13.4 The run-time quality control procedures serve as an indicator of possible emerging problems by
flagging deviations greater than 3 tolerance units as defined for each element in Table 5. Persistently
increasing trends are investigated to determine their cause(s) before they impact the results of SRM
analyses.
13.5 The acceptance criteria of results for the elements certified in the SRMs is that the uncertainty
intervals for the analytical results and those of the certified values should overlap each other. If any
element fails this then the run of unknowns is repeated. Repeated failures indicate the need for
recalibration.
13.6 A value for chi-square is calculated and reported with the data to indicate the quality of the fit.
Chi-square values that are much larger than 1.0 indicate a problem in the fitting procedure. Changes in
detector resolution or gain in the amplifier produce large values for chi-square; however such changes
would be detected by the run-time quality control procedure. Also, large chi-square values can
accompany results for heavily loaded filters even though the relative errors are typical. In addition,
elements analyzed by the titanium and the iron fluorescers may experience large chi-square values due
to interferences from overlapping elements. Chi-square is a more useful measure of goodness-of-fit for
the other fluorescers for this reason.
13.7 To acquire more information about fitting problems the fitted spectra can be viewed on the screen
or a hard copy printed. Such plots can be compared to the unknown spectra, background spectra, or to
the library shape standards to help elucidate the suspected problem. Various statistics such as the
correlation coefficient can be calculated on the fitted and measured spectra as a additional measure of the
goodness-of-fit. Fitted spectrum superposed on its measured spectrum along with the associated statistics
is illustrated in Figure 6.
14. Precision and Accuracy
Precision varies with the element and concentration. At high concentrations (greater than 1 jig/cm2)
a precision of 7.1% caii be expected for elements analyzed by one fluorescer and 5.0% can be expected
for those analyzed by two. Refer to Table 1 for a listing of the elements and the fluorescers which
analyze them. Based upon the analysis of NIST SRMs the accuracy is ± 10%.
15. References
1. Arinc, F., Wielopolski, L., and Gardner, R. P., The Linear Least-Squares Analysis of X-Ray
Fluorescence Spectra of Aerosol Samples using Pure Element Library Standards and Photon Excitation,
X-ray Fluorescence Analysis of Environmental Samples, ed. T. G. Dzubay, Ann Arbor Science, Ann
Arbor, MI p.227.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-11
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Method IO-3.3 Chapter IO-3
X-Ray Analysis Chemical Analysis
2. Bevington, P.R., Data Reduction and Error Analysis for the Physical Sciences, McGrawHill Book
Co., New York, N.Y.
3. Billiet, J., Dams, R., and Hoste, J., X-Ray Spectrum, 9:206-211, 1980.
4. Birks, L.S., and Gilfrich, J.V., "X-Ray Spectrometry," Anal. Chem., 48:273R-28R, 1976.
5, Dzubay, T. G., Analysis of Aerosol Samples by X-Ray Fluorescence, Env. Science Research Lab,
U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711, April 1986.
6. Dzubay, T. G., "Chemical Elements Balance Method Applied to Dichotomous Sampler Data," Annals
New York Academy of Sciences, 1980.
7. Dzubay, T. G., Development and Evaluation of Composite Receptor Methods, EPA Project Summary,
EPA-600/3-88-026, U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711,
September 1988.
8. Dzubay, T. G., Quality Assurance Narrative for SARB XRF Facility, Env. Science Research Lab,
U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711, March 1989.
9. Dzubay, T. G., et al., "Polymer Film Standards for X-Ray Fluorescence Spectrometers," J. Trace
and Microprobe Techniques, 5(4):327-341, 1987-88.
10. Dzubay, T. G., Drane, E. A., Rickel, D. G., and Courtney, W. J., "Computer Code for Analyzing
X-Ray Fluorescence Spectra of Airborne particulate Matter," Advances in X-Ray Analysis, Vol. 23.
11. Dzubay, T. G., Lamothe, P. J., and Yasuda, H., Advances in X-Ray Analysis, ed. H. F.
McMurdie, C.S. Barrett, J. B. Newkirk, and C. O. Ruud, Plenum, New York, N.Y. 20:411-421,1977.
12. Dzubay, T. G., Morosoff, N., Whitaker, G. L., et al., "Evaluation of Polymer Films as Standards
for X-Ray Fluorescence Spectrometers," Presented at Symposium on Electron Microscopy and X-Ray
Applications to Environmental and Occupational Health Analysis.
13. Dzubay, T. G., and Nelson, R. O., Self Absorption Corrections for X-Ray Fluorescence Analysis
of Aerosols, Advances in X-Ray Analysis, ed. W. L. Pickles, et al., Plenum Publishing Corp., New
York, N.Y. 18:619, 1975.
14. Dzubay, T. G., and Rickel, D. G., X-Ray Fluorescence Analysis of Filter-Collected Aerosol
Particles, Electron Microscopy and X-Ray Applications, Ann Arbor Science, 1978.
15. Dzubay, T. G., Stevens, R. K., Gordon, G. E., Olmez, I., Sheffield, A. E., and Courtney, W.
J., "A Composite Receptor Method Applied to Philadelphia Aerosol," Environmental Science &
Technology, 22:46, January 1988.
Page 3.3-12 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.3
Chemical Analysis X-Ray Analysis
16. Dzubay, T. G., Stevens, R. K., Gordon, G. E., Olmez, I., Sheffield, A. E., and Courtney, W.
J., "A Composite Receptor Method Applied to Philadelphia Aerosol," Environmental Science &
Technology, 22:46, January 1988.
17. Giauque, R. D., Goulding, F. S., Jaklevic, J. M., and Pehl, R. H., "Trace Element Determination
with Semiconductor Detector X-Ray Spectrometers," Anal. Chem., 45:671, 1973.
18. Goulding, F. S., and Jaklevic, J. M., Fabrication of Monitoring System for Determining Mass and
Composition of Aerosol as a Function of Time, EPA-650/2-75-045, U. S. Environmental Protection
Agency, Research Triangle Park, NC 27711, 1975.
19. Inhalable Paniculate Network Operations and Quality Assurance Manual, Office of Research and
Development, Env. Monitoring Systems Lab, U. S. Environmental Protection Agency, Research Triangle
Park, NC 27711.
20. Jaklevic, J. M., Landis, D. A., and Goulding, F. S., "Energy Dispersive X-Ray Fluorescence
Spectrometry Using Pulsed X-Ray Excitation, Advances in X-Ray Analysis, 19:253-265, 1976.
21. Jenkins, R., and deVries, J. L., Practical X-Ray Spectroscopy, Springer-Verlag, New York, NY,
1967.
22. Loo, B. W., Gatti, R. C., Liu, B. Y. H., Chong-Soong, K., and Dzubay, T. G., "Absorption
Corrections for Submicron Sulfur Collected in Filters," X-Ray Fluorescence Analysis of Environmental
Samples, Ann Arbor Science, Ann Arbor, MI p. 187, 1977.
23. NBS Standard Reference materials Catalog 1986-87, National Bureau of Standards Publ. 260, U. S.
Department of Commerce, Washington, DC p. 64, June 1986.
24. Rhodes, J. R., X-Ray Spectrom., 6:171-173, 1977.
25. Wagman, J., Bennett, R. L., and Knapp, K. T., "Simultaneous Multiwavelength Spectrometer for
Rapid Elemental Analysis of Particulate Pollutants," X-Ray Fluorescence Analysis of Environmental
Samples, ed. T. G. Dzubay, Ann Arbor Science Publishers, Inc. Ann Arbor, MI, pp, 35-55, 1977.
26. Volume II: Protocols for Environmental Sampling and Analysis, Particle Total Exposure Assessment
Methodology (P-Team): Pre-Pilot Study, EPA 68-02-4544, U. S. Environmental Protection Agency,
Research Triangle Park, NC 27709, January 27, 1989.
27. Jaklevic, et al., X-ray Fluorescence Analysis of Environmental Samples, ed. T. G. Dzubay, Ann
Arbor Science, Ann Arbor, MI, p. 63.
28. Cooper, J. A., Valdovinos, L. M., Sherman, J. R., Pollard, W. L., Sarver, R. H., and Weilder,
J. K., "Quantitative Analysis of Aluminum and Silicon in Air Particulate Deposits on Teflon® Membrane
Filters by X-ray Fluorescence Analysis," NEA, Inc., Beaverton, OR, July 15, 1987.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.3-13
-------
Method IO-3.3 Chapter IO-3
X-Ray Analysis Chemical Analysis
29. GHfrich, et al., X-ray Fluorescence Analysis of Environmental Samples, ed. T. G. Dzubay, Ann
Arbor Science, Ann Arbor, MI, p. 283.
Page 3.3-14 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
TABLE 1.
FLUORESCER USAGE
Fluorescer
Element Al Ti
Na x
Mg x
AI x
Si x
P XX
S x x
Cl xx
Ar xx
K xx
Ca xx
Sc xx
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Rb
Sr
Y
Zr
Mo
Rh
Pd
Ag
Cd
Sn
Sb
Te
I
Cs
Ba
La
W
Au
Hg
Pb
[Note: The 'x' marks
element.]
Fe Ge Ag Zr
x x
x x
x x
X X
x x
X X
X X
X X
X
X
X
X
X
X
X X
X
X
X
X
X X
X X
X X
X X
the fluorescers that analyze
Gd
x
X
X
X
X
X
X
X
X
X
X
X
X
X
each
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-15
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
TABLE 2. DETECTION LIMITS (Iff) FOR TEFLO AND
NUCLEPORE BLANK FILTERS
Teflo® - fine element
Detection Limit DL (ng/cm2)
NA
MG
AL
SI
P
S
CL
K
CA
'SC
TT
¥
CR
MN
EE
'O©
NI
OU
ZN
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
TABLE 3. DATA REPORT FORMAT FOR A FINE/COARSE PAIRED SAMPLE
KEVEX SUMMARY: ADOBE FLATS URBAN PARTICULATE STUDY
SITE = ADB
DURATION
(MIN) = 714 . 0
FLOW FRAC = .0859
SAMPLE DATE =
FLOW (L/MIN) =
3/20/92 AND 1900 HOURS
37.105 + - .500
XRF ID
SAMPLE ID
MASS
*NA
MG
*AL
SI
* P
S
CL
K
CA
*SC
*TI
* v
*CR
MN
FE
*CO
NI
CU
ZN
*GA
*GE
AS
SB
BR
*RB
SR
* Y
*ZR
*MO
*RH
*PD
*AG
*CD
SN
*SB
*TE
* I
*CS
*BA
*LA
* W
*AU
*HG
PB
= 999906
= T0033
' FINE, NG/M3
XRF ID
SAMPLE ID
= 999956
= NU0033
COARSE, NG/M3
77912. +- 1962.
211.9 +-
564.6 +-
162.2 + -
213.4 + -
12.1 +-
2653.4 +-
1164.4 + -
193.6 +-
43.4 + -
3.6 + -
17.6 +-
4.6 +-
2.0 + -
10.0 + -
243.7 + -:
2.8 +-
3.8 +-
14.3 + -
167.5 +-
2.4 + -
3.3 + -
24.7 + -
4.7 +-
29.0 + -
1.7 + -
2.9 + -
12.4 +-
2.9 + -
7.3 +-
.0 +-
-3.6 +-
-6.4 +-
8.5 +-
54.3 +-
-1.6 +-
2.5 +-
25.0 +-
-4.0 +-
-7.7 + -
-4.8 +-
-1.1 +-
-.9 +-
-.4 +-
221.6 + -
71.4
89.4
74.1
40.4
18.5
183.7
79.3
13.8
5.6
4.1
6.6
2.3
1.0
1.4
21.9
1.8
1.2
1.9
14.9
1.0
1.3
3.6
.8
2.8
.8
.9
6.1
4.8
4.8
3.2
3.1
3.4
4.5
9.4
6.4
7.5
9.6
11.2
13.7
34.5
2.6
1.8
1.9
19.7
MASS
*NA
MG
AL
SI
* P
S
*CL
K
CA
*SC
TI
* v
CR
MN
FE
*CO
*NI
CU
ZN
*GA
*GE
*AS
*SE
BR
*RB
SR
* Y
*ZR
*MO
*RH
*PD
*AG
*CD
*SN
*SB
*TE
* I
*CS
BA
*LA
* W
*AU
*HG
PB
11347.. +-
53.3 +-
443.9 +-
539.9 + -
909.5 +-
-5.5 +-
285.7 +-
34.8 +-
63.5 +-
181.7 +-
-1.3 +-
54.7 +-
3.2 ,+ -
9.8 +-
10.1 +-
783.5 +-
4.8 +-
.3 +-
8.8 +-
27.6 +-
-.0 +-
.0 +-
1.8 +-
.7 +-
7.9 +-
1.0 -f-
2.2 +-
3.9 +-
4.3 +-
-3.2 +-
-1.2 •+-
-1.0 +-
1.2 +-
-.7 +-
2.3 +-
-.6 +-
-7.2 +-
2.4 +-
12.4 +-
25.1 +-
22.6 +-
1.5 +-
.2 +-
1.5 +-
46.0 +-
812.
27.1
40.8
173.8
232.7
11.3
84.9
24.6
8.9
13.9
2.2
9.6
1.7
1.6
1.3
78.2
1.7
.6
1.3
4.9
.4
.6
1.2
.4
1.1
.4
.5
2.9
2.6
2.2
1.6
1 .7
1.9
2.2
3.9
3.3
3.8
4.7
5.9
7.4
17.9
1.3
.9
1.0
6.2
INDICATES THAT THE CONCENTRATION IS BELOW 3 TIMES THE UNCERTAINTY
XRF DATE= 04/29/1992 16:35 RBK (F): 04/29/1992 20:35 RBK (C)
SPECTRAL ANALYSIS DATE= 5/20/1992
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-17
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
TABLE 4. CALIBRATION STANDARDS AND CONCENTRATIONS
Standard
ID
C«F237
CaF229
CaF290
CaF291
C*F2102
CaF266
CaF228
CaF233
CaF239
CaF2 54
CaF2291
C»F230
CaF2S2
CaF248
CaF245
CaF236
C«F2134
CaF21IO
Nad 57
NaCl 87
NaCI446
NaCl715
NaC!497
NaClSOl
NaCl 51
NaC1512
NaC1519
MgSl
Mg 41
Mg 41.3
Mg43
Mg 43.8
Mg 60.2
Al 57
A137.9
A137.4
A129
M43.2
A162
AI75
SiO 46
SiO47
SiO 5U
SiO 51b
SiO 56
SiO SO
SSO27.6
SiO46.1
SI072.2
GaP34
Gap 40
GaP70
GaP 105
Element
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
Na
Na
Na
Na
Na
Na
Na
Na
Na
Mg
Mg
Mg
Mg
Mg
Mg
Al
Al
Al
Al
Al
Al
Al
Si
Si
Si
Si
Si
Si
Si
Si
Si
P
P
P
P
;tg/cm2
18.00
14.10
43.80
44.30
49.60
32.10
13.60
16.10
19.00
26.30
14.10
14.60
25.30
23.40
21.90
17.50
65.20
53.50
22.40
34.20
17.60
28.10
19.60
19.70
20.10
20.10
20.40
81.00
41.00
41.30
43.00
43.80
60.20
57.00
37.90
37.40
29.00
43.20
62.00
75.00
29.30
29.90
32.50
32.50
35.70
51.00
17.60
29.40
46.00
10.50
12.30
21.50
32.30
Standard
ID
CuS1124
CuS58.6
CuS57.6
CuS58.2
NaCl 57
NaCl 87
NaC1446
NaC1715
NaC1497
NaClSOl
NaCl 51
NaC15l2
NaC1519
KC145
KC153.3
KC170
KC149
KC148.7
KC147.9
XC148
KCI47.6
KCI45
KC153.3
KC170
KC149
KC148.7
KC147.9
KC148
KC147.6
CaF2 37
CaF229
CaF290
CaF291
CaF2102
CaF266
CaF228
•:aF233
CaF2 39
CaF254
CaF2291
CaF230
CaF252
CaF2 48
CaF245
CaF2 36
CaF2134
CaF2110
ScF357
Ti39
Ti95
TiGe33d
TiGe29x
V45
Element
S
S
S
S
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
K
K
K
K
K
K
K
K
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ca
Ga
Ca
Sc
Ti
Ti
Ti
Ti
V
fig/cm2
31.90
16.50
13.90
14.00
34.60
52.80
27.10
43.40
30.20
30.40
31.00
31.10
31.50
21.40
25.40
33.30
23.30
23.20
22.80
22.80
22.60
23.60
28.00
36.70
25.70
25.50
25.10
25.20
25.00
19.00
14.90
46.20
46.70
52.40
33.90
14.40
16.90
20.00
27.20
14.90
15.40
26.70
24.60
23.10
1,8.50
68.60
56.50
25.10
39.00
95.00
2.46
2.36
45.00
Standard
ID
Cr85
Cr84
Cr75
Cr74
Cr 122
CrCu32a
CrCu26g
MnZn24b
Mn57
Mn 183
MnZn27x
Mn43
Mn 46.9
Mn 44.5
Mn 46.6
Mn43.7
Mn69
FePb37y
Fe 107
Fel27 -
Fe46
Fe88
FePb38y
Co45a
Co45b
RbCo29c
RbCo25b
Ni54
Ni88
NiV 21c
Ni 101
Cu96
Cu 104
Cu 128
CrCu26g
CrCu32a
Cu38
Zn51
Zn 125
MnZn27x
MnZn24b
GaP 34 "
GaP 40
GaP 70
GaP 105
Ge37
TiGe33d
TiGe29x
Ge 140
BaAs23y
BaAs36w
CsBr 53
CsBr 54
Element
Cr
Cr
Cr
Cr
Cr
Cr
Cr
Mn
Mn
Mn
Mn
Mn
Mn
Mn
Mn
Mn
Mn
Fe
Fe
Fe
Fe
Fe
Fe
Co
Co
Co
Co
Ni
.Ni
Ni
Ni
Cu
Cu
Cu
Cu
Cu
Cu
Zn
. Zn
Zn
Zn
Ga
Ga
Ga
Ga
Ge
Ge
Ge
Ge
As
. As
Br
Br
/tg/cm2
85.00
84.00
75.00
74.00
122.00
9.19
8.14
8.57
57.00
183.00
9.10
43.00
46.90
44.50
46.60
43.70
69.00
7.72
107.00
127.00
46.00
88.00
7.71
45.00
45.00
7.43
7.65
54.00
88.00
5.77
101.00
96.00
104.00
128.00
7.65
8.63
38.00
51.00
125.00
8.46
7.97
23.50
27.70
48.50
72.70
37.00
6.22
5.94
140.00
5.60
5.52
19.90
20.30
Standard
ID
RbNOSll
RbNO322
RbNO3 a
RbN03 b
RbNO3 c
SrF2 57
SbSr29z
SrF2 50
SbSrSly
SrF2137
SrF2184
SrF2 92
SrF2103
YF346
ZrCd24c
ZrCd20w
MoO3145
MoO3106
MoOSllO
MoO3 59
MoO3 54
Rh 16
Pd33
Pd 198
Ag35
Agl32
Cd83
ZrCd20w
ZrCd24c
Cd77
Sn40
Sn 185
Sn97a
Sn97b
Sn79
Sb 194
Sb47
Sb 147
Sb42
SbSr29z
SbSrSly
Te53
KI46
CsBr 53
CsBr 54
CsBr 51
BaF2108
BaF248
BaF2 60
BaF257
BaF2143
BaF2114
BaAs23y
Element
Rb
Rb
Rb
Rb
Rb
Sr
Sr
Sr
Sr
Sr
Sr
Sr
Sr
Y
Zr
Zr
Mo
Mo
Mo
Mo
Mo
Rh
Pd
Pd
Ag
Ag
Cd
Cd
Cd
Cd
Sn
Sn
Sn
Sn
Sn
Sb
Sb
Sb
Sb
Sb
Sb
Te
I
Cs
Cs
Cs
Ba
Ba
- Ba
Ba
Ba
Ba
,Ba
fj
fig/cm
69.00
12.90
24.90
24.90
24.90
39.80
4.97
34.90
5.14
95.60
12.80
64.20
71.80
28.00
9.85
10.77
96.70
70.70
73.30
39.30
36.00
16.00
33.00
198.00
35.00,
132.00
83.00.
9.15
8.38
77.00
40.00
185.00
97.00,
97.00
79.00
194.00
47.00
147.00
42.00
5.01
5.18
53.00
35.20
33.10
33.70
31.90
84.60
37.60
47.00
44.70,
112.00
89.40
4.98:
Page 3.3-18
Compendium of Methods for Inorgflnic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
TABLE 4. (continued)
Standard Standard Standard
ID Element pg/cm2 ID Element ^g/cm2 ID Element
/tg/cm2
Standard
ID
Element jug/cm2
CuS1052
CuS48
CuS 136
CuS39.6
S
s
S
s
30.80
13.00
33.00
10.20
V53
NiV 21c
Cr30
Cr53
V
V
Cr
Cr
53.00
6.64
30.00
53.00
CsBr 51
RbNO346
RbCo25b
RbCo29c
Br
Rb
Rb
Rb
19.10
26.60
7.88
7.65
BaAs36w
LaF3157
LaF3 62
Ba
La
La
4.91
111.30
44.00
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-19
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
TABLE 5. TARGET AND TOLERANCE VALUES FOR QC RESULTS
FILE:
0:QCBEGTGT
STDEL
ID
1833
1833
1833
1833
1833
1833
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BaNa
BaNa
FILE:
EL
Pb
Zn
Fe
Ti
Si
K
Sn
Pb
Cu
Sr
Ni
Fe
s
Al
AT
Na
Na
Ba
AREA
(cts)
31112.12
31772.52
313475.41
216978.09
69021.60
220344.80
111.52
85.82
497.06
72.92
648.99
459.10
266.76
396.30
747.74
120.85
27711.44
7369.12
0:OCBEGTOL
STDEL
ID
1833
1833
1833
1833
1833
1833
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BLKt
BaNa
BaNa
EL
Pb
Zn
Fe
Ti
Si
K
Sn
Pb
Cu
Sr
Ni
Fe
S
Al
Ar
Na
N
Ba
AREA
(cts)
1.66
1.66
1.66
1.66
1.66
1.66
12.98
8.93
4.95
17.61
3.81
7.57
8.71
7.23
17.39
16.00
1.66
2.53
(TARGET VALUES)
FILE: 0:QCENDTGT
CENTROID
(keV)
10.5449
8.6306
6.3935
4.5037
1.7322
3.3069
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
1.0278
32.0701
FWHM
(ev)
207.4653
179.6835
159.4537
142.4946
121.7406
132.4137
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
107.2698
670.6336
(TOLERANCE
STD
ID
1832
1832
1832
1832
1832
1832
1832
1832
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BaSr
BaSr
UNITS in
EL
Cu
Mn
Ca
V
Al
Si
Na
Ba
W
Zn
Sr
Ni
Fe
S
Si
Ar
Mg
Sr
Ba
*)
AREA
(cts)
17548.85
5303.84
86202.33
217562.00
99761.96
16562.45
67688.42
10332.21
183.14
241.42
148.48
83.00
654.44
603.55
3047.53
936.48
751.18
3622.12
210871.20
7464.85
CENTROID
(keV)
8.0411
6.9247
5.8891
3.6847
4.9443
1.4779
1.7319
1.0256
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000 .
0.0000
0.0000
0.0000
14.1410
32.0692
FWHM
(ev)
174.1389
167.1478
154.6347
135.3520
146.1904
119.5793
118.4960
114.4485
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
227.8625
671.0372
FILE: 0:QCENDTOL
CENTROID
(keV)
0.0313
0.0131
0.0224
0.0259
0.0616
0.0323
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.1103
0.0979
FWHM
(ev)
0.9901
1.7328
0.9361
0.9768
1.4120
0.9235
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
1.2599
3.9782
STD
ID
1832
1832
1832
1832
1832
1832
1832
1832
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BLKn
BaSr
BaSr
EL
Cu
Co
Mn
Ca
V
Al
Si
Na
Ba
W
Zn
Sr
Ni
Fe
S
Si
Ar
Mg
Sr
Ba
AREA
(cts)
1.66
1.70
1.66
1.66
1.66
2.02
1.66
1.78
9.92
8.20
11.45
10.88
6.55
5.63
2.88
6.75
22.14
5.64
1.66
1.86
CENTROID
(keV)
0.0104
0.0308
0.0198
0.0253
0.0243
0.1173
0.0481
0.1560
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0073
0.0279
FWHM
(ev)
1.9331
2.4345
1.3536
1.1311
1.1031
3.3722
0.8888
1.5333
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
0.4538
2.8094
Page 3.3-20
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
TABLE 6. EXAMPLE PRINTOUT OF SRM 1833
KEVEX SUMMARY: TEFLO® BLANKS LOT
SITE
DURATION
SS
(MIN) = .0
FLOW FRAC = .0000
XRFID
SAMPLE ID
MASS
*NA
MG
AL
SI
P
*S
*CL
K
*CA
*SC
IT
*v
CR
MN
FE
*CO
NI
*CU
ZN
*GA
*GE
*AS
*SE
*BR
*RB
*SR
*Y
*ZR
MO
*RH
*PD
*AG
= 112141
= SRM1833
FINE, NG/CM2
0. +-
-801.2 +-
161.3 +-
1027.5 +-
34806.8 +-
79.8 +-
-28.2 +-
-68.6 +-
16734.7 +-
-3.9 +-
-17.1 +-
12852.9 +-
46.0 +-
108.2 +-
13.8 +-
14332.4 +-
-2.6 +-
62.5 +-
3.8 +-
3800.9 +-
-30.9 +-
5.9 +-
5.7 +-
-2.0 +-
-2.3 +-
.5 +-
-5.0 +-
-2.6 +-
-7.6 +-
45.4 +-
156.7 +-
79.2 +-
114.0 +-
#457803 (NEW TUBE)
SAMPLE DATE = 99/99/99 AND 9999 HOURS
FLOW
398.
326.4
18.2
102.2
3023.4
19.9
782.8
113.8
1018.7
61.4
5.4
822.1
52.2
12.7
2.9
872.4
2.9
4.6
1.5
327.7
7.7
3.6
14.6
2.6
2.5
1.4
2.9
7.5
3.5
5.6
69.5
67.1
69.7
(L/MIN) .=
NIST
MASS
NA
MG
AL
SI
P
S
CL
K
CA
SC
TI
V
CR
MN
FE
CO
NI
CU
ZN
GA
GE
AS
SE
BR
RB
SR
Y
ZR
MO
RH
PD
AG
.000 +- .200
CERTIFIED VALUES
15447
.0 +-
.0 +-
.0 +-
33366.0 +-
.0 +-
.0 +-
.0 +-
17147.0 +-
.0 +-
.0 +-
12821.0 +-
.0 +-
.0 +-
.0 +-
14212.0 +-
.0 +-
.0 +-
.0 +-
3862.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0
.0
.0
2163.0
.0
.0
.0
1699.0
.0
.0
1854.0
.0
.0
.0
463.0
.0
.0
.0
309.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-21
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
TABLE 6. (continued)
FINE, NG/CM^
MIST CERTIFIED VALUES
*CD
*SN
*SB
*TE
*I
*cs
*BA
*LA
W
*AU
*HG
PB
24.7
-1496.1
88.2
240.8
134.8
-209.3
-5098.1
-1416.4
59.9
8.7
-30.6
16886.2
+- 66.3
+- T88.1
+- 96.2
•+- 93.8
-+- 107,5
+- 106.6
H-- 517.8
+- 202.2
+- 17.6
•4- 6.8
+- 5.9
+- 1028.1
CD
-SN
'SB
TE
I
CS
BA
LA
W
AU
HG
PB
.0
.0
.0
.0
.0
.0
.0
,.0
.0
.0
.0
16374.0
+- ;0
+- ;0
+- ^0
•+- ;0
+- JO
+- .0
+- ;0
+- ;0
+- .0
+- .cd
+- .0
+- 772.0
INDICATES THAT THE CONCENTRATION IS BELOW 3 TIMES THE UNCERTAINTY.
XRF DATE= 28-SEP-93 10:58:37 RBK
SPECTRAL ANALYSIS DATE= 12/14/1993
Page 3.3-22
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
TABLE 7. EXAMPLE PRINTOUT OF SRM 1832
KEVEX SUMMARY: TEFLO® BLANKS LOT
SITE
DURATION
«
(MEN) = .0
FLOW FRAC = .0000
XRFID
SAMPLE ID
MASS
NA
MG
AL
SI
P
S
CL
*K
CA
*SC
*n
V
*CR
MN
FE
CO
*NI
CU
ZN'
*GA
*GE
*AS
*SE
BR
*RB
*SR
* Y
*ZR
MO
*RH
= 112191
= SRM1832
FINE, NG/CM2
0. +-
11891.5 +-
92.2 +-
15856.5 +-
34398.8 +-
492.0 +-
402.1 +-
156.8 +-
18.5 +-
20011.7 +-
-21.8 +-
-4.7 +-
4593.6 +-
7.4 . +-
4959.3 +-
30.5 +-
1055.1 +-
-6.8 +-
2400.1 +-
9.3 +-
2.1 +-
.3 +-
-3.7 +-
1.0 +-
10.7 +-
-.2 +-
2.8 +-
-5.0 +-
-6.5 +-
26.8 +-
25.2 +-
#457803 (NEW TUBE)
SAMPLE DATE = 99/99/99 AND 9999 HOURS
FLOW
398.
1035.0
13.0
1373.2
2964.2
32.1
27.3
15.9
18.0
1218.2
5.6
130.6
281.1
7.3
302.4
3.9
64.7
1.8
146.3
2.7
2.1
2.4
2.2
1.2
1.8
.9
2.3
1.6
1.8
4.2
58.2
(L/MIN) =
NIST
MASS
NA
MG
AL
SI
P
S
CL
K
CA
SC
TI
V
CR
MN
FE
CO
NI
CU
ZN
GA
GE
AS
SE
BR
RB
SR
Y
ZR
MO
RH
.000 +- .200
CERTIFIED VALUES
16431
11173.0 +-
.0 +-
14953.0 +-
35491.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
19225.0 +-
.0 +-
.0 +-
4272.0 +-
.0 +-
4437.0 +-
.0 +-
970.0 +-
.0 +-
2300.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0
.0
986.0
1150.0
.0
.0
.0
.0
1315.0
.0
.0
493.0
.0
493.0
.0
66.0
.0
164.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-23
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
TABLE 7. (continued)
FINE, NG/CM2
NIST CERTIFIED VALUES
*PD
*AG
*CD
*SN
*SB
*TE
*I
*cs
*BA
*LA
W
*AU
*HG
*PB
-69.0
151.2
24.2
-640.8
-73.5
-9.3
-46.6
3.6
-2352.9
-509.9
40.0
-5.6
-5.4
-10.4
+- 54.7
+- 63.4
+- 58.2
+- 138.6
+- 81.3
+- 73.9
+- 91.6
+- 96.7
+- 328.6
+- 156.5
+- 12.9
+- 2.5
+- 3.0
+- 4.2
PD
AG
CD
SN
SB
TE
I
CS
BA
LA
W
AU
HG
PB
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +-
.0 +r
.0 +-
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
XRF DATE= 29-SEP-93 13:27:55 RBK
SPECTRAL ANALYSIS DATE= 12/14/1993
Page 3.3-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
1.01
DAYS SINCE CAUBHAT1ON
uppar Control Limit Lowar contiol Llml
Figure 1. Quality control indicator associated with Fe peak area.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-25
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
1.3
1.2
1.1
0.3
0.0
o,r
2O 4Q
DAYS SINCg CALIBRATION
Upper control Limit Lower control Limit
Figure 2. Quality control indicator associated with S background area.
Page 3.3-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
BEG QC
1.O3
1.01
033
2O 4O
DAYS SINCE CALIBRATION
upper Control Limit Lower control LlrnK
Figure 3. Quality control indicator associated with Fe FWHM.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-27
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
1.0011
1JOO1
1.OCQQ
1.0C05
1.000T
1.0005
1.CCOS
1.OOO4
1.COO3
1.00GQ
1.OOO1
1
OS999
OSG&T
OJ9995
OSSS4
O-SS22
DAYS SINCE CALIBRATION
uppar coniroi umtt iawstcomtot LtmR
Figure 4. Quality control indicator associated with Pb centroid.
Page 3.3-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.3
X-Ray Analysis
u
:*
O
1.16
1.14
1.12
• 1.1
1.O8
1.O6
1.O4
1.O2
1
o.se
03G
O.94
O.92
O.9
O.88
\
2O
4O
DAYS SINCE CALIBRATION
Upper control Limit Lower control Limit
Figure 5. Quality control indicator associated with Pb in SRMs.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.3-29
-------
Method IO-3.3
X-Ray Analysis
Chapter IO-3
Chemical Analysis
1 1 I —
1 1 « I 1 1
01
0
00
d
UD in •*
d d d
n
d
o
(spups.no.Ljj.)
Page 3.3-30
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.4
DETERMINATION OF METALS
IN AMBIENT PARTICULATE
MATTER USING INDUCTIVELY
COUPLED PLASMA (ICP)
SPECTROMETRY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-3.4
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both hi the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
• Dewayne Ehman, Texas Natural Resource Conservation Committee, Austin, TX
• David Harlos, Environmental Science and Engineering, Gainesville, FL
• Doug Duckworth, Martin Marietta Energy Systems, Inc. Oak Ridge, TN
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
n
-------
Method IO-3.4
Determination of Metals in Ambient Participate Matter Using
Inductively Coupled Plasma (ICP) Spectrometry
TABLE OF CONTENTS
1. Scope 3.4-1
2. Applicable Documents 3.4.2
2.1 ASTM Standards 3^4_2
2.2 Other Documents 3.4-2
3. Summary of Method 3.4-2
3.1 Instrument Description 3.4-2
3.2 Sample Extraction 3.4.3
3.3 Sample Analysis 3.4-3
4. Significance 3 4.3
5. Definitions 3 4.4
6. Ranges, Sensitivities, and Detection Limits 3.4.5
7. Precision and Accuracy 3 4.5
8. Interferences 3 4.5
8.1 Spectral Interferences 3 4.5
8.2 Matrix Interference 3 4.5
9. Apparatus 3 4_7
10. Reagents 3 4.7
11. Analysis 3 4_g
11.1 Chemical Preparations 3 4_g
11.2 ICP Operating Parameters 3.4-10
11.3 Instrumental Preparations 3.4-10
11.4 Sample Receipt in the Laboratory 3 4.11
11.5 ICP Operation '.'.'.'.'.'.'.'.'.'.'.'.'. 3.4-11
12. Data Processing 3 4^3
12.1 Filter Blanks and Discrimination Limit 3.4-13
12.2 Data Transmittal to Data Management Analysis Division (DMAD) 3.4-13
12.3 Data and Record Keeping 3.4-14
13. Quality Assurance 3 4.^5
13.1 Instrumental Tuning and Standardization 3.4-15
13.2 Calibration For Quantitative Analysis 3.4-15
13.3 Daily QA Check and Analytical Run Sequence 3.4-15
13.4 Corrective Actions 3.4-15
13.5 Routine Maintenance 3 4.15
14. Method Safety -'.'.'.'.'.'.".'.'.'.'.'.'. 3.4-16
15. References 3 4_j7
in
-------
-------
Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF FILTER-COLLECTED SPM
Method IO-3.4
DETERMINATION OF METALS IN AMBIENT PARTICULATE MATTER USING
INDUCTIVELY COUPLED PLASMA (ICP) SPECTROMETRY
1. Scope
1.1 Suspended paniculate matter (SPM) in air generally is a complex multi-phase system consisting of
all airborne solid and low vapor pressure liquified particles have aerodynamic particle sizes ranging from
below 0.01-100 jim and larger. Historically, SPM measurement has concentrated on total suspended
particulates (TSP), with no preference to size selection.
1.2 On July 1, 1987, the U. S. Environmental Protection Agency (EPA) promulgated a new size-specific
air quality standard for ambient particulate matter. This new primary standard applies only to particles
with aerodynamic diameters _<.10 ^m (PM1Q) and replaces the original standard for TSP. To measure
concentrations of these particles, the EPA also promulgated a new federal reference method (FRM). This
method is based on the separation and removal of non-PM^Q particles from an air sample followed by
filtration and gravimetric analysis of PM^Q mass on the filter substrate.
1.3 The new primary standard (adopted to protect human health) limits PM10 concentrations to
150 jtg/std m3, averaged over a 24-h period. These smaller particles are able to reach the lower regions
of the human respiratory tract and, therefore, are responsible for most of the adverse health effects
associated with suspended particulate pollution. The secondary standard, used to assess the impact of
pollution on public welfare, has also been established at 150 /xg/std. m3.
1.4 Ambient air SPM measurements are used (among other purposes) to determine whether defined
geographical areas are in attainment or non-attainment with the national ambient air quality standards
(NAAQS) for PM^Q. These measurements are obtained by the states in their state and local air
monitoring station (SLAMS) networks as required under 40 CFR Part 58. Further, Appendix C of Part
58 requires that the ambient air monitoring methods used in these EPA-required SLAMS networks must
be methods that have been designated by EPA as either reference or equivalent methods.
1.5 The procedure for analyzing the elemental metal components in ambient air particulate matter
collected on high volume filter material is described in this method. The high volume filter material may
be associated with either the TSP or PM10 sampler, as delineated in Inorganic Compendium Method
10-2.1.
1.6 Filters are numbered, pre-weighted, field deployed and sampled, returned to the laboratory, extracted
using microwave or hot acid, then analyzed by inductively coupled plasma (ICP) spectrometry. The
extraction procedure is accomplished by following Inorganic Compendium Method IO-3.1.
1.7 This method should be used by analysts experienced in the use of ICP, the interpretation of spectral
and matrix interferences and procedures for their correction. A minimum of 6-months experience with
commercial instrumentation is required.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.4-1
-------
Method IO-3.4 Chapter IO-3
ICP Methodology Chemical Analysis
1.8 Those metals and their associated method detection limit (MDL) applicable to this technology are
listed in Table 1.
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Planning the Sampling of the Ambient Atmosphere.
• D4096 Application of the High Volume Sample Method for Collection and Mass Determination
of Airborne Particle Matter.
2.2 Other Documents
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94/038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, .Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b.
• Reference Method for the Determination of Paniculate Matter in the Atmosphere, 40 CFR 50,
Appendix J.
• Reference Method for the Determination of Suspended Particulates in the Atmosphere (High
Volume Method), 40 CFR 50, Appendix B.
• Reference Method for the Determination of Lead in Suspended Paniculate Matter Collected from
Ambient Air, Federal Register 43 (194): 46258-46261.
• U. S. EPA Project Summary Document (1).
• U. S. EPA Laboratory Standard Operating Procedures (2).
• Scientific Publications of Ambient Air Studies (3-7).
3. Summary of Method
3.1 Instrument Description
3.1.1 The analytical system is an inductively coupled plasma atomic emission spectrometer, as
illustrated in Figure 1. The plasma is produced by a radio frequency generator. The current from the
generator is fed to a coil placed around a quartz tube through which argon flows. The oscillatory current
flowing in the coil produces an oscillating magnetic field with the lines of force aligned axially along the
tube. The argon is seeded with electrons by momentarily connecting a Tesla coil to the tube where the
plasma forms inside. The ions in the gas tend to flow in a circular path around the lines of force of the
oscillatory magnetic field and the resistance to their flow produces the heat. To avoid melting the silica
tube, a flow of argon is introduced tangentially in the tube, which centers the plasma away from the walls
of the tube. The plasma is formed in the shape of a toroid or doughnut, and the sample is introduced
as an aerosol through the middle of the toroid. The hottest part of the plasma is in the ring around the
center of the toroid, where temperatures of about 10,000 K are achieved. Through the center of the
toroid where the sample is introduced, the temperature is somewhat lower, and the sample is subjected
Page 3.4-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.4
Chemical Analysis • ICP Methodology
to temperatures of about 7,000 K. From the very hot region in the plasma and just above it, a continuum
is radiated because of the high electron density. Above this region, the continuum emission is reduced
as the temperature falls and the spectral lines of the elements in the sample may be observed. Since this
plasma is generated in an inert atmosphere, few chemical interferences exist.
3.1.2 The spectrum is resolved in a spectrometer. The relative intensities and concentrations of the
elements are calculated by a small computer or processor. Samples containing up to 61 preselected
elements can be analyzed by ICP simultaneous analysis at a rate of 1 sample per minute. The ICP
technique can analyze a large range of concentrations. A single calibration curve can accomodate changes
in concentration of 5 orders of magnitude.
3.2 Sample Extraction
Two extraction procedures may be performed: hot acid extraction or microwave extraction, as
documented in Inorganic Compendium Method IO-3.1. Extraction involving hot acids is hazardous and
must be performed in a well-ventilated fume hood.
3.3 Sample Analysis
A technique for the simultaneous or sequential multi-element determination of trace elements in an acid
solution is described in this Compendium method (see Figure 2). The basis of the method is the
measurement of atomic emission by an optical spectroscopic technique. Samples are nebulized and the
aerosol that is produced is transported to the plasma torch where excitation occurs. Characteristic
atomic-line emission spectra are produced by a radio frequency ICP. The spectra are dispersed by a
grating spectrometer, and the intensities of the line are monitored by photo multiplier tubes. The photo
currents from the photo multiplier tubes are processed and controlled by a computer system. A
background correction technique is required to compensate for variable background contribution to the
determination of trace elements. Background must be measured adjacent to analyte lines on samples
during analysis. The position selected for the background intensity measurement, on either or both sides
of the analytical line, will be determined by the complexity of the spectrum adjacent to the analyte line.
The position used must be free of spectral interference and reflect the same change in background
intensity as occurs at the analyte wavelength measured. Data is processed by computer and yields
micrograms of metal of interest per cubic meter of air sampled (/jg/m^).
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently, the use of receptor models has documented the need for elemental composition of atmospheric
aerosol into components as a means of identifying their origins. The assessment of human health impacts,
resulting in major control actions by federal, state, and local governments, is based on these data.
Accurate measures of toxic air pollutants at trace levels are essential for proper assessments. The advent
of inductively coupled plasma spectroscopy has improved the speed and performance of metals analysis
in many applications.
4.2 ICP spectroscopy is capable of quantitatively determining most metals at levels that are required, by
federal, state, and local regulatory agencies. Sensitivity and detection limits may vary from instrument
to instrument.
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5. Definitions
Mote: Definitions used in this method are consistent with ASTM methods. All pertinent abbreviations and
symbols are defined within this document at point of use.]
5.1 Autosampler. Device that automatically sequences injections of sample solutions into the ICP.
5.2 Background Correction. Removing a high or variable background signal, using only the peak
height of intensity for calculating concentration. Instruments measure background at one or more points
slightly off the emission wavelength and subtract the intensity from the total intensity measured at the
analytical wavelength.
5.3 Channels. Simultaneous ICPs have an array of photo multiplier tubes positioned to look at a fixed
set of elements (wavelengths); each wavelength is a "channel," which varies by instrument.
5.4 Detection Limits. Determined by calibrating the ICP and determining the standard deviation of
apparent concentrations measured, in pure water. The result (a) is multiplied by a factor from 2 to 10
(usually 3) to define a "detection limit." Complex sample matrices result in a higher background noise
than pure water, so actual detection limits vary considerably with sample type. EPA requires an
instrument detection limit (IDL) to be measured in a standard whose concentration is about three times
the expected detection limit.
5.5 Detectors. Photomultiplier tubes (PMTs).
5.6 Fixed Optics. The most crucial element in the optical design. If the grating moves during
measurement, uncertainties in the results are inevitable.
5.7 Grating. The optical element that disperses light.
5.8 Integration Time. The length of time the signal from the PMT is integrated for an intensity
measurement. The most precise measurements are taken at the peak intensity.
5.9 Inter Element Intereference. When emission lines from two elements overlap at the exit slit, light
measured by the PMT is no longer a simple measure of the concentration of one element. The second
element interferes with the measurement of the first at that wavelength. If lines free of interference can't
be found, approximate concentrations of the element of interest can be calculated by calibrating that
element and the interferent (inter element correction).
5.10 Linear Dynamic Range. The light intensity in an ICP source varies linearly with the concentration
of atoms over more than 6 orders of magnitude (the linear dynamic range). This variation allows for
determination of trace and major elements in a single sample, without dilution. Fewer standards for
calibration are needed, often a high standard and a blank suffice.
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Chapter IO-3 Method IO-3.4
Chemical Analysis ICP Methodology
5.11 Limit of Quantitation. The lowest level at which reliable measurements can be made. Defined
as ten times the standard deviation of a measurement made in a blank (pure water), which is 3.3 times
the "3ff" detection limit.
5.12 Monochromator. The spectrometer design on a sequential ICP.
5.13 Nebulizer. A device creating a fine spray of sample solution to be carried into the plasma for
measurement. Its performance is critical for good analyses.
5.14 Photo Multiplier Tubes (PMTs). Light detectors in ICP instruments. When struck by light, the
PMT generates a current proportional to the intensity.
5.15 Polychromator. The spectrometer design of a simultaneous ICP.
6. Ranges, Sensitivities, and Detection Limits
6.1 Sensitivity, instrumental detection limit, precision, linear dynamic range, and interference effects
must be investigated and established for each individual analyte line on a particular instrument. All
measurements must be within the instrument linear range where correction factors are valid. The analyst
must verify that the instrument configuration and operating conditions satisfy the analytical requirements
and to maintain quality control data, i.e., confirming instrument performance and analytical results.
6.2 For comparison, Table 1 provides typical maximum element concentrations obtained on a Thermo
Jarrell Ash Model 975 Plasma AtomComp (see Section 9.9.4) ICP.
6.3 Calibration sensitivities are dependent upon spectral line intensities. For comparison, Table 1
provides typical sensitivities for the ICP mentioned in Section 6.2 for a Jarrell Ash Model 975 Plasma
AtomComp ICP.
6.4 Detection limits vary for various makes and models. Typical detection limits achievable by the
Thermo Jarrell Ash Model 975 ICP are given in Table 1. These are computed as 3.3 times the standard
deviation of the distribution of outputs for the repeated measurement of a standard, which contains no
metals and is used as the zero point for a two-point instrument standardization described in Section 12.3.
The acid concentrations of this standard must match the acid concentrations of blanks and samples.
7. Precision and Accuracy
7.1 Accuracy for this procedure has not been determined. Spiked strips used for audits have been
developed by the EPA. The main use of the audit results is to document chronologically the consistency
of analytical performance. One multi-element audit sample should be extracted daily with normal ambient
air samples. Audit samples can only approximate true atmospheric particulates, which contributes to the
overall uncertainty. Attempts should be made to use National Institute of Standards and Technology
(NIST) 1648 (urban particulate) to judge recovery. This material is not ideal because (1) there is no filter
substrate; (2) relatively large amounts (100 mg) are required to overcome problems of apparent
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Method IO-3.4 Chapter IO-3
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inhomogeneity, which in turn necessitates dilutions not required in normal application of this method; and
(3) element ratios differ somewhat from those found in real samples. Typical recoveries experienced with
die spiked strips and NIST 1648 are presented in Table 2.
7.2 Typical precision, bias, and correlation coefficients calculated from audit samples vs. blind replicate
analyses are shown in Table 3. Treatment of the glass fibers during filter manufacture affects both
recovery and precision of sample replicate pairs. This fact should be considered when studies are
designed.
7.3 Good precision data does not imply accuracy; bias is still possible. Bias is nearly impossible to
detect when a given type of sample is always analyzed by the same method using the same
instrumentation. In this method, bias, if any, is most likely to arise during the sampling and sample
preparation steps.
7.4 Quality assurance (QA) activities are discussed in Section 14 of this method. QA data for the
method are composed of QA data for the instrument and for the sampling and sample preparation steps.
The former are relatively easy to obtain by the analysis of known solutions and are usually quite good
because of the inherent stability and linearity of the plasma and associated electronics. QA data for the
sampling and sample preparation steps are nearly always poorer than for the instrument and thus dictate
the QA data for the method as a whole. Consequently, a good instrumental calibration does not guarantee
that the data produced are accurate. For instance, independent analysis (by neutron activation analysis)
of real samples and of NIST SRM 1648 has revealed that Cr and Ti extractions are 25-75% efficient
using the method described herein, yet both elements in solution are recovered very well by the plasma
instrument.
8. Interferences
8.1 Spectral Interferences
Spectral interferences result when spectrally pure solutions of one element produce a finite output on
channels assigned to other elements. When the quantitative correction is made, the order of correction
is arranged so that only "true" (that is, interference-free or previously corrected) values are used in any
quantitative correction of another element for comparison. The quantitative correction factors are listed
in Table 4 in the order in which they are applied in the data-processing step for the analysis of ambient
air using the Thermo Jarrell Ash Model 975 ICP. The correction relation for any affected element is:
«*_ // *_.*• (apparent cone.)-(correction factor "true")
"true" concentration = ^-^ . v ; , —: ^
(concentration of the affecting element)
8.2 Matrix Interference
Matrix interferences do exist. This problem has been minimized by matrix matching of standards and
samples. Matrix interferences depend on the types and quantities of acids used; element emission lines
may be enhanced or depressed. These interferences may be circumvented by careful matrix matching
of standards, QC solutions, and samples. Careful matches were made in the development of this
procedure.
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Chapter IO-3 Method IO-3.4
Chemical Analysis ICP Methodology
9. Apparatus
[Note: This method was developed using an ICP provided by Thermo Jarrell Ash, 27 Forge Parkway,
Franklin, MA 02038, (508) 520-1880, as a guideline. EPA has experience in use of this equipment
during various field monitoring program over the last several years. Other manufacturers' equipment
should work as well. However, modifications to these procedures maybe necessary if another
commercially available sampler is selected.]
9.1 Desiccator. For cooling oven-dried chemicals.
9.2 Gravity Convection Type Drying Oven. Drying chemicals and glassware, Precision Scientific
31281 or equivalent.
9.3 Mechanical Convection Type Drying Oven. For drying plastic ware (Blue Island Electric OV
510A-2 or equivalent).
9.4 Inductively Coupled Plasma Emission Spectrometer. The ICP described in this method is the
Thermo Jarrell Ash Model 975 Plasma AtomComp, 27 Forge Parkway, Franklin, MA 02038,
(508) 520-1880. The instrument uses a Plasma Therm HFS 2000D R.F. generator as the power supply
for the plasma. The excitation source is a three-turn inductively coupled plasma torch with a cross-flow
pneumatic nebulizer for sample introduction. Samples are pumped to the nebulizer with a Gilson
Minipuls II single channel peristaltic pump. The instrument is equipped to read 48 elements as identified
in Table 4. A dedicated PDP-8E (Digital Equipment Corporation) minicomputer controls the instrument
and yields a concentration printout. To achieve data storage capability, the PDP-8E has been interfaced
with a POP 11/34.
9.5 Bottles. Linear polyethylene or polypropylene with leakproof caps for storage of samples.
(500 mL, 125 mL, and 30 mL). Teflon bottles for storing multi-element standards.
9.6 Pipettes. Volumetric 50 mL, 25 mL, 20 mL, 15 mL, 10 mL, 9 mL, 8 mL, 7 mL, 6 mL, 5 mL,
4 mL, 3 mL, 2 mL, Class A borosilicate glass.
9.7 Pipettes. Graduated 10 mL, Class A Borosilicate glass.
9.8 Pipette. Automatic dispensing with accuracy of 0.1 mL or better and repeatability of 20 pL
(Grumman Automatic Dispensing Pipet, model ADP-30DT, or equivalent).
10. Reagents
10.1 Hydrochloric Acid. Ultrex grade (12.12 M) (Baker 1-4800) for preparing standards.
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10.2 Nitric Acid. ACS reagent grade, concentrated (16 M) for preparing 20% v/v nitric acid, to clean
labware only (Fisher A-200). Acid is not for sample preparation; it contains excessive metals. (Fisher
A-200).
10.3 Nitric Acid. Ultrex grade (15.95 M) (Baker 1-4801) for preparing standards.
10.4 Stock Calibration Standards. Multi-element concentrated calibration standards are obtained
commercially (Spex Industries). When properly diluted, these produce the working standards described
m Section 12.1. (Alternatively, single-element stock standards, prepared as directed in Appendix A, may
be used to produce the working standards).
10.5 High Quality Control (QC) Solution. A multi-element solution of 48 metals at approximately
80% the concentration of working standards. It is prepared from single element master stock standards
described in Appendix A, according to instructions in Section 12.1. This solution may be obtained
commercially if the source is different from the source for stock calibration standards.
10.6 Low Quality Control Solution. A dilution of one part high QC solution and four parts Standard
No. 1.
10.7 Standard No. 1. The acid matrix blank solution (no metals) used as the zero point during
instrument standardization.
10.8 Compressed Argon in Cylinders and Liquid Argon in Tanks, Purity 99.95%. Best source.
10.9 ASTM Type II water (ASTMD1193). Best source.
11. Analysis
11.1 Chemical Preparations
11.1.1 All labware should be scrupulously cleaned. The following procedure is recommended: Wash
with laboratory detergent or ultrasonic for 30 min with laboratory detergent. Rinse and soak a minimum
of 4 h in 20% V/V nitric acid. Rinse 3 times with deionized, distilled water, and oven dry.
[Mote; Nitric and hydrochloric add fumes are toxic. Prepare in a well-ventilated fume hood. Mixing
results in an exothermic reaction. Stir slowly.]
11.1.2 Prepare a 1.34 M HC1 Solution. Add about 250 mL of deionized, distilled water to a clean
500-mL volumetric flask. Add 55.48 mL of Ultrex-grade hydrochloric acid (12.12 M). Dilute to
500 mL with deionized, distilled water. Shake and store in a 500-mL Teflon® bottle.
11.1.3 Prepare a Working Standard No. 1 (EPA 1). This acid matrix blank (no metals) solution is
used as the zero point during instrument standardization. Add about 500 mL of deionized, distilled water
to a clean 1-L volumetric flask. Add 55.2 mL of Ultrexgrade hydrochloric acid (12.12 M) and 19.5 mL
of Ultrex-grade nitric acid (15.95 M). Dilute to 1 L with deionized, distilled water. Shake and store in
a 1-L Teflon* bottle.
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Chapter IO-3 Method IO-3.4
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11.1.4 Prepare a Working Standard No. 2 (EPA 2). This standard is prepared from the stock
calibration standard designated EPA NC-2 by the supplier (Spex Industries). Composition and
concentration of the stock and the diluted working standard are given in Table 5A. Add about 50 mL
of deionized distilled water to a clean 100-mL volumetric flask. Add 5.52 mL of Ultrex-grade
hydrochloric acid (12.12 M), 1.85 mL of Ultrex-grade nitric acid (15.95 M), and 5.0 mL of the stock
EPA NC-2 standard. Dilute to volume with deionized, distilled water. Shake thoroughly and transfer
to a 100-mL Teflon® bottle. Fresh working standards should be prepared at least once every 2 weeks.
Alternatively, Working Standard No. 2 may be prepared from in-house, single-element stock standards
described in Appendix A. The elements, acids, and aliquots required to prepare a 500-mL volume are
listed in Table 5B.
11.1.5 Prepare a Working Standard No. 3 (EPA 3). This standard is prepared from the stock
calibration standard designated EPA NC-3 by the supplier. Composition and concentration of the stock
and the diluted working standards are shown in Table 6A. Add about 50 mL of deionized distilled water
to a clean 100-mL volumetric flask. Add 4.52 mL of Ultrexgrade hydrochloric acid (12.12 M), 1.95 mL
of Ultrex-grade nitric acid (15.95 M), and 5.0 mL of the stock EPA NC-3 standard. Dilute to volume
with deionized distilled water. Shake thoroughly and transfer to a 100-mL Teflon® bottle. Alternatively,
Working Standard No. 3 may be prepared from in-house single-element stock standards described in
Appendix A. The elements, acids, and aliquots required to prepare a 5OO-mL volume are listed in
Table 6B.
11.1.6 Prepare a Working Standard No. 4 (EPA 4). This standard is prepared from the stock
calibration standards designated EPA NC-4A and EPA NC-4B by the supplier. Compositions and
concentrations of the stocks and the diluted working standard are shown hi Table 7A. Add about 50 mL
of deionized, distilled water to a clean 100-mL volumetric flask. Add 5.52 mL of Ultrex-grade
hydrochloric acid (12.12 M), 1.70 mL of Ultrex-grade nitric acid (15.95 M), 5.0 mL of the stock EPA
NC-4A standard, and 5.0 mL of the stock EPA NC-4B standard. Dilute to volume with deionized
distilled water. Shake thoroughly and transfer to a 100-mL Teflon® bottle. Alternately, Working
Standard No. 4 may be prepared from in-house, single-element stock standards described in Appendix A.
The elements, acids, and aliquots required to prepare a 500-mL volume are listed in Table 7B.
11.1.7 Prepare a Working Standard No. 5 (EPA 5). This standard is prepared from the stock
calibration standards designated EPA NC-SA and EPA NC-SB by the supplier. Composition and
concentration of the stocks and the diluted working standard are shown in Table 8A. Add about 50 mL
of deionized, distilled water to a clean 100-mL volumetric flask. Add 4.52 mL of Ultrex-grade
hydrochloric acid (12.12 M), 1.95 mL of Ultrex-grade nitric acid (15.95), 5.0 mL of the stock EPA
NC-SA standard, and 5.0 mL of the stock EPA NC-SB standard. Shake thoroughly and transfer to a
100-mL Teflon bottle. Alternatively, Working Standard No. 5 may be prepared from in-house,
single-element stock standards described in Appendix A. The elements, acids, aliquots to prepare a 500-
mL volume are listed in Table 8B.
11.1.8 Prepare a High Quality Control (QC) Solution. This solution is prepared by adding about 500
mL of working Standard No. 1 (EPA 1) to a clean 1-L flask. Add 32 mL of 1.34 M Ultrex-grade
hydrochloric acid prepared as directed in Section 12.1.4. Refer to Table 9 and pipette indicated aliquots
of the single-element stock standards described in Appendix A into the same flask. Swirl the flask after
each addition. Dilute to 1 L with additional working Standard No. 1. Shake thoroughly and transfer to
a 1-L Teflon® bottle.
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Method IO-3.4 Chapter IO-3
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Niobium, Tantalum, and Tungsten slowly precipitate from this solution. A faint precipitate is
observed in about 1 month. If these elements are analytically important, afresh solution of a smaller
quantity should be prepared.]
11.1.9 Prepare a Low Quality Control Solution. This solutions is prepared by dilution of the high
QC solution. Add about 200 mL of working Standard No. 1 (EPA 1) to a clean 500-mL volumetric
flask. Pipette a 125-mL aliquot of the high QC solution into the flask. Dilute to volume with additional
working Standard No. 1. Shake thoroughly and transfer to a 500-mL Teflon bottle.
11.1.10 Prepare a Reagent Blanks. Reagent blanks are not prepared separately. Choose a centrifuge
tube with 12.0 mL of extracting acid at random from the set to be used with real samples. Due not add
a filter strip; however, subject the tube to all processing steps with the real sample set. The running
frequency of reagent blanks is about 1 for every 40 real samples.
11.2 ICP Operating Parameters
A daily log of the operating parameters should be maintained for reference. Entries are made by the
analyst of periodic intervals throughout the run. An example of one day's log, which has been typed for
clarity, is shown in Figure 3. The data in Figure 3 and the following list of parameters are examples
from the Thermo Jarrell Ash Model 975 Plasma AtomComp.
ICP HARDWARE SPECIFICATIONS
• Plasma power 1 . 1 kW forward automatic control
1 1 W reflected (minimum possible)
• Argon coolant flow 18 1/min liquid argon source
• Argon nebulizer flow 16 psi (approx. 700 mL/min)
• Sample uptake Avg. 1.85 mL/min
• Observation Zone Centered 16 mm above the load coil
• Sample preflush time 45 s; preburn, 1 s
• Exposure 10 s
* H2O Post Flush 10 s then proceed to next sample
• Slits 25-jwn entrance slit; 75-j«n exit slit
• Photomultiplier tube voltage 900 V
11.3 Instrumental Preparations
11.3.1 Calibration Curve Linearity. ICP spectrometers generally are considered to yield a linear
response over wide concentration ranges; however, investigation for linearity for elements expected to
exceed concentrations of about 25 mg/L may be necessary. Linearity may vary among manufacturers
and according to perating parameters. The method and conditions described in this procedure have
imposed the following limitations:
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Chapter IO-3 Method IO-3.4
Chemical Analysis ^ ICP Methodology
• Ca response is linear to 40 mg/L, becoming non-linear.
• Cr saturates the electronics at 50 mg/L.
• Cu saturates the electronics at 40 mg/L.
• Fe saturates the electronics at 230 mg/L.
• Mg response is curvilinear to 40 mg/L, becoming unuseable.
• Na response is curvilinear to 80 mg/L, becoming unuseable.
The curvilinear nature of Mg and Na responses below the levels specified were made acceptable by
programming the ICP computer with segmented calibration curves as described in the manufacturer's
instructions.
11.3.2 Spectral Interferences. Section 8 described briefly spectral interferences. A thorough
determination of spectral interferences is a lengthy, time-consuming study in itself. The following are
some of the factors influencing the presence or absence and magnitude of interferences:
• Wavelength of lines being read.
• Expected concentrations of the elements involved.
« Quality and the stability of the system optics (i.e., minimal deterioration with time).
• Quality and stability of photo multiplier tubes and electronics.
• Purity of chemicals in use.
A thorough study of interferences has been conducted by EPA in the development of this method and
have been addressed in the data processing program listed in Table 10.
11.3.3 Matrix Interferences. Matrix interferences depend on the types and quantities of acids used;
element emission lines may be enhanced or depressed. These interferences may be circumvented by
careful matrix matching of standards, QC solutions, and samples. Careful matches should be made in
the use of this procedure.
11.4 Sample Receipt in the Laboratory
11.4.1 The sample should be received from the extraction laboratory in a 10-mL flask, diluted to the
mark, as documented in Inorganic Compendium Method IO-3.1.
11.4.2 No additional preservation is needed at this time. Sample is ready for ICP analysis.
11.5 ICP Operation
[Note: Because of the differences between various makes and models of satisfactory instruments, no
detailed operating instructions can be provided. Instead, the analyst should follow the instructions
provided by the manufacturer of the particular instrument. The following step-by-step procedures, used
with the JarrellAsh Model 975 Plasma AtomComp configured as described in Section 9.2.9, are provided
as guidance to be modified as necessary for the specific instrument used.]
11.5.1 Start and allow the instrument at least 45 min for warmup.
11.5.2 Profile following manufacturer's directions. Run 12 warmup burns of old high QC solution
to exercise the photomultiplier tubes.
11.5.3 Standardize by opening the standardization buffers with a J command on the CRT operating
off-line from the PDP-11/34. Flush for 2 min with the first working standard. Make two exposures,
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print the average ratio on the teletype, and identify the standard when queried. Repeat for all five
working standards. Complete with an S command and answer the query "Enter LCN" with a carriage
return (RTN). Calibration data are not stored in the PDP-11.
11.5.4 Go on-line to the PDP-11 by typing "RUN JA" and answer PDP-11 queries to identify the
operator, data storage, and operating condition codes.
11.5.5 The PDP-11 will automatically acquire gains and offsets (slopes and X-intercepts of the
calibration curve) determined by the ICP standardization. Values falling outside a previously determined
bandwidth will be reported by the computer. When this occurs, corrective action must be taken. Gain
and offset values are element-specific.
11.5.6 Measure the sample-pump uptake rate which should be approximately 1.8 mL/min.
11.5.7 Select a QC solution for analysis. On the CRT, enter RTN "QC" RTN "21", RTN for high
QC, or "QC11 RTN "22", RTN for low QC. When "DSC" appears on CRT, type "HIQC" or "LOQC",
as applicable, followed by its prep date and RTN. The number "1.0" will appear twice, indicating the
multiplication and dilution factors have been set to 1.0. This step is followed by the query "OK?"
11.5.8 Begin pumping the QC solution selected in Section 11.5.7 from an aliquot. Start the
stopwatch when the leading edge of the solution has just entered the nebulizer. Time for 45 s and press
RTN on the CRT to begin the exposure. The end is signaled by the CRT bell. Transfer the pickup tube
to deionized distilled water.
11.5.9 When the PDP-11 has acquired the data, it will query "QC SMP:." Type RTN, "STD," RTN
"21," RTN to identify the zero standard (Working Standard No. 1; see Section 11.1). After "DCS:" As
in Section 11.5.7, the multiplication and dilution factors will default to 1.0, and the query "OK?" will
appear.
11.5.10 Begin pumping from an aliquot of the zero standard and time for 45 s, as in Section 11.5.8.
Start the exposure with RTN on the CRT. At the bell, return the pickup to deionized, distilled water.
11.5.11 When the PDP-11 has acquired the data, it will query "STD SMP:." Type "1," RTN, RTN,
and it will query "OK?" Type "NO," RTN and the cursor will move to the left end of the line.
11.5.12 Select the first sample. On the CRT, enter the Project I.D. from the label. Press RTN.
Type numerical sample number and RTN. After "DCS:," type the four letter I.D. code and RTN. The
computer next queries "MLT:" (for multiplication factor); enter "360", RTN.. After "DIL:" (for dilution
factor), enter "1," RTN. The computer then asks "OK?"
11.5.13 Begin pumping the sample from the sample bottle and time for 45 s before pressing RTN.
At the bell, return the pickup to deionized, distilled water and select the next sample.
11.5.14 Enter second sample by typing the sample number, RTN, 4-letter I.D., RTN, and another
RTN to begin the exposure.
11.5.15 Present 8 samples to the instrument.
11.5.16 Challenge the instrument with the QC solution that was not selected in Section 11.3.7.
Repeat CRT entries and procedure in Sections 11.5.7 and 11.5.8.
11.5.17 Resume sample analysis. Repeat Sections 11.5.11 through 11.5.13.
11.5.18 Analyze nine samples.
11.5.19 Return to Section 11.5.6 and repeat through Section 11.5.17.
11.5.20 End the analytical session after about 3 to 3.5 h. Type "-1," RTN. The computer will query
"DO YOU WISH TO SAVE THIS SESSION'S DATA?" Type "YES," RTN. The computer will back
up the data and issue instructions. This terminates the RUN JA program.
11.5.21 Usually two sessions per day are attempted. Repeat Sections 11.5.2 through 11.5.20 for the
second session.
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11.5.22 Instrument operating parameters are recorded before and after every 20 burns. A typical
day's record is shown in Figure 3.
11.5.23 With minimal experience, the instrument operator will be able to compress the above steps
(i.e., process more than one sample at a time by overlapping the steps required for the different samples).
12. Data Processing
12.1 Filter Blanks and Discrimination Limit
Since individual blanks are not available from each filter used for sampling, the mean unexposed filter
value is subtracted from the result for each exposed sample to obtain the best estimate of each element
in the filter particulate material. A discrimination limit must be defined so that possible contributions
from an individual filter are not falsely reported as being from the particulate material. Calculate the
filter batch mean, Fm, and the standard deviation of the Fm values for each filter. If Fm is greater than
the instrumental detection limit, then Fm must be subtracted from the total elemental content for each
particulate bearing filter when the net metal in the particulate material is calculated. Determine the
smallest atmospheric concentration of the element that can be reliably distinguished from the filter's
contribution by multiplying the standard deviation for the filter batch by 3.3 and dividing by the average
volume of air sampled, usually 1700 m3. The resulting value will be the discrimination limit for that
element.
12.2 Metal Concentration in Filter
12.2.1 Calculate the air volume sampled, corrected to EPA-reference conditions:
where:
Vstd = volume of ambient air sampled at EPA-reference conditions, m3.
Vg = volume of ambient air pulled through the sampler, m3.
Tstd = absolute EPA-reference temperature, 298 °K.
Tm = average ambient temperature, °K.
Pbar = barometric pressure during sampling measurement condition, mmHg.
Pstd = EPA-reference barometric pressure, 760 mmHg.
12.2.2 Metal concentration in the air sample can then be calculated as follows:
C = Gig metal/mL)(40 mL/strip)(9) - Fm]/Vstd
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.4-13
-------
Method 10-3.4 ChaPter I0:3
ICP Methodology Chemical Analysis
where:
•3
C = concentration, jig metal/m .
Hg metal/mL = metal concentration determined from Section 11.5.
40 mL/strip = total sample volume, mL.
Useable filter area T2Q cm x 23 cm (8" x 9 "VI
Exposed area of one strip [2.5 cm x 20 cm (1" x 8")]
Fm = average concentration of blank filters, jig.
Vstd = standard air volume pulled through filter, std m3, (25°C and 760 mmHg).
12.3 Data and Record Keeping
12.3.1 General Information. The PDP-8 of the Thermo Jarrell Ash ICP spectrometer outputs
elemental concentrations in micrograms per milliliter to the PDP-11 for storage and data analysis following
each sample analysis. Project analysis periods may last from several days to a month or more, depending
on the number of samples to analyze. Virtually all computations are performed by programs available
on the PDP-11. The following sections describe the various check samples and solutions analyzed to
provide results against which to judge the validity of the real sample results. Anomalous data are studied
for occurrence patterns or related events. Historical data, past experience, and additional statistical tests,
as needed, contribute to the decision-making process. Interactive computer commands and sample
printouts are supplied that enable the transmittal process to be performed, producing the data necessary
for the validation procedures described in the remainder of this section.
12.3.2 Standard No. 1. All determinations of Standard No. 1 made during the analysis period are
retrieved by the PDP-11 and the mean and standard deviation computed for each element. The latter is
multiplied by 3.3 to determine the instrumental detection limit for each element. The detection limits are
then compared with previous values to evaluate the instrument performance.
12.3.3 Solutions. The PDP-11 is used to compute the mean, standard deviation, and coefficient of
variation for each element, with the high and low QC solutions each serving as an individual set.
Recoveries are computed from these data by hand, and all results are examined and compared with
previous results. Recoveries of reportable elements are usually 97 to 103 %
12.3.4 Blank Filter Analysis Results. Blank filter strips are analyzed at random during the analysis
period. The PDP-11 uses these data to produce files of mean blank values and discrimination limits for
each element. These values should agree with values obtained during acceptance testing.
12.3.5 Sample-Replicate Data. Throughout an analysis period, blind replicates are interspersed with
the real samples. Following analysis, the identities of the blinds are disclosed, and the PDP-11 compares
the sample and replicate data. Typical precision values for some elements are shown in Table 3.
12.3.6 Quality Assurance Division Quality Control Strips. Single or multielement-spiked 1" x 8"
strips must be analyzed at least once a day.
12.3.7 Operating Parameters. A daily instrument operating parameters log should be maintained.
Such a record is invaluable for verifying past instrument performance if data are questioned and also
potentially useful in investigating long-term Instrument drift.
Page 3.4-14 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.4
Chemical Analysis ICP Methodology
13. Quality Assurance (QA)
13.1 Instrumental Tuning and Standardization
13.1.1 The instrument must be tuned by the manufacturer at installation. However, the element lines
should be checked periodically to determine if they have maintained their positions relative to the mercury
profile line. Follow the manufacturer's instructions.
13.1.2 The Thermo Jarrell Ash Company published directions for performing instrument diagnostic
checks and pertinent acceptable data limits (Ward, 1978, 1979 a, b, 1980 a, b). Diagnostic checks should
be run periodically at a frequency dictated by the "goodness" of instrumental QC checks.
13.1.3 The instrument does not require an initial calibration except as noted in Section 11.3. Daily
standardization is described in Section 11.5.
13.2 Calibration For Quantitative Analysis
See Sections 11.3 and 11.5.
13.3 Daily QA Check and Analytical Run Sequence
Data validation steps described in this section are primarily instrumental and do not guarantee extraction
efficiency.
13.3.1 Real-Time Judgments: Standards, Gains, Offsets. This system requires virtually no data
computations by the operator. However, the operator is required at several points to judge, based on
historical experience, the validity of numbers generated and to decide whether to continue or stop.
During the standardization, the operator must observe element response to determine if values are normal.
The operator must watch for computer-generated messages reporting gains or offsets that exceed the
tolerance limits. Proper corrective action is based on operator experience and is discussed in
Section 14.5.
13.3.2 QC Solutions. Two QC solutions are analyzed alternately every tenth burn. Each of these
two solutions contain all elements observed by the spectrometer. The PDP-11 stores expected values and
a bandwidth determined by experience and makes the relevant comparison immediately upon receipt of
the QC data. Any out-of-control response is immediately indicated on the CRT display. If all values are
within the tolerance bank, the computer simply calls for the next sample. If some elements are out of
control, the operator must use judgment to determine a course of action. If nearly all elements are out
of control, the cause must be located. Usually this condition is caused by a partially plugged nebulizer.
Unreported elements slightly out of control are usually ignored. When sources of error have been found
and corrected, the instrument is either rechallenged with the QC solution or restandardized, and the 10
samples preceding the error are rerun. The original 10 sample analyses are later deleted from the PDP-11
by an editing routine.
13.3.3 General Quality Control. The general requirements from analysis using this method are
summarized in Table 11.
13.4 Corrective Actions
13.4.1 The plasma must operate in a stable mode with a uniform sample feed rate. Failure to
reproduce standards' responses or QC values usually is caused by a partially or totally plugged nebulizer.
This condition may be verified by observing a decrease in the pump rate or the absence of a fog in the
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.4-15
-------
Method IO-3.4 Chapter IO-3
ICP Methodology Chemical Analysis
nebulizer spray chamber. A similar effect will be observed if the argon supply pressure or the RF power
should change. Experience with the sample pump and the RF power supply has been excellent, and both
appear to be very stable electronically.
13.4.2 Intermittent failure of QC solutions to fall within the tolerance band may be due to an
intermittent failure in a spectrometer circuit or to a broken nebulizer needle. Both are difficult to detect
without extensive testing or dismantling of equipment. Leaks hi the argon supply lines are also likely
causes of such problems. Leaks in the ground-glass joints of the torch-spray chamber can be eliminated
by the light use of a good grade stopcock grease (not silicone-base) (see Section 13.5).
13.4.3 One intended purpose of the repeated analysis of QC solutions was to detect and correct
instrument drift occurring within any 1 day. Experience has shown that drift is not a problem when the
instrument is standardized twice daily. When drift has been detected, it has been attributed to thermal
drift and corrected by repro filing (i.e., adjusting the optical alignment). The instrument must be
restandardized after profiling.
13.4.4 Long-term drift is more difficult to detect. A gradual increase in the gains of short-
wavelength elements over a period of weeks or months is probably due to degradation of mirror coatings.
Washing the mirrors may help in the short term, but usually they must be replaced. Mirrors may be
ruined if washed improperly; manufacturer-approved procedures should be followed. Gradual degrada-
tion of electronic circuits will also cause long-term drift.
13,5 Routine Maintenance
13.5.1 The torch and spray chambers occasionally must be cleaned. Frequency of cleaning must be
determined through experience, as a schedule and criteria have not been established. Ultrasonic the
chambers in a hot detergent for at least 30 min, soak in aqua regia overnight, and rinse in deionized,
distilled water.
fftote: Aqua regia is a strong oxidizing agent. Wear protective clothing and a face shield. J
13.5.2 The ground-glass joints of the torch-spray chamber should be greased with a good grade of
non-silicone base stopcock grease. After reassembly, the torch must be optimized for maximum flux
throughput according to rrinufacturer's instructions.
13.5.3 Should the plasma be extinguished during an analysis session, the session must be ended.
Restandardization is necessary after the plasma is reignited. Restandardization must be delayed until the
reflected power has been at a minimum for approximately 10 min.
14. Method Safety
The toxicity or carcinogenicity of each reagent used in this method has not been defined precisely;
however, each chemical compound should be treated as a potential health hazard. The laboratory is
responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of
the chemicals specified in this method. A reference file of material handling data sheets should be made
available to all personnel involved in the chemical analysis.
Page 3.4-16 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.4
Chemical Analysis ICP Methodology
15. References
1. "Standard Operating Procedures for the ICP-DES Determination of Trace Elements in Suspended
Paniculate Matter Collected on Glass-Fiber Filters," EMSL/RTP-SOP-EMO-002, Revision, October,
1983.
2. "Reference Method for the Determination of Suspended Particulates in the Atmosphere (High Volume
Method)," Code of Federal Regulations, Title 40, Part 50, Appendix B, pp. 12-16 (July 1, 1975).
3. "Reference Method for the Determination of Lead in Suspended Particulate Matter Collected from
Ambient Air.," Federal Register 43 (194): 46262-3, 1978.
4. Rhodes, R. C., 1981, "Special Extractability Study of Whatman and Schleicher and Schuell Hi-Vol
Filters," Memo to file, August 5, 1981, Quality Assurance Division, Environmental Monitoring
Systems Laboratory, U. S. Environmental Protection Agency, Research Triangle Park NC.
5. Ward, A. F., The Jarren-Ash Plasma Newsletter, Volumes I, II, and III.
6. Nygaard, D., and Sot, J. J., "Determination Near the Detection Limit: A Comparison of Sequential
and Simultaneous Plasma Emission Spectrometers," Spectroscopy, Vol. 3(4).
7. "Simplex Optimization of Multielement Ultrasonic Extraction of Atmospheric Particulates," Harper,
et. al., Analytical Chemistry, Vol. 55(9), August 1983.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.4-17
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 1. CONCENTRATIONS OF THE MOST CONCENTRATED
WORKING STANDARD,1 TYPICAL ICP CALIBRATING SENSITIVITIES
AND TYPICAL INSTRUMENTAL DETECTION LIMITS2
Element
Al
As
Au
B
Ba
Be
Bi
Ca
Cd
Ce
Co
Cr
Cu
Fe
Ge
Ho
• •
In
K
La
Li
Mg
Mn
Mo
Na
Mb
Ni
P
Pb
Pd
Pt
Re
Rh
Ru
Sb
Sc
Si
Sm
Sn
Sr
Ta
Te
Ti
Tl
V
W
Y
Zn
Zr
Most Cone. Working
Std., mg/L
50.0
5.0
5.0
1--.0
10.0
2.0
10.0
40.0
4.0
5.0
5.0
4.0
20.0
50.0
5.0
5.0
5.0
20.0
2.0
2.0
40.0
10.0
5.0
80.0
2.0
5.0
20.0
25.0
5.0
5.0
10.0
5.0
10.0
5.0
i-.O
50.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
20.0
5.0
Calibrating
Sensitivity, counts//*g
metal
4,887
5,063
11,683
42,892
13,430
57,457
467
52,787
37,438
13,859
2,787
76,772
159,213
16,985
1,645
9,031
520
253
44,468
12,500
70,951
108,751
5,266
186
59,859
4,306
2,941
10,324
7,996
847
288
32,421
5,227
4,246
930
9,152
52,532
469
55,091
21,030
4,676
58,777
3,063
107,250
1,170
35,800
478
18,010
Detection-*
Limit
mg/L
0.061
0.025
0.009
0.030
0.003
0.002
1.030
0.103
0.005
0.048
0.015
0.012
0.010
0.034
0.079
0.055
0.081
0.205
0.007
0.003
0.024
0.004
0.009
inoperative
0.11
0.014
0.104
0.032
0.130
0.107
0.150
2.000
0.187
0.025
0.156
0.172
0.024
0.042
0.001
0.145
0.021
0.003
0.152
0.007
0.057
0.004
0.120
0.008
nK/m3
13.5
5.5
1.9
6.6
0.7
0.4
226.6
22.7
1.1
10.6
3.3
2.6
2.2
7.5
17.5 •
12.1
18.5
45.1
1.5
0.7
5.3
0.9
1.9
inoperative
2.4
3.1
22.9
7.0
7.0
23.5
33.0
440.0
41.1
5.5
34.3
37.8
5.4
9.2
0.2
52.1
4.6
0.7
33.4
1.5
12.5
0.9
26.4
1.8
*The lease concentrated working standard contains no metals. . »,.»,„
2Data source is 48 determinations of standard no.l made from 01/26/83-03/22/83 during analysis of 1982 NAMS
3Based*upon sampling rate of 1.13 m3/min for 24-hr for a total sample volume of 1627.2 m3; factor of 9 for
partial filter analysis; digestion of 0.040 L/filter.
Page 3.4-18
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 2. RECOVERIES FROM SPIKED STRIPS1 AND FROM NIST SRM 1648
: Element
Spiked Strips1
As
Co
Cu
Fe
Mn
Ni
Pb
Sr
V
Zn
NIST SRM 1648
Ba
Be
Cd
Cu
Fe
Mn
Mo
Ni
Pb
V
Zn
% Recovery
96.5
95.5
76.1
98.3
96.9
96.4
99.1
96.4
94.0
. 89.4
80
not listed by NIST
114
100
68
88
not listed by NIST
90
95
79
97
%RSD
2.7
3.4
4.3
3.7
4.0
3.9
1.9
4.4
2.1
6.2
0.8
8.5
1.4
1.4
1.6
9.0
1.1
1.9
3.8
'•Recovery values based on X-ray florescence analytical values taken as "true"
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-19
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 3. TYPICAL PRECISION, BIAS, AND CORRELATION COEFFICIENTS
OBTAINED BY SAMPLE/REPLICATE PAIR ANALYSIS1
Element
B
Ba
Cd
Cu
Fe
Mn
Ni
Pb
Sb
Sr
V
Zn
Pairs Found
32
32
17
32
32
32
14
31
4
32
25
31
Coefficient
Variation (%>
10
9
11
4
8
21
10
3
5
7
6
16
Coefficient
Bias (%)
1.0
0
0
-1.0
1.0
5.0
-2.0
0.0
3.0
1.0
-1.0
-3.0
Coefficient
0.95
1.0
1.0
1.0
0.99
0.99
1.0
1.0
0.99
1.0
LO
0.94
the analysis of 32 sample/replicate pairs of 1982 NAMS filters from 01/26/83 - 03/22/83. Because
these data were obtained from real samples, there was no control over the actual concentrations. Elements
displaying a. large coefficient of variation tended to have mean concentrations in the lower end of the quantifiable
range.
Page 3.4-20
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 4. ICP SPECTROMETER ELEMENTS WITH WAVELENGTHS
Element
Al
As
Au
B
Ba
Be
Bi
Ca
Cd
Ce
Co
Cr
Cu
Fe
Ge
Hg
In
K
La
Li
Mg
Mn
Mo
Na
Wavelength.
308.22
193.76
242.80
249.77
493.41
313.04
195.33
396.85
226.50
446.02
228.62
357.87
324.75
259.94
199.82
253.65
230.69
766.49
379.48
670.78
279.55
257.61
202.03
589.00
, Element V
Nb
Ni
P
Pb
Pd
Pt
Re
Rh
Ru
Sb
Se
Si
Sm
Sn
Sr
Ta
Te
Ti
Tl
V
W
Y
Zn
Zr
Wavelength .
316.34
231.60
214.91
220.35
363.47
265.95
209.24
343.49
297.66
206.84
196.09
288.16
442.43
189.99
407.77
240,06
214.28
334.90
351.92
292.40
202.99
371.03
206.19
339.20
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-21
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 5A PREPARATION OF WORKING STANDARD NO. 2 (EPA 2)
FROM COMMERCIALLY PREPARED MULTIELEMENT STOCK
Component
D.L water
HC1, 12.12M
HNO3, 15.95 M
EPA NC-2 containing
Ca
Cd
Co
Cu
Mg
Mn
Pb
Zn
D.I. water
—
Stock Cone.,
mg/L
„
800
80
100
400
800
200
500
400
—
• •
Aliquot,
mL
ca.50
5.52
1.85
5f\
.0
—
—
—
—
—
—
—
—
dilute to 100
Working Std.
Cone,, mg/L
—
0.67 M
0.33 M
40
4
5
20
40
1 f\
10
25
20
~
TABLE 5B PREPARATION OF WORKING STANDARD NO. 2 (EPA 2)
FROM SINGLE-ELEMENT, IN-HOUSE PREPARED STOCKS
Element
Std. No.l
HCi, 1.34M
Ca
Cd
Co
Cu
Mg
Mn
Pb
Zn
Std. No. 1 (mg/1)
Stock Cone.,
mg/L
—
4,000
400
500
2,000
4,000
1,000
2,500
2,000
—
Aliquot,
mL
ca.200
—
5
5
5
5
5
5
5
5
dilute to 500
v Working Std.
Cone.; mg/L •
—
40
4
5
20
40
1 f\
10
25
20
Page 3.4-22
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 6A. PREPARATION OF WORKING STANDARD NO. 3 (EPA 3)
FROM COMMERCIALLY PREPARED MULTIELEMENT STOCK
Component •;•_••.• \
D.I. water
HCI, 12.12 M
HN03, 15.95 M
EPA NC-3 containing
Al
Ba
Be
Fe
Li
Mo
Na
Ni
Sb
Sn
Sr
Ti
Tl
V
Zr
D.I. water
Stock Cone., '"•'•'.",-
"mg/L '-'.:;V --.•..-;."••
—
4.52
5.0
1000
200
40
1000
40
100
1600
100
100
100
100
100
100
100
100
—
Aliquot,
mL
ca50
0.67 M
1.95
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
dilute to 100
Working Std.
Cone., mg/L
«
0.33 M
50
10
2
50
2
5
80
5
5
5
5
5
5
5
5
—
TABLE 6B. PREPARATION OF WORKING STANDARD NO. 3 (EPA 3)
FROM SINGLE-ELEMENT, IN-HOUSE PREPARED STOCKS
Element
Std. No. 1
Al
Ba
Be
Fe
Li
Mo
Na
Ni
Sb
Sn
Sr
Ti
Tl
V
Zr
Std. No. 1
Stock Cone;, mg/L • ;
—
5,000
1,000
500
5,000
500
500
10,000
500
500
500
500
500
500
500
500
—
Aliquot, mL
ca.200
5
5
2
5
2
5
4
5
5
5
5
5
5
5
5
dilute to 500
Working Std.
Conc;;*mg/L
_
50
10
2
50
2
5
80
5
5
5
5
5
5
5
5
—
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-23
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 7A. PREPARATION OF WORKING STANDARD NO. 4 (EPA 4)
FROM COMMERCIALLY PREPARED MULTIELEMENT STOCK
Component
D.I. water
HC1, 12.12M
HNO3, 15.95 M
EPA NC-4A
containing
Cr
Se
Te
EPA NC4B
containing
As
B
Ge
P
Si
D.I. water
Stock Cone.,
mg/L
—
5.0
80
100
100
100
200
100
400
1000
—
Aliquot^
mL
ea50
5.52
1.70
5.0
—
—
—
5.0
—
—
—
—
—
dilute to 100
Working
Std. Cone.,
mg/L
— _
0.67 M
0.33 M
—
4
5
5
5
10
5
20 '
50
—
TABLE 7B. PREPARATION OF WORKING STANDARD NO. 4 (EPA 4)
FROM SINGLE-ELEMENT, IN-HOUSE PREPARED STOCKS
Element
Std. No. 1
As
B
Cr
Ge
P
Se
Si
Te
Std. No. 1
Stock Cone., mg/L
—
500
1,000
500
500
2,000
500
5,000
500
—
Aliquot, mL
ca. 200
5
5
4
5
5
5
5
5
dilute to 500
Working Std.
Cone., mg/L
5
10
4
5
20
5
50
5
—
Page 3.4-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 8A. PREPARATION OF WORKING STANDARD NO. 5 (EPA 5)
FROM COMMERCIALLY PREPARED MULTIELEMENT STOCK
Component ;
D.I. water
HC1, 12.12M
HNO3, 15.95 M
NC-5A containing
Nb
Ta
W
NC-58 containing
Au
Bi
Ce
Hg
In
K
La
Pd
Pt
Re
Rh
Ru
Sm
Y
D.I. water
Stock Cone.,
mg/L
—
5.0
40
100
100
5.0
100
200
100
100
100
400
40
100
100
200
100
200
100
100
—
Aliquot,
mL
ca. 50
4.52
1.95
—
—
—
—
—
—
—
— .
—
—
—
—
—
—
—
—
—
—
dilute to 100
Working Std.
Cone., mg/L
0.67 M
0.33 M
2
5
5
5
10
5
5
5
20
2
5
5
10
5
10
5
5
—
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-25
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 8B. PREPARATION OF WORKING STANDARD NO. 5 (EPA 5)
FROM SINGLE-ELEMENT, IN-HOUSE PREPARED STOCKS
Element
Std. No. 1
HCI, 1.34M
Au
Bi
Ce
Hg
In
K
La
Nb
Pd
Pt
Re
Rh
Ru
Sm
Ta
W
Y
Std. No. 1
Stock Cone.,
mg/L
—
—
500
1,000
500
500
500
2,000
500
500
500
- 500
1,000
500
1,000
500
500
500
500
—
Aliquot,
mL
ca.200
15
1 5
5
5
: 5
: 5
5
5
5
; 5
5
5
5
5
5
5
: 5
5
dilute to 500
Working Std.
Cone.,, mg/L
—
:
5
10
5
; 5
5
20
'• 2
' 2
5 '
5
10
: 5 •
10
5
5
5
5
—
Page 3.4-26
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 9. HIGH QUALITY CONTROL SOLUTIONS: ALIQUOTS FROM
SINGLE-ELEMENT STOCK STANDARDS (SEE APPENDIX A)
Element
Std. No. 1
HC1, 1.34 M
Al
As
Au
B
Ba
Be
Bi
Ca
Cd
Ce
Co
Cr
Cu
Fe
Ge
Hg
In
K
La
Li
Mg
Mn
Mo
Mixed
Cone.,
: mg/L
—
—
40
4
4
8
8
1.5
8
32
3
4
4
3
16
40
4
4
4
16
1.5
1.5
32
8
4
Stock
Aliquot,
mL
ca.400
32
8
8
8
8
8
3
8
8
6
8
8
6
8
8
8
8
8
8
3
3
8
8
8
Element
Na
Nb
Ni
P
Pb
Pd
Pt
Re
Rh
Ru
Sb
Se
Si
Sm
Sn
Sr
Ta
Te
TL
Tl
V
w
Y
Zn
Zr
Std. No. 1
Mixed
Cone.,
mg/L
60
1.5
4
16 .
20
4
4
8
.4
8
4
4
40
4
4
4
4
4
4
4
4
4
4
16
4
•
Aliquot,
mL
6
3
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
dilute to one-
liter
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-27
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
TABLE 10. CORRECTION FACTORS FOR SPECTRAL INTERFERENCES
Affected
Element
Ta
TA
Al
Al
B
Be
Be
Ce
Hg
Hg
La
La
Pb
Pd
Pd
Pd
Pt
Pt
Pt
Pt
Si
Si
Si
Te
Tl
Tl
Zn
As
As
As
Bi
Bi
Bi
Bi
Bi
Bi
Affecting
Factor
0.0166
0.0026
0.0141
0.0375
0.0181
0.0020
0.0025
0.2313
0.0574
0.0151
0.0028
0.0122
0.1104 •
0.0247
0.1649
0.0125
0.0600
0.0175
0.1300
0.0210
0.0281
0.1300
0.2495
0.0254
0.0607
0.0229
0.0132
0.0119
0.1736
0.0125
0.0083
0.0212
0.0065
0.0326
0.0155
0.0312
Affected
Element
Co
Fe
Ta
V
Zr
Nb
V
V
Co
Fe
Fe
V
Nb
Nb
Sm
Ti
Cr
Nb
Ta
V
Nb
Ta
Zr
V
Ce
Zr
Ta
Al
Pt
V
Al
Cr
Fe
La
Mg
Mn
Affecting
Element
Bi
Bi
Bi
Bi
Ge
Ge
Ge
Ge
Ge
P
P
P
P
P
P
P
Re
Re
Re
Re
Re
Re
Re
Ru
Ru
Ru
Ru
Ru
Ru
Ru
Ru
W
W
W
As
Factor
0.0268
0.0116
0.0041
0.0125
0.0071
0.0015
0.0085
0.0293
0.1489
0.0017
0.0265
0.0016
0.0032
0.0100
0.0017
0.0010
0.0240
0.0110
0.1609
1.2400
0.0556
0^0044
0,2146
0.0141
0.0843
0.0233
0.0827
0.2531
0.0364
5.5170
0.4996
0.0021
0.0039
0.0027
0.0218
Element
Rh
Se
Si
Sr
Al
Be
Mo
Nb
Ta
Al
Cu
Fe
Mg
Nb
Si
Zn
Al
B
Mn
Mo
Pd
Si
V
Fe
Mn
Mo
Nb
Ta
Ti
V
Zr
Al
Mg
Zn
Ge
Page 3.4-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
TABLE 11. REQUIRED QUALITY CONTROL REQUIREMENTS FOR ICP ANALYSIS
QC procedure
Initial calibration
Initial calibration verification
Initial calibration blank
High standard verification
Interference check standard
Continuing calibration
verification
Continuing blank verification
Method blank
Laboratory control spike
Duplicate and/or spike
duplicate
Matrix spike
Serial dilution
Sample dilution
Typical frequency
At the beginning of the
analysis
Immediately after initial
calibrations
Immediately after initial
calibration verification
Following the initial
calibration blank analysis
Following the high standard
verification, every 8 hours,
and at the end of a run
Analyzed before the first
sample, after every 10
samples, and at the end of
the run
Analyzed following each
continuing calibration
verification
1 per 20 samples, a
minimum of 1 per batch
1 per 20 samples, a
minimum of 1 per batch
1 per 10 samples per matrix
type
1 per 10 samples per matrix
type
1 per analysis per matrix
type
Dilute sample beneath the
upper calibration limit and at
least 5X the MDL
Criteria
None
90-110% of the actual
concentration
Must be less than project
detection limits
95-105% of the actual
concentration
80-120% of the actual
concentration
90-110% of the actual
concentration
Must be less than project
detection limits
Must be less than project
detection limits
80-120% recovery, with the
exception of Ag and Sb
RPD <: 20%
Percent recovery of 75-
125%
90-110% of undiluted
sample
As needed
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-29
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
induction coil
Torch
Lens
Spectrometer
and
readout
Figure I. Schematic diagram of a typical inductively coupled plasma-optical emission spectroscopy
instrument featuring parts of the instrument most important to the user.
Page 3.4-30 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.4
ICP Methodology
Computer
controlled
scanning
monochromator
Tailflama
Sample plume
Data out
Figure 2. Simultaneous or sequential multi-element determination of trace elements by ICP.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.4-31
-------
Method IO-3.4
ICP Methodology
Chapter IO-3
Chemical Analysis
JARRELL ASH PLASMA ATOHCOHP OPERATING PARAMETERS
Date: 3/11/80 Project: N82
Objective: NAHS Smples
Profile Setting: 594.4/587.7
Observation Zone: 16 nm
Time Plasma On: 0735
Settings-Auto: 5.96
ARGON Pawer
Operator: XXX
Time of Stds: 0833
Matchbox: 10.75
Tiiae ml
0830
0319
0947
1013
1046
1112
1141
1226
Sample
uptake
mln s-
2
2
2
2
2
2
2
2
End session
1259 2
1346 2
1413 2
1439 2
1505 2
1530 ^
155S 2
1632 2
End session
Profile time
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4.6
4.8
4.6
4.2
4.6
4.8
4.4
5.2
4.4
4.4
4.6
4.2
4.8
4.4
4.2
4.6
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Cool Nebul.
Rate LPH ps1
.86
.85
.86
.87
.86
.85
.86
.84
.86
.86
.86
.87
.85
.86
.87
.86
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
16
IE
16
16
16
16
16
16
16
16
16
16
16
16
16
16
Fwd. Ref.
kU V Garments
1
1
1
1
1
1
1
1
.1
.1
.1
.1
.1
.1
.1
.1
1.1
1.1
1.1
1.1
1.1
1.1
1.1
1.1
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
Heter Set Point
Micrometer Readings
Peak Location
Heter, Peak Reading
Before stds.
After 21 burns
After 41 burns
After 61 burns
After 81 burns
After 101 burns
After 121 burns
After 152 burns
Before stds.
After 21 burns
After 41 burns
After 61 burns
After 81 burns
After 101 burns
After 121 burns
After 150 burns
30? burps today
0826 1254
7A \t\
OU ou
649.1 645.2
540.0 531.0
690.0 640.1
539.4 530.0
36.0 36.2
Figure 3. Typical ICP Operating Parameters Record.
Page 3.4-32
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
EPAy625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.5
DETERMINATION OF METALS
IN AMBIENT PARTICULATE
MATTER USING
INDUCTIVELY COUPLED PLASMA/
MASS SPECTROMETRY (ICP/MS)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-3.5
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R~96/060a), which was prepared under Contract No. 68:C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Peer Reviewers
• Doug Duckworth, Martin Marietta Energy Systems, Inc. Oak Ride, TN
• David Brant, West Virginia University, Morgantown, WV
• Jiansheng Wang, Midwest Research Institute, Kansas City, MO
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
ii
-------
Method IO-3.5
Determination of Metals in Ambient Particulate Matter Using
Inductively Coupled Plasma/Mass Spectrometry (ICP/MS)
TABLE OF CONTENTS
1. Scope 3.5-1
2. Applicable Documents 3.5-2
2.1 ASTM Standards 3.5-2
2.2 Other Documents 3.5-2
3. Summary of Method 3.5-2
4. Definitions 3.5-3
4.1 Instrument Detection Limit (IDL) 3.5-3
4.2 Method Detection Limit (MDL) 3.5-3
4.3 Linear Dynamic Range (LDR) 3.5-3
4.4 Laboratory Reagent Blank (LRB) (Preparation Blank) 3.5-3
4.5 Calibration Blank 3.5-3
4.6 Internal Standard 3.5-3
4.7 Stock Standards Solutions 3.5-3
4.8 Calibration Standard (CAL) 3.5-3
4.9 Tuning Solution 3.5-3
4.10 Laboratory Fortified Blank (LFB) 3.5-4
4.11 Laboratory Fortified Sample Matrix (LFM) 3.5-4
4.12 Quality Control Sample (QCS) 3.5-4
5. Interferences 3.5-4
5.1 Isobaric Elemental Interferences '. 3.5-4
5.2 Abundance Sensitivity 3.5-4
5.3 Isobaric Polyatomic Ion Interferences 3.5-5
5.4 Physical Interferences 3.5-5
5.5 Memory Interferences 3.5-5
6. Safety 3.5-6
7. Apparatus and Equipment 3.5-6
7.1 Inductively Coupled Plasma/Mass Spectrometer (ICP/MS) 3.5-6
7.2 Labware 3.5-6
7.3 Sample Processing Equipment 3.5-7
8. Reagents and Consumable Materials 3.5-7
8.1 Reagents 3.5-7
8.2 Water 3.5-8
8.3 Standard Stock Solutions 3.5-8
8.4 Multi-Element Stock Standard Solutions 3.5-10
8.5 Internal Standards Stock Solution, 1 mL = 100 /*g 3.5-11
8.6 Blanks 3.5-11
8.7 Tuning Solution 3.5-11
8.8 Quality Control Sample (QCS) 3.5-11
8.9 Laboratory Fortified Blank (LFB) 3.5-11
9. Sample Receipt in the Laboratory 3.5-12
10. Calibration and Standardization 3.5.-12
10.1 Calibration 3.5-12
10.2 Internal Standardization 3.5-12
10.3 Instrument Performance 3.5-13
111
-------
TABLE OF CONTENTS (continued)
11. Quality Control (QC) 3.5-13
11.1 Laboratory 3.5-13
11.2 Initial Demonstration of Performance 3.5-13
11.3 Assessing Laboratory Performance—Reagent and Fortified Blanks 3.5-14
11.4 Assessing Analyte Recovery - Laboratory Fortified Sample Matrix 3.5-15
11.5 Internal Standards Responses 3.5-15
12. Procedure 3.5-16
13. Calculations 3.5-16
14. Precision and Accuracy 3.5-18
15. References 3.5-18
IV
-------
Chapter IO-3
Chemical Species Analysis
of Filter-Collected SPM
Method IO-3.5
DETERMINATION OF METALS IN AMBIENT PARTICULATE MATTER USING
INDUCTIVELY COUPLED PLASMA/MASS SPECTROMETRY
1. Scope
1.1 Suspended particulate matter (SPM) in air generally is a complex multi-phase system of all airborne
solid and low vapor pressure liquified particles having aerodynamic particles sizes from below
0.01-100 fj.m and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.2 On July 1, 1987, the U. S. Environmental Protection Agency (EPA) promulgated a new size-specific
air quality standard for ambient particulate matter. This new primary standard applies only to particles
with aerodynamic diameters < 10 ^m (PM^) and replaces the original standard for TSP. To measure
concentrations of these particles, the EPA also promulgated a new federal reference method (FRM). This
method is based on the separation and removal of non-PM^Q particles from an air sample, followed by
filtration and gravimetric analysis of PM^Q mass on the filter substrate.
1.3 The new primary standard (adopted to protect human health) limits PMjg concentrations to
150 jig/std m , averaged over a 24-h period. These smaller particles are able to reach the lower regions
of the human respiratory tract and, therefore, are responsible for most of the adverse health effects
associated with suspended particulate pollution. The secondary standard, used to assess the impact of
pollution on public welfare, has also been established at 150 /^g/std. m .
1.4 Ambient air SPM measurements are used (among other purposes) to determine whether defined
geographical areas are in attainment or non-attainment with the national ambient air quality standards
(NAAQS) for PM^Q. These measurements are obtained by the states in their state local air monitoring
station (SLAMS) networks as required under 40 CFR Part 58. Further, Appendix C of Part 58 requires
that the ambient air monitoring methods used in these EPA-required SLAMS networks must be methods
that have been designated by EPA as either reference or equivalent methods.
1.5 The procedure for analyzing the elemental metal components in ambient air particulate matter
collected on high volume filter material is described in this method. The high volume filter material may
be associated with either the TSP or PM^Q sampler, as delineated in Inorganic Compendium Method
IO-2.1.
1.6 Filters are numbered, pre-weighted, field deployed and sampled, returned to the laboratory, extracted
using microwave or hot acid, then analyzed by inductively coupled plasma/mass spectrometry (TCP/MS).
The extraction procedure is accomplished by following Inorganic Compendium Method IO-3.1. Those
metals and their associated method detection limit (MDL) applicable to this technology are listed in
Table 1.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.5-1
-------
Method IO-3.5 Chapter IO-3
ICP/MS Methodology Chemical Analysis
1.7 This method should be used by analysts experienced in the use of ICP/MS, the interpretation of
spectral and matrix interferences and procedures for their correction. A minimum of 6-months'
experience with commercial instrumentation is required.
2. Applicable Documents
2.1 ASTM Standards
* DI356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• DI357 Planning the Sampling of the Ambient Atmosphere.
• D4096 Application of the High Volume Sample Method for Collection and Mass Determination of
Airborne Particle Matter.
2.2 Other Documents
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94-038a.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b.
• Reference Method for the Determination of Particulate Matter in the Atmosphere, Code of Federal
Regulations. 40 CFR 50, Appendix J.
• Reference Method for the Determination of Suspended Particulates in the Atmosphere (High
Volume Method), Code of Federal Regulations. 40 CFR 50, Appendix B.
• Reference Method for the Determination of Lead in Suspended Particulate Matter Collected from
Ambient Air, Federal Register 43 (194): 46258-46261.
* U. S. EPA Project Summary Document (1).
• U. S. EPA Laboratory Standard Operating Procedures (2).
• Scientific Publications of Ambient Air Studies (3-14).
3. Summary of Method
3.1 The method describes the multi-element determination of trace elements by ICP/MS. Sample
material in solution is introduced by pneumatic nebulization into a radiofrequency plasma where energy
transfer processes cause desolvation, atomization, and ionization.
3.2 The ions are extracted from the plasma through a differentially pumped vacuum interface and
separated on the basis of their mass-to-charge ratio by a quadruple mass spectrometer having a minimum
resolution capability of 1 amu peak width at 5% peak height.
3.3 The ions transmitted through the quadruple are registered by a continuous dynode electron multiplier
or Faraday detector and the ion information processed by a data handling system.
Page 3.5-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.5
Chemical Analysis ICP/MS Methodology
3.4 Interferences relating to the technique (see Section 5) must be recognized and corrected for. Such
corrections must include compensation for isobaric elemental interferences and interferences from
polyatomic ions derived from the plasma gas, air, reagents, or sample matrix. Instrumental drift as well
as suppressions or enhancements of instrument response caused by the sample matrix must be corrected
for by internal standardization.
4. Definitions
[Note: Definitions used in this document are consistent with ASTM. methods. All pertinent abbreviations
and symbols are defined within Ms document at point of use.]
4.1 Instrument Detection Limit (DDL). The concentration equivalent of the analyte signal, which is
equal to three times the standard deviation of the blank signal at the selected analytical mass(es).
4.2 Method Detection Limit (MDL). The minimum concentration of an analyte that can be identified,
measured and reported with 99% confidence that the analyte concentration is greater than zero. MDLs
are intended as a guide to instrumental limits typical of a system optimized for multi-element
determinations and employing commercial instrumentation and pneumatic nebulization sample
introduction. However, actual MDLs and linear working ranges will be dependent on the sample matrix,
instrumentation and selected operating conditions.
4.3 Linear Dynamic Range (LDR). The concentration range over which the analytical working curve
remains linear.
4.4 Laboratory Reagent Blank (LRB) (Preparation Blank). An aliquot of reagent water that is treated
exactly as a sample including exposure to all labware, equipment, solvents, reagents, and internal
standards that are used with other samples. The LRB is used to determine if method analytes or other
interferences are present in the laboratory environment, the reagents or apparatus.
4.5 Calibration Blank. A volume of ASTM Type I water acidified with the same acid matrix as is
present in the calibration standards.
4.6 Internal Standard. Pure analyte(s) added to a solution in known amount(s) and used to measure
the relative responses of other method analytes that are components of the same solution. The internal
standard must be an analyte that is not a sample component.
4.7 Stock Standards Solutions. A concentrated solution containing one or more analytes prepared in
the laboratory using assayed reference compounds or purchased from a reputable commercial source.
4.8 Calibration Standard (CAL). A solution prepared from the stock standard solutions) which is used
to calibrate the instrument response with respect to analyte concentration.
4.9 Tuning Solution. A solution used to determine acceptable instrument performance prior to
calibration and sample analyses.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.5-3
-------
Method IO-3.5 Chapter IO-3
ICP/IVIS Methodology Chemical Analysis
4.10 Laboratory Fortified Blank (LFB). An aliquot of reagent water to which known quantities of the
method analytes are added in the laboratory. The LFB is analyzed exactly like a sample, and its purpose
is to determine whether method performance is within accepted control limits.
4.11 Laboratory Fortified Sample Matrix (LEM). An aliquot of an environmental sample to which
known quantities of the method analytes are added in the laboratory. The LFM is analyzed exactly like
a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical
results. The background concentrations of the analytes in the sample matrix must be determined in a
separate aliquot and the measured values in the LFM corrected for the concentrations found.
4.12 Quality Control Sample (QCS). A solution containing known concentrations of method analytes
which is used to fortify an aliquot of LRB matrix. The QCS is obtained from a source external to the
laboratory and is used to check laboratory performance.
5. Interferences
[Note: Several interference sources may cause inaccuracies in the determination of trace elements by
ICP/MSJ
5.1 Isobaric Elemental Interferences
Isobaric elemental interferences are caused by isotopes of different elements that form single- or double-
charged ions of the same nominal mass-to-charge ratio and cannot be resolved by mass spectrometer in
use. All elements determined by this method have, at a minimum, one isotope free of isobaric elemental
interference. Of the analytical isotopes recommended for use with this method, only molybdenum-98
(ruthenium) and selenium-82 (krypton) have isobaric elemental interferences. If alternative analytical
isotopes having higher natural abundance are selected to achieve greater sensitivity, an isobaric
interference may occur. All data obtained under such conditions must be corrected by measuring the
signal from another isotope of the interfering element and subtracting the appropriate signal ratio from
the isotope of interest. A record of this correction process should be included with the report of the data.
These corrections will only be as accurate as the accuracy of the isotope ratio used in the elemental
equation for data calculations. Relevant isotope ratios and instrument bias factors should be established
prior to the application of any corrections.
5.2 Abundance Sensitivity
Abundance sensitivity is a property defining the degree to which the wings of a mass peak contribute to
adjacent masses. The abundance sensitivity is affected by ion energy and quadruple operating pressure.
Wing overlap interferences may result when a small ion peak is being measured adjacent to a large one.
The potential for these interferences should be recognized and the spectrometer resolution adjusted to
minimize them.
Page 3.5-4 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3 Method IO-3.5
Chemical Analysis ICP/MS Methodology
5.3 Isobaric Polyatomic Ion Interferences
Isobaric polyatomic ion interferences are caused by ions consisting of more than one atom that have the
same nominal mass-to-charge ratio as the isotope of interest and that cannot be resolved by the mass
spectrometer in use. These ions are commonly formed in the plasma or interface system from support
gases or sample components. Most of the common interferences have been identified and are listed in
Table 2, together with the method elements affected. Such interferences must be recognized, and when
they cannot be avoided by the selection of alternative analytical isotopes, appropriate corrections must
be made to the data. Equations for the correction of data should be established at the time of the
analytical run sequence as the polyatomic ion interferences will be highly dependent on the sample matrix
and chosen instrument conditions.
5.4 Physical Interferences
Physical interferences are associated with the physical processes that govern the transport of sample into
the plasma, sample conversion processes in the plasma, and the transmission of ions through the
plasma-mass spectrometer interface. These interferences may result in differences between instrument
responses for the sample and the calibration standards. Physical interferences may occur in the transfer
of solution to the nebulizer (e.g., viscosity effects), at the point of aerosol formation and transport to the
plasma (e.g., surface tension), or during excitation and ionization processes within the plasma itself.
High levels of dissolved solids in the sample may contribute deposits of material on the extraction and/or
skimmer cones reducing the effective diameter of the orifices and therefore ion transmission. Internal
standardization may be effectively used to compensate for many physical interference effects. Internal
standards ideally should have similar analytical behavior to the elements being determined.
5.5 Memory Interferences
Memory interferences result when isotopes of elements in a previous sample contribute to the signals
measured in a new sample. Memory effects can result from sample deposition on the sampler and
skimmer cones and from the buildup of sample material in the plasma torch and spray chamber. The site
where these effects occur is dependent on the element and can be minimized by flushing the system with
a rinse blank between samples (see Section 8.6.3). The possibility of memory interferences should be
recognized within an analytical run and suitable rinse times should be used to reduce them. The rinse
times necessary for a particular element should be estimated prior to analysis. This estimate may be
calculated by aspirating a standard containing elements corresponding to 10 times the upper end of the
linear range for a normal sample analysis period, followed by analysis of the rinse blank at designated
intervals. The length of time required to reduce analyte signals to within a factor of 10 of the method
detection limit, should be noted. Memory interferences may also be assessed within an analytical run by
using a minimum of three replicate integrations for data acquisition. If the integrated signal values drop
consecutively, the analyst should be alerted to the possibility of a memory effect and should examine the
analyte concentration in the previous sample to identify if this was high. If a memory interference is
suspected, the sample should be reanalyzed after a long rinse period.
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6. Safety
6.1 The toxicity or carcinogenicity of reagents used in this method have not been folly established. Each
chemical should be regarded as a potential health hazard, and exposure to these compounds should be as
low as reasonably achievable. Each laboratory is responsible for maintaining a current awareness file
of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be available to all personnel involved in the chemical
analyses.
6.2 Analytical plasma sources emit radiofrequency radiation in addition to intense UV radiation. Suitable
precautions should be taken to protect personnel from such hazards.
7. Apparatus and Equipment
7.1 Inductively Coupled Plasma/Mass Spectrometer (ICP/MS)
7.1.1 ICP/MS Instrument. Capable of scanning the mass 5-250 amu with a minimum resolution
capability of 1 amu peak width at 5% peak height. Instrument may be fitted with a conventional or
extended dynamic range detection system.
7.1.2 Argon Gas Supply (high-purity grade, 99.99%). Best source.
7.1.3 A Variable-Speed Peristaltic Pump. Required for solution delivery to the nebulizer.
7.1.4 A Mass-Blow Controller. On the nebulizer gas supply is required. A water-cooled spray
chamber may reduce some types of interferences (e.g., from polyatomic oxide species).
7.1.5 Operating Conditions. • Because of the diversity of instrument hardware, no detailed
instalment operating conditions are provided. The analyst is advised to follow the recommended
operating conditions provided by the manufacturer. The analyst must verify that the instrument
configuration and operating conditions satisfy the analytical requirements and maintain quality control data
verifying instrument performance and analytical results. Instrument operating conditions used to generate
precision and recovery data for this method (Section 14) are included in Table 3.
7.1.6 Electron Multiplier Detector. If an electron multiplier detector is being used, precautions
should be taken, where necessary, to prevent exposure to high ion flux. Otherwise, changes in
instrument response or damage to the multiplier may result. Samples having high concentrations of
elements beyond the linear range of the instrument and with isotopes falling within scanning windows
should be diluted prior to analysis.
7.2 Labware
To determine trace level elements, contamination and loss are of prime consideration. Potential
contamination sources include improperly cleaned laboratory apparatus and general contamination within
the laboratory environment from dust, etc. A clean laboratory work area designated for trace element
sample handling must be used. Sample containers can introduce positive and negative errors in the
determination of trace elements by (1) contributing contaminants through surface desorption or leaching
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and (2) depleting element concentrations through adsorption processes. All reusable labware (glass,
quartz, polyethylene, Teflon®, etc.), including the sample container, should be cleaned prior to use.
Labware may be soaked overnight and thoroughly washed with laboratory-grade detergent and water,
rinsed with water, and soaked for 4 h in a mixture of dilute nitric and hydrochloric acid (1+2+9). It
should then be rinsed with ASTM type I water and oven-dried.
[Note: Do not use chromic acid to clean glassware.]
7.2.1 Glassware. Volumetric flasks, graduated cylinders, funnels and centrifuge tubes.
7.2.2 Assorted Calibrated Pipettes. Dust sources.
7.2.3 Conical Phillips Beakers, 350-mL with 50-mm Watch Glasses. Griffin beakers, 350-mL
with 75-mm'watch glasses.
7.2.4 Storage Bottles. Narrow mouth bottles, Teflon® FEP (fluorinated ethylene propylene) with
Tefzel ETFE (ethylene tetrafluorethylene) screw closure, 125-mL and 250-mL capacities.
7.3 Sample Processing Equipment
7.3.1 Air Displacement Pipetter. Digital pipet system capable of delivering volumes from 10 to
2,500 pL with an assortment of high quality disposable pipet tips.
7.3.2 Balance. Analytical, capable of accurately weighing to 0.1 mg.
7.3.3 Hot Plate. (Corning PC100 or equivalent).
7.3.4 Centrifuge. Steel cabinet with guard bowl, electric timer and brake.
7.3.5 Drying Oven. Gravity convection oven with thermostatic control capable of maintaining
105°C + 5°C.
8. Reagents and Consumable Materials
8.1 Reagents
[Note: Owing to the high sensitivity of ICP/MS, high-purity reagents should be used whenever possible.
All acids used for this method must be of ultra high-purity grade. Suitable acids are available from a
number of manufacturers or may be prepared by sub-boiling distillation. Nitric acid is preferred for
ICP/MS to minimize polyatomic ion interferences. Several polyatomic ion interferences result when
hydrochloric acid is used (see Table 2). However, hydrochloric acid is required to maintain stability in
solutions containing antimony and silver. When hydrochloric acid is used, corrections for the chloride
polyatomic ion interferences must be applied to all data.]
8.1.1 Nitric Acid, Concentrated (sp.gr. 1.41). Best source.
8.1.2 Nitric Acid (1 + 1). Add 500 mL cone, nitric acid to 400 mL of ASTM type I water and dilute
to 1 L.
8.1.3 Nitric Acid (1+9). Add 100 mL cone, nitric acid to 400 mL of ASTM type I water and dilute
to 1 L.
8.1.4 Hydrochloric Acid, Concentrated (sp.gr. 1.19). Best source.
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8.1.5 Hydrochloric Acid (1+1). Add 500 mL cone, hydrochloric acid to 400 mL of ASTM type I
water and dilute to 1 L.
8.1.6 Hydrochloric Acid (1+4). Add 200 mL cone, hydrochloric acid to 400 mL of ASTM type I
water and dilute to 1 L.
8.1.7 Ammonium Hydroxide, Concentrated (sp.gr. 0.902). Best source.
8.1.8 Tartaric Acid (CASRN 87-69-4). Best source,
SJJ Water
For all sample preparation and dilutions, ASTM type I water (ASTM Dl 193) is required. Suitable water
may be prepared by passing distilled water through a mixed bed of anion and cation exchange resins.
8.3 Standard Stock Solutions
Standard stack solutions may be purchased from a reputable commercial source or prepared from ultra
high-purity grade chemicals or metals (99.99 - 99.999% pure). All salts should be dried for 1 h at
105°C, unless otherwise specified. Stock solutions should be stored in Teflon® bottles. Use the
following procedures for preparing standard stock solutions:
Caution: Many metal salts are extremely toxic if inflated or swallowed. Wash hands thoroughly after
handling.
[Note: Some metals, particularly those that form surface oxides, require cleaning prior to being weighed,
which requires pickling the surface of the metal in acid. An amount in excess of the desired weight should
be pickled repeatedly, rinsed with water, dried, and weighed until the desired weight is achieved.]
8.3.1 Aluminum Solution, Stock. 1 mL = 1,000 jig Al: Pickle aluminum metal in warm (1 + 1)
HCI to an exact weight of 0.100 g. Dissolve in 10 mL cone. HC1 and 2 mL cone, nitric acid, heat to
dissolve. Continue heating until volume is reduced to 4 mL. Cool and add 4 mL ASTM type I water.
Heat until the volume is reduced to 2 mL. Cool and dilute to 100 mL with ASTM type I water.
8.3.2 Antimony Solution, Stock. 1 mL = 1,000 jwg Sb: Dissolve 0.100 g antimony powder in 2
mL (1 + 1) nitric acid and 0.5 mL cone, hydrochloric acid, heat to dissolve. Cool and add 20 mL ASTM
type I water and 0.15 g tartaric acid. Warm the solution to dissolve the white precipitate. Cool and
dilute to 100 mL with ASTM type I water.
8.3.3 Arsenic Solution, Stock. 1 mL = 1,000 jig As: Dissolve 0.1320 g As2C>3 in a mixture of
50 mL ASTM type I water and 1 mL cone, ammonium hydroxide. Heat gently to dissolve: Cool and
acidify the solution with 2 mL cone, nitric acid. Dilute to 100 mL with ASTM type I water.
8.3.4 Barium Solution, Stock. 1 mL = 1,000 /*g Ba: Dissolve 0.1437 g BaCO3 in a solution
mixture of 10 mL ASTM type I water and 2 mL cone, nitric acid. Heat and stir to dissolve and
degassing. Dilute to 100 mL with ASTM type I water.
8.3.5 Beryllium Solution, Stock. 1 mL = 1,000 fig Be: Dissolve 1.965 g BeSO4 • 4H2O (DO NOT
DRY) in 50 mL ASTM Type I water. Add 1 mL cone, nitric acid. Dilute to 100 mL with ASTM type I
water.
8.3.6 Bismuth Solution, Stock. 1 mL = 1,000 jig Bi: Dissolve 0.1115 g Bi2O3 in 5 mL cone.
nitric acid. Heat to dissolve. Cool and dilute to 100 mL with ASTM type I water.
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8.3.7 Cadmium Solution, Stock. 1 mL = 1,000 fig Cd: Pickle cadmium metal in (1 +9) nitric acid
to an exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to dissolve. Cool and dilute
to 100 mL wit ASTM type I water.
8.3.8 Chromium Solution, Stock. 1 mL = 1,000 ng Cr: Dissolve 0.1923 g CrO3 in a solution
mixture of 10 mL ASTM type I water and 1 mL cone, nitric acid. Dilute to 100 mL with ASTM type I
water.
8.3.9 Cobalt Solution, Stock. 1 mL = 1,000 jug Co: Pickle cobalt metal in (1+9) nitric acid to
an exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to dissolve. Cool and dilute
to 100 mL with ASTM type I water.
8.3.10 Copper Solution, Stock. 1 mL = 1,000 /ig Cu: Pickle copper metal in (1+9) nitric acid
to an exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to dissolve. Cool and dilute
to 100 mL with ASTM type I water.
8.3.11 Indium Solution, Stock. 1 mL = 1,000 /*g In: Pickle indium metal in (1 +1) nitric acid to
an exact weight of 0.100 g. Dissolve in 10 mL (1 +1) nitric acid, heating to dissolve. Cool and dilute
to 100 mL with ASTM type I water.
8.3.12 Lead Solution, Stock. 1 mL = 1,000 ng Pb: Dissolve 0.1599 g PbNO3 in 5 mL (1 + 1)
nitric acid. Dilute to 100 mL with ASTM type I water.
8.3.13 Magnesium Solution, Stock. 1 mL = 1,000 fig Mg: dissolve 0.1658 g MgO in 10 mL
(1 +1) nitric acid, heating to dissolve. Cool and dilute to 100 mL with ASTM type I water.
8.3.14 Manganese Solution, Stock. 1 mL = 1,000 fig Mn: Pickle manganese flake in (1 +9) nitric
acid to an exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to effect solution. Cool
and dilute to 100 mL with ASTM type I water.
8.3.15 Molybdenum Solution, Stock. 1 mL = 100 fig Mo: Dissolve 0.1500 g MoO3 in a solution
mixture of 10 mL ASTM type I water and 1 mL cone, ammonium hydroxide, heating to dissolve and
1 mL cone, ammonium hydroxide, heating to effect solution. Cool and dilute to 100 mL with ASTM
type I water.
8.3.16 Nickel Solution, Stock. 1 mL = 1,000 jtg Ni: Dissolve 0.100 g nickel powder in 5 mL
cone, nitric acid, heating to dissolve. Cool and dilute to 100 mL with ASTM type I water.
8.3.17 Scandium Solution, Stock. 1 mL = 1,000 fig Sc: Dissolve 0.1534 g sc^ in 5 mL (1 +1)
nitric acid, heating to dissolve. Cool and dilute to 100 mL ASTM type I water.
8.3.18 Selenium Solution, Stock. 1 mL = 1,000 fig Se: Dissolve 0.1405 g SeO2 in 20 mL ASTM
type I water. Dilute to 100 mL with ASTM type I water.
8.3.19 Silver Solution, Stock. 1 mL = 100 fig Ag: Dissolve 0.100 g silver metal in 5 mL (1 +1)
nitric acid, heating to dissolve. Cool and dilute to 100 mL with ASTM type I water. Store in dark
container.
8.3.20 Terbium Solution, Stock. 1 mL = 1,000 /tg Tb: Dissolve 0.1176 g Tb4O7 in 5 mL cone.
nitric acid, heating to dissolve. Cool and dilute to 100 mL with ASTM type I water.
8.3.21 Thallium Solution, Stock. 1 mL = 1,000 fig Tl: Dissolve 0.1303 g T1NO3 in a solution
mixture of 10 mL ASTM type I water and 1 mL cone, nitric acid. Dilute to 100 mL with ASTM type I
water.
8.3.22 Thorium Solution, Stock. 1 mL = 1,000 fig Th: Dissolve 0.2380 g Th(NO3)4 • 4H2O (DO
NOT DRY) in 20 mL ASTM type I water. Dilute to 100 mL with ASTM type I water.
NOT
8;3.23 Uranium Solution, Stock. 1 mL = 1,000 fig U: Dissolve 0.2110 g UO2(NO3)2 • 6H2O (DO
T DRY) in 20 mL ASTM type I water and dilute to 100 mL with ASTM type I water.
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8.3.24 Vanadium Solution, Stock. 1 mL = 1,000 \>.g V: Pickle vanadium metal in (1+9) nitric
acid to an exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to dissolve. Cool and
dilute to 100 mL with ASTM type I water.
8.3.25 Yttrium Solution, Stock. 1 mL = 1,000 jig Y: Dissolve 0.1270 g Y2O3 in 5 mL (1 + 1)
nitric acid, heating to dissolve. Cool and dilute to 100 mL with ASTM type I water.
8.3.26 Zinc Solution, Stock. 1 mL = 1,000 fig Zn: Pickle zinc metal in (1+9) nitric acid to an
exact weight of 0.100 g. Dissolve in 5 mL (1 +1) nitric acid, heating to effect solution. Cool and dilute
to 100 mL with ASTM type I water.
8.4 Multi-Element Stock Standard Solutions
Care must be taken in the preparation of multi-element stock standards so that the elements are compatible
and stable. Originating element stocks should be checked for impurities that might influence the accuracy
of the standard. Freshly prepared standards should be transferred to acid-cleaned, not previously used
FEP fluorocarbon bottles for storage and monitored periodically for stability. Suggested element
combinations are;
Standard Solution A
Aluminum
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead-
Manganese
Molybdenum
Nickel
Selenium
.Thallium
Thorium
Uranium
Vanadium
Zinc
Standard Solution B
Barium
Silver
Multi-element stock standard solutions A and B (1 mL = 10 /tg) may be prepared by diluting 1 mL of
each single element stock in the combination list to 100 mL with ASTM type I water containing 1 % (v/v)
nitric acid.
Fresh multi-element calibration standards should be prepared every 2 weeks, or as needed. Dilute each
of the stock multi-element standard solutions A and B to levels appropriate to the operating range of the
instrument using ASTM type I water containing 1 % (v/v) nitric acid. The element concentrations in the
standards should be sufficiently high to produce good measurement precision and to accurately define the
slope of the response curve. Concentrations of 200 jtg/L are suggested. If the direct addition procedure
and internal standards (see Section 8.5) to the calibration standards are being used, store in Teflon®
bottles. Calibration standards should be verified initially using a quality control sample (see Section 8.8).
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8.5 Internal Standards Stock Solution, 1 mL = 100 /tg
Dilute 10 mL of scandium, yttrium, indium, terbium and bismuth stock standards (Section 8.3) to 100 mL
with ASTM type I water and store in Teflon® bottle. Use this solution concentrate to add to blanks,
calibration standards, and samples or dilute by an appropriate amount using 1 % (v/v) nitric acid, if the
internal standards are being added by peristaltic pump.
8.6 Blanks
Three types of blanks are required for this method. A calibration blank establishes the analytical
calibration curve. The laboratory reagent blank assesses possible contamination from the sample
preparation procedure and spectral background. The rinse blank flushes the instrument between samples
to reduce memory interferences.
8.6.1 Calibration blank consists of 1 % (v/v) nitric acid in ASTM type I water. If the direct addition
procedure is being used, add internal standards.
8.6.2 Laboratory reagent blank (LRB) must contain all the reagents in the same volumes as used in
processing the samples. The LRB must be carried through the entire sample digestion and preparation
scheme. If the direct addition procedure is being used, add internal standards to the solution after
preparation is complete.
8.6.3 Rinse blank consists of 2% (v/v) nitric acid in ASTM type I water.
8.7 Tuning Solution
This solution is used for instrument tuning and mass calibration prior to analysis. The solution is
prepared by mixing beryllium, magnesium, cobalt, indium and lead stock solutions (see Section 8.3) in
1,% (v/v) nitric acid to produce a concentration of 100 jtg/L of each element. Internal standards are not
added to this solution.
8.8 Quality Control Sample (QCS)
The QCS should be obtained from a source outside the laboratory. Dilute an appropriate aliquot of
analytes (concentrations not to exceed 1,000/xg/L) in 1% (v/v) nitric acid. If the direct addition
procedure is being used, add internal standards after dilution, mix, and store in a Teflon® bottle.
8.9 Laboratory Fortified Blank (LFB)
To an aliquot of LRB, add aliquots from multi-element stock standards A and B (see Section 8.4) to
produce a final concentration of 100 /zg/L for each analyte. The LFB must be carried through the entire
sample digestion and preparation scheme. If the direct addition procedure is being used, add internal
standards to this solution after preparation.
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9. Sample Receipt in the Laboratory
9.1 The sample should be received from the extraction laboratory in a 10-mL flask and diluted to the
mark, as documented in Inorganic Compendium Method IO-3.1.
9.2 No additional preservation is needed at this time. Sample is ready for ICP/MS analysis.
10. Calibration and Standardization
10.1 Calibration
[ftote: Demonstration and documentation of acceptable initial calibration is required before samples are
analyzed and periodically throughout sample analysis as dictated by results of continuing calibration
checks. After initial calibration is successful, a calibration check is required at the beginning and end
of each period during which analyses are performed and at requisite intervals.]
10.1.1 Allow a period of not less than 30 min for instrument warm up. During this process, conduct
mass calibration and resolution checks using the tuning solution. Resolution at low mass is indicated by
magnesium isotopes 24, 25, and 26. Resolution at high mass is indicated by lead isotopes 206, 207, and
208. For good performance, adjust spectrometer resolution to produce a peak width of approximately
0.75 amu at 5% peak height. Adjust mass calibration if it has shifted by more than 0.1 amu from unit
mass.
10.1.2 Instrument stability must be demonstrated by running the tuning solution (see Section 8.7) a
minimum of five times with resulting relative standard deviations of absolute signals for all analytes of
less than 5%.
10.1.3 Prior to initial calibration, set up proper instrument software routines for quantitative analysis.
The instrument must be calibrated for the analytes to be determined using the calibration blank (see
Section 8.6.1) and calibration standards A and B (see Section 8.4) prepared at one or more concentration
levels. A minimum of three replicate integrations are required for data acquisition. Use the average of
the integrations for instrument calibration and data reporting.
10.1.4 The rinse blank should be used to flush the system between solution changes for blanks,
standards, and samples. Allow sufficient rinse time to remove traces of the previous sample or a
minimum of 1 min. Solutions should be aspirated for 30 s prior to the acquisition of data to establish
equilibrium.
10.2 Internal Standardization
10.2.1 Internal standardization must be used in all analyses to correct for instrument drift and
physical interferences. A list of acceptable internal standards is provided in Table 4.
10.2.2 For full mass range scans, a minimum of three internal standards must be used. Procedures
described in this method for general application detail five internal standards: scandium, yttrium, indium,
terbium, and bismuth. These standards were used to generate the precision and recovery data attached
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to this method. Internal standards must be present in all samples, standards, and blanks at identical
levels.
10.2.3 This may be achieved by directly adding an aliquot of the internal standards to the CAL
standard, blank, or sample solution or alternatively by mixing with the solution prior to nebulization using
a second channel of the peristaltic pump and a mixing coil. The concentration of the internal standard
should be sufficiently high to obtain a precise measurement of the isotope used for data correction and
to minimize the possibility of correction errors if the internal standard is naturally present in the sample.
10.2.4 A concentration of 200 jtg/L of each internal standard is recommended. Internal standards
should be added to blanks, samples, and standards in a like manner so that dilution effects from the
addition may be disregarded.
10.3 Instrument Performance
[Note: Check the performance of the instrument and verify the calibration using data gathered from
analyses of calibration blanks, calibration standards and the QCS.J
10.3.1 After establishing calibration, it must be initially verified for all analytes by analyzing the
QCS (see Section 8.8). If measurements exceed ± 10% of the established QCS value, terminate the
analysis, identify and correct the problem, recalibrate the instrument, and reverify the calibration
reverified before continuing analyses.
10.3.2 To verify that the instrument is properly calibrated on a continuing basis, run the calibration
blank and calibration standards as surrogate samples after every 10 analyses. The results of the analyses
of the standards will indicate whether the calibration remains valid. If the indicated concentration of any
analyte deviates from the true concentration by more than 10%, reanalyze the standard. If the analyte
is again outside the 10% limit, the instrument must be recalibrated and the previous ten samples
reanalyzed. The instrument responses from the calibration check may be used for recalibration purposes.
If the sample matrix is responsible for the calibration drift, the previous 10 samples should be reanalyzed
in groups of five between calibration checks to prevent a similar drift situation from occurring.
11. Quality Control (QC)
11.1 Laboratory
Each laboratory using this method is required to operate a formal QC program. The minimum
requirements of this program are an initial demonstration of laboratory capability and the analysis of
laboratory reagent blanks, fortified blanks, and samples as a continuing check on performance. The
laboratory is required to maintain performance records that define the quality of the data thus generated.
11.2 Initial Demonstration of Performance
11.2.1 The initial demonstration of performance is used to characterize instrument performance
(method detection limits and linear calibration ranges) for analyses conducted by this method.
11.2.2 Method detection limits (MDL) should be established for all analytes, using reagent water
(blank) fortified at a concentration of two to five times the estimated detection limit. To determine MDL
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values, take seven replicate aliquots of the fortified reagent water and process through the entire analytical
method. Perform all calculations defined in the method and report the concentration values 'in the
appropriate units. Calculate the MDL as follows:
MDL ~ MX®)
t = Student's t value for a 99% confidence level and a standard jieviation estimate with n-1 degrees
of freedom [t = 3.14 for seven replicates].
S = standard deviation of the replicate analyses.
MDLs should be determined every 6 months or whenever a significant change in background or
Instrument response is expected (e.g., detector change).
11.2.3 Linear calibration ranges are primarily detector limited. The upper limit of the linear
calibration range should be established for each analyte by determining the signal responses from a
minimum of three different concentration standards, one of which is close to the upper limit of the linear
range. Avoid damage to the detector during this process. The linear calibration range, which may be
used for the analysis of samples, should be judged by the analyst from the resulting data. Linear
calibration ranges should be determined every 6 months or whenever a significant change in instrument
response is expected (e.g., detector change).
11.3 Assessing Laboratory Performance— Reagent and Fortified Blanks
11.3.1 Laboratory Reagent Blank (LRB). The laboratory must analyze at least one LRB (see
Section 8.6.2) with each set of samples. LRB data are used to assess contamination from the laboratory
environment and to characterize spectral background from the reagents used in sample processing. If an
analyte value in the reagent blank exceeds its determined MDL, laboratory or reagent contamination
should be suspected. Any source of contamination should be corrected and the samples reanalyzed.
11.3.2 Laboratory Fortified Blank (LFB). The laboratory must analyze at least one LFB (see
Section 8.9) with each batch of samples. Calculate accuracy as percent recovery (see Section 11.4.2).
If the recovery of any analyte falls outside the control limits (see Section 11.3.3), that analyte is judged
out of control, and the source of the problem should be identified and resolved before continuing
analyses.
11.3.3 Until sufficient LFB data become available (usually a minimum of 20-30 analyses), the
laboratory should assess laboratory performance against recovery limits of 85-115%. When sufficient
internal performance data becomes available, develop control limits from the percent mean recovery (x)
and the standard deviation (S) of the mean recovery. These data are used to establish upper .and lower
control limits as follows:
UPPER CONTROL.LIM1T = x +.3S
LOWER CONTROL LIMIT = x -:3S -
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After each 5-10 new recovery measurements, new control limits should be calculated using only the
most recent 20-30 data points.
11.4 Assessing Analyte Recovery - Laboratory Fortified Sample Matrix
11.4.1 The laboratory must add a known amount of analyte to a minimum of 10% of the routine
samples or one sample per sample set, whichever is greater. For water samples, the analyte concentration
should be the same as that used in the LFB (see Section 11.3.2). For solid samples, the concentration
added should be 50 mg/kg equivalent (100 /ig/L in the analysis solution). Over time, samples from all
routine sample sources should be fortified.
11.4.2 Calculate the percent recovery for each analyte, corrected for background concentrations
measured in the unfortified sample and compare these values to the control limits established in
Section 11.3.3 for the analyses of LFBs. Recovery calculations are not required if the concentration of
the analyte added is less than 10% of the sample background concentration. Percent recovery may be
calculated in units appropriate to the matrix using the following equation:
R = (Cs - C)/s x 100
where:
R = percent recovery, %.
Cs = fortified sample concentration, ng/L.
C = sample background concentration, ng/L.
s = concentration equivalent of fortifier added to sample, ng/L.
11.4.3 If recovery of any analyte falls outside the designated range and laboratory performance for
that analyte is shown to be in control (see Section 11.3), the recovery problem encountered with the
fortified sample is judged to be matrix-related, not system-related. The analyte in the unfortified sample
must be labelled "suspect/matrix" to inform the user that the results are suspect due to matrix effects.
11.5 Internal Standards Responses
The analyst is expected to monitor the responses from the internal standards throughout the sample set
being analyzed. Ratios of the internal standards responses against each other should also be monitored
routinely. This information may be used to detect potential problems caused by mass dependent drift,
errors incurred in adding the internal standards, or increases in the concentrations of individual internal
standards caused by background contributions from the sample. The absolute response of any one
internal standard should not deviate more than 60-125% of the original response in the calibration blank.
If deviations greater than this are observed, use the following test procedure:
11.5.1 Flush the instrument with the rinse blank and monitor the responses in the calibration blank.
If the responses of the internal standards are now within the limit, take a fresh aliquot of the sample,
dilute by a further factor of two, add the internal standards and reanalyze.
11.5.2 If the test (see Section 10.5.1) is not satisfied or if it is a blank or calibration standard that
is out of limits, terminate the analysis and determine the cause of the drift. Possible causes may be a
partially blocked sampling cone or a change in the tuning condition of the instrument.
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12. Procedure
12.1 Samples should be received from the extraction laboratory in a 10-mL volumetric flask diluted to
the mark. The sample contains the necessary solution in appropriate concentration for ICP\MS
determination.
12.2 For every new or unusual matrix, a semi-quantitative analysis should be carried out to screen for
high element concentrations. Information gained from this procedure may be used to prevent potential
damage to the detector during sample analysis and to identify elements that may be higher than the linear
range. Matrix screening may be carried out by using intelligent software, if available, or by diluting the
sample by a factor of 500 and analyzing in a semi-quantitative mode. The sample should also be screened
for background levels of all elements chosen for use as internal standards to prevent bias.
12.3 Initiate instrument operating configuration. Tune and calibrate the instrument for the analytes of
interest (see Section 10).
12.4 Establish instrument software run procedures for quantitative analysis. For all sample analyses,
a minimum of three replicate integrations are required for data acquisition. Discard any integrations
considered to be statistical outliers and use the average of the integrations for data reporting.
12.5 Monitor all masses that might affect data quality during the analytical run. At a minimum, those
masses prescribed in Table 5 must be monitored in the same scan as is used for the collection of the data.
This information should be used to correct the data for identified interferences.
12.6 Use the rinse blank to flush the system between samples. Allow sufficient time to remove traces
of the previous sample or a minimum of 1 min. Aspirate the samples for 30 s prior to the collection of
data.
12.7 Dilute samples having concentrations higher than the established linear dynamic range should be
diluted into range and reanalyzed. First, analyze the sample for trace elements, protecting the detector
from the high concentration elements, if necessary, by selecting appropriate scanning windows. Then
dilute the sample to determine the remaining elements. Alternatively, the dynamic range may be adjusted
by selecting an alternative isotope of lower natural abundance, provided quality control data for that
isotope have been established. Do not adjust the dynamic range by altering instrument conditions to an
uncharacterized state.
13. Calculations
13.1 Elemental equations recommended for sample data calculations are listed in Table 6. Sample data
should be reported in units of ng/m3.
Page 3.5-16 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.5
Chemical Analysis ICP/MS Methodology
13.1.1 Calculate the air volume sampled, corrected to EPA-reference conditions:
T P
V = V ( ^V bar1
vstd s ^T P
Lm rstd
where:
•2
Vst(j = volume of ambient air sampled at EPA-reference conditions, m°
V§ = volume of ambient air pulled through the sampler, m .
Tstcj = absolute EPA-reference temperature, 298 °K.
Tm = average ambient temperature, °K.
^bar = barometric pressure during sampling measurement condition, mm Hg.
^std = EPA-reference barometric pressure, 760 mm Hg.
13.1.2 Metal concentration in the air sample can then be calculated as follows:
C = [0*g metal/mL) x (40 mL/strip)(9) - Fm]/Vstd
where:
•^
C = concentration, /*g metal/m .
(j.g metal/mL = metal concentration determined from Section 12.
40 mL/strip = total sample volume, mL.
9 _ Useable filter area, [20 cm x 23 cm (8" x 9")]
Exposed area of one strip, [2.5 cm x 20 cm (1" x 8")]-
Fm = average concentration of blank filters, /ig.
Vst(j = standard air volume pulled through filter, std. m (25°C and 760 mm Hg).
Do not report element concentrations below the determined MDL.
13.2 For data values less than 10, use two significant figures to report element concentrations. For data
values greater than or equal to 10, three significant figures.
13.3 Reported values should be calibration blank subtracted (see Inorganic Compendium Method IO-3.1).
13.4 Correct data values for instrument drift or sample matrix induced interferences by applying internal
standardization. Corrections for characterized spectral interferences should be applied to the data.
Chloride interference corrections should be made on all samples, regardless of the addition of
hydrochloric acid, as the chloride ion is a common constituent of environmental samples.
13.5 If an element has more than 1 monitored isotope, examine the concentration calculated for each
isotope, or the isotope ratios, to detect a possible spectral interference. Consider both primary and
secondary isotopes when evaluating the element concentration. In some cases, secondary isotopes may
be less sensitive or more prone to interferences that the primary recommended isotopes; therefore,
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.5-17
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Method IO-3.5 Chapter IO-3
ICP/MS Methodology Chemical Analysis
differences between the results do not necessarily indicate a problem with data calculated for the primary
isotopes.
13.6 The QC data obtained during the analyses provide an indication of the quality of the sample data
and should be provided with the sample results.
14. Precision and Accuracy
14.1 Instrument operating conditions for single laboratory testing of the method are summarized in
Table 6. Total recoverable MDLs determined are listed in Table 7.
14.2 Data obtained from single laboratory testing of the method are summarized in Table 8 for five
water samples representing drinking water, surface water, ground water, and waste effluent. For each
matrix, five replicates were analyzed and the average of the replicates used to determine the sample
background concentration for each element. Two additional pairs of duplicates were fortified at different
concentration levels. For each method element, the sample background concentration, mean percent
recovery, standard deviation of the'percent recovery, and relative percent difference between the duplicate
fortified samples are listed in Table 8.
14.3 Data obtained from single laboratory testing of the method for three solid samples consisting of
SRM 1645 River Sediment, EPA Hazardous Soil, and EPA Electroplating Sludge are summarized in
Table 9. For each method element, the sample background concentration, mean percent recovery,
standard deviation of the percent recovery, and relative percent difference between the duplicate fortified
samples were determined as for Section 14.2.
14.4 Activities required to be performed using ICP/MS to validate method precision and accuracy are
summarized in Table 10.
15. References
I. "Standard Operating Procedures for the ICP-DES Determination of Trace Elements in Suspended
Particulate Matter Collected on Glass-Fiber Filters," EMSL/RTP-SOP-EMO-002, Revision, October,
1983.
2. "Reference Method for the Determination of Suspended Particulates in the Atmosphere (High
Volume Method)," Code of Federal Regulations, Title 40, Part 50, Appendix B, pp. 12-16 (July 1,
1975).
3. "Reference Method for the Determination of Lead in Suspended Particulate Matter Collected from
Ambient Air.," Federal Register 43 (194): 46262-3, 1978,
Page 3.5-18 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.5
Chemical Analysis ICP/MS Methodology
4. Rhodes, R.C., 1981, "Special Extractability Study of Whatman and Schleicher and Schuell Hi-Vol
Filters," Memo to file, August 5, 1981, Quality Assurance Division, Environmental Monitoring
Systems Laboratory, U. S. Environmental Protection Agency, Research Triangle Park NC.
5. Ward, A. F., The Jarren-Ash Plasma Newsletter, Volumes I, II, and III.
6. Nygard, D., and Sot, J., "Determination Near the Detection Limit: A Comparison of Sequential and
Simultaneous Plasma Emission Spectrometers," Spectroscopy, Vol. 3(4).
7. "Simplex Optimization of Multielement Ultrasonic Extraction of Atmospheric Particulates," Harper,
et. al., Analytical Chemistry, Vol 55(9), August 1983.
8. .A. L. Gray and A. R. Date, Analyst, Vol 108:1033.
9. R. S. Houk et al., Anal. Chem., Vol 52:2283.
10. R. S. Houk, Anal. Chem. Vol. 58(97A).
11. J. J. Thompson and R. S. Houk, Appl. Spec., Vol. 41:801, 1987.
12. "OSHA Safety and Health Standards, General Industry," (29 CFR 1910), Occupational Safety and
Health Administration, OSHA 2206, revised January 1976.
13. "Proposed OSHA Safety and Health Standards, Laboratories," Federal Register, July 24, 1986.
14. Code of Federal Regulations 40, Ch. 1, Pt. 136 Appendix B.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.5-19
-------
Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 1. ESTIMATED METHOD DETECTION3 LIMITS
Element
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Molybdenum
Nickel
Selenium
Silver
Thallium
Thorium
Uranium
Vanadium
Zinc
Recommended analytical
mass
27
121
75
137
9
111
52
59
63
206,207,208
55
98
60
82
107
205
232
238
51
66
Estimated Method Detection Limits
' ''''. "•' ''^'^^P^d^:.--. .••••;.
'.'jig/L
0.05
0.08
0.9
0.5
0.1
0.1
0.07
0.03
0.03
0.08
0.1
0.1
0.2
5
0.05
0.09
0.03
0.02
0.02
0.2
•:-:;" ;:|-;tng/m^ ••;" ' '
0.01
0.01
0.30
0.10
0.02
0.02
0.01
0.01
0.01 .
0.01
0.02
0.02
0.02
1.10
0.01
0.01
0.01
0.01
0.01
0.04
Instrument detection limits (3a) estimated from seven replicate integrations of the blank (1% v/v nitric acid) following
calibration of the instrument with three replicate integrations of a multi-element standard.
"Based upon sampling rate of 1.13 nv*/min for 24-h for a total sample volume of 1,627.2 m^, factor of 9 for partial filter
analysis; digestion of 0.040 L/filter.
Page 3.5-20
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 2. COMMON POLYATOMIC ION INTERFERENCES IN ICP-MS
BACKGROUND MOLECULAR IONS
Molecular Ion
NH +
OH +
OH9 +
r +
2
CN+
co+
N2+
£, l
N2H+
NO+
NOH +
°z +
OH +
36ArH +
38ArR +
4°ArH +
CO2 +
CO2H +
ArC + , ArO +
ArN +
ArNH +
ArO +
ArOH +
40Ar36Af+
40Ar38Ar+
" 4°Ar2
'^Mass .
15
17
18
24
26
28
28
29
30
31
32
33
37
39
41
44
45
52
54
55
56
57
76
78
80
Element Interference
Sc
Cr
Cr
Mn
Se '
Se
Se
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-21
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Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 2. (continued)
MATRIX MOLECULAR IONS
CHLORIDE
Polyatomic Ion
35CIO +
35CIOH+
37CIO +
37C10H +
Ar^Cl*
Ar^CI*
SULFATE
Polyatomic Ion
32SO+
32SOH +
34SO +
34SOH*
SO-,. S2+
A^V
Ar34S+
PHOSPHATE
Polyatomic Ion
PO*
POH*
PO7*
ArP2
GROUP I, II METALS
Polyatomic Ion
ArNa*
ArK+
ArCa+
MATRIX OXIDES2
Polyatomic Ion
TiO
ZrO
MoO
Mass
51
52
53
54
75
77
Mass
48
49
50
51
64
72
74
Mass
47
48
63
71
Mass
63
79
80
Masses
62-66
106-112
108-116
Element Interference
V
Cr
Cr
Cr
As
Se
Element Interference
Ti
Ti
V, Cr
V
Zn
Element Interference
Cu
Element Interference
Cu
Element Interference
Ni, Cu, Zn
Ag, Cd
Cd
Method elements or internal standards affected by the polyatomic ions.
^Oxidc interferences will normally be very small and will only impact the method elements when present at relatively high
concentrations. Some examples of matrix oxides are listed of which the analyst should be aware. It is recommended that
Ti and Zr isotopes are monitored in solid waste samples, which are likely to contain high levels of these elements. Mo is
monitored as a method analyte.
Page 3.5-22
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 3. INSTRUMENT OPERATING CONDITIONS
FOR PRECISION AND RECOVERY DATA
Instrument
Plasma forward power
Coolant flow rate
Auxiliary flow rate
Nebulizer flow rate
Solution uptake rate
Spray chamber temperature
Data Acquisition
Detector mode
Replicate integrations
Mass range
Dwell time
Number of MCA channels
Number of scan sweeps
Total acquisition time
VG PlasmaQuad Type I
1.35kW
13.5 L/min
0.6 L/min
0.78 L/min
0.6 mL/min
15°C
Pulse counting
3
8 - 240 amu
320 JKS
2048
85
3 min per sample
TABLE 4. INTERNAL STANDARDS AND LIMITATIONS OF USE
Internal Standard
Lithium
Scandium
Yttrium
Rhodium
Indium
Terbium
Holmium
Lutetium
Bismuth
Mass
6
45
89
103
115
159
165
175
209
Possible Limitation
a
polyatomic ion interference
a,b
isobaric interference by Sn
a
aMay be present in environmental samples.
^In some instruments yttrium may form measurable amounts of YO+ (105 amu) and YOH+ (106 amu). If this is the case,
care should be taken in the use of the cadmium elemental correction equation.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-23
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Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 5. RECOMMENDED ANALYTICAL ISOTOPES
AND ADDITIONAL MASSES WHICH
MUST BE MONITORED
Isotope
27
121.123
25.
135,137
9
106,108,111,114
52,53
52
£3,65
206,207,208
55
95,97,98
fiQ.,62
77,8.2
107.109
203.205
232
238
Si
66,67,68
83
99
105
118
Element of Interest
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Molybdenum
Nickel
Selenium
silver
Thallium
Thorium
Uranium
Vanadium
Zinc
Krypton
Ruthenium
Palladium
Tin
NOTE: Isotopes recommended for analytical determination are underlined.
Page 3.5-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 6. RECOMMENDED ELEMENTAL EQUATIONS FOR
DATA CALCULATIONS
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Bi
In
Sc
Tb
Y
Element Equation ; ••'.••" r,7\;:';-V ;•''.:•'.;>•
(1.000)(27C)
(1.000)(121C)
(1 .000)(75C)-(3 . 127)[(77C)-(0. 8 15)(82C)]
(1.000)(137C)
(1.000)(9C)
(1.000)(llIC)-(1.073)[(108C)-(0.712)(106C)]
(1.000)(52C)
(1.000)(59C)
(1.000)(63C)
(1 .000)(206C) + ( 1 .000)(207C) + (1 .000)(208C)
(1.000)(55C)
(1.000)(98C)-(0. 146)(99C)
(1.000)(60C)
(1.000)(82C)
(1.000)( C) -
(1.000)(205C)
(1.000)(232C)
(1.000)(238C)
(1.000)(5 'C)-(3. 127)[(53C)-(0. 1 13)(52C)]
(1.000)(66C)
(1.000)(209C)
(1.000)(115C)-(0.016)(118C)
(1.000)(45C)
(1.000)(159C) '
(1.000)(89C)
;,:;::7v,77:Note;'; ' ':?
(1) .
(2)
(3)
(4)
(5)
(6)
(7)
(S)
C - calibration blank subtracted counts at specified mass.
(1) - correction for chloride interference with adjustment for Se77. ArCl 75/77 ratio may be determined from
the reagent blank.
(2) - correction for MoO interference. An additional isobaric elemental correction should be made if
palladium is present.
(3) - in 0.4% v/v HC1, the background from C1OH will normally be small. However, the contribution may be
estimated from the reagent blank.
(4) - allowance for isotopic variability of lead isotopes.
(5) - isobaric elemental correction for ruthenium.
(6) - some argon supplies contain krypton as an impurity. Selenium is corrected for Kr82 by background
subtraction.
(7) - correction for chloride interference with adjustment for Cr53 ratio may be determined from the reagent
blank.
(8) - isobaric elemental correction for tin.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-25
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Method IQ-3,5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 7. TOTAL RECOVERABLE METHOD DETECTION LIMITS FOR
SOLIDS/WASTE/LIQIJIDSl
Element
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Lead
Manganese
Molybdenum
Nickel
Selenium
Silver
Thallium
Thorium
Uranium
Vanadian
Zinc
Recommended
Analytical Mass
27
121
75
137
9
111
52
59
63
206,207,208
55
98
60
82
107
205
232
238
51
66
Method Detection Limits
Aqueous, jtg/L
1.0
0.4
1.4
0.8
0.3
0.5
0.9
0.09
0.5
0.6
o.i
0.3
0.5
7.9
0.1
0.3
0.1
0.1
2.5 .
1.8
Solids, mg/kg
0.4
0.2
0.6
0.4
0.1
0.2
0.4
0.04
0.2
0.3
0.05
0.1
0.2
3.2
0.05
0.1
0.05
0.05
1.0
0.7
MDL concentrations are computed for original matrix with allowance for sample dilution during preparation.
Page 3.5-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 8. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES
DRINKING WATER
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Sample
Concn.
:'G«g/L>
175
<0.4
<1.4
43.8
<0.3
<0.5
<0.9
0.11
3.6
0.87
0.96
1.9
1.9
<7.9
<0.1
<0.3
<0.1
0.23
<2.5
5.2
Low
Spike
.CWS/L>
50
10
50
50
10
10
10
10
10
10
10
10
10
50
50
10
10
10
50
50
Average
Recovery
R(%)
115.8
99.1
99.7
94.8
113.5
97.0
111.0
94.4
101.8
97.8
96.9
99.4
100.2
99.0
100.7
97.5
109.0
110.7
101.4
103.4
SCR)
5.9
0.7
0.8
3.9
0.4
2.8
3.5
0.4
8.8
2.0
1.8
1.6
5.7
1.8
1.5
0.4
0.7
1.4
0.1
3.3
RPD
0.4
2.0
2.2
5.8
0.9
8.3
9.0
1.1
17.4
2.8
4.7
3.4
13.5
5.3
4.2
1.0
1.8
3.5
0.4
7.7
High
Spike
Og/L)
200
100
200
200
100
100
100
100
100
10
100
100
100
200
200
100
100
100
200
200
Average
Recovery
R<»)
102.7
100.8
102.5
95.6
111.0
101.5
99.5
93.6
91.6
99.0
95.8
98.6
95.2
93.5
99.0
98.5
106.0
107.8
97.5
96.4
S(R)
1.6
0.7
1.1
0.8
0.7
0.4
0.1
0.5
0.3
0.8
0.6
0.4
0.5
3.5
0.4
1.7
1.4
0.7
0.7
0.5
RPD
1.1
2.0
2.9
1.7
1.8
1.0
0.2
1.4
0.3
2.2
1.8
1.0
1.3
10.7
1.0
4.9
3.8
1.9
2.1
1.0
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-27
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Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 8. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES (Cont).
WELL WATER
, Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Sample
Concn.
(M!/L)
34.3
0.46
<1.4
106
<0.3
1.6
<0.9
2.4
37.4
3.5
2770
2.1
11.4
<7.9
<0.1
<0.3
<0.1
1.8
<2.5
554
Low
Spike
Gig/L)
50
10
50
50
10
10
10
10
10
10
10
10
10
50
50
10
10
10
50
50
Average
Recovery
R(%)
100.1
98.4
110.0
95.4
104.5
88.6
111.0
100.6
104.3
95.2
*
103.8
116.5
127.3
99.2
93.9
103.0
106.0
105.3
*
S(R)
3.9
0.9
6.4
3.9
0.4
1.7
0.0
1.0
5.1
2.5
*
1.1
6.3
8.4
0.4
0.1
0.7
1.1
0.8
*
RPD
0.8
1.9
16.4
3.3
1.0
3.8
0.0
1.6
1.5
1.5
1.8
1.6
6.5
18.7
1.0
0.0
1.9
1.6
2.1
1.2
High
Spike
;Og/L)
200
100
200
200
100
100
100
100
100
10
100
100
100
200
200
100
100
100
200
200
Average
Recovery
R(%) :
102.6
102.5
101.3
104.9
101.4
98.6
103.5
104.1
100.6
99.5
*
102.9
99.6
101.3
101.5
100.4
104.5
109.7
105.8
102.1
S(R) .
1.1
0.7
0.2
1.0
1.2
0.6
0.4
0.4
0.8
1.4
*
0.7
0.3
0.2
1.4
1.8
1.8
2.5
0.2
5.5
RPD
1.3
1.9
0.5
1.6
3.3
1.6
1.0
0.9
1.5
3,9
0.7
1.9
0.0
0.5
3.9
5.0
4.8
6.3
0.5
3.2
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
Page 3.5-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 8. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES (Cont).
POND WATER
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Sample
Concn.
•0»g/L)
610
<0.4
<1.4
28.7
<0.3
<0.5
2.0
0.79
5.4
1.9
617
0.98
2.5
<7.9
0.12
<0.3
0.19
0.30
3.5
6.8
Low
Spike
(MS/L)
50
10
50
50
10
10
10
10
10
10
10
10
10
50
50
10
10
10
50
50
Average
Recovery
R(%)
*
101.1
100.8
102.1
109.1
106.6
107.0
101.6
107.5
108.4
*
104.2
102.0
102.7
102.5
108.5
93.1
107.0
96.1
99.8
S(R)
*
1.1
2.0
1.8
0.4
3.2
1.0
1.1
1.4
1.5
*
1.4
2.3
5.6
0.8
3.2
3.5
2.8
5.2
1.7
RPD
1.7
2.9
"5.6
2.4
0.9
8.3
1.6
2.7
1.9
3.2
1.1
3.5
4.7
15.4
2.1
8.3
10.5
7.3
14.2
3.7
High :
Spike
G*g/L)
200
100
200
200
100
100
100
100
100
100
100
100
100
200
200
100
100
100
200
200
/-Average
: .1 Recovery •
R(%) ; :
78.2
101.5
96.8
102.9
114.4
105.8
100.0
101.7
98.1
106.1
139.0
104.0
102.5
105.5
105.2
105.0
93.9
107.2
101.5
100.1
S(R)
9.2
3.0
0.9
3.7
3.9
2.8
1.4
1.8
2.5
0.0
11.1
2.1
2.1
1.4
2.7
2.8
1.6
1.8
0.2
2.8
RPD
5.5
8.4
2.6
9.0
9.6
7.6
3.9
4.9
6.8
0.0
4.0
5.7
5.7
3.8
7.1
7.6
4.8
4.7
0.5
7.7
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
* Spike concentration < 10% of sample background concentration.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-29
-------
Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 8. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES (Cont).
SEWAGE TREATMENT PRIMARY EFFLUENT
Element
AI
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Sc
Ag
Tl
Th
U
V
Zn
Sample
Concn.
(M5/L)
1150
1.5
<1.4
202
<0.3
9.2
128
13.4
171
17.8
199
136
84.0
<7.9
10.9
<0.3
0.11
0.71
<2.5
163
Low
Spike
-------
Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 8. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES (Cont).
INDUSTRIAL EFFLUENT
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Z
Sample
Concn. :
(M8/L)
44.7
2990
<1.4
100
<0.3
10.1
171
1.3
101
294
154
1370
17.3
15.0
<0.1
<0.3
0.29
0.17
<2.5
43.4
Low
Spike
vfrg/L)
50
10
50
50
10
10
10
10
10
10
10
10
10
50
50
10
10
10
50
50
Average
Recovery:;
R(%) •
98.8
*
75.1
96.7
103.5
106.5
*
90.5
*
*
*
*
' 107.4
129.5
91.8
90.5
109.6
104.8
74.9
85.0
S(R) -; v
8.7
*
1.8
5.5
1.8
4.4
*
3.2
*
*
*
*
7.4
9.3
0.6
1.8
1.2
2.5
0.1
4.0
:RPD
5.7
0.3
6.7
3.4
4.8
2.4
0.0
8.7
0.9
2.6
2.8
1.4
5.0
15.1
1.7
5.5
2.7
6.6
0.3
0.6
: High
' Spike
"(Mg/D :
200
100
200
200
100
100
100
100
100
100
100
100
100
200
200
100
100
100
200
200
Average
iRecovery
; :R(%)
90.4
*
75.0
102.9
100.0
97.4
127.7
90.5
92.5
108.4
103.6
*
88.2
118.3
87.0
98.3
108.7
109.3
72.0
97.6
S(R)
2.1
*
0.0
1.1
0.0
1.1
2.4
0.4
2.0
2.1
3.7
*
0.7
1.9
4.9
1.0
0.0
0.4
0.0
1.0
RPD
2.2
0.0
0.0
0.7
0.0
2.8
1.7
1.3
1.6
0.0
1.6
0.7
1.0
3.6
16.1
2.8
0.0
0.9
0.0
0.4
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
* Spike concentration < 10% of sample background concentration.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-31
-------
Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 9. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES
EPA HAZARDOUS SOIL #884
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Sample
Concn.
(fg/L)
5170
5.4
8.8
113
0.6
1.8
83.5
7,1
115
152
370
4.8
19.2
<3.2
1.1
0.24
1.0
1.1
17.8
128
Low
Spike
(M5/L)
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
Average
Recovery
R(%)
*
69.8
104.7
54.9
100.1
97.3
86.7
98.8
86.3
85.0
*
95.4
' 101.7
79.5
96.1
94.3
69.8
100.1
109.2
87.0
S(R)
*
2.5
5.4
63.6
0.6
1.0
16.1
1.2
13.8
45.0
*
1.5
3.8
7.4
0.6
1.1
0.6
0.2
4.2
27.7
RPD .
„
4.7
9.1
18.6
1.5
1.4
8.3
1.9
3.4
13.9
12.7
2.9
1.0
26.4
0.5
3.1
1.3
0.0
2.3
5.5
High
Spike
>g/L>
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Average
Recovery :
R(*)
*
70.4
102.2
91.0
102.9
101.7
105.5
102.9
102.5
151.7
85.2
95.2
102.3
100.7
94.8
97.9
76.0
102.9
106.7
113.4
S(R)
*
1.8
2.2
9.8
0.4
0.4
1.3
0.7
4.2
25.7
10.4
0.7
0.8
9.4
0.8
1.0
2.2
0.0
1.3
12.9
RPD
-
6.5
5.4
0.5
1.0
1.0
0.0
1.8
4.6
23.7
2.2
2.0
0.8
26.5
2.3
2.9
7.9
0.0
2.4
14.1
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
* Spike concentration < 10% of sample background concentration.
- Not determined.
+ Equivalent.
Page 3.5-32
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 9. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES
NBS 1645 RIVER SEDIMENT
. Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
Se
Ag
Tl
Th
U
V
Zn
Sample
: Coricn.
:&g/L)
5060
21.8
67.2
54.4
0.59
8.3
29100
7.9
112
742
717
17.1
41.8
<3.2
1.8
1.2
0.90
0.79
21.8
1780
'.•• Low :
Spike
:--fog/L>';v
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
Average
Recovery
R(%)
*
73.9
104.3
105.6
88.8
92.9
*
97.6
121.0
*
*
89.8
' 103.7
108.3
94.8
91.2 '
91.3
95.6
91.8
*
S(R)
*
6.5
13.0
4.9
0.2
0.4
*
1.3
9.1
*
*
8.1
6.5
14.3
1.6
1.3
0.9
1.8
4.6
*
RPD
_
9.3
7.6
2.8
0.5
0.0
-
2.6
1.5
-
-
12.0
4.8
37.4
4.3
3.6
2.6
5.0
5.7
-
High
Spike
0*g/L>
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Average
Recovery
R(%)
*
81.2
107.3
98.6
87.9
95.7
*
103.1
105.2
.
.
98.4
102.2
93.9
96.2
94.4
92.3
98.5
100.7
*
S(R)
*
1.5
2.1
2.2
0.1
1.4
*
0.0
2.2
_
_
0.7
0.8
5.0
0.7
0.4 .
0.9
1.2
0.6
*
RPD
3.9
2.9
3.9
0.2
3.9
-
0.0
1.8
„
_
0.9
0.0
15.1
1.9
1.3
2.8
3.5
0.8
-
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
* Spike concentration < 10% of sample background concentration.
- Not determined.
4- Equivalent.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-33
-------
Method IO-3.5
ICP/MS Methodology
Chapter IO-3
Chemical Analysis
TABLE 9. PRECISION AND RECOVERY DATA IN AQUEOUS MATRICES
EPA ELECTROPLATING SLUDGE #286
Element
Al
Sb
As
Ba
Be
Cd
Cr
Co
Cu
Pb
Mn
Mo
Ni
So
Ag
Tl
Th
U
V
Zn
Sample
Conen.
(«5/L)
5110
8.4
41.8
27.3
0.25
112
7980
4.1
740
1480
295
13.3
450
3.5
5.9
1.9
3.6
2.4
21.1
13300
Low
Spike
C«g/L)
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
Average
Recovery
R (%)
*
55.4
91.0
1.8
92.0
85.0
*
89.2
*
*
*
82.9
*
89.7
89.8
96.9
91.5
107.7
105.6
*
S(R)
*
1.5
2.3
7.1
0.9
5.2
*
1.8
*
*
*
1.2
*
3.7
2.1
0.9
1.3
2.0
1.8
*
RPD
_
4.1
1.7
8.3
2.7
1.6
-
4.6
6.0
-
-
1.3
6.8
4.2
4.6
2.4
3.2
4.6
2.1
-
High
, Spike
0"g/L)
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Average
Recovery
R(%)
*
61.0
94.2
0
93.4
88.5
*
88.7
61.7
*
-
89.2
83.0
91.0
85.1
98.9
97.4
109.6
97.4
*
S(RJ:
*
0.2
0.8
1.5
0.3
0.8
*
1.5
20.4
*
-
0.4
10.0
6.0
0.4
0.9
0.7
0.7
1.1
*
'•:. RPD
.
0.9
1.5
10.0
0.9
0.5
-
4.6
5.4
-
-
1.0
4.5
18.0
1.1
2.4
2.0
1.8
2.5
-
S(R) Standard deviation of percent recovery.
RPD Relative percent difference between duplicate spike determinations.
< Sample concentration below established method detection limit.
* Spike concentration < 10% of sample background concentration.
- Not determined.
4- Equivalent.
Page 3.5-34
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.5
ICP/MS Methodology
TABLE 10. REQUIRED QUALITY CONTROL REQUIREMENTS FOR ICP/MS ANALYSIS
QC procedure
Initial calibration
Initial calibration verification
Initial calibration blank
High standard verification
Interference check standard
Continuing calibration
verification
Continuing blank verification
Method blank
Laboratory control spike
Duplicate and/or spike
duplicate
Matrix spike
Serial dilution
Sample dilution
Typical frequency
At the beginning of the
analysis
Immediately after initial
calibration
Immediately after initial
calibration verification
Following the initial
calibration blank analysis
Following the high standard
verificatino, every 8 hours,
and at the end of a run
Analyzed before the first
sample, after every 10
samples, and at the end of the
run
Analyzed following each
continuing calibration
verification
1 per 20 samples, a minimum
of 1 per batch
1 per 20 samples, a minimum
of 1 per batch
1 per 10 samples per matrix
type
1 per 10 samples per matrix
type
1 per analysis per matrix type
Dilute sample beneath the
upper calibration limit and at
least 5X the MDL
Criteria
None
90%-110% of the actual
concentration
May be less than project
detection limits
95% -105% of the actual
concentration
80% -120% of the actual
concentration
90%-110% of the actual
concentration
Must be less than project
detection limits
Must be less than project
detection limits
80%-120% recovery, with the
exception of Ag and Sb
RPD j<20%
Percent recovery of 75%-
125%
See Section 9. 12; 90%-110%
of undiluted sample
As needed
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.5-35
-------
-------
EPA/625/R-%/OiOa
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-3.6
DETERMINATION OF METALS
IN AMBIENT PARTICULATE MATTER
USING PROTON INDUCED X-RAY
EMISSION (PIXE) SPECTROSCOPY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-3.6
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McCIenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• J. William Nelson, Florida State University, Tallahassee, FL
• Thomas Lapp, Midwest Research Institute, Gary, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• John Glass, SC Department of Health and Environmental Control, Columbia, SC
• David Harlos, Environmental Science and Engineering, Gainesville, FL
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
11
-------
10. References
Method IO-3.6
Determination of Metals in Ambient Particulate Matter
Using Proton Induced X-Ray Emission (PIXE)
Spectroscopy
TABLE OF CONTENTS
!• Scope [[[ gg-i
2. Applicable Documents . . . . .................... ................ 36-2
2.1 ASTM Standards .................. '..'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. 3.6-2
2.2 Other Documents ........................................ 3 6-2
3. Summary Of Method ......................................... 3.6-2
3.1 Transport of Ambient Air Paniculate Filters and Impaction Surfaces. ........ 3.6-2
3.2 Multi-Element PIXE Analysis ................................. 3^6-2
4. Significance ............................................ 3 5.3
5. Definitions ........................................... 3 5.3
6. Descriptions of Air Sampling and Analytical Systems ..................... 3.6-4
6.1 Air Particulate Samples .................................... 3 5.4
6.2 Air Sampling Media (filters and impaction surfaces) ................... 3.6-4
6.3 Air Particulate Samplers, ........................ . ........... 3 5.4
6.4 Description of PIXE Analysis System ............................ 36-5
6.5 Laboratories with PIXE Capability ............................. 3,6.7
7. X-ray Spectra .............................. ................ 3 g_7
7.1 X-ray Production ........................................ 3 g_7
7.2 Computing Methods for Spectral Analysis ......................... 3.6-7
7.3 Elemental Mass Per Unit Area ........................ ........ 36-7
7.4 Atmospheric Aerosol Concentrations ............................ 3.6-8
7.5 Detection Limits ......................................... 36-8
8. Quality Control and Assurance ................................... 3^-8
9. Precision and Accuracy ....................................... 36-9
9.1 Precision ............. ................... ............. 3 6.9
9.2 Accuracy ........................ ..... 3 6-9
-------
-------
Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF FILTER COLLECTED SPM
Method IO-3.6
DETERMINATION OF METALS IN AMBIENT PARTICULATE MATTER
USING PROTON INDUCED X-RAY EMISSION (PIXE)
SPECTROSCOPY
1. Scope
1.1 Suspended participate matter (SPM) in air generally is a complex multi-phase system consisting of
all airborne solid and low vapor pressure liquified particles having aerodynamic particle sizes from below
0.01-100 jtm and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.2 Research on the health effects of TSP in ambient air has focused increasingly on particles that can
be inhaled into the respiratory system, i.e., particles of aerodynamic diameters less than 10 pm. The
health community generally recognizes that these particles may cause significant, adverse health effects.
Recent studies involving particle transport and transformation suggests strongly that atmospheric particles
commonly occur in two distinct modes. The fine (<2.5 /*m) mode and the coarse (2.5 to 10.0 ^m)
mode. The fine or accumulation mode (also termed the respirable particulate matter) is attributed to
growth of particles from the gas phase and subsequent agglomeration, while the coarse mode is made of
mechanically abraded or ground particles. Particles that have grown from the gas phase tend to grow
rapidly to accumulation mode particles around 0.5 pm, which are relatively stable in the air. This range
of particle sizes includes inorganic ions such as sulfate, nitrate, ammonia, combustion-form carbon,
organic aerosols, metals, and other combustion products. Coarse particles, on the other hand, are mainly
produced by mechanical forces such as crushing and abrasion. Coarse particles, therefore, normally
consist of finely divided minerals such as oxides of aluminum, silicon, iron, calcium, and potassium.
Coarse particles of soil or dust primarily result from entrainment by the motion of air or from other
mechanical action within their area. The suspended particulate matter of urban atmospheres contains
substantial quantities of trace metals sulfates, organic matter, and other non-metallic constituents.
1.3 The procedure for analyzing the elemental metal components in ambient air particulate matter is
described in this Compendium method. The method is based upon active sampling using particulate
matter samplers. The ambient air particulate is collected on Polycarbonate Track Etched (PCFE) filters,
Teflon®, and Kapton® impaction surfaces, which are then analyzed by Proton Induced X-ray Emission
Spectroscopy (PIXE). The trace element concentrations of each fraction are determined with nondestruc-
tive proton induced X-ray system. The data are processed by a computer to yield micrograms of trace
element per square centimeter (/tg/cm2) and/or ^glrr? of metal constituents in air.
1.4 The PIXE method is a form of elemental analysis based on the characteristics of X-rays and the
nature of X-ray detection. The method uses beams of energetic ions, produced by an accelerator to
generate a beam of protons in the 2-5 MeV range, to create inner electron shell vacancies. As these inner
shell vacancies are filled by outer shell electrons, the characteristic X-rays emitted by this cascade effect
can be detected by wavelength dispersion. In this method, the X-rays are detected by Lithium drifted
Silicon (SiLi) detectors and the electrical pulses from the detector transferred to the pulse processor.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-1
-------
Method IO-3.6 Chapter IO-3
FIXE Methodology Analysis of SPM
1.5 Computer codes are used to perform data reduction of the acquired X-ray spectrum to produce
quantitative results. The method provides the sensitivity for accurate measurements at the nanogram or
less level for many important trace metals in the urban atmosphere. The PIXE method has the capability
to analyze a very small sample diameter in addition to evenly-distributed wide-area samples, which is
advantageous because it permits analysis of individual particle size fractions collected with single orifice
type cascade impactors.
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
* D1357 Planning the Sampling of the Ambient Atmosphere.
2.2 Other Documents
• ASM Metals Handbook (9th Ed.) Vol 10. Materials Characterization.
• U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94/038a.
• U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b.
• Scientific Publications of Ambient Air Studies (1-12).
3. Summary Of Method
3.1 Transport of Ambient Air Particulate Filters and Impaction Surfaces.
The filters and impaction surfaces transported from the sampling site to the laboratory are shipped
in holders specially designed to avoid contamination and minimize particle loss, then sealed in ziplock
plastic bags. Care should be exercised when handling the samples so as to prevent tearing, punctures,
and contamination.
3.2 Multi-Element PIXE Analysis
The trace element concentrations of each filter or impaction surface are determined using proton
excitation with energy-dispersive X-ray detection by a Lithium drifted Silicon (SiLi) detector with
associated amplifiers and a multichannel analyzer. The X-ray detection system consists of an X-ray
spectrometer and a pulse processor. After the X-ray detection system is calibrated with gravimetric
standards, the sample filters or impaction surfaces are placed in the instrument and analyzed. The data
output from the system is processed by computer to yield micrograms of trace element per square
centimeter ()tg/cm ) and subsequently fig/nr of air. PIXE is one of the more commonly used elemental
Page 3.6-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.6
Analysis of SPM PIXE Methodology
analysis methods because of its relatively low cost, nondestructive multi-element capabilities, high
detection limits, and preservation of the filter for any additional chemical analyses.
4. Significance
4.1 PIXE analysis represents a broad range method for rapid measurement of air particulate matter
collected by filtration and impaetion. The mass of elements ranging from sodium to uranium are
simultaneously measured with a few minutes bombardment and evaluated by computer code in a similar
time. As such, PIXE is a useful tool in monitoring both the behavior of the aerosol in time as well as
its distribution among particle sizes. Since the method requires samples in the microgram range, it allows
the use of air samplers of modest size and cost.
4.2 The area of toxic air pollutants has been the subject of interest and concern for many years. The
use of receptor models has resolved the elemental composition of atmospheric aerosol into components
related to emission sources. The assessment of human health impacts resulting in major decisions on
control actions by federal, state, and local governments are based on these data.
5. Definitions
[Note: Definitions used in this document are consistent with ASTM methods. All pertinent abbreviations
and symbols are defined within this document at point of use.]
5.1 Accuracy. The agreement between an experimentally determined value and the accepted reference
value.
5.2 Attenuation. Reduction of amplitude or change in wave form due to energy dissipation or distance
with time.
5.3 Calibration. The of comparing a standard or instrument with one of greater accuracy smaller
uncertainty for the purpose of obtaining quantitative estimates of the actual values of the standard being
calibrated, the deviation of the actual value from the nominal value, or the difference between the value
indicated by an instrument and the actual value.
5.4 Emissions. The total of substances discharged into the air from a stack, vent, or other discrete
source.
5.5 Filter. A porous medium for collecting particulate matter.
5.6 Fluorescent X-rays (Fluorescent Analysis). Characteristic X-rays emitted by excited atoms.
5.7 Impaetion Surface. A non-porous medium for collecting particulate matter.
5.8 Inhalable Particles. Particles with aerodynamic diameter of < 10 /im that can be inhaled into the
human lung.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-3
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Method IO-3.6 Chapter IO-3
FIXE Methodology Analysis of SPM
5.9 Interference. An overlap of spectral peaks due to two different elements.
5.10 Precision. The degree of mutual agreement between individual measurements, namely repeatability
and reproducibility.
5.11 Standard. A concept that has been established by authority, custom, or agreement to serve as a
model or rule in the measurement of quantity or the establishment of a practice or procedure.
5.12 Traceability to NIST. A documented procedure by which a standard is related to a more reliable
standard verified by the National Institute of Standards Technology (NIST).
5.13 Uncertainty. An allowance assigned to a measured value to take into account two major
components of error: systematic errors and random errors attributed to the imprecision of the
measurement process.
6. Descriptions of Air Sampling and Analytical Systems
6.1 Air Particulate Samples
Aerosols, among other things, are comprised of particulates that are composed of elements in the form
of compounds. These particulates range in size from submicron to > 100 jim. The mass of elements
in these particulates are almost never uniformly distributed across the size range of the aerosol. The
character or composition of aerosols is due to their proximity to local sources and any regional transport
associated with the air flow. The EPA has mandated that particular attention should be paid to the
particulates that are deemed respirable. This respirable range, defined as < 10 /on, is significant because
this is the range of particles that can be retained in the lungs.
Because aerosols are dynamic, the aerosol with temporal resolutions ranging from 1 h to days should
be studied. Numerous devices are available that can fractionate the aerosol while providing the temporal
resolution desired.
6.2 Air Sampling Media (filters and impaction surfaces)
For optimum results using PIXE analysis, samples should be collected on the thinnest possible backing
materials composed exclusively from low atomic number elements such as carbon, hydrogen, oxygen or
nitrogen. PCTE (Polycarbonate Track Etched) and Teflon® filters are often used, as are impaction
surfaces such as Kapton® and Mylar®. Thicknesses should not exceed 1,000 ^g/cm to keep the
background during PIXE analysis low and therefore provide the best detection limits. Thick filters or
thick particle deposits on the filter substrate will scatter the excitation protons and lower the
signal-to-noise ratio.
6.3 Air Particulate Samplers
Samples collected by many samplers are analyzed via PIXE analysis. The most extensive use has
been on those from the dichotomous sampler, as documented in Inorganic Compendium Method IO-2.2.
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Chapter IO-3 Method IO-3.6
Analysis of SPM FIXE Methodology
6.4 Description of PIXE Analysis System
A PIXE analysis system typically consists of an accelerator that produces a proton beam in the range
of 2 to 5 MEV, a beam transport system, optics, and a chamber for analysis. The detectors monitor the
X-rays generated and the number of protons (charge) used to generate those X-rays. Lithium drifted
Silicon (SiLi) detectors are commonly used to allow simultaneous collection of a range of X-rays
generated by collision of the proton beam with the sample atoms. A typical PIXE arrangement in a thin
target mode is depicted in Figure 1. Following is a description of a typical PIXE installation.
6.4.1 Accelerator.
6.4.1.1 The vertical 4MV Van De Graff accelerator HVEC model KN, with stainless steel
electrode acceleration tube, produces and directs beams into a 90° analyzing magnet. Beam energy
calibration is based upon measurements of the accurately known 13C(p,n)*3N and 7Li(p,n)7Be neutron
threshholds. The magnetic field intensity is measured by a proton resonance gaussmeter with frequency
readout for proton energy. The beam proceeds horizontally from the analyzing magnet via a 51 mm
diameter beam line through a control slit/ beam collimator assembly and magnetic quadrupole lens into
the target chamber area. Cyrogenic pumping is used at the target area, and a vacuum of 10~7 Torr is
maintained during irradiation of targets.
6.4.1.2 Immediately behind the target chamber is the doorway to the control room, which houses
both the accelerator controls and the data acquisition-analysis computer.
6.4.1.3 Samples are irradiated for a preset amount of charge as measured by a Tomlinson 2000
AEC rate meter and beam current integrator in which frequency output is gated off during busy periods
in the counting system. Count rates are normally limited to 2,000 counts per second. For analysis of
nonuniformly distributed samples, a homogeneous beam density is required, which is created with a
quadrupole lens to focus the beam into a horizontal line that is then vertically swept across the
collimators.
6.4.1.4 Automation of data acquisition in a PIXE analytic system is more than a convenience in
that the accuracy required for quality assurance of final analytic results can best be achieved with a
minimum of human operator intervention in a repetitive process. Analysis of air particulate samples
requires accurate location of the samples. While a variety of encoders for angular position are available,
an encoder was developed (based upon a 10-turn linear potentiometer) with advantages over standard units
in cost, size, mounting convenience, and ease of interface to the computer.
6.4.2 Acquisition System Hardware.
6.4.2.1 The overall data acquisition system is diagrammed in Figure 2 and consists of a mixture
of CAMAC and NIM modules, with the exception of the stepping motor interface. Beam current
integration is conventional with termination of a run by a preset scalar that monitors charge (exclusive
of dead periods). Target positioning in the bombardment chamber is controlled by the computer via the
Alpha Products interface and stepping motor. The position information is read as a voltage from a
potentiometer by an Alpha 12 Bit Analog Input card, as shown in Figure 3. A 10-turn potentiometer was
chosen for its small size (length 19 mm> diam 22 mm), resolution (0.007%), linearity (0.20%), and
dependability when operated in vacuum. For the sample holding wheel, both high and low mechanical
stops are accurately located in the chamber so that the built-in stops of the potentiometer are not used.
For a single 7.5° step of the motor, a 600:1 overall gear ratio results in a 0.0125° angular displacement!
6.4.2.2 Under a calibration routine, the stepping motor is operated at a conservative rate (to insure
dependable stepping) to establish the nonlinear characteristic of the particular potentiometer. This
information is stored in a table of position versus voltage and thereafter utilized for correct angular
positioning of the sample holding wheel. As shown in Figure 3, a panel meter is provided for general
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-5
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Method IO-3.6 Chapter IO-3
FIXE Methodology Analysis of SPM
indication to the operator; however, it does not reflect the nonlinearity correction. A switch is used to
select meter calibration resistance so that streaker position is read in hours while a discrete eight position
sample holder, used for individual targets, appears as digits 0 through 7.
6.4.3 Acquisition System Codes.
6.4.3.1 The software for the data acquisition is written in Microsoft Quick BASIC, version 3.0.
This software was chosen for the following reasons:
• Allows structured code (e.g., IF...THEN...ELSE).
• Allows true subroutine and function calls (Format same as FORTRAN).
• Graphic functions are built into the language.
• Runs in "interpretive" mode for development and testing and uses compiled code for actual data
acquisition.
• Direct access to absolute memory and I/O ports, enabling simple interface to special devices such
as CAMAC, Alpha Products controller, etc.
6.4.3.2 The system is menu-driven and uses the cursor keys to control pull down menus. Both
live mode and acquisition mode are available options. The system features many safeguards under the
acquisition mode to protect data from being overwritten or erased inadvertently. Provisions for archival
and retrieval are also available under the tape options menu. Complete chain of custody identifiers,
including tape labels, run numbers, irradiation date and time, sample identification, client, job number,
and duration of irradiation are required prior to beginning data acquisition. All identifiers are written
on the disk, along with the spectrum, as a single record in a random access file. Thus, no data collected
can be written without identification information. Each file is capable of storing up to 500 1024 channel
spectra in approximately two megabytes of disk space. The tape archival/retrieval submenu utilizes an
escape to DOS/Batch file execution process, so that any commercially available archival program can be
used for long-term data crunching and storage. PCTOOLS Backup/Restore utilities are being used
successfully for this purpose, but other packages could also be employed. The tape options submenu also
includes the ability to store up to six archived files (each containing 500 spectra) on the disk and allows
the user to select any archived tape for spectral display.
6.4.3.3 Under acquisition, mode control is transferred to the CAMAC crate until sealer presets
for irradiation duration are reached. Update frequency is approximately every 3-5 s to the screen. Once
irradiation is complete, data must be written on disk or erased before the next sample irradiation can
begin. A complete log file- is maintained, which stores all write-and-erase operations and is transparent
to the user. Another useful feature available under the acquisition mode is the auto/manual option. This
option allows the user to run one irradiation at a time or set up for automated irradiation and stepping
to the next target so that multiple irradiations can be completed without further user intervention. This
feature is particularly advantageous for sequential type samples.
6.4.3.4 The system is also capable of displaying up to three spectra simultaneously with options
for multiple overlaying, addition, subtraction, square root, and linear scaling, expansion between markers,
overlay of multiple spectra, and peak energy identification. Computer hardware requirements are an IBM
PC with an 80386 or later CPU, serial and parallel ports, an external floppy drive, and at least a
20 megabyte hard disk.
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Chapter IO-3 Method IO-3.6
Analysis of SPM PIXE Methodology
6.5 Laboratories with PIXE Capability
Positive ion accelerators capable of proton energies of 2 million volts and above generally are used
to bombard samples and produce the characteristic X-rays. Beam diameters range from jum to
centimeters. Approximately 100 laboratories having PIXE capability were counted in 1990.
7. X-ray Spectra
7.1 X-ray Production
The air particulate sample is placed in an evacuated (or helium-filled) chamber and subjected to
bombardment by the proton beam. The resulting characteristic X-rays are detected by an energy
dispersive (SiLi) detector with an associated pulse processor and multichannel pulse height analyzer
producing a display of the peaks. A spectrum for an indoor industrial aerosol is shown in Figure 4. For
a typical system, the efficiency for producing and detecting of the X-rays is shown as Figure 5. Using
. K, L, and M lines, the elements F and above are observable with varying sensitivities.
7.2 Computing Methods for Spectral Analysis
Several well documented computer codes are available to perform data reduction of the acquired X-ray
spectrum to produce quantitative results. A typical example of a code that produces an automated
evaluation of spectra is the computer code HEX, originally named REX. This code uses a library of
measured X-ray intensities for each element, as determined from gravimetric thin film standards, to
simultaneously fit the entire spectrum. The quality of the fit is judged by a non-linear least squares
analysis. The background continuum is fit by a ninth order constrained polynominal. Interferences are
accounted for in the fitting process since the library contains all the lines of each element and their ratios
to one another. In the example shown as Figure 4, lines are drawn through both the fit and the
background.
7.3 Elemental Mass Per Unit Area
From the spectral analysis, the mass per unit area of an element is found using the previously
measured efficiency curves (shown in Figure 4). PIXE is an absolute analysis method in that the
efficiency curve is fundamentally due to the physics of the atom, as reflected in the X-ray production
cross-section curve for a specific proton energy. Such curves are functions that mirror the changes in
the electronic structure of the inner shells of atoms as the atomic number increases. Therefore, they
provide an additional criteria by which the accuracy of gravimetric standards can be verified.
The measured efficiency in the calibration of a particular laboratory system also includes the effects
of solid angle subtended by the detector and the absorption of X-rays in reaching the detector. The
measured efficiency, referred to as the sensitivity curve, has units of counts per microgram per centimeter
squared per microCoulomb of collected charge, cts/Otg/cm2)/(/*C). To convert the output of the spectral
fitting to a quantifiable value, /ig/cm2, the number of integrated counts in a peak is divided by the
sensitivity for that element and the amount of charge collected to acquire the spectrum. For non-uniform
samples (such as those from impactors), a proton beam of uniform area! density envelops the sample,
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-7
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Method IO-3.6 Chapter IO-3
FIXE Methodology Analysis of SPM
which results in a measurement of the mass of the elements within the beam envelope instead of
mass/area.
7.4 Atmospheric Aerosol Concentrations
The mass per unit volume of sampled air, /tg/nr*, is found by multiplying the mass/area by the sample
area and dividing by the volume of air Vgt(j used to collect the sample, corrected to EPA's standard
temperature (25°C) and standard pressure (760 mmHg). The sampled air volume is corrected to EPA
reference conditions by:
V = V
Vstd VS
where:
Vst(j s volume of ambient air sampled at EPA-reference conditions, m^.
Vg ** volume of ambient air pulled through the sampler, mr*.
Tst£j = absolute EPA-reference temperature, 298°K.
Tm = average ambient temperature, °K.
Pjjjy. — barometric pressure during sampling measurement condition, mmHg.
Pstcj «= EPA-reference barometric pressure, 760 mmHg.
7.5 Detection Limits
A detection limit for each element can be calculated using the calibrated sensitivity curve (Figure 5);
however, this figure is not a good figure of merit because it represents the best case sensitivity for single
(or two element) standards on very thin backings with no consideration as to what other factors affect
detection limits. A more realistic approach for typical detection limits for a PIXE analysis in aerosol
measurement should also include the sampling substrate material as shown in Table 1. This table lists
minimum detection limits (in ng/cm2) for three commonly used filter substrates—Teflon® 2 /an pore size,
mixed cellulose ester, and PCTE® 0.4 (am pore size. Minimum detection limit is defined here as the
mass/area that is required to produce a peak spectral area that exceeds the background by a factor of
three. In Table 1, the Teflon® filters detection limits are higher than those of PCTE and cellulose filters
due largely to the additional background produced by inelastic scattering from the ^F nucleus with the
impinging proton at beam energies used in PIXE analysis.
A detection limit in terms of atmospheric concentration can only be stated if the corresponding sample
flowrate and time of sample collection are specified.
8. Quality Control and Assurance
The objective of a laboratory quality control and assurance program is to assure the accuracy,
precision, and reliability of the laboratory results for its customers. As such, the QA/QC program must
be all-encompassing and start well before any analysis is ever performed. Numerous sources for
Page 3.6-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.6
Analysis of SPM FIXE Methodology
establishing a QA/QC program, including those outlined in the section on XRF analysis for NBA, Inc.,
have been established. Protocols for establishing such programs are also available from EPA, NIOSH,
Industrial Hygiene Association, American Association for Laboratory Accreditation ISO90CK)'
ANSI/ASQC, etc. '
9. Precision and Accuracy
9.1 Precision
Precision is defined as the ability for a measurement to be reproduced. Many factors can affect the
stability of a measurement system that would alter its precision. Stability of the system parameters should
be constantly monitored to ensure minimal variability. In PIXE these variables include beam energy,
sample position, current integration, detector solid angle and efficiency, and system transmission. A good
QA/QC program will include routine monitoring of these variables through the use of standards validation
to ensure a high degree of precision. In general, a PIXE laboratory with such protocols in place should
be able to maintain precision to about ±1.5% relative for its standards; that is, a standard of 5.0 jig/cm2
should be reproducible from 4.925-5.075 jig/cm2. •
9.2 Accuracy
Accuracy is somewhat more difficult to define for aerosol samples. The usual procedure as outlined
above would entail calibration with known thin film standards. These standards have a certain error
associated with them in accordance with their methods of preparation. Many laboratories use thin films
from MicroMatter, Inc., which certifies their values at ±5% based on gravimetric determinations. This
uncertainty can be reduced somewhat based upon the known sensitivity curves for the elements, as
described above under Section 7.3. Since the curves are continuous functions, outliers in the suite of
standards used for calibration can be readily determined. In addition, standards obtained from other
sources (for example, NIST) can further reduce this error. In general, considering all possible sources
of error, analytical accuracies usually can be held to about ±2.5% for the standards.
Defining accuracies is somewhat more difficult for aerosol samples since errors associated with
sampling procedures, as well as analytical errors due to self-absorption on large particles, are much more
difficult to quantify. Although statistical procedures have been developed to correct for self-absorption
on large particles, they are only approximations based upon a uniform distribution of the trace elements
with the particles themselves. Of course, this assumption can never be known a priori and hence always
remains an uncertainty. For small particles, this uncertainty is not a problem since self-absorption is
minimal. The best methodologies for determining absolute accuracies for aerosol samples would have
to involve inter-comparisons among samplers under various experimental conditions as well as inter-
laboratory comparisons on the same filters to validate technique biases. Many such experiments have
been conducted using many different types of samplers followed by analysis using ICP, AA, XRF, PIXE,
and neutron activation. Absolute uncertainties of 10-20% on an element analysis are not uncommon in
such comparisons.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-9
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Method IO-3.6 Chapter IO-3
PIXE Methodology Analysis of SPM
10. References
1. Bauman, S., Nelson, J.W., and Hudson, G.M., "An Ion Beam Analysis Facility," Proc. IEEE
Trans. Nucl. Set., NS-28:1374, 1981.
2. Cahill, T.A., "Particle Induced X-ray Emission", ASM Metals Handbook, 9th Ed., Vol. 10:213.
3. Bauman, S., Houmere, P.D., Leonard, R., and Nelson, J.W., "A Dedicated PIXE Analysis
Laboratory Based upon a 4 MV Van De Graaff Accelerator," Nucl. Inst. and Meth., Vol B3:119,
1984.
4. Johansson, I.E., et al., "Automation in PIXE Data Acquisition," Nucl. Inst. and Meth., Vol
849:179, 1990.
5. Norman, L., et al., "A Bombardment Chamber for PIXE Analysis," Nucl. Inst. and Meth., Vol
B3:122, 1984.
6. Bauman, S., Houmere, P.D., and Nelson, J.W., "Cascade Impactor Aerosol samples for PIXE and
PESA Analysis," Nucl. Inst. and Meth., Vol. 181:499, 1981.
7. Cahill, T.A., Miranda, J. and Morales, R., "Survey of PIXE Programs - 1991," Int. Jour, of PIXE,
Vol. 1:297, 1991.
8. Kaufmann, H.C., Akselsson, K.R., and Courtney, W.J., "REX - A Computer Programme for PIXE
Analysis," Nucl. Inst. and Meth., Vol. 142:251, 1977.
9. Nelson, R.O. and Nelson, J.W., "A Programable Controller for the Streaker® Air Sampler," Nucl.
Inst. and Meth., Vol. B22:353, 1987.
10. Cahill, T.A., et al., "The Stacked Filter Unit Revisited," Visibility and Fine Particles, Ed. C.V.
Mathai, 213, 1990.
11. Johansson, S.A.E., and Campbell, J.L., PIXE: A Novel Technique for Elemental Analysis, Wiley,
1988.
12. Dzubay, T.G. (Ed.), X-ray Fluorescence Analysis of Environmental Samples, Ann Arbor Sci. Publ.,
1977.
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Chapter IO-3
Analysis of SPM
Method IO-3.6
PIXE Methodology
TABLE 1. DETECTION LIMIT COMPARISON OF VARIOUS FILTER MEDIA FOR
PIXE ANALYSIS DETECTION LIMITS ARE EXPRESSED IN NG/CM2
Element
Na
Mg
Al
Si
P
S
cr
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
Teflon*
94
62
54
47
48
43
41
33
27
26
22
18
13
10
9
8
8
9
12
12
14
18
21
41
59
77
95
117
148
190
243
297
348
446
551
670
Cellulose
79
46
43
38
35
31
30
26
25
27
18
11
7
4
3
3
2
2
2
2
2
3
3
6
9
11
13
15
19
24
30
37
43
59
83
83
PCTE
75
42
36
30
26
22
21
15
14
15
11
6
3
3
2
1
1
1
1
1
2
2
2
5
8
9
11
14
18
23
28
33
41
53
68
69
Element
In
Sn
Sb
Te
I
Cs
Ba
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tin
Yb
Lu
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Th
U
Teflon*
761
906
1250
103
97
84
75
69
60
53
50
42
40
35
34
31
32
31 '
29
34
35
36
35
36
40
44
43
41
45
48
48
55
59
59
112
146
Cellulose
100
127
142
120
94
75
61
48
39
31
26
22
19
16
15
14
13
10
9
10
8
8
17
19
8
13
11
8
8
8
8
9
9
9
18
20
PCTE
92
112
149
55
50
46
36
28
20
.16
17
19
10
10
9
8
8
5
5
6
5
5
5
5
4
6
5
5
6
6
6
7
6
8
13
20
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.6-11
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Method IO-3.
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Chapter IO-3
Analysis of SPM
Method IO-3.6
PIXE Methodology
Faraday
Cup 2
Beam <^1 3'
ItoV VtoF
CAMAC
Quad Scalar
CAMAC
Interface
Detector pu|se
Preamp processor
Busy
Ungated
Gated
Fast Des. Out
Signal
MCA
Hist. Mem.
Busy
Stepping
Motor &
Encoder
ALPHA
interface
Figure 2. PIXE Data Aquisition System.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.6-13
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Method IO-3.6
PIXE Methodology
Chapter IO-3
Analysis of SPM
SAMPLE CHAMBER
CONTROL PANEL
* 1
AAAA_1
GEAR 10:1
HIGH
STOP
1 STEP-0.0125
POTENTIOMETER ABSOLUTE ENCODER
Figure 3. Absolute angular encoder based upon a ten-turn linear potentiometer.
Page 3.6-14
Compendium of Methods for Inorganic Air Pollutants
January 1997
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Chapter IO-3
Analysis of SPM
Method IO-3.6
PIXE Methodology
10
0 50 100 150 200 250 300 350 400 «JSO 500
CHflNNEL NUMBER
Figure 4. Spectrum for an indoor industrial aerosol.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.6-15
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Method IO-3.6
PEXE Methodology
Chapter IO-3
Analysis of SPM
10'
c
Q
•*-•-
Ci
-------
Compendium of Methods
for the Determination of
inorganic Compounds
'in Ambient Air
Compendium SVIethod tO-3.7
DETERMINATION OF METALS
IN AMBIENT PARTICULATE
MATTER USING
NEUTRON ACTIVATION ANALYSIS
(NAA) GAMMA SPECTROMETRY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
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Method IO-3.7
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-
10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG),
and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning,
Center for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure
Research Laboratory (NERL), both in the EPA Office of Research and Development, were the project
officers responsible for overseeing the preparation of this method. Other support was provided by the
following members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTF, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTF, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
• Jack Weaver, North Carolina State University, Raleigh, NC
Peer Reviewers
• David Brant, National Research Center for Coal and Energy, Morgantown, WV
• Ron Fleming, Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI
• Joseph Lambert, Raleigh, NC
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
11
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Method IO-3.7
Determination of Metals in Ambient Particulate Matter Using
Neutron Activation Analysis (NAA) Gamma Spectrometry
TABLE OF CONTENTS
Page
1. Scope 3.7-1
2. Applicable Documents 3.7-2
2.1 ASTM Documents 3.7-2
2.2 U.S. Government Documents 3.7-2
2.3 Other Documents 3.7-3
3. Summary of Method 3.7.3
4. Significance 3.7-3
5. Interferences 3.7-4
6. Safety 3.7.5
6.1 Chemical Toxicology 3.7-5
6.2 Radioactive Safety 3.7-5
7. Definitions 3.7-5
8. Apparatus and Equipment 3.7-6
8.1 Research Nuclear Reactor 3.7-6
8.2 Gamma Spectroscopy System . 3.7-6
9. Reagents and Consumable Materials 3.7-7
9.1 Reagents 3.7-7
9.2 Standard Stock Solutions 3.7-8
9.3 Blanks 3.7_8
9.4 Quality Control Standard Reference Materials 3.7-8
9.5 Sample Irradiation Vials 3.7-8
10. Sample Receipt in the Laboratory 3.7-8
11. Calibration ; 3.7-9
12. Quality Control .... 3.7-9
13. Procedure 3.7-12
13.1 Unknown Sample Preparation 3.7-12
13.2 Metal Blank Preparation 3.7-12
13.3 Duplicate Sample Preparation 3.7-12
13.4 Standards Preparation 3.7-13
13.5 Irradiation and Counting for Short - Lived Isotopes 3.7-13
13.6 Irradiations and Counting for Medium and Long - Lived Isotopes 3.7-13
14. Calculations and Data Processing . . . 3.7-13
15. Precision and Accuracy 3.7-14
16. References 3.7-15
in
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Chapter IO-3
CHEMICAL SPECIES ANALYSIS
OF FILTER-COLLECTED SPM
Method IO-3.7
DETERMINATION OF METALS IN AMBIENT PARTICIPATE MATTER USING
NEUTRON ACTIVATION ANALYSIS (NAA) GAMMA SPECTROMETRY
1. Scope
1.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state, and local governments is based on these data. Accurate
measures of toxic air pollutants at trace levels are essential to proper assessments.
1.2 Suspended particulate matter (SPM) in air generally is a complex, multi-phase system of all airborne
solid and low vapor pressure liquified particles having aerodynamic particle sizes from below
0.01-100 pm and larger. Historically, SPM measurement has concentrated on total suspended particulates
(TSP), with no preference to size selection.
1.3 The most commonly used device for sampling TSP in ambient air is the high volume (hi-vol)
sampler, which consists essentially of a blower and a filter and usually operates in a standard shelter to
collect a 24-h sample. The sample is weighed to determine the concentration of TSP and is usually
analyzed chemically to determine the concentration of various inorganic compounds. The hi-vol is
considered a reliable instrument for collecting TSP in ambient air. When EPA first regulated TSP, the
national ambient air quality standard (NAAQS) was stated in terms of SPM with aerodynamic particle
sizes of < 100 /tm captured on a filter as defined by the hi-vol TSP sampler. Therefore, the hi-vol TSP
sampler was the reference method. The method is codified in 40 CFR 50, Appendix B.
1.4 More recently, research on the health effects of TSP in ambient air has focused increasingly on those
particles that can be inhaled into the respiratory system, i.e., particles of aerodynamic diameter of
< 10 ^m. These particles are referred to as PM^Q. The health community generally recognizes that
these particles may cause significant, adverse health effects. Therefore, the primary NAAQS for SPM
is now stated in terms of PM10 rather than TSP. The reference method for PM1Q is codified in 40 CFR
50, Appendix J, and specifies a measurement principle based on extracting an ambient air sample with
a powered sampler that incorporates inertial separation of PMjQ size range particles and collection of
these particles on a filter for a 24-h period. Again, the sample is weighed to determine PMjQ
concentration and is usually analyzed chemically to determine the concentration of various inorganic
compounds.
1.5 Current research strongly suggests that atmospheric particles commonly occur in two distinct modes:
the fine (<2.5 pm) mode and the coarse (2.5-10.0 j*m) mode. The fine or accumulation mode (also
termed the respirable particulate matter) is attributed to the growth of particles from the gas phase and
subsequent agglomerization, whereas the coarse mode is made of mechanically abraded or ground
particles. Because of their initially gaseous origin, the fine range of particle sizes includes inorganic ions
such as sulfate, nitrate, and ammonia as well as combustion-form carbon, organic aerosols, metals, and
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.7-1
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Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
other combustion products. Coarse particles, on the other hand, normally consist of finely divided
minerals such as oxides of aluminum silicate, iron, calcium, and potassium.
1.6 Airborne paniculate materials retained on a sampling filter, whether TSP or PMjQ size fractions,
may be examined by a variety of analytical methods. This method describes the procedures for the
neutron activation analysis (NAA) technique. The NAA method provides analytical procedures for
determining percent, ppt, ppm, or ppb levels of 40-50 elements that might be captured on typical glass
fiber filters used in hi-vol and dichotomous sampling devices. The NAA is not matrix dependent and is
therefore highly applicable for elemental analysis of a broad spectrum of paniculate material. A summary
of elements for which NAA is a suitable analysis technique is provided in Table 1.
1.7 NAA should be performed by nuclear applications engineers, radiochemists, and inorganic chemists
with related nuclear expertise. A minimum of 2-year's experience with NAA (of all matrices of interest)
is recommended.
2. Applicable Documents
2.1 ASTM Documents
• D4096 Application of High Volume Sample Method For Collection and Mass Determination of
Airborne Paniculate Matter.
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis.
• D1357 Practice For Planning the Sampling of the Ambient Atmosphere.
• D2986 Method for Evaluation of Air Assay Media by the Monodisperse DOP (Dioctyl Pthalate)
Smoke Test.
2.2 U.S. Government Documents
• STP598 Calibration in Air Monitoring
• U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume I: A Field Guide for Environmental Quality Assurance,
EPA-600/R-94/038a.
• U.S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, Volume II: Ambient Air Specific Methods (Interim Edition),
EPA-600/R-94/038b.
• "Reference Method for the Determination of Paniculate Matter in the Atmosphere," Code of
Federal Regulations, 40 CFR 50, Appendix B.
• "Reference Method for the Determination of Paniculate Matter in the Atmosphere (High Volume
Method)," Code of Federal Regulations, 40 CFR 50, Appendix J.
• "Reference Method for th'e Determination of Paniculate Matter in the Atmosphere (PM^Q
Method)," Code of Federal Regulations, 40 CFR 50, Appendix J.
• " 1978 Reference Method for the Determination of Lead in Suspended Paniculate Matter Collected
From Ambient Air," Federal Register 43 (194):46262-3.
• Test Methods for Evaluating Solid Waste, Method 9022, EPA Laboratory Manual, Vol. 1-A,
SW-846.
Page 3.7-2 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.7
Chemical Analysis Neutron Activation Analysis
2.3 Other Documents
• Crouthamel, C.E., et. al., Applied Gamma Ray Spectrometry, Pergamon Press, 1975.
• Lederer, C.M., et al., Table of the Isotopes, Sixth Edition, John Wiley and Sons, 1967.
• Shapiro, J., Radiation Protection, Harvard University Press, 1972.
• Faw, R., and Shultis, J., Radiological Assessment, Prentice - Hall, 1993.
• H&ydorn,K., Neutron Activation Analysis for Clinical Trace Element Research, Vol. 1, CRC Press,
1984.
• Burn, R., Research, Training, Test and Production Reactor Directory, American Nuclear Society,
Third Edition, 1988.
3. Summary of Method
3.1 NAA is an analytical technique dependent on the measurement of the number and energy of gamma
and X-rays emitted by the radioactive isotopes produced in the sample matrix by irradiation with thermal
neutrons from a nuclear reactor. Typically, the sample matrix plus appropriate blanks, SRMs, duplicates,
and standards of the elements of interest are irradiated for a selected time period in the neutron flux core
region of a research nuclear reactor. After irradiation and an appropriate radioactive decay, a gamma
count-energy spectrum is obtained by counting the sample on a nuclear gamma spectroscopy detection
system.
3.2 The NAA technique is qualitative in the sense that it incorporates the detection of characteristic
radioisotopes (the neutron-induced radioactivity of each trace element emits a characteristic gamma ray
energy spectrum, hence individual nuclear fingerprint); it is quantitative in that the detection system
records not only the energy of a given gamma emission, but also the number of emissions per unit time.
3.3 Quantitative analysis is obtained by comparing the number of characteristic X-ray or gamma-rays
of the unknown with the number determined for a standard. Interferences with a few elements must be
corrected for using the intensity of related interference gamma peaks and computer programs for
processing peak subtraction. Likewise, computer programs should also correct for sample count time,
radioactive decay, sample weight or volume, reactor flux, and detector geometry. Calibration and
efficiency of the detection system must be monitored throughout the counting period. Method detection
limits (MDLs) for elements detected by NAA are listed in Table 2.
3.4 Method detection limits are intended as a guide to instrumental limits of a system optimized for
multi-element determinations and employing commercial instrumentation and computer programs.
However, actual MDLs are dependent on the sample matrix, instrumentations, and selected operating
conditions of the particular nuclear research reactor.
4. Significance
4.1 In general, NAA is a versatile and non-labor intensive analytical technique. Liquids, solids, and
gases can be analyzed by NAA. It is a multi-element technique in that many elements can be analyzed
simultaneously in a given sample spectrum without changing or altering the apparatus as is necessary in
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.7-3
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Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
atomic absorption, etc. Importantly, special sample preparations, such as digestion or extractions, are
not required, and therefore the NAA method is non-destructive, i.e., the integrity of the sample is not
changed in any manner by prechemistry or the addition of any foreign materials for irradiation. Thus,
the problem of reagent-introduced contaminates is completely avoided. For most elements of interest,
the analytical approach for NAA requires little if any post-irradiation chemistry; thus, the amount of
technician contact per sample analysis is reduced considerably. The NAA method is fast and convenient;
for many elements, several samples can be irradiated at a given time and counted later on a given decay
schedule.
4.2 Finally, the NAA method offers high sensitivity to trace elements. The sensitivity obtained by
activation analysis is a function of the neutron cross section of the element in question, available neutron
flux, length of irradiation, resolution of the detector, matrix composition, and the total sample size.
Hence, increasing neutron fluxes, increased irradiation times, and major advances in nuclear technology
in the areas of increased efficiency and resolution have pushed the detection limits of most elements to
very low levels.
5. Interferences
5.1 General Interferences
5.1.1 Elemental Nuclear Parameters. The radioactive elements, their related isotopes, and their
nuclear parameters are shown in Table 3. Interferences with NAA occur in three primary categories as
described in the following paragraphs.
5.1.2 Sensitivity. Sensitivity can decrease when an element exists in sufficient quantity to produce
high gamma activity in the filter sample that masks the lower gamma activity from other elements of
interest. The primary correction for this situation (when feasible) is to pick irradiation times and decay
times that emphasize the elements of interest and de-emphasize the interfering element.
5.1.3 Similar Gamma Ray Emissions. This situation exists when two radionuclides emit a gamma
ray of similar energy that interferes with each other. Possible corrections to this situation are as follows:
• Utilize different irradiation and decay times.
• Use high-quality, high-resolution HPGE or GeLi detectors to resolve close peak, especially when
using sophisticated computer programs that use iterative least square curve fitting and peak search
routines.
* Use computer programs that locate a "clean" gamma photopeak of the interference and use its net
area and known nuclear characteristics to calculate and subtract the interfering peak net area from
the gamma ray of interest along with percent error calculations.
5.2 Duplicate Radionuclide Production
This interference occurs when the nuclei of 2 unrelated elements absorb a neutron and produce the exact
same radionuclide. The correction is to use the net area of a gamma peak of another radionuclide
associated with the interference and the known nuclear characteristics produced by the interference parent
to calculate the actual production rates of the interference and subtract from the radionuclide gamma peak
of interest along with percent error calculations.
Page 3.7-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter 10-3 Method IO-3.7
Chemical Analysis Neutron, Activation Analysis
6. Safety
6.1 Chemical Toxicology. The toxicology or carcinogenicity of all chemicals used in this method is not
completely known. Each chemical should be regarded as a potential health hazard, and exposure to these
compounds should be as low as reasonably possible. Each laboratory is responsible for maintaining a
current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this
method. A reference file of material data handling sheets (MDS) also should be available to all personnel
involved in the chemical analysis. .All chemicals should have the purchase date, and expiration date
written on the container. Each professional or technician working in the laboratory should participate
in yearly chemical safety refresher courses.
6.2 Radioactive Safety
6.2.1 The radiological operations should be under the direction of a radiological safety officer or
health physicist.
6.2.2 The laboratory must have an Agreement State or NRC license to possess controlled levels of
radioactivity.
6.2.3 All professionals and lab technicians should be officially trained, certified, and documented to
work with radioactive materials.
6.2.4 Radiation surveys of the lab area work stations should be performed daily to properly limit the
dose exposure to lab personnel and to lower the background levels of radioactivity subject to the nuclear
detector systems used for NAA.
6.2.5 Contamination swipes of work areas should be performed weekly to protect employees from
internal uptake and to prevent contamination of the nuclear detectors or specific samples being counted.
7. Definitions
/Note: Definitions used in this document are consistent with ASTM methods. All pertinent abbreviations
and symbols are defined within this document at point of use.]
7.1 Instrument Detection Limit (IDL). The concentration equivalent of the element, which is equal
to three times the standard deviation of the blank.
7.2 Method Detection Limit (MDL). The minimum concentration of the element that can be identified,
measured, and reported with a 99% confidence level that the element concentration is greater than zero.'
7.3 Laboratory Reagent Blank (LRB) (Preparation Blank). An aliquot of water that is treated exactly
as a sample, including exposure to all labware, equipment, solvents, reagents, etc. that are used with
other samples. The LRB is used to determine if the method analytes or other interferences are present
in the laboratory environment, the reagents, or apparatus.
7.4 Internal Standard. Pure elements added to a solution in known amounts and used to measure the
relative responses of other elements that are components of the same solution. The internal standard must
be an element that is not a sample component.
7.5 Stock Standards Solution. A concentrated solution containing one or more elements prepared in
the laboratory using certified reference compounds or purchased from a reputable commercial source.
January 1997 Compendium of Methods for Inorganic Mr Pollutants Page 3.7-5
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Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
7.6 Calibration Check. A radioactive standard (i.e., Ra22^) used to determine acceptable instrument
performance prior to calibration and sample analyses.
7.7 Laboratory Fortified Blank (LFB). An aliquot of reagent water to which known quantities of the
method elements are added in the laboratory. The LFB is analyzed exactly like the sample, and its
purpose is to determine whether method performance is within acceptable control limits.
7.8 Laboratory Fortified Sample Matrix (LFM). An aliquot of an environmental sample to which
known quantities of the method elements are added in the laboratory. The LFB is analyzed exactly like
the sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical
results. The background concentrations of the elements in the sample matrix must be determined in a
separate aliquot and the measured values in the LFM corrected for the concentrations found.
7.9 Quality Control Standard Reference Material (SRM's). Elementally certified standard reference
materials (NIST, NRC, IAEA, etc.) of a matrix similar to the unknowns that are analyzed as blind control
samples with the knowns.
8. Apparatus and Equipment
The basic instrumentation for performing neutron activation analysis consists of a nuclear reactor for
irradiating the samples, nuclear detectors for detecting the gamma emissions, and various types of multi-
channel analyzer systems that range from simple data acquisition systems to complex computerized data
acquisition and processing systems. A general summary of the basic NAA process is shown in Figure 1.
8.1 Research Nuclear Reactor
•I O r\
8.1.1 The research nuclear reactor must have a minimum thermal neutron flux: 1 x 10 n/cm -s,
open pool water cooled type containment, rotating, out-of-core, wet sample exposure facilities for uniform
sample irradiation for 1 to 24 h, and pneumatic irradiation facilitates for fast 10 s to 60 min sample
irradiations.
8.1.2 Primary consideration must be given to accurately measuring the thermal neutron flux
distribution within the volume that is intended for irradiation of the samples. Many conditions cause a
distortion of the flux; hence, irradiation facilities need to be found where the flux does not vary over a
few percent (2% or less). If this situation does not exist, small flux monitors must be located in the
different sample positions for monitoring and counting the flux and making appropriate tables of flux
correction factors.
8.2 Gamma Spectroscopy System
8.2.1 Large Volume Lithium-Drifted Coaxial Ge(Li) or HPGe Nuclear Detectors. The primary
component in a gamma spectroscopy system is the gamma detector. This detector typically consists of
a coaxial-shaped lithium-drifted germanium Ge(Li) crystal or a high-purity HPGe coaxial detector
mounted in a vacuum tight cryostat, a liquid-nitrogen Dewar, and a very low noise preamplifier, all in
one complete unit. These detectors are very sensitive to a wide energy range of gammas, from
0-3.0 MeV. Typical efficiencies for commercial detectors run from 10-50% with some possessing up
to 100% efficiency. These detectors typically have an energy resolution of 1.7-2.2 keV and are capable
of effectively providing a clear definitive response to the many different energy gammas in a typical
irradiated sample. Due to their sensitivity to gamma rays from natural background radioactivity, Ge(Li)
Page 3.7-6 Compendium of Methods for inorganic Air Pollutants January 1997
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Chapter 10-3 Method IO-3.7
Chemical Analysis Neutron Activation Analysis
and HPGe detectors must be shielded by several Inches of lead with a copper - cadmium inner liner. The
nuclear characteristics of all radionuclides detectable on detectors such as these are shown in Table 4.
8.2.2 Low Energy Photon Detector (LEPD). A supplementary component of the gamma spectro-
metry system is a low energy photon detector (LEPD or LEPS). This detector is sensitive to low-energy
photons (7-rays and X-rays) and resolves X-ray events that are close in energy value. Since many
elements, when bombarded with thermal neutrons in a reactor, give off X-rays and low energy 7-rays,
the LEPD offers increased NAA sensitivity to many trace metals. The use of X-ray spectrometry when
combined with a low energy photon detector has several notable advantages over routine 7-ray
spectrometry. The isotopes decay with characteristic X-rays unique to the element; gamma decays are
not necessarily so. Therefore, in an X-ray spectrum of a given matrix, many elements can be determined
without the overlapping of photopeaks that sometimes occurs in 7-ray spectrometry. Another useful
characteristic of the LEPD is that it is "blind" to the higher energy 7-rays emitted by the radioactive
matrix. That is, the higher-energy photons tend to pass through the detector without interaction, while
the low-energy particles are absorbed. The low-energy photon detector plus Dewar is very similar'in size
and shape to the standard large-volume Ge(Li) detectors. The LEPD unit is constructed of a virtually
windowless (less than l/*m Ge) lithium-drifted germanium crystal wafer and is maintained at liquid
nitrogen temperatures by a cryosorption pumping and a liquid nitrogen Dewar. The detector has a
standard end cap window of 5 mils of beryllium. Such a detector, when coupled with a 4096 or greater
multichannel analyzer, has a useful range from 3 to approximately 600 keV. At above 500-600 keV, the
relative photopeak efficiency drops off, but the resolution remains sufficient to separate photopeaks as
close as 3 keV. At 270 keV, photopeaks as close as 750 keV can be separated. Typical resolution at
5.9 keV is 225 eV, and at 122 keV, it is 600 eV. The nuclear parameters of elements detected by LEPD
detectors are illustrated in Table 5.
8.2.3 Data Acquisition Systems. The commercial multichannel analyzer (MCA) is a device whose
primary function is to sort and store the myriad of proportion signals coming from the nuclear detector
due to gamma interaction with the detector. Based upon the calibration of the system (usually 0 - 2 MeV
for Ge(Li) and 0 - 200 keV for the LEPD), the analyzer will sort incoming signals according to their
energy and store them in an appropriate memory bit or "channel." Such a system typically might have
4096 or 8192 channels and be attached to microprocessors that have simple data reduction routines for
determining net X-rays counts in a peak and the X-rays energy of the peak. The more complex MCA
data acquisition systems consist of either: (1) multiple 4096 channel analyzers connected to PC type
computers with sufficient storage to have a variety of peak search and radionuclide identification routines,
a library of reference standards, half-life decay corrections, etc.; the final product is a report listing the
various experimental parameters of the sample and a listing of jtg/g, etc. of each element present in the
sample plus the error limits; or (2) multi-job, multi-task data acquisition processing systems, which allow
flexibility in designing specific data acquisition areas for independently operating many separate nuclear
detector systems with built-in microprocessors and minicomputers. The final product is the same as that
for the PC type gamma spectroscopy systems.
9. Reagents and Consumable Materials
9.1 Reagents
[Note: For purposes such as cleaning the hi-purity irradiation vials, acidifying solutions for storage, and
conducting standard dilution procedures, etc., sources of high-purity nitric acid should be maintained.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.7-7
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Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
9.1.1 Nitric Acid, high-purity, concentrated (sp.gr.1.41). Commercial Sources.
9.1.2 Water. ASTM Type I water (ASTM D1193) for use in cleaning procedures, standard
dilutions, etc.
9.2 Standard Stock Solutions
Mote: High-quality commercial grades of (atomic absorption) elemental standard solutions plus mixed
element standards can be effectively used.}
9.2.1 For the elements Ti, I, Cu, Mg, Mn, Na, K, Cl, V, and Al, the acid base for the solution must
be nitric acid. Both HC1 and K^jSC^ produce interferences in the standards for short-lived elements that
are not acceptable.
9.2.2 For all other elements, either a HNO^ or HC1 acid base is suitable.
9.2.3 Both single and multi-element standards should be prepared in bulk in the different size
irradiation container volumes used to eliminate stability problems.
9.3 Blanks
A laboratory reagent blank (LRB) is used to determine potential contamination problems and to determine
background levels of the elements of interest. The LRB must contain all the reagents in the same
volumes as used in preparing the samples. It must be carried through the sample preparation scheme.
9.4 Qualify Control (QC) Standard Reference Materials
The SRMs must be obtained from commercial (outside the lab) and federal sources of certified standard
reference materials. Certification documents and expiration dates must be maintained.
9.5 Sample Irradiation Vials
Pre-cleaned, high-purity Kartell or Olympic linear polyethylene vials in the 1 mL, 2.5 mL, 5 mL, 10 mL,
and 20 mL size should be maintained. A device needs to be maintained in a clean hood for heat-sealing
all sample vials.
10. Sample Receipt in the Laboratory
As you are notified of their availability, personnel within the neutron activation analysis laboratory shall
receive the samples as they are mailed or hand carried. Upon receipt of samples, assign each job a
control number and the chain of custody documents. Assign all samples an ascending NAA Lab number
in the NAA Laboratory Sample Receipt Log. Store all samples requiring refrigeration in refrigerator-
freezers. All other samples should be stored under cool, dry, and dark conditions in laboratory storage
cabinets in the restricted areas of the laboratory. (Samples requiring desiccant storage are stored in that
manner). Limit all contact with these samples to only the personnel assigned to this project.
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Chapter IO-3 Method IO-3.7
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11. Calibration
Ge(Li) or HPGe gamma spectroscopy detection systems are generally operated on- an energy range of 0
to 2000 keV utilizing 4096 to 8192 channels of data acquisition storage. The three calibration items of
daily interest are energy calibration, detector peak resolution, and efficiency stability.
11.1 Maintain a radioactive source (i.e. Ra-226 or an NIST multi-radionuclide source) that provides
gamma emissions from 50-1,750 keV.
11.2 Maintain this calibration source in a condition that allows a fixed, unchanged geometry that can be
duplicated exactly each time it is used.
11.3 Arrange for computer programs that allow daily comparisons of an initial first count of this
standard to all future daily counts.
11.4 Set up a daily QA/QC procedure for each detector that has the following:
• Duplicated geometry.
• Duplicated count time.
• Duplicated computer program parameters.
• Duplicated count comparisons that are compared to initial settings.
11.5 Count the calibration standard and process data.
11.6 For the energy calibration check, review all the designated gamma peak measurements to determine
that all peaks are within + 0.5 keV of their true value.
11.7 For the peak resolution check, review all peaks for anomalies, but concentrate on the
1,172-1,333 keV region to insure a peak resolution of 2.2 keV or less.
11.8 For the efficiency resolution check, compare peaks in the 500 to 600 keV and the 1100 to 1300
keV energy range to determine that the net gamma count in those peaks (corrected for decay) have not
varied more than ±5.0% from the initial preset measured values.
12. Quality Control (QC)
Neutron activation analysis methods shall be controlled by a documented, certified QA/QC program
utilizing validated SOPs and QA/QC document forms. A series of standard operating procedures must
be defined in the following areas for quality control of the complete analytical procedure. Documented
performance records showing quality of performance shall be maintained.
12.1 When samples arrive, verify them against shipping documents. Notify discrepancies and assign
control numbers. Record the samples in the entry log, and assign appropriate (matrix related) storage.
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An analytical job plan should also be formatted. The following control forms and concepts should be
used:
• Sample Receipt Control Numbers. , ;
• Chain of Custody Document Form.
• Unique Sample I.D. Numbers.
• Daily Freezer and Refrigerator Temperature Checks recorded on forms.
• Controlled Access Areas.
12.2 Maintain all laboratory areas in a controlled, clean, and organized atmosphere. Use the following
control forms:
• Daily Hood System Flow Checks.
• Daily Radiation Surveys of the Lab Work Area recorded on forms.
• Weekly Laboratory Radiation Swipe Tests recorded on forms.
12.3 All employees of the laboratory shall have documented training programs. Use the following
control forms:
• Employee Systems Operation Certifications (annual).
* Employee Update Training (annual).
• Employee SOP Certification.
12.4 Prepare all analytical standards and unknowns (as required) in class 100 clean hood conditions
according to documented instructions. Use the following control forms:
• Unknown Preparation Form.
• Standard Preparation Form.
• SRM, Blank, and Duplicates Preparation Form.
• Shelf-Life Certifications.
• Sample Weight QA form.
• Sample Volume QA form.
12.5 Prior to use each day, check and certify each weight balance system (using NIST certified weights).
Each technician using the systems certifies balance compliance. Records are stored on all certifications.
A Daily Balance Calibration Checks control form should be developed for this activity.
12.6 Routinely check pipettes for volume certification using the weighing of deionized water of known
volumes. Records are stored on all certifications. A Weekly Pipette Calibration Checks control form
should be developed for this activity.
12.7 Conduct a daily calibration, efficiency, and resolution check (using an NIST source, etc.) on each
gamma spectroscopy system. A (sign-off) daily review of certification should be made prior to use by
each technician using the system. Stored records are maintained on all QA data. Use the following
control forms and concepts:
• Daily QA/QC Calibration, Efficiency, and Resolution Checks.
• Daily QA/QC Performance Charts.
• Weekly QA/QC Background Checks.
• System Maintenance Logs.
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Chapter IO-3 Method IO-3.7
Chemical Analysis Neutron Activation Analysis
12.8 Nuclear reactor flux monitor irradiations will be made and accurate flux monitor corrections
maintained for the irradiation locations in each of the wet exposure irradiation ports. Certified records
should be maintained for all data and calculations related to these flux correction factors. These
documents are:
• NIST Flux Correction Tables.
• Flux Raw Data Documents and Experimental Parameters.
12.9 For each nuclear detector used in the system, determine all geometry (different sample counting
configurations) correction factors (curves). The following documents should be maintained:
• Certified Geometry Correction Factors Tables.
• Geometry Raw Data Documents and Experiment Parameters.
12.10 Prepare validation documents for the following:
• SOPs.
• All Computer Programs Used.
12.11 Maintain computer backup disks at a different location for the following:
• Gamma Spectroscopy Data Acquisition and Data Processing Programs.
• System QA/QC Gamma Spectroscopy Data.
• Client Project Gamma Spectra and Nuclear Parameters for Samples, Standards, Duplicates, SRMs
and Blanks.
12.12 Thoroughly document all sample irradiation and counting. Establish the following control forms:
• Nuclear Reactor Run Sheet.
• Pneumatic Facility Operation Form.
• Sample Counting and Data Processing Form.
12.13 For QA/QC control, a batch of NAA samples is considered to be a group of samples irradiated
at the same time under the same irradiation conditions, counted on the same gamma Spectroscopy
detectors and data acquisition systems, and processed under the exact same count time, calibration,
efficiency, and geometry conditions. Each NAA sample batch should contain the following QC samples
as a minimum:
• Blank Vial Analyses - 1 blank vial per 20 unknown samples.
• NBS SRM Analyses - 2 SRMs per 20 unknown samples.
• Duplicate Unknown Analyses - 1 duplicate per 20 unknown samples.
• Standards - Triplicate standards per batch of unknowns.
12.14 Use data review forms to evaluate the performance of these categories for each batch (and monthly
summaries) with the following controls:
• Duplicates: Solids = ±20% variance.
Liquids = ±10% variance.
• Method blanks: < 3X method blank average.
•SRMs: Solids ±10% certified value.
Liquids ±5% certified value.
* Standards: ±1% variance.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 3.7-11
-------
Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
12.15 The following system manuals and training documents should be maintained:
• Gamma Spectroscopy System Manuals. -
• Computer Program Software Manuals.
« Radiation Safety Study Guide (Health Physics Manual).
• QA/QC Validation Guidelines.
• QA/QC Lab Inspections.
• Applied Gamma - Ray Spectrometry, Adams and Dams.
• Table of the Isotopes, Lederer, Hollander & Perlman.
• SOP Manual
• Detector Geometry Correction Manual
• Reactor Flux Correction Manual
• Material Safety Data Sheet Manual
13. Procedure
13.1 Unknown Sample Preparation
13.1.1 Pre-punch air filter samples to a 3.0 cm diameter. All sample handling should be performed
in laminar flow clean hoods using new disposable plastic gloves, etc.
13.1.2 Carefully fold each air filter disk into itself until it is 1/4 its original size. See Figure 2 for
an illustration of the folding process.
13.1.3 Carefully insert the filter into pre-cleaned Kartell or Olympic hi-purity linear polyethylene
irradiation vials that are 30 mm long and 8 mm in diameter. Put the sample I.D. number on the vial
using marking pens that use ink that contains none of the elements of interest. Heat-seal and pre-clean
the vial prior to irradiation. All sample preparation should be controlled by instructions on the unknown
QA/QC form. Each of the new Kartell or Olympic hi-purity irradiation polyethylene vials are treated
as follows prior to placing samples into them for irradiation:
• 10 min soak in 20% nitric acid-distilled water solution.
• 60 min soak in deionized water.
• Rinse in distilled water.
In each batch of new irradiation vials, a total of 10 of each type vial and trace element levels determined
to ensure that contamination of the samples by the vial will not occur.
13.2 Metal Blank Preparation
13.2.1 Prepare method blank filters using the same procedures identified in Section 13.1 for
unknowns.
13.2.2 Prepare a minimum of one method blank filter per 20 unknown samples.
13.3 Duplicate Sample Preparation
13.3.1 Prepare duplicate sample filters using the same procedures identified in Section 13.1 for
unknown filter being duplicated.
13.3.2 Prepare a minimum of one duplicate filter per 20 unknown samples.
Page 3.7-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-3 Method IO-3.7
Chemical Analysis Neutron Activation Analysis
13.4 Standards Preparation
13.4.1 Prepare or purchase mixed element standards, liquid or solid, including the three categories
of standards itemized in Table 6.
13.4.2 Using the instructions on the QA/QC Standards preparation form, carefully pipette (using
QA/QC certified and checked calibrated pipettes) 0.5 ml of each mixed standard solution into its own
unique (pre-cleaned) Kartel or Olympic plastic 30 mm by 8 mm irradiation vial that has been labeled as
follows:
SMES (Short Mixed Element Standard)
MMES (Medium Mixed Element Standard)
LMES (Long Mixed Element Standard)
Next trim, heat-seal, and clean vials as per the instructions for the unknowns.
13.4.3 Standards should be prepared in triplicate based on the elements that are being analyzed in
the air particulate filters.
13.5 Irradiation and Counting for Short - Lived Isotopes
Unknown samples, standards, blanks, duplicates, and SRMs are irradiated individually for 20 s to 10 min
in the pneumatic transfer system of the nuclear reactor at a flux of 1.0 x lO1^ n/cnr -sec. (or greater).
After a monitored decay, each sample vial is rinsed in a radioactive hood and placed in non-irradiated
counting vials. After an exact decay time (determined by the results of preliminary sample analyses),
each sample, standard, blank, duplicate and SRM is counted for 30 to 300 s on designated Ge(Li)
detection systems. Data is analyzed (using the nuclear parameters in Tables 2 and 3) and spectra are
permanently stored on disk with appropriate nuclear parameters included. The elements typically
analyzed by short-lived isotopes are Al, V, Ti, Mn, Mg, Cl, Cu, F, O, Na, K, I, etc.
13.6 Irradiations and Counting for Medium and Long - Lived Isotopes
Unknown samples, standards, blanks, duplicates, and SRMs are again irradiated for 1 to 24 h at a flux
of 1.0 x 10" n/cm -s. (or greater) in the rotating wet vertical exposure irradiation facilities of the
nuclear reactor. After approximately a 5-7 day radioactive decay (to allow interfering activities to decay
away) of the samples and reference standards, both unknowns, SRMs, and standards are counted for
400-1,200 s on the gamma detection systems. Data is analyzed (using the nuclear reactor parameters in
Tables 4 and 5) and spectra is permanently stored on disk with appropriate decay time, dead time, etc.
and other nuclear data included. The elements typically analyzed by medium-lived isotopes are Na, K,
As, Sm, Cd, La, Mo, Br, Sb, U, Hg, Au, W, Pt, etc. After a 14-21 day decay, a 1,000-1,800 s gamma
count of each, sample and standard is made for long-lived isotopes. The elements typically analyzed by
long-lived isotopes are Ce, Ca, Lu, Th, Cr, Eu ,Yb, Nd, Zr, Ag, Cs, Fe, Sc, Zn, Co, Sr, Rb, Ni, Ba,
etc. (using nuclear parameters shown in Tables 4 and 5).
14. Calculations and Data Processing
Spectral data from the unknown samples, standards, and SRMs are processed using the commercially
developed computer programs for gamma peak search, least squares fitting, and NAA quantitative
analysis. All spectra and associated nuclear parameters from the analyses are stored on disk for future
January 1997 Compendium of Methods for Inorganic Air Pollutants . Page 3.7-13
-------
Method IO-3.7 Chapter IO-3
Neutron Activation Analysis _ Chemical Analysis
access as needed. Results are reported as Digrams or nanograms element per cubic meter of air with
percent error limits (2 sigma) based on known errors associated with counting statistics, precision,
accuracy of standards, weighing, pipetting, etc. As part of the computer processing during the counting
phase, an automatic peak search performs a gaussian peak fit on all single peaks. Multiples (several
peaks close together) are analyzed by an iterative least squares gaussian fit. The result from this peak
program Is the determination of the centroid channel (energy), FWHM (full width-half max), net
integrated peak area, and background. When no peak area appears, the system calculates a less-than
value (based on all available nuclear parameters) for die elemental determination. The number of counts
per sec per cubic meter of air, etc. of sample (Na) is computed as:
N
( Vstd ) ( tc ) ( D ) ( F ) ( G )
where:
N = the number of counts observed (net peak area).
-2
"Vstd = the standard cubic meters of air sampled (rrr)
F = the sample reactor flux position correction.
G = the sample geometry correction.
tc = the live counting time in seconds established for each count.
D = a dimensionless decay correction related to the end of the sample irradiation and is computed
by:
D = exp.
( 0.693t)
( Ti/2 )
where:
t = the elapsed time from end of irradiation to the middle of the counting sequence in the same
units as T.
T = the half-life of the element being evaluated.
The number of jtg, etc. of element per cubic meter of air is then calculated by dividing (Na) by (Ns),
which is the analogous term to (Na) but obtained for a standard. The output results for each element are
represented in units of jig/m . A sample data output report is provided as Figure 3.
15. Precision and Accuracy
Precision is measured as the percent difference between the values obtained for duplicates (i.e., Naj and
N^). The average of the values is used to base the percentage difference. The measurement of precision
provides us with the best indication of quality control's success. This determination is shown in the sum
Page 3.7-14 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
of errors associated with weighing, pipetting, individual reactor irradiations, counting statistics, detector
efficiency and resolution, and sample homogeneity.
D =
Na2 - Nal
Nal
x 100
15.1 Precision errors associated with typical reactor flux changes in pool type research reactors are
illustrated in Table 7.
15.2 Typical precision errors associated with detector efficiency changes with time are illustrated in
Table 8.
15.3 Typical precision errors associated with all variables involved in the preparation of samples are
illustrated in Table 9. ,
15.4 Accuracy
Accuracy is measured by percent error for standards and the results for analysis of various Standard
Reference Materials from NIST, Canada, IAEA, and other related agencies. Percent error is expressed
as the following equation:
Error =
( Observed - Known )
( Known )
x 100
15.4.1 Tables 10 through 13 represent a typical accuracy check in various matrix Standard Reference
Materials that are routinely irradiated and analyzed with unknowns.
15.4.2 For accurate QA control, a wide variety of SRMs should be maintained in the laboratory
similar to the typical ones listed in Table 14.
16. References
1. Crouthamel, C.E., et al., Applied Gamma Ray Spectrometry. Pergamon Press, 1975.
2. Lederer, C.M., et al., Table of the Isotopes. 6th Edition, John Wiley and Sons, 1967.
3. U. S. Environmental Protection Agency, Test Method for Evaluating Solid Waste, Method 9022, EPA
Laboratory Manual, Vol. #1 - A, SW-846.
4. Shapiro, J., Radiation Protection. Harvard University Press, 1972.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-15
-------
Method IO-3.7 Chapter IO-3
Neutron Activation Analysis Chemical Analysis
5. Faw, R., and Shultis, J. Radiological Assessment. Prentice - Hall, 1993.
6. Heydorn, K., Neutron Activation Analysis for Clinical Trace Element Research. CRC Press, Vol. 1,
1984.
7. Burn, R., Research. Training. Test and Production Reactor Directory. American Nuclear Society,
Third Edition, 1988.
Page 3.7-16 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
TABLE 1. SUMMARY OF ELEMENTS COMPATIBLE
WITH NAA
ELEMENT
TITANIUM
TIN
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MANGANESE
MAGNESIUM
COPPER
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I
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V
Cl
Al
Hg
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W
Mo
U
La
Cd
As
Sb
Br
Na
K
Ce
Ca
Lu
Se
Tb
Th
Cr
Eu
Yb
Hf
Ba
Sr
Nd
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Zr
Cs
Ni
Sc
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Fe
Zn
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January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-23
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
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Page 3.7-24
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-25
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
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Page 3.7-26 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
a
CQ
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H
t
Si
n.
00
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-27
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 5. NUCLEAR PARAMETERS OF LEPD - SENSITIVE ELEMENTS
Element
Selenium
Selenium
Mercury
Cadmium
Cobalt
Platinum
Palladium
Barium
Tungsten
Germanium
Cesium
Tin
Antimony
Europium
Samarium
Gadolinium
Terbium
Dysprosiu
m
Holmium
Erbium
Ytterbium
Ytterbium
Lutetium
Palladium
Isotope
75Se
79mSe
197Hg
H5Cd
60mCo
197pt
109mpd
139Ba
187W
75Ge
134mCs
123Sn
122msb
152mEu
153Sm
159Gd
160-rb
165Dy
166Ho
"Ifir
169yb
l^Yb
'77Lu
109pd
Abundance
0.87
23.52
0.14
28.86
100.00
25.30
26.71
71.66
28.41
36.54
100.00
4.72
57.25
47.82
26.72
24.87
100.00
28.18
100.00
4.88
0.14
31.84
2.59
26.70
Half-life
120.0 days
3.9 min.
65.0 hr.
53.0 hr.
10.5 min.
20.0 hr.
5.0 min.
82.9 min.
24.0 hr.
82.0 min.
2.9 hr.
39.4 min.
3.5 min.
9.3 hr.
46.7 hr.
18.0 hr.
73.0 days
2.3 hr.
27.0 hr.
7.5 hr.
32.0 days
4.2 days
6.8 days
13.6 hr.
Nuclear cross
section
30.0
0.4
905.0
1.2
37
1.0.0
12.2
0.4
40.0
0.5
30.6
0.2
6.0
8730.0
210.0
3.4
46.0
700.0
64.0
9.0
11,000.0
9.0
2100.0
12.2
Low-energy photon
energies (teeV)
10.7,66.3, 96.7, 121.1,
136.0
95.9
66.98, 68.79, 77. 97
24.2
58.5
66.8, 75.7, 99.0, 129.7
188.9
36.4, 165.8
69.3, 71.2, 72.3, 134.3
198.6, 264.6
31.0, 35.0, 127.4
160.2
61.6, 76.3
40, 122
41, 70, 103
44
46, 87
47,98
49, 81
41, 118
54, 190
54
56, 88, 113
22, 41, 88, 104
Page 3.7-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
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January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-29
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 7. GOLD FLUX MONITOR COMPARISON
1
Information in this table is an indication of the potential flux variation from one
reactor irradiation to another throughout the sample year using duplicate reactor
parameters. There is a 0.4% error is associated with the counting statistics.
Flux Monitor &UQ
Flux Run 1
Flux Run 2
Flux Run 3
Flux Run 4
Flux Run 5
Flux Run 6
Flux Run 7
Flux Run 8
Flux Run 9
Flux Run 10
Flux Run 11
Flux Run 12
%\ £H& SN
January
February
March
April
May
June
July
August
September
October
November
December
Average
Net Cott»t& at 0*411 MeV
An-in Oatsma £eafc
58,266 ± 0.4%
58,397 + 0.4%
58,402 ± 0.4%
58,122 ± 0.4%
58,316 ± 0.4%
58,105 ± 0.4%
58,247 ± 0.4%
58,399 ± 0.4%
58,518 ± 0.4%
58,175 ± 0.4%
58,348 ± 0.4%
58,433 ± 0.4%
$8,310 £3$ ^
Page 3.7-30
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
TABLE 8. EXAMPLE OF 38% HPGE DETECTOR
EFFICIENCY STABILITY STUDIES1
t>8te
July 27, 1994
July 28, 1994
July 29, 1994
July 30, 1994
July 31, 1994
June 30, 1994
May 16, 1994
April 18, 1994
March 14, 1994
February 7, 1994
January 10, 1994
December 31, 1993
November 27, 1993
October 21, 1993
September 28, 1993
August 23, 1993
.AVERAGE
609 3 J&?V C&i&jna Counts
26,758 ± 0.6%
26,523 ± 0.6%
26,840 ± 0.6%
26,635 ± 0.6%
26,402 ± 0.6%
26,677 ± 0.6%
26,770 ± 0.6%
26,554 ± 0.6%
26,726 ± 0.6%
26,836 ± 0.6%
26,786 ± 0.6%
26,554 ±0.6%
26,766 ± 0.6%
26,670 ± 0.6%
26,749 ± 0.6%
26,741 ± 0.6%
s ' 26,687 ± 28$
1
Based on 300 second count of Ra-226 Standard
Source in a fixed geometry.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-31
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 9. I, Br, Cl STANDARD COMPARISON
1
Standard
EPA Standard 1
EPA Standard 2
EPA Standard 3
EPA Standard 17
EPA Standard 18
EPA Standard 19
EPA Standard 37
EPA Standard 38
EPA Standard 39
EPA Standard 41
EPA Standard 42
EPA Standard 43
EPA Standard 71
EPA Standard 72
EPA Standard 73
I '
71326
71538
71105
71250
71612
71427
71582
71851
71841
72124
72831
72199
72828
71868
72017
Br ' ' "
28314
28630
28127
28230
29450 -
28421
28819
28844
28560
29006
28861
28796
28860
28723
29495
ci
18220
18357
18201
18488
18245
18119
17860
18092
18031
18545
18344
18566
18339
18316
18221
1 (1) These are integrated gamma ray photopeak net counts for the 442.0 MeV 1-128 gamma ray, the 617.0 Mev
Br-80 gamma ray, and the 1642.0 Mev Cl-38 gamma ray of typical standards used for short-lived analyses.
(2) Each standard is composed of 200 Digrams Cl (200 lambda), 25 /tgrams Br (25 lambda), and 25 /igrams I
(25 lambda) for a total volume of 250 lambda (0.25 ml).
(3) Each standard represents a separate 3 minute pneumatic rabbit irradiation at 1 x 101J n/cm -sec, 21 minute
decay, and 500 sec. count on a 35 percent GeLi Gamma Spectrometry System.
(4) Standards 1 through 3 were prepared as fresh stock solutions.
(5) Standards 17 through 19 were prepared as fresh stock solutions.
(6) Standards 37 through 39 were prepared as fresh stock solutions.
(7) Standards 41 through 43 and 71 through 73 were prepared as fresh stock solutions.
(8) This table provides information on the sum of errors associated with (a) weighing, (b) pipetting, (c)
individual reactor irradiations, (d) counting statistics, and (e) detector efficiency and resolution stability over
a period of 1 year.
Page 3.7-32
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
TABLE 10. NAA OF TRACE ELEMENTS IN NIST 16321
(/^grams/gram)
BleHieni
Titanium
Tin
Iodine
Manganese
Magnesium
Copper
Silicon
Vanadium
Chlorine
Aluminum
Mercury
Samarium
Tungsten
Molybdenum
Uranium
Lanthanum
Cadmium
Gold
Arsenic
Antimony
Bromine
NAA Value
944.17
15.0
2.713
38.957
1625.16
<20.0
31,857.35
34.771
947.63
18,100.96
0.141
1.637
<3.0
3.867
1.414--
10.389
<0.25
<0.00001
5.894
3.629
17.787
NIST
Certified Vatue
(960)
(10.1)
(2.88)
(40)
(1600)
(18)
(33,800)
(35)
(962)
(17,800)
(0.12)
(1.66)
(3.82)
(1.4)
(10.5)
(5.9)
(3.6)
(17.7)
Jilement
Sodium
Potassium
Cerium
Calcium
Lutetium
Europium
Selenium
Thorium
Chromium
Ytterbium
Neodymium
Barium
Cesium
Silver
Nickel
Scandium
Rubidium
Iron
Zinc
Cobalt
&AA Vs&e.
387.95
2854.84
20.06
4225.14
0.13
0.343,
2.947
3.1
20.287
0.788
3.0
351.28
1.52
<0.09
<20.0
3.881
21.441
8741.63
34.256
5.832
MS? ,
Certified Value
(380)
(2900)
(19.6)
(4100)
(0.13)
(0 .34)
(2.9)
(3.1)
(20.2)
(0.78)
(342)
(1.52)
(0.056)
(15)
(3.86)
(21.1)
(8700)
(37)
(5.78)
The value in brackets in the certified or best known value for this element in this Standard Reference Material.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-33
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 11. NAA OF SE IN MIST SRM 1643 - A WATER
(nanograms Se/ml water)
Report No.
333260
333227
333227
333233
333233
333233
333233
333226
333226
315670
315670
315612
315612
NIST Certified Va&e
11.0 ± 1.0
11.0 + 1.0
11.0 + 1.0
11.0 + 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
11.0 ± 1.0
NAA Measured Value
11.092
10.907
11.116
11.202
10.591
11.000
10.967
11.186
11.311
10.550
11.223
10.864
11.142
Page 3.7-34
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
TABLE 12. QA NAA ANALYSES OF NIST SRM 1566 OYSTER
(/igrams element/gram SRM)
,,,, ite&eat # -
•«""•• *
NIST Certified
Values
333266
333266
333296
348760
348766
348766
348778
348114
348115
348115
348112
315668
315668
315668
315668
315668
315668
315648
315685
315695
315685
; % &L> ""
3.5 ± 0.4
. 3.351
3.301
3'.477
3.613
3.485
3.528
3.413
3.496 -
3.67
3.31
3.232
3.867
3.693
3.29
3.877
3.421
3.422
3.565
3.383
3.796
3.226
"""*" ™A* '
13.4 + 1.9
13.618
13.512
13.342
13.371
14.324
13.665
12.188
12.745
12.978
14.185
12.439
13.729
13.023
13.026
13.193
13.178
13.288
13.006
13.317
13.407
13.357
~~~,-" gar-"
852.0 ± 14.0
842.51
846.25
8842.47
843.43
842.26
857.52
854.76
842.92
863.47
846.12
863.92
855.3
856.11
848.85
849.47
867.33
845.83
847.01
860.01
860.85
844.43
- $gbtftm
2.1 ± 0.5
2.278
2.194
2.041
2.044
2.149
2.083
2.137
1.960
2.331
2.099
2.077
2.004
2.081
2.217
2.103
2.072
2.085
2.095
2.234
2.064
2.111
- '•tfcjjf&r ,
63.0 ± 3.5
64.729
63.686
61.149
63.617
62.103
63.152
66.901
64.119
63.253
61.317
61.749
60.355
63.301
61.972
63.580
61.753
60.981
64.620
61.347
65.079
62.318
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-35
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 13. QA NAA ANALYSES OF NIST SRM RM-50 TUNA
(/igrams element/gram SRM)
Report No.
NIST Certified
Values
333215
331215
333266
333266
333296
333296
348766
348766
348766
348766
348766
348766
348766
348778
348115
315685
315685
348760
348760
348760
348760
348760
Mercery ' ' " :
0.95 ± 0.1
1.003
0.086
0.919
0.903
0.996
0.988
1.005
0.946
0.89
1.019
0.957
0.983
1.002
0.923
0.982
0.933
—
0.995
0.942
1.134
0.974
0.956
- Arsenic
3.3 ± 0.4
3.407
3.494
3.278
3.269
3.509
3.164
3.365
3.278
3.497
3.299
3.256
3.56
3.482
3.412
3.544
3.699
3.346
3.348
3.256
3.278
3.544
3.525
Seleuiam
3.6 ± 0.4
3.646
3.852
3.537
3.662
3.578
3.794
3.864
3.828
3.461
3.669
3.627
3.554
3.49
3.483
3.994
3.726
3.514
3.519
3.731
3.695
3.9
3.59
23*tc
13.6 ± 1.0
12.752
13.876
13.417
13.876
13.553
14.172
14.021
14.487
14.134
13.731
12.821
12.878
13.925
14.552
14.238
14.008
13.872
14.347
13.901
13.335
12.843
12.725
Page 3.7-36
Compendium, of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
TABLE 14. CERTIFIED STANDARD REFERENCE MATERIALS
1645
4335
1648
1649
1630
1632
4353
1632-A
1632-B
160-B
1635
1621
1566
1566-A
RM-50
1577
1577-A
1577-B
1575
1570
1549
1573
RM 8505
1571
1084
1633
1572
1643-A
1643-B
1643-C
1646
1568
1567
688
278
2672
2671
697
610-V-611
45-B
950-A
U-100
U-030
NIST
River Sediment
Peruvian Soil
Urban Particulate Matter
Urban Particulate Matter
Coal
Coal
Rocky Flats Soil
Coal
Coal
Steel
Coal
Fuel Oil
Oyster Tissue
Oyster Tissue
Tuna
Bovine Liver "
Bovine Liver
Bovine Liver
Pine Needles
Spinach
Milk
Tomato Leaves
Oil
Orchard Leaves
Oil
Flyash
Citrus Leaves
Water
Water
Water
Estuarine Sediment
Rice Flour
Wheat Flour
Basalt Flour
Obsidian
Urine
Urine
Bauxite
Glass
River Sediment
Uranium
Uranium
Uranium
FDA
101-F
121-D
360-A
2704
V-2-1
Soil 5
SP-M-1
MA-M-1
MA-6
H-4
MA-A-1
MA-A-2
A-ll
V-4
V-8
V-10
MA-B-1
A-2
SL-1
A-3-1
S-7
F-l
S-8
Air-3/1
V-9
SD-B-2
H-9
MA-A-3
H-8
MA-B-3-1
NIST (continued)
Animal Feed
Steel
Steel
Zircalloy
Buffalo River Sediment
IAEA
Wheat Flour
Soil
Seaplant
Oyster Tissue
Fish
Muscle
Copepod
Fish
Milk Powder
Potatoes
Rye Flour
Hay
Clam
Blood
Lake Sediments
Animal Bone
Uranium Ore
Feldspar
Uranium Ore
Air Filters
Cotton Cellulose
Oyster
Diet
Shrimp
Kidney
Fish
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-37
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
TABLE 14. (continued)
CANADA
GRS-1 Gold Tailings
UTS-2 Uranium Tailings
UTS-4 Uranium Tailings
FER-4 Iron Formation Rock
FER-1 Iron Formation Rock
FER-2 Iron Formation Rock
FER-3 Iron Formation Rock
MP-2 W-Mo Ore
DL-1A Uranium-Thorium Ore
DH-1A Uranium-Thorium Ore
KC-1 Zn, Pb, Sn, and Ag
PTC-1 Flotation Rocks
SO-1 Reference Soil
MA-1 Gold Ore
SCH-1 Iron Ore
PD-1 Non Ferrous Dust
GFETC 82-3664 Coal
GFETC 83-0008 Coal
SO-2 Reference Soil
SO-3 Reference Soil
CLV-1 Vegetation
EASTMAN KODAK
NATIONAL RESEARCH
COUNCIL CANADA
PACS-1
DOLT-1
DORM-1
TORT-1
Marine Sediments
Dogfish Liver
Dogfish Muscle
Lobster
TEG-50-C
TEG-50-B
W2
BHVO-1
106-A
107-A
110-A
AGV-1
C20280
CLB-l
Gelatin
Gelatin
uses
Diabase Soil
Basalt
Monazite Sand
Monazite Sand
Monazite Sand
Andesite
Coal
Coal
Page 3.7-38
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
Packaging Sample and
Standards
Irradiation in 1 MW Research
Reactor
Sample/ Standard Counting
on Gamma Detector
Production of voltage signals
proportional (energy-wise) to
gamma energy
Calibrated MCA
Multichannel Buffer for Data
Acquisition
PC Computer with Gamma
Spectroscopy Software
Disk Output
Library Files (.LIB)
Calibration Files (.CLB)
Standard Spectra Files (.SPC)
Standard Constant Rles (.WPC)
Unknown Spectra Rles (.SPC)
Sample Report Files (.RPT)
Hardcopy Output
Processed Data Report
Figure 1. Neutron Activation Analysis process.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-39
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
FOLDING PROCESS
Filter
Filter folded in half
Filter quartered
Irradiation vial with
Inserted filter
Figure 2. Air filter folding process.
Page 3.7-40
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
Sample description
SITE 38597 AIR PARTICULATE FILTER
Spectrum Filename: LONG38.SPC
EPA CONTROL #456238
Acquisition information
Start time 21-SEP-95
Live time 1200
Real time 1333
Dead time 10.01%
Detector/Geometry IDs i &
Detector system
38% GELI DETECTOR
Calibration
Filename: QAQC38.CLB
Created: 22-AUG-95 17:11:57 &.
15:02:54
Zero offset
4.034 keV: Gain
.480 keV/channel
Library Files
Main analysis library:
NAC Files
Concentration per countrate table
LONG38.LIB
LONG38.WPC
1 for an energy of
4048 for an energy of
200.000%
2.7000E+01/ l.OOOOE+00
4
1949
Analysis parameters
Start channel
Stop channel
Peak rejection level
Activity scaling factor
Detection limit method:
MDA - EG&G ORTEC method
Additional random error: 0.OOOOOOOE+00
Additional systematic error: 0.OOOOOOOE+00
Background width: best method (based on spectrum).
Sample weight = 2. 8324.000E+01 grams.
GlkeV
85keV
= 2.7000E+01
Corrections Status
Decay correct to date YES
Decay during acquisition YES
Peaked background correction NO
Absorption (Internal) NO
Geometry correction NO
Random summing NO
Energy calibration normalized difference:
Comments
18-AUG-95 17:00:00
.1415
Figure 3. NAA sample output data report.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-41
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
The energy calibration waa changed to fit the spectrum.
Zero offset 3.430 ieV; Gain .482 keV/channel
************ UNIDENTIFIED PEAK SUMMARY ************
PEAK CENTROID BACKGROUND NET AREA INTENSITY UNCERT FWHM SUSPECTED
CHANNEL ENERGY COUNTS COUNTS CTS/SEC 1 SIGMA % keV NUCLIDE
+_+_+_+-+-+-+-+-+-+-+-+-+-+-+-+-+— 1— +-+-+-+-+-+-+-+-+-+-+-• f-+- +-+-
51.21 28.10 5251. 1080. .90 10.70 1.395
66.
74.
88.
97.
112.
115.
123.
133.
148.
167.
172.
' 182.
188.
197.
208.
222.
229.
245.
264.
268.
' 275.
289,
308.
317.
361,
392.
403.
441.
453.
469.
501.
554.
562.
573.
616.
631.
675.
682.
688.
699.
753.
760.
766.
774.
35
96
37
72
18
51
93
20
01
98
80
10
99
30
44
69
93
86
00
83
42
46
54
45
09
07
73
38
85
35
03
17
28
30
18
29
98
83
93
39
19
14
02
79
35.
39.
46.
50.
57.
59,
63.
67.
74.
84.
86.
91.
94.
98.
103.
110.
114.
121.
130.
132.
136.
142.
152.
156.
177.
192.
197.
215.
221.
229.
244.
270.
274.
279.
300.
307.
328.
332.
335.
340.
366.
369.
372.
376.
39
54
00
50
47
07
12
59
72
34
66
14
46
46
82
69
17
84
58
90
08
84
03
31
33
24
86
98
98
44
69
27
17
47
11
38
88
18
11
14
03
37
20
42
13243.
16460.
19360.
17738.
12119.
11040.
13801.
14945.
15952.
7750.
13764.
14386.
15293.
16534.
14296.
18757.
14112,.
18613.
10443.
12907.
11605.
9832.
13925.
11284.
14993.
17695.
16135.
19900.
18953.
14482.
14303.
14835.
7171.
111-25.
12174.
8492.
5534.
3253.
8620.
9016.
8760.
5445.
6221.
8467.
176.
870.
513.
1437.
489.
591.
1131.
3168.
635.
382,
2284.
608.
4288.
9718.
1027.
3487.
619.
13559.
222.
3811.
2243.
709.
949.
166-.
1456.
5370.
2658.
963.
723.
380.
1747.
238.
96.
1105.
359.
327.
257.
111.
590.
732.'
186.
105.
89.
241.
. 15
.73
.43
1.20
.41
.49
.94
2.64
.53
.32
1 . 90
.51
3.57
8. 10
.86
2.91
.52
11.30
. 18
3.18
1.87
.59
.79
.14
1.21
4.47
2.21
.80
.60
.32
1.46
.20
.08
.92
.30
.27
.21
.09
.49
.61
.15
.09
.07
.20
92.
23.
66.
14.
30.
33.
14.
6.
46.
26.
9.
34.
4.
2.
18.
' 7.
29.
2.
54.
5.
9.
17.
17.
104.
12.
5.
9.
25.
29.
50.
11.
96.
lie.
16.
65.
38.
44.
52.
37.
18.
75.
93.
125.
63.
74
55
58
00
13
52
24
35
80
25
14
39
59
62
67
01
08
19
95
13
84
53
88
79
75
33
35
59
72
33
60
10
89
11
41
27
69
28
16
71
16
75
49
66
. 1.246
1.448
.635
1.451
.838
.799
.848
1 . 090
,.894
.914
.985
.995
1.081
1.132
1.166
2.237
.818
1.100
.000
.967
1.135.
.662
1.209
.638
1.226
1.132
1.313
1.134
1.269
1.071
1.055
1. 162
.858
1 . 403
.768
.891
•.842
.634
1.825
1.164
.912
.792
. 679
.755
Sb-125
Sb-125
-
Pb-210
Np-239
.--
'Am-241
Th-234
Ta-182
—
—
Eu-155
Nd-147
Pu-239
Pu-239
SraGdl53
Lu-177
Lu-177
Eu-152
-
Hf-181
Se-75
Fe-59
Kr-85M
.—
Cs-136
Fe-59
Kr-88
Ba-131
Kr-89
Np-239
Eu-152
—
Pb-214
Se-75
Pb-212
-
La- 140
Au-196
Np-239
Cs-136
Cs-138
-
Ba-131
Pu-239
s
3
.3 .,
S
3
3
3
3
S
3
S
S
.3
S
S
3
sM
sM
•s
s
s
s
3
sM
sM
s
s
3
sM
s
s
s
.3
Figure 3. (continued)
Page 3.7-42
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
CHANNEL
820.28
825.62
846,20
856. 12
915.28
926.27
981.57
1013.96
1126.55
1138.26
1146.70
1163.94
1175.80
1199.96
1248.80
1271.46
1280.63
1333.00 •
1350.89
1485.47
1497.53
1584.24
1603.69
1612.42
1660.63
1728.65
1744.88
1778. 00
1821.02
1926.28
1936.61
1972.85
1997.01
2024. 10
2160.85
2250.63
2304.71
2322.99
2409.68
2443.29
2465.36
2489.02
2554.40
2641. 15
2679. 09
2695.80
2707.22
2722.40
2764. 17
2831.59
2905.96
2921. 52
ENERGY BACKGROUND NET AREA
'398.30
400.88
410.77
415.54
444.00
449.29.
475.89
491.46
545 . 60
551.23
555.29
563. 57
569.27
580.89
604.37
615.26
619.67
644.84
653.44
718. 11
723.90
765.56
774.90
779. 10
802.26
834. 93
842.72
858.63
879.29
.929.83
934.79
952. 19
963^79
976.79
1042.43
1085.51
1111.46
1120.23
1161.82
1177.94
1188. 53
1199.88
1231.23
1272.84
1291.03
1299.04
1304.52
1311.79
1331.82
1364. 14
1399.79
1407.25
8830.
8333.
8287.
6749.
6511.
8670.
5907.
3699.
8446.
6945.
7829.
12028.
9001.
5782.
15695.
7944.
10441.
11478.
6897.
11230.
9577.
5962.
. 4523.
8659.
10235.
12918.
8944.
8645.
15814.
9567.
3543.
6615.
7314.
5416.
3183.
4158.
3160.
5271.
2061.
1785.
2578.
1499..
1387.
1718.
1910.
1264.
564.
1399.
2024.
1507.
1130.
1226.
155.
443.
360.
613.
• 495.
245.
196.
61.
155.
160.
179.
817.
1054.
68.
8213.
464.
456.
143.
91.
491.
841.
577.
78.
1491.
531.
3744.
361.
243.
1203.
315.
57.
108.
302.
243.
166.
966.
594.
145640.
121.
744.
613.
135.
535.
588.
19017.
162.
72.
118.
9797.
258.
260.
1655.
CNTS/SEC
. 13
.37
.30
.51
.41
.20
. 16
.05
. 13
. 13
. 15
.68
.88
.06
6.84
.39
.38
. 12
. 08
.41.
.70
.48
.07
1.24
.44
3. 12
.30
.20
1.00
.26
.05
.09
.25
.20
. 14
.80
.50
121.37
. 10
.62
.51
. 11
.45
.49
15.85
. 14
.06
. 10
8. 16
.22
.22
1.38
UNCEHT FWHM SUSPECTED
90. 10
48.61
42.31
23.58
24.87
66.03
64.32
111.90
98.76
78.38
78.66
30. 24
15.24
149.45
3.42
29. 18
45.08
183.71
108.61
42.04
24.47
:0.49
114.52
10.39
34.37
6. 14
54.79
66.53
26.47
59.18
139.76
126.38
59. 19
57.05
71. 10
12.72
15.51
.30
65.62
13.22
27.75
54.31
20. 14
14,69
.90
40.04
55.14
67.63
1.65
41.22
27.36
5.33
.810 -
1. 193 Se-75
1.271 Eu-152
1.495 Eu-152
1.772 Eu-152
1.306 -
.923 Bi-214
.832 -
.992 Ca-138
1.381 W-187
1.058 Y-91M
2.078 As-76
l'. 350 Cs-134
1.004 Pb-214
1.598 Cs-134
1.078 Ru-106
1.682 Br-82
.000 -
.501 Sr-91
1.066 Bi-214
2.794 Zr-95
1.548 Nb-95
1. 180 Te-131
1.512 Eu-152
1.741 Cs-134
1.703 Kr-88
.473 -
.000 -
1.666 Tb-160
.726 -
.668 -
.795 -
1.508 Eu-152
.748 -
.753 -
1.910 Au-198
1.383 Eu-152
1.799 Bi-214
1. 116 -
2.337 Tb-160
1.948 Ta-182
1. 118 -
2.678 Ta-182
4.007 Eu-154
1.960 Fe-59
1.259 1-133
.745 -
.624 -
1.963 Co-60
1.421 -
2. 136 -
1.951 Eu-152
sM
sM
s
s
s
sM
s
3
S
S
s
s
s
s
s
sM
3
S
3
S
M
s
3
S
S
3
3
S
3
sM
M
3
sM
s
3
S
S
3
S
a
s
Figure 3. (continued)
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 3.7-43
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
CHANNEL ENERGY BACKGROUND NET AREA
2955.35 1423.46 285. 17.
3002.04 1445.84 635. 79.
3031.48 1459.94 964. 158.
3114.49 1499.7 472. 48.
3167.84 1525.28 504. 20.
3173.70 1528.09 912. 53.
3284.22 1581.03 935. 104.
3325.20 1600.65 690. 65.
3392.88 1633.06 549. 64.
3550.03 1689.16 787. 319.
3625.10 1744.25 331. 23.
3682.28 1771.62 583. 59.
3699.02 1779.63 535. 68.
3962.72 1905.82 146. 17.
3967.78 1908.24 103. 14.
s Peak fails shape tests.
M Peak issclose to a library peak.
************** IDENTIFIED P
CNTS/SEC UNCERT FWHM SUSPECTEI
.01 -113.65 .541 - s
.07 56.53 .909 - s
. 13 40.03 2.032 K-40 s
.04 69.71 .985 - s
.02 152.25 .969 K-42 s
.04 161.75 .662 - s
.09" 61.32 1.464 - s
.05 81.94 .691 - a
.05 69.40 1.192 - s
,27 20.47 1.672 Sb-124 s
.'02 103.11 .585 - s
.05 71.82 1.419 Co-56 • s
.06 66.59 .776 - s
.01 110.18 .582 - s
.01 113.65 .751 - s
E A K SUMMARY **************
NUCLIDE PEAK CENTROID BACKGROUND NET AREA INTENSITY UNCERT FWHM
CHANNEL ENERGY COUNTS
f_4._+_+-+-+-4—+-+-4. -+-+-+-+-+-+-+-+-+-+
CE-141 294.75 145.39 16561.
CA-SC47 323.62 159.29 10932.
LU-177 26.66 208.89 15220.
SE-75 542.49 264.64 10854.
TB-160 614.62 299.36 11566.
TH-PA233 640.52 311.82 12241.
CR-51 657.56 320.02 11009.
EU-152 707.75 344.17 10106.
YB-175 819.38 397.87 9126.
HF-181 994.66 482.18 9142.
BA-131 1025.00 496.77 9825.
HD-857 1083.03 533. S3 13302.
AG-110M 1359.90 657.77 12933.
ZR-95 1566.55 757.06 8927.
CS-134 1647.32 775.86 8888.
NI-CO58 1677.40 810.31 7748.
SC-46 1841.66 889.20 17338.
RB-86 2230,73 1075.96 4884.
FE-59 2278.68 1098.97 4754.
ZN-65 2313.05 1115.46 5486.
CO-60 2432.70 1172.86 2607.
TA-182 2533.41 1221.17 1565.
s Peak fails shape tests.
D Peak area deconvoluted.
COUNTS CTS/SEC 1 SIGMA keV
~f -H—+-H— +-+-+-+— *-+-+-+-+-+— 1— »•-+-+-+
18561. 15.47 1.78 1.049
137. .11 108.06 .564s
270. .23 79. 35 . 987
1337. 1.11 12.62 1.196
4521. 3.77 4.98 2.548s
14737. 12.28 1.57 1.237
9420. 7.85 2.26 1.275
7899. 6.58 2.78 1.383s
613. 51 31.43 1.049s
3986. 3.32 4.45 1.360
526. .44 34.22 1.331
388. .38 32.28 1.939s
336. .28 70.63 .741s
334. .28 51.31 .5923
4812. 4.01 4.47 1.747
474. .39 32.52 1.694
175795. 146.50 .29 1.654
530. 1.27 15.36 1.857s
28146. 23.46 .82 1.813
904. .75 15.69 1. 214s
10668. • 8.89 1. .4 1.899
672. .56 12.39 2.103
Figure 3. (continued)
Page 3.7-44
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-3
Chemical Analysis
Method IO-3.7
Neutron Activation Analysis
*****
NUCLIDE
+--C-+-+-+
CE-141
CA-SC47
LU-177 <
SE-T5
TB-160 <
(UH-BA233
EU-152 #
YB-175 <
HF-181
B8-831 <
ND-147 #
AG-110M*
ZR-95
BS-
-------
Method IO-3.7
Neutron Activation Analysis
Chapter IO-3
Chemical Analysis
SUMMARY OF NUCLIDE
TIME OF COUNT TIME CORRECTED
ELEMENT CONCENTRATION CONCENTRATION
PPM PPM
+-+-+-+-+-+"!
CERIUM
CALCIUM
LUTETIUM
SELENIUM
TERBIUM
THORIUM
CHROMIUM
EUROPIUM
YTTERBIUM
HALFNIUM
BARIUM
STRONTIUM
NEEDYNIUM
SILVER
ZIRCONIUM
CESIUM
NICKEL
SCANDIUM
RUBIDIUM
IRON
ZINC
COBALT
TANTALUM
9.
7.
1.
6.7245E-02
1.8274E-02
O.OOOOE+00
8.3820E-03
9.5249E-04
.5379E-03'
.5336E-02
.6366E-03
2.6731E-04
3.6694E-03
9.9312E-02
2.2194E-01
7.6179E-Q3
1.0487E-02
Y.5958E-02
6.6270E-03
5.1279E-02
1.5329E-02
6.7420E-02
.8756E+01
.9523E-02
2.1168E-02
9.8942E-04
1.
4.
1.3862E-01
1.7325E+01
O.OOOOE+00
1.0180E-02
1.3144E-03
2.2783E-02
1.7550E-01
1.6446E-03
7.1331E-02
6.2163E-03
7.6714E-01
3.2047E-01
6.3831E-02
1.1509E-02
1.0906E-01
6.8363^-03
7.1309E-022
2.0287E-02
2.3767E-01
3.1590E+01
5.4510E-02
2.1734E-02
1.2136E-03
CONCENTRATIONS
UNCERTAINTY 1 SIGMA
COUNTING
.^_4._-|._.|._+_4._+-+-+-+-+-+-+-+-+-
1.70%
108.00%
.00%
12.60%
4.90%
1.50%
2.20%
2.70%
31.40%
4.40%
34.20%
39.30%
52.20%
70.60%
51.30%
4.40%
32.50%
.20%
15.30%
.80%
15.60%
1/40%
.12.30%
********* SUMMARY
208.40 7 LU-177
OF DISCARDED PEAKS *********
* - Peak is too wide, but only one peak in library.
! - Peak ia part of a multiplet and this area went
negative during deconvolution.
? - Peak is too narrow.
9 - Peak is too wide at FW25M, but ok at FWHM.
% - Peak fails sensitivity test.
$ - Peak identified, but first peak of this nuclide
failed one or more qualification tests.
+ - Peak activity higher than counting uncertainty range.
- - Peak activity lower than counting'uncertainty range.
= - Peak outside analysis energy range.
&. - Calculated peak centre id is not close enough to the
library energy centroid for positive identification.
P - Peakbackground subtraction
Figure 3. (continued)
Page 3.7-46
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Chapter IO-4
DETERMINATION OF REACTIVE ACIDIC
AND BASIC GASES AND STRONG
ACIDITY OF ATMOSPHERIC FINE
PARTICLES IN AMBIENT AIR USING THE
ANNULAR DENUDER TECHNOLOGY
OVERVIEW
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
-------
Chapter IO-4
DETERMINATION OF REACTIVE ACIDIC AND BASIC
GASES AND STRONG ACIDITY OF ATMOSPHERIC
FINE PARTICLES IN AMBIENT AIR
USING THE ANNULAR DENUDER TECHNOLOGY
OVERVIEW
Acid aerosols are found in the atmosphere as a result of atmospheric reaction of emissions from a
variety of fossil fuel combustion sources, including power plants, industrial and commercial facilities,
hazardous waste storage and treatment facilities, etc. Awareness of the effects of acid aerosols
concentrations on human health and property has been documented over the past several years. The
Clean Air Act Amendments of 1970 required the U. S. Environmental Protection Agency (EPA) to
develop uniform national ambient air quality standards (NAAQS) for pollutants that were recognized as
widespread (emitted by numerous mobile and stationary sources) and that endangered public health and
welfare. Further, Section 109 of the Clean Air Act, as amended, requires EPA to periodically review
the NAAQS as well as the scientific information and data on which they are based. New pollutants are
identified for NAAQS development if the Administrator concludes that they may reasonably be anticipated
to endanger public health and welfare.
To assist the Administrator ia evaluating the need for new or revised NAAQS, the Clean Air Act
created the Clean Air Scientific Advisory Committee (CASAC). This committee's mandate is to provide
the Administrator with scientific advice and research recommendations on critical areas of knowledge on
new or revised NAAQSs. The Acid Aerosol Subcommittee of CASAC identified a need for a coordinated
acid aerosol research program to assist the Agency in making recommendations on a proposed NAAQS
for fine particle acid aerosol. The Subcommittee recommended a research program that addresses
characterization and exposure assessment, animal toxicity, human exposure research, and epidemiology.
As documented in the CASAC Report to the Administrator, the foundation for any research program and
potential air quality standard development is "...a measurement method, not only because the standard
itself must specify the method, but equally important, because before establishing a standard the
contaminant must be fully characterized and exposure measurements made to correlate with health
outcomes." The National Exposure Research Laboratory (NERL) of EPA was directed by CASAC to
obtain the information needed for scientifically assessing a possible fine particle standard for acid aerosols
to protect human health.
In 1989, NERL conducted a workshop to determine and exchange views on the various methods that
have been and are being used to measure aerosol acidity. The workshop was held in response to
recommendations by CASAC to identify issues associated with characterizing aerosol acidity and acid
aerosol measurement methods. The workshop was structured to accomplish two principal objectives.
The first objective was to identify appropriate indicators and methodologies for characterizing aerosol
acidity; the second was to develop ideas and recommendations for evaluating acid aerosol methods
currently in use. The workshop participants identified the development of an accurate, reliable, and
interference-free method as an important initial research objective.
The participants concluded that the most appropriate indicator of aerosol acidity is the fine particle
strong acidity component of the atmosphere (i.e., the amount of strong acidity available in the fine
particle component of the atmospheric aerosol). Sampling would involve the use of an annular denuder
followed by a 37 mm Teflon® filter to trap the fine particle acid aerosol. After sampling, the filter is
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.0-1
-------
Method IO-4
Overview
Chapter IO-4
Atmospheric Acidity
returned to the laboratory for extraction and analysis. After extracting the acid aerosol from the 37 mm
Teflon® filter with an aqueous solution of perchloric acid at a pH of approximately 4.00 (to prevent
dissociation of weak acids), the available hydrogen ion is measured either by titration or by pH. This
defines atomospheric fine particle acid aerosol as free hydrogen ion and hydrogen ion available from
either undissociated of weak ion available from either undissociated sulfuric acid or from undissociated
bisulfate ion. Atmosphere acidity is reported as either nanomoles of hydrogen ion per standard cubic
meter of air (nmoles/rar) or as equivalent sulfuric acid in micrograms per standard cubic meter of air
In December 1989 and February 1990, Intercomparison Studies were held at the EPA's NERL facility
in Research Triangle Park, NC, to quantify the performance methods currently used to measure fine
particle acid aerosol in epidemiology studies to ensure comparability of measurements by different groups.
The criteria for selecting the participants for the initial Pilot Intercomparison Study was that they
represented monitoring systems that were being used in epidemiological field studies currently in progress
or that they had developed a prototype sampler under contract to EPA that the agency wanted evaluated.
Based upon those criteria, three research groups were invited. They were: Harvard School of Public
Health, Robert Wood Johnson (RWJ) Medical School and Research Triangle Institute (RTI). Each group
used a variation of the annular denuder system (ADS) to determine fine particle acid aerosol of a
standardized test atmosphere.
Based upon the findings of the Pilot Intercomparison Study, NERL developed this Chapter entitled
'Determination of the Reactive Acidic and Basic Gases and Strong Acidity of Atmospheric Fine Particles
in Ambient Air Using Denuder Technology. " This standard methodology represents a composite of the
most viable features of the three research methods utilized in the Pilot Intercomparison Study. The
following table identifies the annual denuder methods discussed in Chapter IO-4 along with the
constituents monitored by those methods.
Method
IO-4.1
IO-4.2
Title
Determination of the Strong Acidity of Atmospheric Fine
Particles (<2.5 jtm) Using Annular Denuder Technology
Determination of Reactive Acidic and Basic Gases and
Strong Acidity of Atmospheric Fine Particles in Ambient
Air Using Annular Denuder Technology
Constituent
Detected
Fine Particl Acid
Aerosol (H+)
HNO3, NH3, HC1,
S02, NHj, SO 4 ,
NO-j, Fine Particle
Acid Aerosol (H+)
The unique features of the annular denuder that separate it from other established monitoring methods
are the elimination of sampling artifacts due to interaction between the collected gases and particles and
the preservation of the samples for subsequent analysis. Compendium Method IO-4.1 utilizes a denuder
for removing ammonia interference and a filter assembly for determining atmospheric fine particle acid
aerosol in ambient air. The method does not, however, account for potential interferences from nitric
acid, ammonium nitrate aerosol (NH^NC^), or other ammonium salts that might bias the acidity
measurement. Compendium Method IO-4.2 does correct for potential biases by an additional denuder
upstream of the filter assembly to selectively remove and quantitate acid gases (nitric acid vapor and
Page 4.0-2
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4 Method IO-4
Overview Atmospheric Acidity
sulfur dioxide) from the gas stream prior to filtration. In addition, to correct for biases due to the
dissociation of ammonium nitrate aerosol captured On the Teflon® filter, Compendium Method IO-4.2
uses a backup Nylon® filter to capture the dissociated HNO3 from NlfyNC^ followed by a glass-fiber
filter impregnated with citric acid to retain the dissociated NH^ from NE^NOj. The ammonia
concentration is subtracted from the nitrate value, and the result is added to the acidity measurement on
the Teflon® filter to give a corrected measurement of the atmospheric fine particle strong acidity.
The techniques, procedures, equipment, and other specifications comprising Compendium
Methods IO-4.1 and IO-4.2 are derived and composited from those used by the contributing research
organizations and, therefore, are known to be serviceable and effective. At this stage, these methods are
unified, consensus, tentative drafts intended for further application and testing. Users should be advised
that the methods have not yet been adequately tested, optimized, or standardized. Many of the
specifications have been initially established by technical judgement and have not been subjected to rugged
testing. In some cases alternative techniques, equipment, or specifications may be acceptable or superior.
In applying these methods, users are encouraged to consider alternatives with the understanding that they
should be tested to determine their adequacy and to confirm and document any advantages.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.0-3
-------
-------
EPA/625/R-96/010a
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-4.1
DETERMINATION OF THE STRONG
ACIDITY OF ATMOSPHERIC
FINE-PARTICLES (< 2.5
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-4.1
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA
No. 2-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc.
(ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A.
Manning, Center for Environmental Research Information (CERI), and Frank F. McElroy, National
Exposure Research Laboratory (NERL), both in the EPA Office of Research and Development, were
the project officers responsible for overseeing the preparation of this method. Other support was
provided by the folio whig members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Cary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
William T. "Jerry" Winberry, Jr., MRI, Cary, NC
Thomas Ellestad, U.S. EPA, RTP, NC
Bob Stevens, U.S. EPA, RTP, NC
Peer Reviewers
Delbert Eatough, Brigham Young University, Provo, UT
Share Stone, University Research Glassware Corp., Chapel Hill, NC- .
Petros Koutrakis, Harvard School of Public Health, Boston, MA
J. Waldman, Robert Wood Johnson Medical School, New Brunswick, NJ
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has
been approved for publication as an EPA document. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
ii
-------
Method IO-4.1
Determination of the Strong Acidity of Atmospheric
Fine-Particles (<2.5 jim)
TABLE OF CONTENTS
1. Scope 4.1-1
2. Applicable Documents 4.1-1
2.1 ASTM Standards 4.1-1
2.2 Other Documents 4.1-1
3. Summary of Method 4.1-2
4. Significance 4.1-2
5. Definitions • 4.1-3
6. Apparatus 4.1-4
6.1 Sampling 4.1-4
6.2 Analysis 4.1-6
7. Reagents and Materials 4.1-7
8. Preparation of Impactor Frit and Denuder Coating 4.1-8
9. Impactor Frit Installation 4.1-8
9.1 Impactor Frit Installation 4.1-8
9.2 Impactor Frit Coating 4.1-9
10. Filter Preparation and Assembly 4.1-9
11. Annular Denuder System Preparation 4.1-10
11.1 Coating Procedure 4.1-10
11.2 Drying Procedure 4.1-10
11.3 Denuder System Assembly 4.1-11
11.4 Laboratory Leak-Check of ADS 4.1-11
12. Sampling 4.1-12
12.1 Placement of Denuder System 4.1-12
12.2 Start-Up 4.1-13
12.3 Sample Shutdown 4.1-14
12.4 Corrective Action for Leak Test Failure 4.1-14
13. ADS Disassembly 4.1-15
14. Extraction Procedure 4.1-15
15. pH ANALYSIS 4.1-16
15.1 Standard and Reagent Preparation 4.1-16
15.2 Calibration of pH Meter 4.1-18
15.3 Pre-Analysis Calibration 4.1-18
15.4 pH Test of HC1O4 Solutions 4.1-19
15.5 Analysis of Working Standard 4.1-19
15.6 Analysis of Filter Extracts 4.1-20
16. Assumption of Annual Denuder System 4.1-20
17. Atmospheric Species Concentration Calculations 4.1-20
17.1 Calculations Using Results from pH Measurement 4.1-20
17.2 Calculation of Air Volume Sampled, Corrected to Standard Conditions 4.1-21
17.3 Calculation of Strong Acidity Aerosol Concentration 4.1-22
18. Method Safety 4.1-23
111
-------
TABLE OF CONTENTS (continued)
Page
19. Performance Criteria and QA 4.1-23
19.1 Standard Operating Procedures (SOPs) 4.1-23
19.2 QA Program 4.1-23
20. References 4.1-23
IV
-------
Chapter IO-4
ATMOSPHERIC ACIDIC CONSTITUENTS
Method IO-4.1
DETERMINATION OF THE STRONG ACIDITY OF ATMOSPHERIC
FINE-PARTICLES (<2.5 fan)
1. Scope
1.1 The quantitative determination of equivalent strong-acid (H2SO4) acidity of fine-particle (< 2.5
in the atmosphere as hydrogen ion by pH analysis, is described in this method. The method is a
composite of methodologies developed by U. S. Environmental Protection Agency (EPA), University of
Kansas, Robert Johnson Medical School, New York State University, Harvard University and the CNR
Laboratories (Italy). It is currently employed in a number of air pollution studies in Italy, United States,
Canada, Mexico, Germany, Austria, and Spain, and in public health services and epidemiology and
environmental research centers. The techniques, procedures, equipment, and other specifications
comprising this method are derived from those used by the contributing research organizations and,
therefore, are known to be serviceable and effective. At this stage, this method is a unified, consensus,
tentative, draft method intended for further application and testing. Users should be advised that the
method has not yet been adequately tested, optimized, or standardized. Many of the specifications have
been initially established by technical judgment but have not been subjected to rugged testing. In some
cases, alternative techniques, equipment, or specifications may be acceptable or superior. In applying
the method, users are encouraged to consider alternatives, with the understanding that they should be
tested to determine their adequacy and to confirm and document their possible advantages. Information
and comments are solicited on improvements, alternative equipment, techniques, specifications,
performance, or any other aspect of the method.
1.2 The equipment described herein can be modified to measure acidity of atmospheric reactive acidic
and basic gases in both indoor and outdoor atmospheres, as documented in Method IO-4.2, entitled
"Determination of Reactive Acidic and Basic Gases and Strong Acidity of Atmospheric Fine Particles in
Ambient Air Using the Annular Denuder Technology." Modifications to this methodology were developed
for monitoring regional-scale acidic and basic gases and particulate matter in support of EPA field
programs involving .the Integrated Air Cancer Research Program and the Acid Deposition Network.
Similarly, the methodology has been used to characterize urban haze in Denver, Houston, Boston, and
Los Angeles.
2. Applicable Documents
2.1 ASTM Standards
• D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2 Other Documents
Ambient Air Studies (1-24).
U.S. EPA Acid Aerosol Document (25).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-1
-------
Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
3. Summary of Method
3.1 The annular denuder system (ADS) consists of an inlet with an impactor or cyclone preseparator
designed to remove all particles with a DP^Q of 2.5 pm or greater, an annular denuder to remove
ammonia, and a filter for collecting the aerosol. In operation, air is drawn through a cyclone or a
elutriator-accelerator jet assembly followed by an impactor frit and coupler assembly, through the denuder
to remove ammonia, and into a single-stage filter assembly. The single-stage filter assembly contains a
47-mm Teflon® filter supported by a stainless steel screen. The filter is a 2 /urn pore-size Teflon®
membrane filter, Zefluor (Gelman Sciences). The Teflon® filter collects the fine aerosol. A pump unit
maintains a flow of 10 Lpm, and a timer allows programmed start and end times. The ADS with a
cyclone assembly, the ADS with an impactor assembly, and the field sampling box with the pump-timer
system are shown in Figure la, Ib, and 2, respectively.
3.2 Following each run, the ADS assembly is removed from its field housing, its ends are capped, and
it is brought back to the laboratory. In the laboratory, the assembly pieces are uncoupled and capped.
The denuder tube is not extracted. The Teflon® filter is unloaded from the filter assembly in an
ammonia-free atmosphere and either immediately extracted or stored in an ammonia-free container for
later extraction. A glove-box, lined with citric-acid soaked paper, is used to maintain an ammonia-free
atmosphere. To remove the Teflon® filter, it is placed in an extraction vessel, particle-laden side down.
The filter is wetted with 200 pL of methanol, then removed with 6.0 mL of extraction solution (ES).
The extraction vessel is put in an ultrasonic bath for 20 min. The extraction solution is then decanted into
a container.
3.3 Acidity determination is made using pH measurements of 1 mL aliquot of the extracted filter
solution. Filter acidity is calculated based on standards made with sulfuric acid. The standards range
from 0-160 /*g, equivalent to strong acid aerosol. A pH meter is used to measure the pH of the filter
extract. For each batch of filter extracts, a calibration curve is calculated using the mean pH of each
standard.
4. Significance
4.1 Acid aerosols are found in the atmosphere as a result of atmospheric reactions of emissions from a
variety of fossil fuel combustion sources, including power plants, industrial and commercial facilitie's,
hazardous waste storage and treatment facilities, etc. The effects of concentrations of acid aerosols on
human health and property has been documented over the past several years. The Clean Air Act
Amendments of 1970 of required EPA to develop uniform national ambient air quality standards
(NAAQS) for criteria pollutants because of the interstate nature of certain air pollutants. NAAQS were
established for pollutants that were recognized as widespread (emitted by numerous mobile and stationary
sources) and that endangered public health and welfare. Further, Section 109 of the Clean Air Act as
amended, requires EPA to periodically review the NAAQS as well as the scientific information and data
on which they are based. New pollutants are to be identified for NAAQS development if the
Administrator concludes that they reasonably may be anticipated to endanger the public health and
welfare. To assist the Administrator in evaluating the need for new or revised NAAQS, the Clean Air
Page 4.1-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4 Method IO-4.1
Atmospheric Acidic _ Strong Acidity
Act created the Clean Air Scientific Advisory Committee (CASAC). This committee's mandate is to
provide the Administrator with scientific advice and research recommendations on critical areas of
knowledge on new or revised NAAQS. The Acid Aerosol Subcommittee of CASAC identified a need
for a coordinated acid aerosol research program to assist the Agency in making recommendations on a
new acid aerosol NAAQS. The Subcommittee recommended a research program involving
characterization and exposure assessment, animal toxicity, human exposure research, and epidemiology.
As documented in the CASAC Reporter to the Administrator, the foundation for any research program
and potential air quality standard development is "...a measurement method, not only because the
standard Itself must specify the method, but equally important, because before establishing a standard the
contaminant must be fully characterized and exposure measurements made to correlate with health
outcomes. "
4.2 Unique features of the annular denuder that separate it from other established monitoring methods
are the elimination of sampling artifacts due to interaction between the collected gases and particles and
the preservation of the samples for subsequent analysis. These features are accomplished in Method IO-
4.2 by removing ammonia (NHj) in the gas stream with the citric acid-coated denuder to reduce the
probability of the acid aerosol captured by the Teflon® filter in the filter pack from being neutralized to
ammonium sulfate
5. Definitions
[Note: Definitions used in this document and any user-prepared Standard Operating Procedures (SOPs)
should be consistent with those used in ASTM D1356. All abbreviations and symbols are defined within
this document at the point of first use.]
5.1 Secondary Particles (or Secondary Aerosols). Aerosols that form in the atmosphere as a result
of chemical reactions, often involving gases. A typical example is sulfate ions produced by
photochemical oxidation of sulfur dioxide.
5.2 Aerosol. A dispersion of solid or liquid particle in a gas-phase medium and a solid or liquid
disperse phase. Aerosols are formed by (1) the suspension of particles due to grinding or atomization
or (2) the condensation of supersaturated vapors.
5.3 Coarse and Fine Particles. Particles with diameters (aerodynamic) greater than 2.5 jtm that are
removed by the sampler's inlet; fine particles are those with diameters (aerodynamic) less than 2.5 fim
that are collected on the Teflon® filter. These two fractions are usually defined in terms of the separation
diameter of a sampler.
5.4 Annular. Refers to rotating to, or forming a ring. In the annular denuder sampler, the annular
refers to the annulus between two concentric tubes. Chemical coating applied to the interior surfaces
removes gaseous pollutants that diffuse to the surface.
5.5 Denuder. Refers to the sections in which interfering gases are removed from the sample stream
prior to filtration in determining fine particle (<2.5 ^m) strong acidity.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-3
-------
Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
5.6 Equivalent Weight. The equivalent weight, or combining weight of a compound or ion is its
formula weight divided by the number of replaceable hydrogen atoms.
5.7 Normal Solution. Solution that contains a gram-equivalent weight of solute in a liter of solution.
6. Apparatus
[Note: This method was developed using the annular denuder system provided by University Research
Glassware, 116 s. Merritt Mill Road, Chapel Hill, NC 27516, (919) 942-2753, as a guideline. EPA has
experience in use of this equipment during various field monitoring program over the last several years.
Other manufacturers' equipment should work as well. However, modifications to these procedures may
be necessary if another commercially available sampler is selected.]
6.1 Sampling
6.1.1 Elutriator and acceleration jet (inlet) assembly. Under normal sampling conditions, the
elutriator or entry tube is made of either Teflon®-coated glass or aluminum, as illustrated in Figure 3.
When using glass, the accelerator jet assembly, which directs the air flow towards an impactor plate, is
fixed onto the elutriator and the internal surfaces of the entire assembly are coated with Teflon®
(Figure 3a). When aluminum is used, the accelerator jet assembly is removable. The jet is made of
Teflon® or polyethylene, and the jet support is made of aluminum (Figure 3b). Again, all internal
surfaces are coated with Teflon®.
6.1.2 Teflon® impactor support pin and impactor frit support tools (see Figure 4). These parts
are made of either Teflon® or polyethylene and aid in assembling, removing, coating and cleaning the
impactor frit.
6.1.3 Impactor frit and coupler assembly (see Figure 5). The impactor frit is 10 mm x 3 mm and
is available with a porosity range of 10-20 pm. The frits should be made of porous ceramic material or
fritted stainless steel. Before use, the impactor frit surface is coated with a Dow Corning 660 oil and
toluene solution and sits in a Teflon® seat support fixed within the coupler. The coupler is made of
thermoplastic and has Teflon® clad sealing "0"-rings that are located on both sides of the seat support
inside the coupler.
[Not?; In situations \vithsubstantialhigh concentrations of coarse particles (>2.5 \sm), a Teflon®-coated
aluminum cyclone should be used in place of the acceleration jet and impactor assembly, as illustrated
in Figure 1. The location of the cyclone with respect to the denuder, heated enclosure, and meter box
is illustrated in Figure LJ
6.1.4 Annular Denuder (see Figure 6). The denuder consists of two or more concentric glass tubes
with an outer stainless steel shell. The tubes create a 1 mm annular spacing, which allows the air sample
to pass through. Flow in the annular space is maintained in the laminar range and allows fine particles
with diameters less than 2.5 pm to pass through with negligible removal. The inner tube is inset 25 mm
from one end of the outer tube; this end is called the flow straightener end. The other end of the inner
tube is flush with the end of the outer tube. Both ends of the inner tube are sealed. In this configuration,
the flow straightener end is etched to provide greater surface area for the coating. The inner glass tubes
are inset 25 mm from one end of the outer Teflon®-coated aluminum tube to serve as the flow
Page 4.1-4 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
straightener end. All denuder types should be equipped with thermoplastic (Bakelite) or polyethylene caps
when purchased.
6.1.5 Caps for Annular Denuder. Caps are made of either polyethylene (Caplugs, Protective
Enclosure, Inc.) or thermoplastic (Bakelite) and are used in the coating and drying processes and for
storage and shipment. The thermoplastic caps include a removable Teflon® seal plate when purchased.
[Note: Recent evaluation of the caps for the denuder system has indicated that the thermoplastic
(Bakelite) screen caps and the polyethylene screw caps are useful to seal the ends of the denuders when
they are dry. However, during coating and extracting, the Caplugs (Protective Enclosures, Inc.) provide
a better seal, preventing contamination that would occur from the Teflon® liner of the thermoplastic screw
caps or direct contact with the unprotected thermoplastic screw caps. Therefore the user should use
Caplugs during coating and extraction operations.]
6.1.6 Annular Denuder Couplers. The couplers should be made of thermoplastic and equipped with
Teflon® "O"-rings that sandwich a silicone rubber ring on three sides. This design provides elasticity
for better sealing under extremely cold temperature conditions in which Teflon® does not give. The
couplers are equipped with permanent seal rings, which provide more even threading and a better seal
when coupled. The couplers are used to couple the annular denuders together when used in series (see
Method IO-4.2) and for coupling the last denuder with the filter assembly.
Caution: When utilizing the couplers, do not overtighten when applying a glass denuder. Overtightening
may "chip" the ends of the denuder, preventing a tight seal
6.1.7 Drying Manifold Assembly (see Figure 7). The manifold is made of glass and is available
to accommodate as many as four drying denuders. The denuders are attached to the manifold with
back-to-back Bakelite bored caps, as illustrated in Figure 7. Air is pushed through an air dryer/cleaner
bottle made of 2 1/2" heavy wall glass that contains silica gel. The Teflon® tubing that connects the
dryer/cleaner bottle to the drying manifold should be secured at each cap with either Teflon® washers or
Teflon® washers coupled with Teflon® hose barbs. The air stream then passes through a fine particle
filter to remove fines. Alternatively, dry compressed air from a cylinder may be used in place of the
dryer/cleaner bottle assembly.
6.1.8 Filter Assembly. The denuder is followed by a single-stage filter assembly containing the
Teflon® membrane filter (see Figure 8). The filter is supported by a stainless steel porous screen and
housed in a polyethylene filter ring housing. The filter housing outlet component is aluminum and
accommodates a polyethylene screw sleeve which seals the filter assembly.
6.1.9 Vacuum Tubing. Low density polyethylene tubing, 3/8" diameter for distances of less than
50 ft., 1/2" diameter for distances greater than 50 ft. [Fisher-Scientific, 711 Forbes Ave., Pittsburgh
PA 15219 (412-787-6322)].
6.1.10 Tube Fitting. Compression fittings (Swagelok®, Gyrolok® or equivalent) are used to connect
vacuum tubing (above) to an NPT female connector or filter holder and connect vacuum tubing to fitting
on differential flow controller. The fittings may be constructed of any material since they are downstream
of the sampler. [Fisher-Scientific, 711 Forbes Ave., Pittsburgh, PA 15219 (412-787-6322)].
6.1.11 Annular Denuder System (ADS) Sampling Box. The housing box is made of a
"high-impact" plastic and is thermally insulated. It is 2 ft long by 6" wide and 6" deep. The box
contains a heater unit, a fan, and an air outlet located in the lid of the housing. The elutriator end of the
ADS protrudes through one end of the box, while the denuder is supported in the box by a chrome plated
spring clip. If the Teflon®-coated aluminum cyclone is used to remove coarse particles, it is also housed
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-5
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
in the heated sampling box, with the elutriator end protruding through the sampling box, as illustrated
in Figure 2.
(Note: Recent studies by the Harvard School of Public Health based on a comparison of utilizing a
sampling box with and without heated enclosure indicated no difference in sampled species from winter
samples. However, EPA recommends controlling the temperature in the sampling box to prevent
condensation.]
6.1.12 Annular Denuder Transport Case. The transport case is made of formica backed with
plywood and insulated. The corners are reinforced with metal. It is made to withstand shipping by
truck, UPS, and Federal Express. Each case is stackable and lockable and has a carrying handle. Seven
total annular denuder systems can be packed in the case.
6.1.13 Pump/Timer Unit. The pump/timer unit draws air through the ADS at a fixed rate of 10
L/min with a precision of ± 10% over the range of 25-250 mm Hg vacuum. A mass flow controller or
a differential flow controller can be used. Typically, the flow rate is monitored with an exhaust flow
rotameter. The unit includes a mechanical 7-day timer and an elapsed-time counter. A dry gas meter,
when available, is placed after the pump to give a direct readout of total volume of air sampled.
Otherwise, flow rate is manually measured (using a rotameter) before and after each run to calculate the
air volume sampled.
6.1.14 Dry Gas Meter (DGM). The DGM should have a capacity of 10 L of gas. per revolution.
(Fisher Scientific, 711 Forbes Ave., Pittsburgh, PA 15129, 412-787-6322).
6.1.15 Electronic Mass Flow Controller. This controller should be capable of maintaining a
constant rate of 10 L/min (+10%) over a sampling period of up to 24 h and under conditions of changing
temperature (5 - 43°C) and humidity. (Tylan General, Flow Division, 19220 S. Normandie Ave.,
Torrance, CA 90502, [213-212-5533], Model FC-262, or equivalent).
6.2 Analysis
6.2.1 pH Meter. A pH or pH/ion meter with "integral" automatic temperature compensation,
temperature probe, 2 and 4 mL analytical vials, and calibrated with standard buffers (pH 4 and 7). The
Ross semi-micro glass electrode from Orion has been used by the Harvard School of Public Health and
found to adequately address the requirements of this protocol. (Orion Research Inc., The Schraffet
Center, 529 Main Street, Boston, MA 02129, 617-242-3900).
6.2.2 Polyethylene Bottles with Polyethylene Screw Caps. 100 mL, used for storage of coating
solution; and 1L, used for storing the KC1 solution.
6.2.3 Erlenmeyer Flasks. 250 mL and 2 L borosilicate glass or polyethylene flasks for calibration,
best source.
6.2.4 Graduated Cylinders. 5 mL, 10 mL, 100 mL, 250 mL, and 1L borosilicate glass or
polyethylene cylinders, best source.
6.2.5 Pipets. Class A 5 mL and 10 mL borosilicate glass pipettes or automatic pipettes. Calibrated
"to deliver," best source.
6.2.6 Pipet Bulb.Made of natural rubber. Recommended to meet OSHA requirements, best source.
6.2.7 Micropipettes. 25 pL, 50 yL, and 100 uL, calibrated "to contain," borosilicate glass
micropipette, best source.
6.2.8 Forceps. Recommended dressing forceps made of stainless steel or chrome-plated steel and
without serrations. Used for handling filter.
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
6.2.9 Stopwatch. Used for measuring flow rate of gas stream through DGM, best source.
6.2.10 Ultrasonic Cleaner. Used for filter extractions and parts cleaning. The ultrasonic cleaner
should have temperature control capability. [Cole-Palmer Instrument Co., 7425 N. Oak Park Ave.,
Chicago, IL 60648 (800-323-4340)].
6.2.11 Clean Air Hood (Optional). Closed air hood with ammonia free air circulation. Used for
Teflon® filter extraction for pH analysis, best source.
6.2.12 Glove-Box. Used for handling exposed filter, which is lined with citric acid impregnated
paper sheets to maintain an ammonia-free atmosphere. Works best with a slight positive pressure.
6.2.13 Refrigerator, (approximately 5°C) is required for sample storage.
6.2.14 Polyethylene-Stoppered Volumetric Flasks. 25 mL, used for making sulfuric acid
standards.
7. Reagents and Materials
7.1 Filter. Zefluor® (PTFE) membrane filter, 47 mm diameter, with a 2 /tm pore size. The Teflon®
filter has a coarse mesh Teflon® side and a fine pore membrane side. The fine pore membrane side
should face the air stream. (Gelman Sciences, 600 S. Wagner Rd., Ann Arbor, MI 48106, Part
No. P5PJ047, 800-521-1520).
7.2 Teflon® Membrane Filter, 47 mm Diameter, with a 2 jtm Pore Size. Filter has a thin Teflon®
membrane stretched across a plastic ring. (Gelman Sciences, 600 S. Wagner Rd., Ann Arbor, MI
48106, Part No. R2PJO47, 800-521-1520).
7.3 Filter Extract Storage Vials. 100 mL polyethylene vials (Nalgene or equivalent).
7.4 Labels. Adhesive for sample vials, best source.
7.5 Parafilm. Used for covering flasks and pH cups during pH analysis, best source.
7.6 Kimwipes® and Kay-dry Towels. Used for cleaning .sampling apparatus and analysis equipment,
best source.
7.7 Stoppers. Polyethylene, best source.
7.8 Sodium Carbonate (NA2CO3). ACS reagent grade, best source.
7.9 Citric Acid [Monohydrate - HOC (CH2CO) OH]2COOH : H2O). ACS reagent grade, best
source.
7.10 Methanol (CH3OH). ACS reagent grade, best source.
7.11 Sulfuric Acid (H2SO4). ACS reagent grade, 1.000 N solution, best source.
7.12 Distilled Deionized Water (DDW). ASTM Type I water.
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
7.13 pH Buffers. Standard buffers, 4.00 and 7.00, for internal calibration of pH meter, best source.
7.14 Silica Gel. ACS reagent grade (indicating type), best source.
7.15 Gloves. Polyethylene disposable. Used for impactor frit assembly and filter assembly, best source.
7.16 Dow Corning High Temperature Vacuum Oil. Dow Corning 660 oil used for impactor frit
coating solution, best source.
7.17 Zero Air. A supply of compressed clean air, free from particles and ammonia. The supply may
be either from a commercial cylinder or generated on site, best source.
7.18 BRIJ-35. Composed of 0.1% of BRU-35 in DI water (Fisher Scientific, 711 Forbes Ave.,
Pittsburgh, PA 15129, 412-787-6322).
7.19 Perchloric Acid (HCIO^j). 60-62%, in water, best source.
7.20 Toluene (C-jHg). ACS reagent grade, best source.
7.21 Potassium Chloride (KC1). ACS reagent grade, best source.
7.22 Acetone (CgHgO). ACS reagent grade, best source.
7.23 1% Glycerol (Glycerine -CH2OHCHOHCH2OH). ACS reagent grade, best source.
8. Preparation of Impactor Frit and Denuder Coating .
8.1 Impactor Frit Coating Solution Preparation. Weigh 1 g of silicone oil (Dow Corning high
temperature 660 oil) and place in a 100 mL polyethylene storage vial. Add 100 mL of toluene. Mix
thoroughly, close container, and store at room temperature. (WARNING - FLAMMABLE LIQUID).
8.2 Annular Denuder Citric Acid Coating Solution. Clean a 100 mL polyethylene storage vial and
let dry at room temperature. Measure 50 mL of methanol (WARNING - TOXIC, FLAMMABLE
LIQUID) with a graduated cylinder and pour into vial. Weigh 0.5 g of citric acid and add to vial. Add
enough glycerol to the vial to make a 1% solution. Mix thoroughly; cover and store at room
temperature.
9. Impactor Frit Installation
9.1 Impactor Frit Installation
The impactor-coupler assembly shown in Figure 4 is composed of two parts: the replaceable impactor
frit and the coupler-impactor housing seat. The impactor surface is a porous ceramic or porous stainless
steel frit, 10 mm x 3 mm. Insert this frit into the coupler-impactor housing using the tools illustrated in
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
Figure 4. Press the impactor frit gently, but firmly, into the seat of the impactor housing with a clean,
gloved finger. The impactor should fit into the housing so that it does not protrude above the seat.
During sampling, particles accumulate on the impactor's plate surface. After each sampling event, clean
the assembly to prevent the build-up of contaminants that may lead to loss of key acidic species being
collected by the ADS. Cleaning involves immersing the elutriator, coupler-impactor, and frit in 0.1%
BRIJ-35 cleaning solution and ultrasonicating for about 5 min. Rinse thoroughly with DDW for
additional 5 min. Rinse and dry with zero air or in dust-fee environment and store with ends plugged
and capped.
9.2 Impactor Frit Coating
With the impactor frit in the impactor seat of either the coupler (see Figure 5) or the Teflon® impactor
seat support pin that fits into the first denuder, pipette 50 fiL (about two drops) of the toluene-660 oil
coating solution onto the impactor frit surface and allow to dry in a dust-free environment at room
temperature. Cap both sides of the coupler impactor or denuder-impactor until use.
[Note: Only the minimum amount of oil should be on the frit because any excess will be blown off during
sampling and will contaminate the surfaces of the first denuder.]
10. Filter Preparation and Assembly
/Note: A clean and dedicated indoor work space is required for the daily preparation, assembly and
disassembly of the denuder and filter assembly. Approximately 2-3 m of bench space is adequate, with
additional space for storing supplies.]
[Note: All loading and unloading of the filter assembly must be performed in an ammonia-free glove box.
Generally, the filter assembly should be reloaded after cleaning, at the same time as unloading.]
10.1 With clean gloves, disassemble the filter assembly (see Figure 8) by unscrewing the large outer
Delrin® collar (sleeve) from the aluminum filter housing outlet component.
[Note: Remove the polyethylene cap first. Lay the pieces out on clean Kimwipes® (see Figure 8).J
10.2 Lay a clean Teflon® filter ring housing, with its large opening face up, on a clean Kimwipe®. Place
a clean stainless steel screen in the filter ring housing.
10.3 Using clean filter forceps, place a Teflon® filter on the screen.
[Note: If a Zefluor® Teflon® filter is used, be sure to place the membrane coated side, not the coarse
side, toward the air stream. By observing the filter in the light, one can differentiate between the coarse
and membrane side.]
10.4 Place the Teflon® filter housing inlet component (see Figure 8) on top of the Teflon® filter. This
design forms a "sandwich" with the Teflon® filter held between the second filter ring housing and the
housing inlet component. The housing inlet component connects the filter assembly to the annular
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
denuder through a thermoplastic coupler. Be careful not to twist the filter assembly components, or
damage will occur to the filter.
10.5 Lay the aluminum filter housing outlet component, with its large opening face up, on a clean
Kimwipe®.
10.6 Insert the filter ring sandwich with the filter housing inlet component extending upward. Place the
larger outer Delrin® sleeve over the filter sandwich and screw onto the aluminum filter base. DO NOT
OVERTIGHTEN!
10.7 Install the "quick-release" plug into the filter outlet component. Tighten the housing outlet to the
Detrin® screw sleeve. DO NOT OVERTIGHTEN!
10.8 Install the polyethylene cap onto the filter inlet component and the orange dust cover onto the quick
release plug. The filter assembly should be sealed tight before it is removed from the glove-box.
10.9 Leak-check the filter assembly is leak-checked according to Section 12.2.4.
11. Annular Denuder System Preparation
Clean all new annular denuder parts obtained from suppliers by placing them in a dilute BRLT-35 solution.
The parts should then be thoroughly rinsed in DDW, rinsed with acetone, and allowed to dry to room
temperature. Store with end caps in place.
11.1 Coating Procedure
11.1.1 Cap one end of a denuder using Caplugs (which has the inner tube flush to the outer tube)
and set the denuder upright on the capped end. For the denuder with flow-straighteners at both ends,
either end may be capped. Measure 10 mL of the citric acid solution and pour into the denuder.
11.1.2 Cap the open end of the denuder and, holding it horizontally, rotate the denuder to distribute
the coating solution evenly, wetting all surfaces.
11.1.3 Remove cap and decant excess coating solution into a 100 mL polyethylene bottle.
11.1.4 For the impactor denuder, the coating is performed without the impactor pin in place.
11.2 Drying Procedure
[Note: As demiders dry, they change from translucent to a frosted appearance. Denuders are dry when
they become uniformly frosted.]
{Note: A supply of zero air is needed to dry the annular denuder tubes after applying the coating
solutions. Tfiis air should be free of ammonia, moisture, and particles. Either a tank of pure air or an
air purifier assembly can be used.]
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidify
11.2.1 Assemble the drying train and manifold as illustrated in Figure 7. Drying train and manifold
clean air flow should be adjusted to 2-3 L/min through each denuder. Close toggle valve controlling
clean air flow through manifold before attaching denuders.
11.2.2 Attach the flow-straightener end of the denuder to the drying manifold port (see Figure 7).
11.2.3 Open the toggle valve and allow clean air to flow through the denuder tube for 5 min.
Caution: Excess airflow will cause uneven coating to the tube watts.
11.2.4 Close toggle valve and reverse ends of the denuder attached to the manifold. Start clean air
flow again.
11.2.5 When an even frosted appearance is achieved, remove denuder from manifold, cap both ends
with clean caps, and store until ready for use. Turn off air to drying manifold. Affix label indicating
coating date on denuder.
11.3 Denuder System Assembly
{Note: Described herein is an annular denuder system consisting of one denuder. Extreme care should
be exercised in handling and assembling of the ADS if the denuder is made of glass. The coupling of
components must be effective to prevent leaks but, at the same time, not stress the glassware. Only
patience and practice with the ADS will enable the operators to obtain optimum performance from the
system with minimum breakage.] .
The annular denuder system (ADS) assembly consists of (1) an inlet nozzle/impactor or cyclone assembly,
(2) 1 glass or stainless steel annular denuder tube, and (3) a 1-stage filter assembly. The following
procedure involves an inlet nozzle/impactor assembly.
11.3.1 Lay the ADS pieces on a clean surface (i.e., Kimwipes®).
11.3.2 Remove the end caps from the citric acid coated denuder. Gently insert the impactor support
pin and coated frit assembly into the denuder-pin support.
11.3.3 Attach a thermoplastic coupler to the opposite denuder end. Place a Teflon® clad "O"-ring
inside the coupler, if needed.
11.3.4 Attach the filter assembly inlet to the denuder coupler assembly. (The filter assembly has
been previously loaded with a Teflon® filter. The components are assembled with plastic couplers.)
11.3.5 Attach the elutriator-acceleration jet assembly to the other end of the denuder. Tighten very
gently. DO NOT OVERTIGHTEN.
11.3.6 Tighten the remaining couplers very gently.
11.3.7 Cap elutriator with orange dust cover until used. Attach "quick-release" tube to outlet of
filter assembly.
11.4 Laboratory Leak-Check of ADS
Caution: Do not subject the system to sudden pressure changes or filter may tear.
11.4.1 Remove the orange dust cap from the impactor opening. Attach the "quick-release" outlet
of the filter assembly to a pump module. Turn on the pump. Be certain that flow through the ADS
occurs by checking die rotameter.
11.4.2 Briefly cap the elutriator with the orange dust cap. The flow, as indicated on the rotameter,
should drop to zero if no leaks exist.
11.4.3 Disconnect the pump from the ADS at the "quick-release" plug. Cap the "quick-release" plug
with an orange dust cover. Turn off the pump. REMEMBER — Never overtighten joints or breakage
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
will result. If the joints cannot be sealed with gentle tightening, then the Teflon® "O"-rings are worn or
defective and must be replaced.
11.4.4 Place the assembled sampler in its field-to-lab carrying case for transport to the field.
[Note: The ADS joints should be loosened slightly when extreme temperature changes are incurred during
transportation. This procedure will prevent unnecessary breakage or distortion of the ADS components.
Remember to allow the system to adjust to the outdoor air temperature before tightening the joints and
checking for leaks. J
11.4.5 Before proceeding to the field, review the following checklist:
• Run IDs on the Field Test Data Sheet match labels affixed to the ADS components and filter
assembly;
• Recessed ends of the denuder face the inlet;
• ADS ends are capped; and
• Transport case is secured firmly containing the ADS along with chain-of-custody and Field Test
Data Sheet.
12. Sampling
12.1 Placement of Denuder System
12.1.1 The placement of the fine particle strong acidity aerosol monitor must conform to a consistent
set of criteria and guidance to ensure data comparability and compatibility. A detailed set of monitor
siting criteria for ambient air monitoring and meteorological programs is given in the EPA document
Ambient Monitoring Guidelines for Prevention of Significant Deterioration (PSD), EPA-450/4-87-007,
EPA Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711, May 1987.
Because aerosol acidity is subject to rapid neutralization by ambient bases, the site must be away from
localized sources of ammonia, such as composting and livestocking operations, landfills, sewage treatment
plants, fertilizer plants and storage facilities, and recently plowed fertilized fields.
12.1.2 A summary of key factors that should be considered as part of the placement of an air quality
monitoring station containing an ADS are:
• Vertical placement above ground;
• Horizontal spacing from obstructions and obstacles;
• Unrestricted air flow; and
• Adequate spacing from roads.
The ADS sampler is mounted on a supported mast pole or tripod. The ADS inlet should be located
2-3 m above ground level. Placing the inlet closer to ground, level should be considered only if the
surface is flat and man-made (i.e., not unpaved dirt).
12.1.3 A summary of key criteria associated with these siting factors for air monitoring stations is
included in Table 1.0. The information included in the table should be used as part of the monitoring
network design to ensure that the monitoring program provides representative and unbiased data.
However, site-specific constraints could make it very difficult to meet all criteria. For example, wooded
areas around a site would make the siting very difficult. The use of the information in Table 1.0, coupled
Page 4.1-12 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
with a balanced evaluation by an experienced air quality and meteorology specialist, is highly
recommended.
12.1.4 In general, for a site with no major obstruction and obstacles, the air sampler intake should
be about 2-3 m aboveground. For a site with nearby roadways, however, intake placement should take
into account the effects of road dust re-entrainment and vehicular emissions. In fact, a linear relationship
should be established between the horizontal distance of the sampler intake from the roadway and the
aboveground elevation of that intake. For any roadway accommodating more than 3,000 vehicles per
day, the intake should be between 5 and 25 m from the edge of the nearest traffic lane. It should also
be 15 m aboveground for a distance of 5 m from the nearest traffic lane and 2 m aboveground for a
distance of 25 m from the nearest lane. For a roadway supporting less than 3,000 vehicles per day, the
intake should be placed at a distance greater than 5 m from the edge of the nearest traffic lane and'at a
height of 2-15 m aboveground.
12.2 Start-Up
12.2.1 Remove the ADS from its field-to-lab carrying case and load into the field sampling box.
Place the assembly in the box with the impactor extended outside the case. The ADS field sampling box
is insulated and configured to hold the ADS without allowing movement. Chrome plated spring clips
hold the denuder in place. Automatic and manual control switches allow the sampling box to control the
temperature of the ADS. The automatic switch should be used when the ADS is not in use and when the
ADS is sampling for extended periods of time without constant supervision to prevent low temperature
or sudden pressure change exposure of the ADS (these types of exposure can cause leaks to occur,
condensation, or the filter to tear). When sampling, the ADS should be kept 1°C above the outdoor
temperature to prevent condensation.
12.2.2 Allow the pump to warm up for about 5 min prior to testing.
12.2.3 To check the Heat/Cool cycles, flip one switch from "AUTO" to "MANUAL" and the other
between "COOL" and "HEAT." Check to insure that the fan and heater work, respectively.
12.2.4 With the elutriator still capped, turn on the pump with the switch on the timer. The rotameter
should indicate zero flow. Run leak check for 5-10 s; then turn off pump and remove elutriator cap.
Record leak rate on Field Test Data Sheet (see Figure 9). If there is a flow, refer to Section 12.4 for
corrective action for leak test failure. The Field Test Data Sheet is used to keep track of the denuder
tube, filter and impactors; it contains information such as when and by whom they are prepared,
assembled, extracted and the installation data and time, run date, sampling period, pump flow rates, start
and end times, and other data relevant to each run.
12.2.5 Attach a DGM output to the inlet of the annular denuder system. Turn on pump. Record
start time on Field Test Data Sheet. Using a stopwatch, record the time for 20.0 L to pass through the
DGM. Record the DGM temperature and the absolute pressure of the DGM.
12.2.6 Calculate the flow rate as follows:
Qstd =
where:
Qstd = flow rate corrected to standard conditions, 25°C and 760 mm Hg, L/min.
V = volume of gas pulled through denuder system, L.
T = time required to pull gas through denuder system, minutes.
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Method IO-4.1 Chapter IO-4
Strong Acidity . Atmospheric Acidic
Pjj = barometric pressure, mm Hg.
Pstcj = standard barometric pressure, 760 mm Hg.
Tstd = standard temperature, 298°K.
Tm = temperature of dry gas meter, °K(= °C + 273).
Fc = dry gas meter correction factor, dimensionless.
12.2.7 If the calculated flow rate is not between 9.5 and 10.5 L/min, readjust the flow rate until the
rate is in the above range. Stop the pump.
12.2.8 Record the flow rate on Field Test Data Sheet.
12.2.9 Remove DGM connection tubing from elutriator inlet. With all information correctly on the
Field Test Data Sheet, start the pump and begin sampling. Periodically check system during sampling
for constant flow rate.
12.3 Sample Shutdown
12.3.1 Attach DGM connection tubing to the elutriator inlet with pump still running. Measure flow
rate. Record calculated flow rate, temperature, and pressure on Field Test Data Sheet.
12.3.2 Turn off the pump. Record time and elapsed time meter reading on Field Test Data Sheet.
Remove DGM connection tubing from elutriator inlet. Remove ADS from the sampling box, cap the
ends, and place the ADS in field-to-lab carrying case for transport to lab. Secure the latches on the
transport case. Be careful not to stress the ADS during the transfer or breakage will result.
Caution: When the ADS is brought from a cold field sampling location to a warm laboratory, loosen the
denuder couplings to prevent thermal expansion from breaking the denuder.
12.4 Corrective Action for Leak Test Failure
(Note: These steps should be followed when failure occurs during testing at the laboratory before
transport to the field and in the field before sampling.]
12.4.1 Sampler Leaks. Note the problem on the Field Test Data Sheet. Check assembly of ADS
components. Replace gaskets. Check for proper seating of denuder surfaces. Replace any defective
parts.
12.4.2 Cracked or Chipped Denuder or Elutriator Assembly. Note problem on Field Test Data
Sheet. Discard defective pieces. Do not try to extract cracked pieces.
WARNING: USE CAUTION WHEN DISASSEMBLING CRACKED GLASSWARE. PIECES MAY
SHATTER AND CAUSE SEVERE CUTS. WEAR PROTECTIVE CLOTHING.
12.4.3 Flow Rate Disagreement. Note problem on Field Test Data Sheet. Check vacuum gauge
on flow module. If a high vacuum exists, the sampler has become blocked. This blockage may be due
to dust or smoke particles clogging the filter or to obstructions in the system or tubing. Check flow
module. Repair as needed.
12.4.4 Inadequate Flow Rate. Note problem on Field Test Data Sheet. Check rotameter on flow
controller. If adequate flow is shown here, a leak exists between the controller and the DGM. If no flow
is shown on rotameter, check vacuum gauge on controller. If no vacuum exists, pump needs repair. If
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidify
a high vacuum is shown, an obstruction exists in the system. Check to see that the paper filter dividers
were not accidentally installed with the filter in the filter assembly. Check tubing for kinks.
13. ADS Disassembly
13.1 In the laboratory, remove the ADS from the field-to-lab carrying case using both hands. To
prevent stress, hold the ADS by its ends.
Caution: Do not stress the ADS while removing it from the case.
13.2 Decouple the elutriator-jet assembly from the first denuder-impactor-coupler assembly.
13.3 The impactor assembly and the denuders will not be extracted. However, begin each run with a
clean impactor and charged denuder.
13.4 Handling the exposed Teflon® filter requires protection from contamination with NHg, which
rapidly neutralize aerosol acidity on the filter and bias the sample results. To ensure ammonia-free air
occupies the glove-box, a positive pressure is maintained by blowing air through a PVC tube (4" O.D.)
filled with glass-wool dosed with citric acid before entering the manifold which enables uniform
distribution of air from top of the glove-box. Flow the ammonia-free air for 5 min before retrieving the
filter. Place a citric acid soaked filter paper on the bottom to deplete ammonia when unused.
Disassemble the filter assembly in the clean, ammonia-free glove-box. Clean all glove-box surfaces and
utensils with methanol. Wearing clean gloves and using clean filter forceps, remove the filter and place
in the 100 mL bottle, with the exposed filter surface facing downward. Label the bottle with appropriate
information.
14. Extraction Procedure
14.1 Samples should be analyzed as soon after collection as possible. The solutions and extraction
procedures must be prepared and performed on the day of pH analysis. Keep samples in a refrigerator
until extracted and analyzed.
14.2 Samples should not be extracted until the day of analysis; however, if samples are extracted and
it is not possible to analyze them that day, they should be refrigerated. Allow the samples to return to
room temperature before analysis.
14.3 The same extract solution (ES) must be used for the samples to be analyzed, the working standards,
and the EA solution. Also, the same batch of alcohol must be used to prepare the EA solution and the
working standards and to extract the Teflon® filters.
14.4 Handling and extraction must take place in an ammonia-free glove box.
[Note: Teflon® is not wetted by water; therefore, the filter will float on top of an aqueous solution. The
use of alcohol aids wetting. Also, all types of Teflon® curl to some extent. The analyst must ensure that
the extraction solution makes complete contact with the particle deposit on the Teflon® filter during
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-15
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
extraction. A clean plastic (Teflon® or polyethylene) rod or tubing stub may be needed to hold the filter
in better contact \vith the fluid during extraction.]
14.5 Teflon® Filter Extraction
14.5.1 Flush the glove-box with ammonia-free air for at least 5 min before proceeding.
14.5.2 Process the filters in the same order in which they will be analyzed.
14.5.3 Open the sample vial and pipet 0.2 mL methanol onto the filter.
14.5.4 As soon as the methanol has wet the entire surface of the filter, deliver 6.00 mL of ES
solution into the vial. Cap the vial.
14.5.5 Put a batch of vials into the ultrasonic bath and sonicate for a total of 20 min, rotating the
position of the vials 90° every 5 min.
14.6 Aliquot Preparation
14.6.1 Using a 1 mL automatic pipet,.transfer 1 mL of the sample extract into each of two labeled
2 mL vials, one labeled A and the other labeled Al. Subsequent samples will be labeled B and Bl, C
and Cl, etc.
14.6.2 Recap each vial after its aliquots are drawn. Store the original sample vials in a refrigerator
for possible repeat analysis or for analysis of other components.
14.6.3 Proceed immediately with pH analysis.
15. pH ANALYSIS
15.1 Standard and Reagent Preparation
15.1.1 Standard H2SO4 Solution, 1.000 N
[Note: Each of the standard H2SO4 stock solutions must be prepared fresh 'he day ofpH analysis.}
15.1.1.1 Label seven 25 mL polyethylene stoppered volumetric flasks. Also, label each flask with
the volume of 1.000 N H2SO4 solution.
15.1.1.2 Use the 25 jtL automatic pipet to add the 1 N stock H2SO4 solution to flasks 2 and 3.
Use the 100 /iL pipet to add 1.000 N stock H2SO4 solution to flasks 4 through 7. Dilute all flasks to
the 25 mL mark with methanol. Cap with stoppers or parafilm and mix well. Proper dilution ratios are
indicated in Table 2.
15.1.2 2 M Potassium Chloride (KC1) Solution
15.1.2.1 Weigh 149.2 ± 0.1 g of KC1. Add the KC1 to.a 2 L flask.
15.1.2.2 Add about 700 mL of DDW water to the flask. Swirl the solution until the KC1 is
completely dissolved.
15.1.2.3 Pour this mixture into a 1 L graduated cylinder. Rinse the flask with a small amount
of DDW water and transfer the rinse into the cylinder. Fill the cylinder to the -1 L mark.
15.1.2.4 Pour the solution from the cylinder into the 1 L polyethylene bottle. Cap and shake the
bottle to mix well. Mark the bottle with date of preparation.
15.1.3 0.100 N Perchloric Acid (HCIO^ Solution
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
15.1.3.1 Fill a 1 L graduated cylinder about half full with DDW. Transfer 10 ± 0.1 mL of
60-62% HC104 into the 1 L cylinder with a 10 mL pipet.
15.1.3.2 Fill the cylinder to the 1 L mark. Pour the solution into the 1 L polyethylene bottle.
15.1.3.3 Cap and shake the bottle to mix well. Mark the date of preparation on the bottle.
15.1.4 0.010 N HC1O4 Solution
15.1.4.1 Fill a 1 L graduated cylinder about 1/2 full with DDW.
15.1.4.2 Measure 100 mL of the 0.1 N HC1O4 solution with the 100 mL graduated cylinder.
Add this to the 1 L cylinder.
15.1.4.3 Fill the 1 L cylinder with DDW to the 1 L mark. Pour the solution into the 1 L
polyethylene bottle.
15.1.4.4 Cap and shake the bottle to mix well. Mark the date of preparation on the bottle.
15.1.5 Extraction Solution (ES)
[Note: This solution must be prepared fresh on the day ofpH analysis.]
15.1.5.1 Measure 20 ± 0.5 mL of 2 M KC1 into 2 L erlenmeyer flask.
15.1.5.2 Using a 5 mL calibrated automatic pipet, add 10 + 0.1 mL of 0.01 N perchloric acid
(HC1C>4), to the flask. Add 980 ± 10 mL of DDW to the flask.
15.1.5.3 Mix well and cover with parafilm until ready for use.
15.1.6 Extraction Solution with methanol (EA Solution)
15.1.6.1 Measure 150 ± 2 mL of ES (prepared in Section 15.1.5) into a 250 mL graduated
cylinder. Transfer to a 250 mL erlenmeyer flask.
15.1.6.2 Using a 5 mL graduated cylinder, add 5 ± 0.1 mL of methanol (from the same fresh
bottle of methanol that was used to prepare the standards in Section 15.1.1) to the flask.
15.1.6.3 Mix well and cover with parafilm until ready for use. (pH of the EA solution should
be 4.09 ± 0.04. If not, the solution must be reprepared.)
15.1.7 Working Standard Test Solutions
15.1.7.1 Place fourteen-4 mL polystyrene sample vials (as used with Technicon Auto-Analyzer
II system) labeled 1A, IB, 2A 2B...7A, 7B into support racks. Using the calibrated dispensing pipet
bottle, add 3 mL of ES solution to each 4 mL vial.
15.1.7.2 Using the displacement pipet, add 50 /xL of methanol to each vial. Pour about 3 mL of
Standard Flask #1 H2SO4 standard (see Section 15.1.1) into a labeled 4 mL vial.
15.1.7.3 Immediately pipet 50 /*L of this standard into the 4 mL vials labeled 1A and IB
containing the ES solution and methanol.
{Note: This transfer must be done without delay to prevent the standard concentration from increasing
significantly due to evaporation of the methanol solvent.]
15.1.7.4 Repeat the procedure for each of the other 6 standards. If there is a delay of more than
5 min between the preparation of these mixtures and the next step, put caps on the 4 mL vials.
[Note: There should be 14 vials, each containing SmLofES solution, 50 \iL of methanol, and 50 /jL
of Standard H2SO4 solution (see Section 15.1.1). Two aliquots from each vial (1A, IB, 2A, 2B, 3A,
3B,...7A, 7B) will be analyzed.]
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-17
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
15.1.7.5 Place vial 1A in a rack. In a second rack place two-2 mL vials labeled 1A1 and 1A2.
Use the 1 mL automatic pipet to mix the contents of vial 1A by drawing 1 mL into the pipet tip and then
dispensing it back into the vial three times. Then use the same pipet to transfer 1 mL of the contents of
vial 1A to each of the two labeled (1A1,1A2) 2 mL vials. Place caps on the vials. After transferring
the two aliquots, rinse the automatic pipet tip in a flask of DDW. Repeat the transfer procedure for each
of the other working standard pairs. (IB aliquot into vials 1B1 and 1B2, 2A aliquot into vials 2A1 and
2A2, etc.). These are the working standards.
15.2 Calibration of pH Meter
The pH meter requires temperature calibration whenever a new electrode is used. Use the manufacturer's
procedure in the instrument manual. This calibration should be repeated every 3 months when not in use.
The pH meter is left with the power cord plugged into the AC outlet, the mode control knob is left in
the standby position, and the combination electrode is immersed in a 4 M KC1 solution (a slit rubber
stopper seals the bottle with the electrode in it). Keep a record of the temperature calibrations in a lab
notebook.
15.3 Pre-Analysis Calibration
[Note: Tlie steps for proper calibration and set-up for analysis of the Teflon® filter sample for pH
determination are outlined in Figure 10. Analysis should be performed at room temperature.]
[Note: Tfie pH buffer solutions are not used for any quantitative purpose. They are used to standardize
the electrodes and as a diagnostic to verify that the pH measurement system is working as expected before
beginning analysis of the samples.]
15.3.1 Use a pH Analytical Laboratory Log Form (see Figure 11) to record all data.
15.3.2 Fill three 4 mL vials with pH 7 buffer. Withdraw the electrode from the 4 M KC1 bottle and
wipe the tip gently with a Kimwipe® to remove the bulk of the solution. Rinse the electrode with one
vial of pH 7 buffer. Do not test pH of the first vial.
15.3.3 Immerse the electrode in the second vial of the pH 7 buffer. !'Tse a small bottle or other
support to hold the vial up to the electrode while waiting for the meter reading to equilibrate.
15.3.4 Test the pH by turning to the pH mode of the meter. Allow the reading to stabilize for at
least 30 s. Record the result on the Analytical Laboratory Log Form for pH 7, entry 2.
15.3.5 Turn to standby mode and test the last vial of pH 7 buffer. Record the results on the log form
for pH 7, entry 3. If the pH value for the 2nd cup is not 7.00 ± 0.01, adjust the "calib." knob to obtain
a reading of 7.00. Note this adjustment on the log form.
15.3.6 Fill three 4 mL vials with pH 4 buffer. With the meter in the standby mode, remove the cup
containing pH 7 buffer, wipe the tip of the electrode gently with a Kimwipe®, and then rinse the electrode
with the first vial of pH 4 buffer. Do not record pH.
15.3.7 Test the next two vials of pH 4 buffer as above, recording the results on the log form. If the
pH value for the third vial is not 4.00 ± 0.01, adjust the "slope" knob to get a reading of 4.00. If the
value for the second vial was not 4.00 ± 0.01, the calibrations at pH 7 and at pH 4 must both be
repeated.
Page 4.1-18 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
15.4 pH Test of HC1O4 Solutions
[Note: The 0.01 N HCIO4 solution is used to prepare the ES solution, which is used to prepare the EA
solution. The pH value for the EA solution must be 4.09 ± 0.04. Ifthis pH value is not achieved, or
more of the HCIO^ solutions must be reprepared.]
15.4.1 Finish the calibration of the pH meter with pH 4 buffer.
15.4.2 Rinse the pH electrode with DDW. Wipe the tip of the electrode with a Kimwipe®.
15.4.3 Fill three 4 mL vials with EA solution. Measure the pH of the test EA solution in similar
fashion to the buffer solutions. The values must be 4.09 ± 0.04.
15.4.4 If the above pH values are not achieved, follow Section 15.1.6 to reprepare the solutions.
Test the pH of the new solutions. Repeat as necessary to obtain an average pH of 4.09 ± 0.04.
15.4.5 Leave the electrode immersed in the "3rd vial" with the meter in the standby mode until ready
to start analysis of the working standards.
15.5 Analysis of Working Standard
[Note: Immediately following the EA analysis, start testing the working standards.]
15.5.1 With the pH meter still in the standby mode, remove the. last vial from the electrode, gently
wipe the tip with a Kimwipe®, and immerse the electrode into the working standard vial 1A1.
[Note: Only two vials are available for each working standard (also for filter extracts). Thus, pH
measurement is made for both of the two vials for each sample. Also, the electrode tip is not wiped
between the 1st and 2nd vials of each sample.]
15.5.2 After testing the pH of vial 1A1, test vial 1A2. Record the results of both on the Analytical
Laboratory Log Form.
15.5.3 With the meter in the stand-by mode, remove vial 1A2, wipe the electrode with a Kimwipe®
and test one 2 mL vial of EA solution.
15.5.4 Test a 2nd vial of EA solution; record the results on the log form. Discard the 1st vial of EA,
but retain the 2nd vial to be used as the 1st vial for the next EA test.
15.5.5 Mean pH value for the EA solutions should be 4.09 ± 0.04. If the above pH values are not
achieved, follow Section 15.1.6 to reprepare the EA solution. Retest. If still outside range, investigate
the problem with the probe and review previous recorded pH data for samples and EA solutions to
determine validity of measurements.
15.5.6 Continue testing the remainder of the working standards, 1B1, 1B2, 2A1, 2A2, 2B1, 2B2,
...7B1, 7B2. Remember to wipe the electrode tip both before and after each pair of test solutions, but
not in between two vials of the same sample.
[Note: If there is trouble in obtaining constant pH values, a magnetic stirrer may be used to keep the
contents to be measured uniform. If employed, ensure that the sample vials are insulated from any
temperature increase of the stirring platform that may occur during extended use.]
15.5.7 Use the mode control knob in the "temp." position to measure the temperature of the test
solutions every 5-10 samples and record the results on the Analytical Laboratory Log Form.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-19
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
15.6 Analysis of Filter Extracts
After measuring the pH of the working standards, measure the pH of the filter extract and record on the
Analytical Laboratory Log Form. After ten filter extracts have been tested, make an additional test with
the EA solution and record temperature. At the end make a final test of pH 4 buffer. If not
4.00 ± 0.04, perform a new calibration; the laboratory manager must then decide (and document) how
to reduce the unknowns based on pre- and post-calibrations. Criteria and corrective action should be met
according to Section 15.5.5. Follow manufacturer's directions for shut-down of pH meter. Immerse the
electrode tip in the bottle of 4 M KC1.
16. Assumption of Annual Denuder System
16.1 Measuring acid aerosol requires that ammonia be eliminated from the sample stream to prevent
inaccurate measurement of the acid aerosol, thus biasing the results. To address this issue, a citric acid
coated denuder to remove (denuder) ammonia from the gas stream is positioned in front of the filter
assembly where strong acid aerosols are collected. The efficiency of the citric acid denuder to remove
NH3 is assumed to be 100%.
16.2 The efficiency of the impactor collection system decreases with increased particulate loading. The
average operational time before such loading occurs has not been determined. Likewise, the removal
efficiency of the denuders have not been fully explored. Therefore, both the impactor and denuders are
removed after each sampling event and replaced with new components.
16.3 Other assumptions associated with the performance of the annular denuder system for validity of
die calculations presented in Section 17 are:
• All alkaline particles (> 2.5 pm) are removed at the sampler inlet;
• The cyclone or elutriator/impactor assembly have D?5o cut size of 2.5 /mi;
• The citric acid coated-denuder removes 100% of ammonia from the gas sample stream;
• Fine (<2.5 /tm) acid (K^SO^ aerosol losses in the denuder are less than 1 %;
• The Teflon® filter is 100% efficient in collecting fine acid aerosols; and
• The molar ratio of NH4NO3 to H2SO4 is assumed to be less than 10 %. However, if NH4NO3
is captured on the Teflon® filter, its dissociation during sampling may occur, thus affecting
acidity measurements. This user is responsible for determining what is and is not a "significant"
molar ratio of NH4NO3 to H2SO4.
17. Atmospheric Species Concentration Calculations
17.1 Calculations Using Results from pH Measurement
17.1.1 A convenient method of expressing concentration of the hydrogen ion was first proposed by
Sorensen in 1909 and has been widely adopted by chemists.
Page 4.1-20 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
[H+] = 10-PH
17.1.2 For each working standard on a given analytical day, calculate the "apparent net strong acid
concentration" as follows:
q . IQ-PHWSJ . 10-PHEA
where:
, Cj = apparent net strong acid concentration, molar.
pHWSj = measured mean pH of a working standard.
pHEA = measured mean pH of the EA solution.
17.1.3 For each analytical day, utilizing a particular set of freshly prepared daily working standards,
develop a standard curve by calculating the linear regression of Cj vs. Ceq, as documented in
Section 15.1.2.4. Calculate slope and intercept of the standard curve.
17.1.4 Calculate the corresponding "apparent net strong acid concentration" from the sample pH
using the following equation:
c 1Q-pHS . 10-pHEA
s
where:
Cg = apparent net strong acid concentration for unknown sample, molar.
pHS = measured pH of the sample (S).
pHEA = measured pH of the EA solution.
17.1.5 Utilizing the slope and intercept of the standard curve, calculate equivalent mass of strong
acid:
Cf = [Intercept] + [Cs] [Slope]
where:
Cf = apparent net strong acid mass, fug, as calculated from standard curve.
Intercept = calculated relationship from linear regression analysis of Cj vs. CEq.
Slope = calculated relationship from linear regression analysis of Cj vs. CEq.
17.2 Calculation of Air Volume Sampled, Corrected to Standard Conditions
17.2.1 The actual sample air value, V, for each sample is calculated using the data from the Field
Test Data Sheet. These data include the initial and final elapsed times, the initial rotameter reading, and
the rotameter I.D. No. Use the calibration curve for the given rotameter to calculate the flow for the
sample, in LPM, if applicable. Calculate the value of V as follows:
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-21
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Method IO-4.1 Chapter IO-4
Strong Acidity Atmospheric Acidic
vs = m m
where:
F «= flow from the calibration curve, L per minute.
T = net elapsed time, min.
Vg = total sample volume, L.
17.2.2 Convert L to in3 by:
Vs = Vx(l(r3)
where:
o
Vg = total sampling volume, m .
10"3 = conversion factor, m3/L.
17.2.3 Calculate the air volume sampled, corrected to EPA-reference conditions:
" v
v
Lm
^3std
where:
Vs — volume of sample at EPA-reference conditions, m.
Vs = volume of gas sample through the dry gas meter, or calculated volume sampled as
indicated by rotameter (see Section 17.2.1), m.
Tstcj = absolute EPA-reference temperature, 298 °K.
Tm = average flowmeter or dry gas meter temperature, °K.
^bar = barometric pressure of flow or volume measurement condition, mm Hg.
Pst(j = EPA-reference barometric pressure, 760 mm Hg.
Y = dry gas meter calibration factor (if applicable), dimensionless.
17.3 Calculation of Strong Acidity Aerosol Concentration
17.3.1 Calculate the final concentration of apparent net fine particle (<2.5 ^tm) strong acidity (as
H2SC>4):
CR+ = Cf/ V, „
11 i sstd
Page 4.1-22 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic _ Strong Acidity
where:
Cjj+ = apparent net fine particle strong acidity concentration, /tg/m3.
Cf = apparent net strong acid, ^g, as calculated from standard curve.
= volume of sampled gas at EPA-reference conditions (see Section 17.2.3), m3.
18. Method Safety
This procedure may involve hazardous materials, operations, and equipment. This method does not
purport to address all of the safety problems associated with its use. The user must establish appropriate
safety and health practices to determine the applicability of regulatory limitations prior to the
implementation of this procedure. These precautions should be part of the user's SOP manual.
19. Performance Criteria and QA
Required quality assurance measures and guidance concerning performance criteria that should be
achieved within each laboratory are summarized and provided in the following section.
19.1 Standard Operating Procedures (SOPs)
19.1.1 SOPs should be generated by the users to describe and document the following activities in
their laboratory: (1) assembly, calibration, leak check, and operation of the specific sampling system and
equipment used; (2) preparation, storage, shipment, and handling of the sampler system; (3) purchase,
certification, and transport of standard reference materials; and (4) all aspects of data recording and
processing, including lists of computer hardware and software used.
19.1.2 Specific instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the monitoring work.
19.2 QA Program
The user should develop, implement, and maintain a quality assurance program to ensure that the
sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted regularly and should be part of the QA program.
Additional QA measures (e.g., trouble shooting) and further guidance in maintaining the sampling system
are provided by the manufacturer. For detailed guidance in setting up a quality assurance program, the
user is referred to the Code of Federal Regulations (see Section 20, Citation 1 1) and the EPA Handbook
on. Quality Assurance (see Section 20, Citation 12).
20. References
1. Waldman, J. M., Operations Manual for the Annular Denuder System Used in the USEPA/RIVM
Atmospheric Acidity Study, UMPNJ - Robert Wood Johnson Medical School, Piscataway, NJ, August 28
1987.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-23
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Method IO-4.1 Chapter IO4
Strong Acidity Atmospheric Acidic
2. American Chemical Society Subcommittee on Environmental Chemistry, "Guidelines for Data
Acquisition and Data Quality Evaluation in Environmental Chemistry," Analytical Chemistry,
Vol. 52:2242-2249, 1980.
3. Sickles, II, J. E., Sampling and Analytical Methods Development for Dry Deposition Monitoring,
Research Triangle Institute Report No. RTI/2823/00-15F, Research Triangle Institute, Research Triangle
Park, NC, July 1987.
4. Forrest, J., and Newman, L., "Sampling and Analysis of Atmospheric Sulfur Compounds for
Isotopic Ratio Studies," Atmos. Environ., Vol. 7:562-573, 1973.
5. Stevens, R. K., et al., "Inlets, Denuders and Filter Packs to Measure Acidic Inorganic Pollutants in
the Atmosphere," Abstract for ACGIH Symposium: On Adran COS in Air Sampling, Asilomar
Conference Center, Pacific Grove, CA, February 16, 1986.
6. Appel B. R., Povard V., and Kothney E. L., "Loss of nitric acid within inlet devices for
Atmospheric Sampling," Paper presented at 1987 EPA/APCA Symposium: Measurement of Toxic and
Related Air Pollutants, Research Triangle Park, NC, May 3-6, 1987.
7. Braman R. S., Shelley T. J., and McClenny W. A., "Tungstic Acid for Preconcentration and
Determination of Gaseous and Particulate Ammonia and Nitric Acid in Ambient Air," Analyt. Chem.,
Vol. 54:358-364, 1983.
8. Perm, M., Concentration Measurements and Equilibrium Studies of Ammonium, Nitrate and Sulphur
Species in Air and Precipitation, Doctoral Thesis, Department of Inorganic Chemistry, Goteborg
University, Goteborg, Sweden, 1986.
9. Perm, M., and Sjodin A., "A Sodium Carbonate Coated Denuder for Determination of Nitrous Acid
in the Atmosphere," Atmos. Environ., Vol. 19:979-985, 1985.
10. Stevens, R. K., and Rickman, E., Jr., "Research Protocol/Method for Ambient Air Sampling with
Annular Denuder Systems," prepared for Environmental Protection Agency, Atmospheric Chemistry and
Physics Division, Office of Research and Development, Research Triangle Park, NC, ASRL-ACPD-RPM
003, January 1988.
11. 40 CFR Part 58, Appendix A, B.
12. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II - Ambient Air
Specific Methods, EPA 600/4-77-0272, May 1972.
13. Bolleter, C.J., Bushwan, and Tidwell, P.W. "Spectrophotometric Determination of Ammonia as
Indophenol," Anal. Chem., Vol. 33:592-594.
14. Harwood, J.E. and Kuhn, A.L., "A Colorimetric Method for Ammonia in Natural Water," Water
Res., Vol. 4:8055-811, 1970.
Page 4.1-24 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.1
Atmospheric Acidic Strong Acidity
15. Koutrakis, P., Wolfson, J.M., Slater, J.L., Brauer, M., Spengler, J.D., Stevens, R.K., and Stone,
C.L., "Evaluation of an Annular Denuder/Filter Pack System to Collect Acidic Aerosols and Gases,"
Environ. Sci. & Tech., Vol. 22:1463-1468, L988.
16. Mann, L.T., Jr., "Spectrophotometric Determination of Nitrogen in Total Micro-kjedahl Digests,"
Anal. Chem., Vol. 35:2179-2182, 1963.
17. Possanzini, M., Febo, A., and Liberti, A., "New Design of a High-performance Denuder for the
Sampling of Atmospheric Pollutants," Atmos. Environ., Vol. 17:2605-2610, 1983.
18. Stevens, R.K., and Rickman, E.E., Research Protocol/Method for Ambient Air Sampling with
Annular Denuder Systems, Report ASRL-ACPD-RPM 003, EPA, Research Triangle Park, NC,
January 1988.
19. Koutrakis, P., Wolfson, J.M., and Spengler, J.D., "An Improved Method for Measuring Aerosol
Strong Acidity: Results from a Nine-Month Study in St. Louis, Missouri and Kingston, Tennessee,"
Atmospheric Environment, Vol. 22:157-162, 1988.
20. Brauer, M., Koutrakis, P., Wolfson, J.M., and Spengler, J.D., "Evaluation of the Gas Collection
of an Annular Denuder System Under Simulated Atmospheric Conditions," Atmosperhic Environment,
Vol 23:1981-1986, 1989.
21. Koutrakis, P., Wolfson, J.M., Brauer, M., and Spengler, J.D., "Design of a Glass Impactor For
an Annual Denuder/Filter Pack System," Aeros. Sci., and Techn., Vol. 12:607-612, 1990.
22. Sjodin A. and Perm, M., "Measurements of Nitrous Acid In An Urban Area," Atmospheric
Environment, Vol. 19:985-992, 1985.
23. Vossler, T.L., Stevens, R.K., Paur, R.J., Baumgardner, R.E., and Bell, J.P., "Evaluation of
Improved Inlets and Annular Denuder Systems to Measure Inorganic Air Pollutants," Atmos. Environ.
Vol. 22:1729-1736, 1988.
24. Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds in Ambient
Air, EPA-600/8-90-005, Environmental Protection Agency, Research Triangle Park, NC, 1990.
25. Winberry, W. T., Jr., Determination of the Strong Acidity of Atmospheric Fine-Particles (<2.5 \an)
Using Annular Denuder Technology, EPA Publication EPA-600/R-93-D37, November 1992.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.1-25
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Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
TABLE 1. SUMMARY OF KEY PROBE SITING CRITERIA FOR
ACID AEROSOL MONITORING STATIONS
Factor
Vertical spacing above ground
Horizontal spacing from
obstruction and obstacles
Unrestricted airflow
Spacing from roads
Criteria
• Representative of the breathing zone and avoiding effects of
obstruction, obstacles, and roadway traffic. Height of probe
intake above ground in general, 2-3 m above ground and
2-15 m above ground in the case of nearby roadways.
• About 1 m or more above the structure where the sampler is
located.
• Minimum horizontal separation from obstructions such as
trees is >20 m from the dripline and 10 m from the dripline
when the trees act as an obstruction.
• Distance from sampler inlet to an obstacle such as a building
must be at least twice the height the obstacle protrudes above
the sampler.
• If a sampler is located on a roof or other structures, there
must be a minimum of 2 m separation from walls, parapets,
penthouses, etc.
• There must be sufficient separation between the sampler and a
furnace or incinerator flue. The separation distance depends
on the height and the nature of the emissions involved.
Unrestricted airflow must exist in an arc of at least 270°
around the sampler, and the predominant wind direction for
the monitoring period must be included in the 270° arc.
A sufficient separation must exist between the sampler and
nearby roadways to avoid the effect of dust re-entrainment
and vehicular emissions on the measured air concentrations.
Sampler should be placed at a distance of 5-25 m from the
edge of the nearest traffic lane on the roadway depending on
the vertical placement of the sampler inlet which could be
2-15 m above ground.
Page 4.1-26
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.1
Strong Acidity
TABLE 2. DILUTION RATIOS
Standard
H2S04
flask
1
2
3
4
5
6
7
Volume of 1.000 N
H2S04
added to each flask,
0
25
50
100
200
400
800
Working standard
concentration, 10'^N
H2S04
0
1
2
4
8
16
32
Equivalent strong
acid mass
collected OB filter
(Cgq), W?4
0
4.90
9.80
19.60
39.20
78.40
156.80
Approximate pH
4.09
4.01
3.95
3.84
3.68
3.48
3.23
aBased on 6.2 mL extraction volume.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-27
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
Air Flow
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
'Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler with
Built-in Seal Ring
Aerosol (H*) Collected
NHa Removal
Cyclone, Aluminum,
Teflon® Coated,
10 Lpm, 2.5 urn cut
Figure la. Annular Denuder System (ADS) with Cyclone.
Air Flow
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler-lmpactor with
Built-in Teflon® Seat Support
Elutriator, with Accelerator Jet,
Glass, Teflon® Coated
Figure Ib. Annular Denuder System With Impactor Assembly.
Page 4.1-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.1
Strong Acidity
Temperature Control Fan
Field Sampling Box
Heater
Temperature
Control Unit
Heater
Includes:
• Field Sampling Box
• 13" x 7" x 28" Heated and Cooled
• Pump-Timer System, Single Channel
with Mass Flow Controller
• Cyclone
• Annular Denuder
• Filter Pack
110Vor220V
Pump-Timer System
Figure 2. Annular Denuder System in Field Sampling Box With Pump-timer System.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-29
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
Acceleration Jet
Elutrlator
(a) Glass Assembly
Aluminum •
Elutrlator •
To Pump and
Row Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length.
Row Stralghtener, Teflon® Coated
Coupler-tmpactorwlth
Built-in Teflon® Seat Support QJJJ
Elutrlator, with Accelerator Jet, I
Glass, Teflon® Coated
Glass Assembly
Shown in line
Teflon
Acceleration Jet
Air
(b) Aluminum and Teflon Assembly
Acceleration Jet
Removal Tool
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring 13033
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Row Straightoner, Teflon® Coated
Coupler-lmpactor with
Built-in Teflon® Seat Support
Elutrlator, with Removable
Accelerator Jet, Aluminum,
Teflon® Coated
Aluminum and Teflon® Assembly
Shown-in line
Figure 3. Available Elutriator and Acceleration Jet Assemblies.
Page 4.1-30
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.1
Strong Acidity
Pin Removal Tool
Impactor Support Pin
and Frit
Viton O-ring
#30 Threads
Coupler/Impactor
Housing Seat
Annular Denuder/
Impactor (242 mm long)
#30 Threads
Cap
Filter Pack
Assembly, 47 mm
Air Flow
Coupler with
Built-in Seal Ring
Annular Denuder-lmpactor,
Glass, 242 mm Length,
Flow Straightener
Teflon® Coated
• Impactor Support Pin
Frit
Coupler with
Built-in Seal Ring
•4 Elutriator, with
Accelerator Jet, Glass
Teflon® Coated
Glass Annular Denuder
with Inset Impactor Assembly
Shown in line
Figure 4. Glass Annular Denuder With Inset Impactor Assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-31
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Air Flow
Annular Dcnuder, Stainless Steel,
MulU-Channol, 242 mm length,
Flow Straightonar, Toflon® Coated
Coupler-lmpactor
with Built-in Teflon®
Seat Support
Etutrlator, with Accelerator Jet,
Glass, Teflon® Coated
Annular Denuder Filter Pack
Assembly with Coupler-lmpactor
Shown in line
Air Flow
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler-lmpactor
with Built-in Teflon®
Seat Support
Elutriator, with Removable
Accelerator Jet, Aluminum,
Teflon® Coated
Annular Denuder Filter Pack
Assembly with Coupler-lmpactor
Shown in line
Teflon Seat Support
Side View
Figure 5. Side View Impactor/Coupler Assembly.
Page 4.1-32
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Air Flow
Stainless Steel
Sheath, Inner
Concentric Glass
Teflon-Coated
Flow Straightener
End Cap
Annular Denuder
Method IO-4.1
Strong Acidity
1 mm Annular Space
Cross-Sectional View
Internal Schematic of Annular Denuder
Internal Surface
Teflon-Coated
Figure 6. Internal Schematic of Annular Denuder.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-33
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
Wall Clamp
Dryer/Cleaner
Bottle
Frit
Thermoplastic Caps with
Teflon Seal Rings and Hose Barbs
Teflon Tubing
Back-to-Back
Connectors
Annular Denuder,
Stainless Steel,
Multi-Channel,
242 mm Length,
Row Straightener,
Teflon® Coated
End Caps
Manifold
Air
Figure 7. Drying Train and Manifold.
Page 4.1-34
Compendium of Methods for inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Quick-Release Plug
Aluminum Filter
Housing Outlet
Method IO-4.1
Strong Acidity
Spacer, Teflon®
Porous Screen, Stainless
Steel, Teflon® Coated
Teflon® Filter
Filter Housing Inlet,
Aluminum Teflon® Coated
X-Y
Delrin Screw Sleeve
Acid Aerosol Filter Assembly
Acid Aerosol -
Filter
Air Flow
Coupler with [
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm Length
Coupler with
Built-in Seal Ring
Cyclone, Aluminum
Teflon® Coated, ft/
10 Lpm, 2.5 urn cut I";
Acid Aerosol Filter Assembly
Shown in line
Figure 8. Acid Aerosol Filter Assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-35
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
DETERMINATION OF THE STRONG ACIDITY OF
ATMOSPHERIC FINE-PARTICLES
Project:
Site: —
GENERAL
Location:
Date:
Location of Sampler:
Sample Code:
Operator:
Mass Flow
Controller No.:
Lab Calibration Date:
Flow Rate Set Point:
Calibrated By:
Rotameter No.:
DGM No.:
EQUIPMENT
Sampler
Citric Acid Denuder No.:
Filter Assembly No.:
Time:
Flow Rate: _
Temperature:
Pressure:
SAMPLING DATA
Time
Stop
Avg. Flow Rate:
Leak Check (Before):
(After):—
Total Sample Vol.:
Flow Maintained Rate:
(±5%)
Time
Flow
Rate (Q),
L/min
Ambient
Temperature,
°C
Barometric
Pressure,
mm Hg
Relative ;
Humidity,
% •':'•
Comments
Figure 9. Annular Denuder Field Test Data Sheet.
Page 4.1-36
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
pH 7 Buffer
pH 4 Buffer
Method IO-4.1
Strong Acidity
EA Solution
Working Standards
EA Solution
YES
Temperature
Analysis of up
to 10 Filter Extracts
EA Solution
Temperature
YES
pH 4 Buffer
NO
NO
Figure 10. Calibration and Analysis Step for pH Determination.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-37
-------
Method IO-4.1
Strong Acidity
Chapter IO-4
Atmospheric Acidic
Determination of the Strong Acidity of
Atmospheric Fine-Particles (<2.5
Name:
Date: _
LAB:_
Sample I.D.:
Location: .—
Constituent
pH 7 Buffer
1
2
3
pH 4 Buffer
1
2
3
EA Solution
1
2
3
Working Standards
1AI
1A2
EA
IB1
1B2
EA
2A1
2A2
Temp.
EA
2BI
2B2
EA
3A1
3A2
EA
Temp.
3BI
3B2
EA
RUN NUMBER
1
•
2
i
'
3
-
•.
4
.
%
5
;
'
6
•
1
Figure 11. pH Analytical Laboratory Log Form.
Page 4.1-38
Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.1
Strong Acidity
Constituent
4A1
4A2
EA
4B1
4B2
Temp. '
EA
5A1
5A2
EA
5B1
5B2
EA
6A1
6A2
Temp.
EA
6B1
6B2
EA
EA
7A1
7A2
EA
7B1
7B2
Temp.
Sample Extracts
A
Al
B
Bl
C
Cl
D
Dl
E
El
EA
Temp.
EA Solution
1
2
3
pH4 Buffer
2
3
RUN NUMBER
1
2
,
3
4
5
-
6
7
Figure 11 (cont). pH Analytical Laboratory Log Form.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.1-39
-------
-------
EPA/
-------
Method IO-4.2
Acknowledgements
This Method is a part of Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-10,
by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG), and
under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning, Center
for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure Research
Laboratory (NERL), both in the EPA Office of Research and Development, were the project officers
responsible for overseeing the preparation of this method. Other support was provided by the following
members of the Compendia Workgroup:
* James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in
the preparation and review of this methodology.
Author(s)
William T. "Jerry" Winberry, Jr., MRI, Gary, NC
Thomas Ellestad, U.S. EPA, RTP, NC
Bob Stevens, U.S. EPA, RTP, NC
Peer Reviewers
Delbert Eatough, Brigham Young University, Provo, UT
Shere Stone, University Research Glassware Corp., Chapel Hill, NC
Petros Koutrakis, Harvard School of Public Health, Boston, MA
J. Waldman, Robert Wood Johnson Medical School, New Brunswick, NJ
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
-------
Method IO-4.2
Determination of Reactive Acidic and Basic
Gases and Strong Acidity of Atmospheric
Fine Particles (<2.5/tm) in Ambient Air
TABLE OF CONTENTS
Page
1. Scope 4.2-1
2. Applicable Documents 4.2-2
2.1 ASTM Standards , 4.2-2
2.2 Other Documents , 4.2-2
3. Summary of Method 4.2-2
4. Significance 4.2-3
5. Definitions 4.2-3
6. Factors Affecting Denuder Efficiency 4.2-4
7. Apparatus 4.2-4
7.1 Sampling 4.2-5
7.2 Analysis 4.2-7
8. Reagents and Materials 4.2-8
9. Preparation of Coating and Extraction Reagents 4.2-10
9.1 Impactor Frit Coating Solution Preparation 4.2-10
9.2 Impactor Frit Extraction Solution Preparation 4.2-10
9.3 Annular Denuder Coating Solutions Preparation 4.2-10
10. Elutriator and Acceleration Jet (Inlet) Assembly 4.2-10
11. Impactor Frit Preparation and Installation 4.2-11
11.1 Impactor Frit Installation 4.2-11
11.2 Impactor Frit Preparation 4.2-11
12. • Filter Pack Preparation and Assembly 4.2-12
13. Annular Denuder System Preparation 4.2-13
13.1 Annular Denuder Coating Procedure '. 4.2-13
13.2 Annular Denuder Drying Procedure 4.2-13
13.3 Annular Denuder System (ADS) Assembly 4.2-13
13.4 Laboratory Leak-Check of ADS 4.2-14
14. Sampling 4.2-15
14.1 Placement of Denuder System 4.2-15
14.2 Start-Up 4.2-16
14.3 Sample Shutdown 4.2-17
14.4 Corrective Action for Leak Test Failure 4.2-17
15. ADS Disassembly 4.2-18
16. Extraction Procedures '. 4.2-18
16.1 Impactor Frit Coating Extraction . . 4.2-19
16.2 Denuder Extraction 4.2-19
16.3 Filter Extraction 4.2-19
in
-------
TABLE OF CONTENTS (continued)
Page
17. Ion Chromatography Analysis 4.2-20
17.1 Standards Preparation 4.2-21
17.2 Reagent Preparation 4.2-22
17.3 Sample Preparation 4.2-23
17.4 Basic System Operations - Start-up and Shut-down 4.2-23
17.5 Basic Troubleshooting 4.2-26
18. Ammonia Analysis by Technicon Autoanalysis 4.2-27
18.1 Standards and Stock Solutions Preparation 4.2-27
18.2 Reagent Preparation 4.2-29
19. pH Analysis 4.2-30
19.1 Standard and Reagent Preparation 4.2-30
19.2 Calibration of pH Meter , 4.2-32
19.3 Pre-Analysis Calibration 4.2-32
19.4 pH Test 0.01 NHC1O4 Solution 4.2-32
19.5 Analysis of Working Standard 4.2-33
19.6 Analysis of Filter Extracts 4.2-33
20. Atmospheric Species Concentration Calculations 4.2-34
20.1 Assumptions of the Annular Denuder System 4.2-34
20.2 Calculations Using Results from 1C Analysis 4.2-35
20.3 Calculations Using Results from pH Analysis 4.2-35
21. Variations of Annular Denuder System Usage 4.2-38
22. Method Safety 4.2-39
23. Performance Criteria and Quality Assurance (QA) '.. 4.2-39
23.1 Standard Operating Procedures (SOPs) 4.2-40
23.2 QA Program 4,2-40
24. References 4.2-40
IV
-------
Chapter IO-4
Atmospheric Basic & Acidic Constituents
Method IO-4.2
DETERMINATION OF REACTIVE ACIDIC AND BASIC
GASES AND STRONG ACIDITY OF
ATMOSPHERIC FINE PARTICLES (<2.5fjaa)
1. Scope
1.1 The quantitative measurement of reactive acidic and basic gases and strong acidity of atmospheric
fine particles in ambient air using annual denuder technology is described in this method. The difference
between Inorganic Compendium Methods IO-4.1 and IO-4.2 is that the latter accounts for possible
interference from the dissociation of ammonium nitrate aerosol from particles collected on the filer by
two mechanisms:
NH4NO3 = NH3(g) + HNO3(g)
NH4NO3 + NH4HSO4 = (NH4)2SO4 + HNO3
Consequently, an accurate and quantitative value for determining strong acidity of atmospheric fine
particle is calculated by subtracting the ammonia concentration from the nitrate value and the result added
to the acidity measurement on the Teflon® filter to give a correct strong acidity measurement.
1.2 The chemical species that can be determined by this method are gaseous SO2> HNO2, HNO3, and
NH3 and particulate SO 4, NO§, NH \, and H +. Detection and quantitation limits are given in Table 1.
1.3 This method is a composite of methodologies developed by the U. S. Environmental Protection
Agency (EPA), Harvard University and the CNR Laboratories (Italy). A number of air pollution studies
in Italy, United States, Canada, Mexico, Germany, Austria, and Spain, and in public health services,
epidemiology, and environmental research centers have used this method.
1.4 The equipment described herein is used to measure acidic and basic gases and particulate matter
contained in ambient air. The methodology originally was developed for monitoring regional-scale acidic
and basic gases and particulate matter in support of EPA's field programs involving the Integrated Air
Cancer Research Program and the Acid Deposition Network. Similarly, the methodology has been used
to characterize the urban haze in Denver, Houston, and Los Angeles.
1.5 The techniques, procedures, equipment, and other specifications comprising this method are derived
and composited from those actually used by contributing research organizations and, therefore, are known
to be serviceable and effective. At this stage, this method is a unified, consensus, tentative, draft method
intended for further application and testing. Users should be advised that the method has not yet been
adequately tested, optimized, or standardized. Many of the specifications have been initially established
by technical judgement but have not been subjected to rugged testing. In some cases, alternative
techniques, equipment, or specifications may be acceptable or superior. In applying the method, users
are encouraged to consider alternatives, with the understanding that they should test any such alternatives
to determine their adequacy and confirm and document their advantages. Information and comments are
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-1
-------
Method 10-4.2 Chapter IQ-4
Acidic/Basic Constituents Atmospheric Acidic
solicited on improvements, alternative equipment, techniques, specifications, performance, or any other
aspect of the method.
2. Applicable Documents
2.1 ASTIV1 Standards
• D1356 Definitions of Terms Related to Atmospheric Sampling and Analysis.
2.2 Other Documents
• Ambient Air Studies (1-14).
• U. S. EPA Acid Aerosol Document (15).
3. Summary of Method
3.1 The annular denuder system (ADS) consists of (1) an inlet with an impactor or cyclone preseparator
designed to remove all particles with a DP50 of 2.5 /*m or greater, (2) annular denuders to quantitate
acidic and basic.gases, and (3) a filter pack for atmospheric acidity and particles. In operation, ambient
air is drawn through an elutriator-accelerator jet assembly, an impactor frit and coupler assembly, and
past glass denuder walls that have been etched and coated with chemicals that absorb the gaseous species
of interest. The remaining air stream is then filtered through Teflon® and Nylasorb® membrane filters.
Teflon® and nylon membrane filters are used to capture ammonium and nitrate aerosol and sulfate
paniculate matter. Nitric acid and sulfur dioxide will also be collected by the nylon filter but these
measurements are treated as interference. The ADS is illustrated in Figure 1. The field sampling box
with the ADS and pump-timer system is shown in Figure 2.
3.2 Following each run, the ADS assembly is removed from its field housing, its ends are capped, and
it is brought back to the laboratory. In the laboratory, the assembly pieces are uncoupled and capped.
The annular denuders are extracted with 5 mL of deionized water. The extracted solutions are
subsequently analyzed for ions corresponding to the collected gaseous species (see Figure 1). The filters
are placed into filter bottles where 5 or 10 mL of the ion chromatographic (1C) eluent are pipetted into
each filter bottle with the filters faced downward and completely covered by the eluent. The filter bottle
is capped and put in an ultrasonic bath for 30 min. The bottles are stored in a clean refrigerator at 5°C
until analysis.
3.3 The analysis of anion and cation concentrations collected by the denuders and filter pack is typically
performed by ion chromatographic and Technicon® colorimeter autoanalytic procedures. The H
concentration of extracts from the Teflon® filter downstream of the denuders is performed by pH
measurements using commercially available pH meters calibrated with standards.
Page 4.2-2 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
4. Significance
4.1 Reactive acidic (SC>2 and HNOj) and basic (NH^) gases and particles are found in the atmosphere
as a result of emissions from a variety of fossil fuel combustion sources, including industrial and
commercial facilities, industrial processes, etc. Measurements of these chemical species are currently
being used in a range of environmental studies, such as in (1) epidemiological programs to assess the
impact of acid aerosols on respiratory impairment, (2) receptor modeling to determine the origin of
particles that impact EPA's PMjQ air particulate standard, (3) assessment of the impact of particulate
nitrate and sulfate on visibility, and (4) quantification of the impact of acidic and basic air pollutants on
issues related to acid rain.
4.2 Unique features of the annular denuder that.separate it from other established monitoring methods
are the elimination of sampling artifacts due to interaction between the collected gases and particles and
the preservation of the samples for subsequent analysis. This preservation is accomplished by removing
NHg in the gas stream by the citric acid coated denuder and reducing the probability of the particulate
sulfate (804"") captured by the filter pack from being neutralized to ammonium sulfate [(NH^SO^.
If NH3 is not extracted from the gas stream prior to filtration, particulate sulfate and gaseous sulfur
dioxide correction would be required for accurate measurements. These biases in its configuration and
analytical methodology are addressed in this method.
5. Definitions
Definitions used in this document and any user prepared Standard Operating Procedures (SOPs) should
be consistent with ASTM D1356. All abbreviations and symbols are defined within this document at the
point of use.
5.1 Particulate Mass. A generic classification in which no distinction is made on the basis of origin,
physical state, and range of particle size. (The term "particulate" is an adjective, but it is commonly used
incorrectly as a noun.)
5.2 Primary Particles (or Primary Aerosols). Dispersion aerosols formed from particles that are
emitted directly into the air and that do not change form in the atmosphere. Examples include windblown
dust and ocean salt spray.
5.3 Secondary Particles (or Secondary Aerosols). Dispersion aerosols that form in the atmosphere as
a result of chemical reactions, often involving gases. A typical example is sulfate ions produced by
photochemical oxidation of SO?.
5.4 Particle. Any object having definite physical boundaries in all directions, without any limit with
respect to size. In practice, the particle size range of interest is used to define "particle." In
atmospheric sciences, "particle" usually means a solid or liquid subdivision of matter that has dimensions
greater than molecular radii (~ 10 nm); there is also not a firm upper limit, but in practice it rarely
exceeds 1 mm.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-3
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
5.5 Aerosol. A disperse system with a gas-phase medium and a solid or liquid disperse phase. Often,
however, individual workers modify the definition of "aerosol" by arbitrarily requiring limits on
individual particle motion or surface-to-volume ratio. Aerosols are formed by (1) the suspension of
particles due to grinding or atomization or (2) the condensation of supersaturated vapors.
5.6 Coarse and Fine Particles. Coarse particles are those with diameters greater than 2.5 /^m but less
than 10 fim; fine particles are those with diameters less than 2.5 jtm. These two fractions are usually
defined in terms of the separation diameter of a sampler.
[Note: Separation diameters other than 2.5 [an have been used.]
5.7 Annular. Refers to rotating to, or forming a ring. In the annular denuder sampler, the annular
refers to the cylinder to which coating is applied to the interior parallel planes to remove gaseous
pollutants by diffusion chemistry.
5.8 Denuder. The process gaseous pollutants from the gas stream.
5.9 Equivalent Weight. The equivalent weight, or combining weight, of a compound or ion is its
formula weight divided by the number of replaceable hydrogen atoms.
5.10 Normal Solution. Solution that contains a gram-equivalent weight of solute in a liter of solution.
6. Factors Affecting Denuder Efficiency
6.1 Operation below 20% relative humidity (RH) may result in less than quantitative collection of SO2.
Atmospheric water vapor in concentrations above 30% RH has been shown not to be an interferant for
SOo collection.
^f
6.2 Studies are being conducted to identify interferents, and calculations are being developed to correct
the measurements obtained by the annular denuder system for identifiable interferents. For example, the
presence of ozone (03) is known to oxidize nitrous acid (HNO2) to nitric acid (HNX^); therefore, HNO2
measurements are often underestimates. Calculations have been developed to adjust for this oxidation
process and to provide more accurate estimations of HNO2 concentrations in the atmosphere.
6.3 Other studies include the possible chemical reactions (organic and inorganic) that may occur with
selected coating solutions that interfere with the accurate measurement of the chemical species of interest.
6.4 The efficiency of impactor collection decreases when the impactor surface is loaded. The average
operational time before such loading occurs has not been determined.
7. Apparatus
[Note: This method was developed using the annular denuder system produced by University Research
Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC 27516, (919) 942-2753, as a guideline. EPA has
Page 4.2-4 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic ^ _Acidic/Basic Constituents
experience in use of this equipment during various field monitoring programs over the last several years.
Other manufacturers' equipment should work as well. However, modifications to these procedures may
be necessary if another commercially available sampler is selected.]
7.1 Sampling
7.1.1 Elutriator and Acceleration Jet Assembly (see Figure 3). Under normal sampling
conditions, the elutriator or entry tube is made of either Teflon®-coated glass or aluminum. When using
glass, the accelerator jet assembly is fixed onto the elutriator, and the internal surfaces of the entire
assembly are coated with Teflon®. When aluminum is used, the accelerator jet assembly is removable.
The jet is made of Teflon® or polyethylene, and the jet support is made of aluminum. Again, all internal
surfaces are coated with Teflon®. Both assemblies are available with 2, 3 and 4 mm inside diameter jets
(nozzles).
7.1.2 Teflon® Impactor Support Pin and Impactor Frit Support Tools (see Figure 4). Made of
either Teflon® or polyethylene and used to aid in assembling, removing, coating and cleaning the
impactor frit.
7.1.3 Impactor Frit and Coupler Assembly (see Figure 5). The impactor frit is 10 mm x 3 mm
and is available with a porosity range of 10-20 /im. The frits should be made of porous ceramic material
or fritted stainless steel. Before use, the impactor frit surface is coated with a Dow Corning 660 oil and
toluene solution and sits, in a Teflon® seat support fixed within the couple"- The coupler is made of
thermoplastic and has Teflon® clad sealing "0"-rings that are located on both sides of the seat support
inside the coupler. The couplers are composed of two free moving female threads that house the support
tools when assembling and removing the impactor frit, and couple the denuders when sampling. Arrows
on the metal band hold the female threads together. These arrows should be pointing in the direction of
air flow (see Figure 1.) when the ADS is assembled.
[Note: In situations when there are substantial high concentrations of coarse particles (>2.5 /j,m), a
Teflon-coated aluminum cyclone should be used in place of the acceleration jet and impactor assembly,
as illustrated in Figure 6.J
The cyclone is made of Teflon®-coated stainless steel. The location of the cyclone with respect to the
denuder, heated enclosure, and meter box is illustrated in Figure 6.
7.1.4 Annular Denuder (see Figure 7). The denuder consists of two concentric glass tubes. The
tubes create a 1 mm orifice, which allows the air sample to pass through. The inner tube is inset 25 mm
from one end of the outer tube; this end is called the flow straightener end. The other end of the inner
tube is flush with the end of the outer tube. Both ends of the inner tube are sealed. In this configuration,
the glass surfaces facing the orifice are etched to provide greater surface area for the coating. Three
types of denuders are available. One is the older version that accommodates the impactor support pin
assembly and can only be the first denuder in sequence. It is available in glass with the impactor support
holder made of glass and the impactor support pin assembly made of Teflon®. The denuder is 265 mm
long with size #30 threads for coupling. It is available with flow straighteners at both ends; however,
most denuders in use today only have one flow straightener end. The second most recent denuder
version, which can be used as any denuder in sequence, is available in glass with only one flow
straightener end. It is 242 mm long and has size #30 threads. Finally, the third denuder design involves
two inner concentric glass tubes (1 mm separation) positioned around a solid center glass rod, as
illustrated in Figure 5. Once again, the glass surfaces are etched to provide greater surface area for the
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-5
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Method 10-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
coating. The inner glass tubes and coater rod are inset 25 mm from one end of the outer Teflon®-coated
stainless steel tube to serve as the flow straightener end. All denuder types should be equipped with
thermoplastic or polyethylene caps when purchased.
7.1.5 Caps for Annular Denuder (see Figure 2). Caps are made of either polyethylene or
thermoplastic and are used in the coating and drying processes and for storage and shipment. The
thermo-plastic caps include a removable Teflon® seal plate when purchased. Repeated reuse of these
types of caps have caused some contamination due to improper cleaning of the cap and Teflon® seal plate,
i.e., fluid tends to be trapped under the seal plate. The polyethylene caps are not equipped with seal
plates. Polyethylene caps tend to dry faster and seal better than the thermoplastic caps.
7.1.6 Annular Denuder Couplers (see Figure 4). The couplers should be made of thermoplastic
and equipped with Teflon® "O"-rings that sandwich a silicone rubber ring on three sides. This design
provides elasticity for better sealing under extremely cold temperature conditions in which Teflon® does
not give. Two types of couplers are available. In the older version, the couplers have removable seal
rings. Problems with denuder breakage and leakage due to improper threading of the couplers with the
denuders led to the development of a second type of coupler. The new couplers are equipped with
permanent seal rings that provide more even threading and a better seal when coupled. Some couplers
have built-in flow-straighteners. The couplers are used to couple the annular denuders and for coupling
the last denuder with the filter pack.
7.1.7 Filter Pack Assembly (see Figure 8). The filters are supported by stainless steel porous
screens and housed in a polyethylene filter ring housing. The Teflon® filter ring housing directly follows
the Teflon® filter housing inlet component. The "nylon" filter ring housing follows the Teflon® filter ring
housing and sits on a Teflon® "O"-ring, which seals the filter ring housing components to the filter
housing outlet component. Four filters may be in series depending on the species of interest. The filter
housing outlet component is aluminum and accommodates a polyethylene screw sleeve that seals the filter
pack assembly. The sleeve is available in different lengths to accommodate up to four filter ring housing
units. A stainless steel "Quick-Release" plug screws into the aluminum outlet component for connecting
the pump-timer to the filter pack assembly. It is equipped with an orange "dust cover" (male plug) upon
purchase.
7.1.8 Drying Manifold Assembly (see Figure 9). Made of pyre'x and is available to accommodate
as many as four drying denuders. The denuders are attached to the manifold with back-to-back Bakalite
bored caps. The bored caps are connected with a Teflon® connector ring. Air is pushed through an air
dryer/ cleaner bottle made of 2 1/2" heavy wall pyrex that contains silica gel, calcium sulfate, and
activated charcoal (not available with assembly). The tubing that connects the dryer/cleaner bottle to the
drying manifold should be secured at each cap with either Teflon® washers or Teflon® washers coupled
with Teflon® hose barbs.
7.1.9 Vacuum Tubing. Low density polyethylene tubing, 3/8" diameter for distances of less than
50 ft., 1/2" diameter for distances greater than 50 ft. Since this tubing is used downstream from the
sampler, similar sized tubing or pipe of any material may be substituted. The tubing must have sufficient
strength to avoid collapsing under vacuum (Fisher-Scientific, 711 Forbes Ave., Pittsburgh, PA 15219,
412-787-6322).
7.1.10 Tube Fitting. Compression fittings (Swagelok®, Gyrolok® or equivalent) to connect vacuum
tubing (above) to an NPT female connector or filter holder and connect vacuum tubing to fitting on
differential flow controller. The fittings may be constructed of any material since they are downstream
of the sampler (Fisher-Scientific, 711 Forbes Ave., Pittsburgh, PA 15219, 412-787-6322).
7.1.11 Annular Denuder System Sampling Case (see Figure 10). Made of a "high-impact" plastic
and insulated with polyurethane. It is 4 ft long by 6" wide and 6" deep. Two heater units, a fan blower,
Page 4.2-6 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
and an air outlet are located in the lid of the housing. Also, located on the lid are the automatic and
manual control switches and a 12-V power supply outlet for the heater and fan. The bottom of the box
houses the ADS. The elutriator end of the ADS protrudes through one end of the box, while the
denuders are supported in the box by chrome plated spring clips. If the Teflon®-coated aluminum cyclone
is used to remove coarse particles, it is also housed in the heated sampling box, with the elutriator end
protruding through the sampling box, as illustrated in Figure 4. A vacuum plug known as a
"quick-release" coupler is linked to the filter pack of the ADS. This plug connects the ADS to 1 1/4"
Teflon® rubber "clad" shrink tubing that exhausts the air stream to the ambient air. The box is sledge
hammer proof.
7.1.12 Annular Denuder Field-to-Lab Case (Optional). The field-to-lab case is made of rigid plastic
and insulated with polyurethane. It is made to be hand carried, not shipped, and is used to transport four
total annular denuder systems, each consisting of either three annular denuder sections or two annular
denuder sections and one denuder-impactor assembly. The systems are packed already assembled and
capped; they are ready for sampling or sample analysis. The case has a carrying handle, a lock, and
three latches and is equipped with two keys.
7.1.13 Annular Denuder Shipping Case (Optional). Made of formica, backed with plywood and
insulated with polyurethane. The corners are reinforced with metal. It is made to withstand shipping
by truck, UPS, and Federal Express. Each case is stackable and lockable and has a carrying handle.
Seven total annular denuder systems can be packed in the case, provided each system contains four
denuders each. The systems can consist of either three denuders (242 mm long) and one
denuder-impactor assembly (265 mm long) or four denuders (242 mm long). Each component of the
system is packed in its own storage compartment. The personal sampler assemblies can also be placed
and shipped in this case.
7.1.14 Differential Flow Controller (Pump). Pumps air through the sampler at a fixed rate of
between 5 and 20 standard L/min (typically 10 L/min) with a precision of ±5% over the range of 25 to
250 mm Hg vacuum.
7.1.15 Dry Gas Meter (DGM). Pulls 10 L of gas per revolution (Fisher-Scientific, 711 Forbes
Ave., Pittsburgh, PA 15219, 412-787-6322).
7.2 Analysis
7.2.1 Ion Chromatograph. A chromatograph equipped with the appropriate anion and cation
exchange resin filled separator and suppressor columns and conductivity detector for measuring acidic
(SO2, HNO2 and HNO^) and basic (NHg) ions in solution (i.e. denuder and filter extracts) (Dionex
Corp., 1228 Titan Way, Sunnyvale, CA 94086, 408-737-0700).
7.2.2 Technicon Colorimeter Autoanalyzer. Clorimetic analyzer able to detect specific ions of
interest in aqueous extracts (Technicon Industrial Systems Corp., 511 Benedict Ave., Tarrytown, NY,
10591-5097, 800-431-1970).
7.2.3 pH Meter. A pH or pH/ion meter with an "integral" automatic temperature compensation and
calibrated with (U. S. EPA, N.S.T.) standard buffers (pH 4 and 7), including 2 and 4 mL analysis cups
(Orion and other vendors).
7.2.4 Polyethylene Bottles with Polyethylene Screw Caps. 50 mL and 100 mL. Used for storage
of coating solutions, best source.
7.2.5 Erlenmeyer Flasks. 250 mL and 2 L borosilicate glass or polyethylene flasks with calibration,
best source.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-7
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
7.2.6 Graduated Cylinders. 10 mL and 100 mL borosilicate glass or polyethylene cylinders, best
source.
7.2.7 Pipets. Class A 5 mL and 10 mL borosilicate glass pipettes or automatic pipettes. Calibrated
"to deliver," best source.
7.2.8 Pipet Bulb. Made of natural rubber. Recommended to meet OSHA requirements, best
source.
7.2.9 Micropipettes. Recommended 50 /tL. Calibrated "to contain," borosilicate glass micropipette,
best source.
7.2.10 Forceps. Recommended dressing forceps made of stainless steel or chrome-plated steel and
without serrations. Used for handling filters (Millipore).
7.2.11 Stopwatch. Used for measuring flow rate of gas stream through DGM, best source.
, 7.2.12 Ultrasonic Cleaner. Used for filter extractions and parts cleaning. Most are temperature
controlled. Temperature should be controlled during extraction at 65°C (Cole-Palmer Instrument Co.,
7425 N. Oak Park Ave., Chicago, IL 60648, 9800-323-4340).
7.2.13 Clean Air Hood. Closed air hood with ammonia free air circulation. Used for Teflon® filter
extraction for pH analysis,.best source.
8. Reagents and Materials
8.1 Teflon® Filters. Zefluor® (PTFE) membrane filters 47 mm diameter with a 2 pm pore size. Only
one side is Teflon®-coated; this side should face the air stream Gelman Sciences, 600 S. Wagner Rd.,
Ann Arbor, MI, 48106, 800-521-1520).
8.2 Nylasorb* Filters. Membrane filters 47 mm diameter with a 1 pm pore size. These filters are
specially prepared and batch analyzed for low $04=, NO2~, and NOg" background levels. If other
brands of nylon membrane filters are used, they should be batch analyzed to ensure low and replicable
levels of SO4", NO2", and NO3" Gelman Sciences, 600 S. Wagner Rd., Ann Arbor, MI, 48106
800-521-1520).
8.3 Denuder Extract Storage Vials. 30 mL (1 oz) screw-cap polyethylene sampling vials (Nalgene or
equivalent). Allow eight per sample for each sampling period, best source.
8.4 Filter Extract Storage Vials. 100 mL polyethylene vials (Nalgene or equivalent). Allow two vials
for each sampling period, best source.
8.5 1C Analysis Vials and Caps. Available in 5 mL and 0.5 mL and are made of polypropylene. The
filter caps are made of plastic and contain a Teflon® filter through which the sample is extracted for
analysis. Both the vials and filter caps should be disposable, best source.
8.6 Labels. Adhesive, for sample vials, best source.
8.7 Parafilm. Used for covering flasks and pH cups during pH analysis, best source.
8.8 Kimwipes® and Kay-dry Towels. Used for cleaning sampling apparatus and analysis equipment,
best source.
Page 4.2-8 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic ^ Acidic/Basic Constituents
8.9 Stoppers. Cork or polyethylene; best source.
8.10 Sodium Carbonate (Na2CO3). ACS reagent grade, best source.
8.11 Sodium Chloride (NaCl). ACS reagent grade, best source.
8.12 Methanol (Methyl Alcohol - CHjOH). ACS reagent grade, best source.
8.13 Toluene. ACS reagent grade, best source.
8.14 Glycerol (Glycerine - CH2OHCHOHCH2OH). ACS reagent grade, best source.
8.15 Citric Acid (Monohydrate - HOC (CH2CO) OH)2COOH : H2O). ACS reagent grade, best
source.
8.16 Hydrogen Peroxide (H2O2). ACS reagent grade, best source.
8.17 Ethanol (C2H5OH). ACS reagent grade, best source.
8.18 Sulfuric Acid (H2SO4). ACS reagent grade, best source.
8.19 Potassium Chloride (KC1). ACS reagent grade, best source.
8.20 Perchloric Acid (HCIO^. ACS reagent grade (60-62%), best source.
8.21 Distilled Deionized Water (DDW). ASTM Type I water.
8.22 pH Buffers. Standard buffers 4.00 and 7.00 for internal calibration of pH meter, best source.
8.23 Silica Gel. ACS reagent grade (indicating type), best source.
8.24 Sodium Bromide (NaBr). ACS reagent grade, best source.
8.25 Activated Charcoal. ACS reagent grade, best source.
8.26 Balance. Electronic analytical with internal calibration weights and enclosed weighing chamber.
Precision of 0.1 mg (Fisher-Scientific, 711 Forbes Ave., Pittsburgh, PA, 15219, 412-787-6322).
8.27 Gloves. Polyethylene disposable. Used for impactor frit assembly and filter pack assembly, best
source.
8.28 Dow Corning High Temperature Vacuum Oil. Dow Corning 660 oil used for impactor frit
coating solution, best source.
8.29 Zero Air. A supply of compressed clean air, free from particles, oil, NO, NO2, SO2, HNO3, and
HONO. The supply may be either from a commercial cylinder or generated on site, best source.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-9
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Method 10-4.2 Chapter Ip-4
Acidic/Basic Constituents Atmospheric Acidic
8.30 Ion Chromatographic (1C) Eluent Solution. For extracting filters. This solution should be the
same eluent as used for the ion chromatographic analysis of the filters. If the filter analysis is not to be
performed by ion chromatography, a slightly basic solution (e.g., 0.003 N NaOH or sodium
carbonate/bicarbonate) should be used to extract the Nylasorb® filter, while the Teflon® filter should be
extracted with DDW.
9. Preparation of Coating and Extraction Reagents
9.1 Impactor Frit Coating Solution Preparation. Weigh 1 g of silicone oil (Dow Corning high
temperature 660 oil) and place in a 100 mL polyethylene storage bottle. Add 100 mL of toluene. Mix
thoroughly, close container, and store at room temperature. (WARNING - FLAMMABLE LIQUID).
9.2 Impactor Frit Extraction Solution Preparation. Add 100 mL of 1C eluent to a clean polyethylene
storage container. Pipette 5 mL of methanol into container. Mix thoroughly. Store, covered at room
temperature.
9.3 Annular Denuder Coating Solutions Preparation
Different coatings may be used depending on the chemical species of interest.]
9.3.1 NaCI Coating Solution. Clean a 100 mL polyethylene storage vial and let dry at room
temperature. Weigh 0.1 g of reagent grade NaCI and add to vial. Add 90 mL of deionized water and
10 mL of methanol. Mix thoroughly; store, covered at room temperature.
9.3.2 Na2CC>3 Coating Solution. Clean a 100 mL polyethylene storage vial and let dry at room
temperature. Measure 50 mL of methanol (WARNING - TOXIC, FLAMMABLE LIQUID) with a
graduated cylinder and pour into vial. Measure 50 mL of DDW with a graduated cylinder and add to
vial. Weigh 1 g of glycerol and add to DDW. Weigh 1 g of Na2CO3 and add to vial. Mix thoroughly,
solution may fizz; wait for fizzing to stop before sealing vial. Store at room temperature.
9.3.3 Citric Acid Coating Solution. Clean a 100 mL polyethylene storage vial and let dry at room
temperature. Measure 50 mL of methanol (WARNING - TOXIC, FLAMMABLE LIQUID) with a
graduated cylinder and pour into vial. Weigh 0.5 g of citric acid and add to vial. Mix thoroughly; store,
covered at room temperature.
10. Elutriator and Acceleration Jet (Inlet) Assembly
(Note: The all-glass configuration is shown in Figure 6A.J
10.1 The internal walls of the elutriator and jet assembly are coated with Teflon® to prevent losses of
reactive species (SO2, HNO3, NH3) during sampling. The elutriator prevents water and large particles
from entering the inlet and thus extends the life of the impaction surface located immediately downstream
of this assembly.
10.2 An aluminum version of this inlet is shown in Figure 3b. All inner surfaces of the aluminum unit
are Teflon®-coated. The main difference between the all glass and the aluminum inlet is the jet
Page 4.2-10 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
component of the aluminum inlet is replaceable, as shown in Figure 3b. The jet component is made of
either Teflon® or polyethylene and is available in various diameters as needed to accommodate selected
sample flow rates. The jet may be replaced using the tool shown in Figure 3b. The jet diameter for a
sample flow rate of 10 L/min is 3.33 mm. At this flow rate, the inlet has a D$Q cutpoint of 2.5 ^m.
If a different flow rate is used, the jet diameter must be changed to retain a D^Q cutpoint to 2.5 /on. The
relationship between jet diameter and flow rate to retain a D^Q at 2.5 pm is shown in Figure 12. Table 2
contains the jet diameters and Reynolds number to maintain a D$Q of 2.5 urn cutpoint at different flow
rates between 1 and 20 L/min.
[Note: If the sampling area has substantial concentrations of coarse particles (>2.5 fun), the user may
replace the acceleration jet and impactor assembly with the Teflon®-coated aluminum cyclone.]
The D^Q cutpoint at a flow rate of 10 L/min is 2.5 /*m, as illustrated in Figure 12.
11. Impactor Frit Preparation and Installation
11.1 Impactor Frit Installation
11.1.1 Impactor-Coupler. The impactor-coupler assembly (shown in Figure 13) is composed of two
parts: the replaceable impactor frit and the coupler-impactor housing seat. The impactor surface is a
porous ceramic or porous stainless steel frit, 10 mm x 3 mm. This frit is inserted into the
coupler-impactor housing using the tools shown in Figure 13. The in-tool must be completely screwed
in behind the impactor seat before the frit is pressed into place. Press the impactor frit gently but firmly
into the seat of the impactor housing with your clean gloved finger. The impactor should fit into the
housing so that it does not protrude above the seat. The impactor frit has a slight bevel. The narrow
surface should be inserted into the impactor seat.
11.1.2 Impactor-Denuder. The impactor-denuder assembly (shown in Figure 4) is of three parts:
the replaceable impactor frit, the impactor seat support pin, and the annular denuder impactor-pin
support. The impactor frit is the same as described in Section 11.1.1 and is inserted into the impactor
seat support pin. The impactor support pin can be hand-held while inserting the frit or it can be placed
upright into the stainless steel frit holder #3 (see Figure 11). Press the support pin into the denuder pin
support. The pin is grooved and has a viton "O"-ring to keep the pin snug in the denuder support during
cold weather use (Teflon® tends to shrink at low temperatures). The support pin is removed by using
the removal tool shown in Figure 4.
11.2 Impactor Frit Preparation
With the impactor frit in the impactor seat of either the coupler (see Figure 13) or the Teflon® impactor
seat support pin that fits into the first denuder (see Figure 4), pipette 50 fiL of the toluene-660 oil coating
solution onto the impactor frit surface and allow to dry at room temperature. Cap both sides of the
coupler impactor or denuder-impactor until use.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-11
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
12. Filter Pack Preparation and Assembly
[Note: Any number of filters can be used depending on the target species of interest. The configuration
referred to in this section does not collect NH^.J
12.1 With clean gloves, disassemble the filter pack (see Figure 8) by unscrewing the large outer Teflon®
collar (sleeve) from the aluminum filter housing outlet component.
[Note: Remove the red Bakelite® cap first. Lay the pieces out on clean Kimwipes®.]
12.2 Lay a clean Teflon® filter ring housing, with its large opening face up, on a clean Kimwipe®. Place
a clean stainless steel screen in the filter ring housing.
12.3 Using clean filter forceps, place a Nylasorb® nylon filter on the screen. Insert a second filter ring
housing on top of the nylon filter with its large opening face up. This design forms a "sandwich" with
the nylon filter held between the two filter ring housings.
12.4 Place another clean screen on the second filter ring housing. Using clean filter forceps, place a
Teflon® filter on the screen.
[Note: If a Tefiasorb® Teflon9 filter is used, be sure to place the Teflon®-cp_ated side, not the webbed
side, toward the air stream. If the webbed side is facing the air stream, SO4~ extraction from the filters
may be inefficient*]
12.5 Place the Teflon® filter housing inlet component (see Figure 11) on top of the Teflon® filter, which
forms another "sandwich" with the Teflon® filter held between the second filter ring housing and the
housing inlet component. The housing inlet component connects the filter pack assembly to the last
annular denuder through a thermoplastic coupler. Be careful not to twist the filterpack components, or
damage will occur to the filters.
12.6 Lay the aluminum filter housing outlet component, with its large opening face up, on a clean
' Kimwipe®.
12.7 Insert the filter ring sandwiches (prepared in Sections 12.1-12.5) with the filter housing inlet
component extending upward, in the aluminum filter base. Place the large outer Teflon® sleeve over the
filter sandwich and screw onto the aluminum filter base. DO NOT OVERTIGHTEN! DO NOT TWIST
FILTER PACK COMPONENTS!
12.8 Install the "Quick-Release" plug into the filter outlet component. DO NOT OVERTIGHTEN!
12.9 Install the red Bakalite® cap onto the filter inlet component and the orange dust cover onto the
Quick-Release plug until ready to attach denuders.
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
13. Annular Denuder System Preparation
All new annular denuder parts obtained from suppliers should be cleaned with a dilute soap solution. The
parts should then be thoroughly rinsed in DDW and allowed to dry at room temperature.
13.1 Annular Denuder Coating Procedure
/Note: If the first denuder holds the impactor, a blank Teflon® impactor support pin should be installed
in the pin support holder before the coating procedure.]
13.1.1 Cap the end of the denuder that has the inner tube flush to the outer tube and set denuder
upright on the capped end. For the denuders with flow-straighteners at both ends, either end can be
capped. Measure 10 mL of the appropriate coating solution into a graduated cylinder. Pipette the 10
mL into the flow-straightener end of the upright capped annular denuder.
13.1.2 Cap the open end of the denuder, and holding horizontally, rotate the denuder to distribute
the coating solution evenly.
13.1.3 Remove cap from flow-straightener end of denuder and decant excess coating solution into
a clean denuder extract storage bottle labeled "denuder blank." Bottle label should include denuder
number, coating solution and date.
13.1.4 Repeat this procedure with each denuder; label the denuders and bottles appropriately.
13.2 Annular Denuder Drying Procedure (see Figure 9)
/Note: As denuders dry, they change from translucent to a frosted appearance. Denuders are dry when
they become uniformly frosted.]
13.2.1 Adjust drying train and manifold clean air flow to 2 to 3 L/min. Close toggle valve
controlling clean air flow through manifold before attaching denuders.
13.2.2 Attach flow-straightener end to drying manifold port at the back-to-back bored caps (see
Figure 9).
13.2.3 Open toggle valve and allow clean air to flow through the tube for several minutes.
13.2.4 Close toggle valve and reverse ends of tubes attached to manifold.
13.2.5 When an even frosted appearance is achieved, remove tubes from manifold, cap both ends
with clean caps, and store until ready for use. Turn off air to drying manifold.
13.3 Annular Denuder System (ADS) Assembly
[Note: Described herein is an annular denuder system consisting of four denuders in series. Any number
of denuders can be used at the operators' discretion. The denuders should be assembled in such a way
that the flow-straightener end always follows the flush end of the previous denuder, except, if denuders
with flow- straighteners at both ends are used. This type of assembly allows laminar flow conditions to
be restored quickly.]
13.3.1 Lay the ADS pieces on a clean surface (i.e., Kimwipes®).
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
13.3.2 Remove the end caps from the first denuder. Denuder 1 is coated with NaCl and may or may
not hold the impactor frit pin support. If the first denuder is equipped with the impactor frit pin-support,
remove the blank impactor support pin. Gently insert the impactor support pin and coated frit assembly
into the denuder-pin support. If the first denuder does not hold the impactor pin-support, attach the
impactor frit seat equipped coupler assembly to the flow-straightener end of the first denuder.
(Note: DO NOT TIGHTEN! Do not tighten during the following procedure until Section 13.4.12 is
reached.]
13.3.3 Attach a thermoplastic coupler to the opposite denuder end. Place a Teflon® clad "O"-ring
inside the coupler, if needed.
13.3.4 Remove the end caps of the second denuder (Na2CO3 coated). Attach the end with the
flow-straightener section to the first denuder-coupler assembly.
13.3.5 Attach a thermoplastic coupler to the opposite denuder end. Place a Teflon® clad "O"-ring
inside the coupler, if needed.
13.3.6 Remove the end caps of the third denuder (Na2CO3 coated). Attach the end with the
flow-straightener section to the second denuder-coupler assembly.
13.3.7 Attach a thermoplastic coupler to the opposite denuder end. Place a Teflon® clad "O"-ring
inside the coupler, if needed.
13.3.8 Remove the end caps from the fourth denuder (citric acid coated). Attach the end with the
flow-straightener section to the third denuder-coupler assembly.
13.3.9 Attach a thermoplastic coupler to the opposite denuder end. Place a Teflon® clad "O"-ring
inside the coupler, if needed.
13.3.10 Attach the filter pack inlet to the fourth denuder coupler assembly.
13.3.11 Attach the elutriator-acceleration jet assembly to the first denuder-coupler assembly. Tighten
very gently-DO NOT OVERTIGHTEN!
13.3.12 Tighten the remaining couplers very gently - DO NOT OVERTIGHTEN!
13.3.13 Cap elutriator with orange dust cover until use.
[Note: When collecting and measuring gaseous HNO3, SO2, and NH3, and particulate NO3, NH4+,
and SO^=, assemble the annular denuders as previously described. The difference between deposited
HNO2 and HNO3 cannot be distinguished if the NaCl coated denuder does not precede the Na2CO3
coated denuder. The amount ofHNO2 collected cannot be quantified if two Na2CO3 coated denuder s
are not in series. Also, NH3 must be taken out of the gas stream prior to the air stream entering the filter
pack. Othenvise, reaction of the unneutralized sulfate will result. If ammonia (NH3) and/or H+
measurements are not to be analyzed for, then the use of a citric add coated denuder is not important.
However, with the removal. ofNH3, some nitrate collected on the Teflon®Jilter will evaporate and be
found on the nylon filter.]
13.4 Laboratory Leak-Check of ADS
[Not?: CAVTION—Do not subject the system to sudden pressure changes or filters may tear.]
13.4.1 Remove the orange dust cap from the impactor opening. Attach the "Quick-Release" to a
pump module. Turn on the pump. Be certain that flow through the ADS occurs by checking the
rotameter.
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
13.4.2 Briefly cap the elutriator with the orange dust cap. The flow as indicated on the rotameter
should drop to zero if no leaks exist.
13.4.3 Disconnect the pump from the ADS at the "Quick-Release" plug. Cap the "Quick-Release"
plug with an orange dust cover. Turn off the pump. REMEMBER—never overtighten joints or breakage
will result. If the joints can not be sealed with gentle tightening, the Teflon® "O"-rings are worn or
defective and must be replaced.
13.4.4 Place the assembled sampler in its field-to-lab carrying case for transport to the field.
/Note: The ADS joints should be loosened slightly when extreme temperature changes are incurred during
transportation. This precaution will prevent unnecessary breakage or distortion of the ADS components.
Remember to allow the system to adjust to the indoor air temperature before tightening the joints and
checking for leaks.}
14. Sampling
14.1 Placement of Denuder System
14.1.1 The placement of the annular denuder system must conform to a consistent set of criteria and
guidance to ensure data comparability and compatibility. A detailed set of monitor siting criteria for
ambient air monitoring and meteorological programs is given in the EPA document Ambient Monitoring
Guidelines for Prevention of Significant Deterioration (PSD), EPA-450/4-87-007, U. S. Environmental
Protection Agency Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711,
May 1987.
The site must be away from localized sources of ammonia, such as composting and livestocking
operations, landfills, sewage treatment plants, fertilizer plants and storage facilities, and recently plowed
fertilized fields because aerosol acidity is subject to rapid neutralization by ambient bases.
14.1.2 A summary of key factors that should be considered as part of the placement of an air quality
monitoring station containing an ADS are:
• Vertical placement above ground;
• Horizontal spacing from obstructions and obstacles;
• Unrestricted air flow; and
• Adequate spacing from roads.
The ADS sampler is mounted on a supported mast pole or tripod. The ADS inlet should be located
2-3 m above ground level. Placing the inlet closer to ground level should be considered only if the
surface is flat and man-made (i.e., not unpaved dirt).
14.1.3 A summary of key criteria associated with these siting factors for air monitoring stations is
included in Table 3".0. The information included in the table should be used to the extent possible as part
of the monitoring network design to ensure that the monitoring program provides representative and
unbiased data. However, site-specific constraints could make it very difficult to meet all criteria. For
example, wooded areas around a site would make the siting very difficult. The use of the information
in Table 3.0, coupled with a balanced evaluation by an experienced air quality and meteorology specialist,
is highly recommended.
14.1.4 In general, for a site with no major obstruction and obstacles, the air sampler intake should
be about 2-3 m aboveground. For a site with nearby roadways, however, intake placement should take
into account the effects of road dust re-entrainment and vehicular emissions. In fact, a linear relationship
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-15
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents _ Atmospheric Acidic
should be established between the horizontal distance of the sampler intake from the roadway and the
aboveground elevation of that intake. For any roadway accommodating more than 3,000 vehicles per
day, the intake should be between 5 and 25 m from the edge of the nearest traffic lane. It should also
be 15 m aboveground for a distance of 5 m from the nearest traffic lane and 2 m aboveground for a
distance of 25 m from the nearest lane. For a roadway supporting less than 3,000 vehicles per day, the
intake should be placed at a distance greater than 5 m from the edge of the nearest traffic lane and at a
height of 2-15 m aboveground.
14.2 Start-Up
14.2.1 Remove the ADS from its field-to-lab carrying case and load into the field sampling box. The
ADS field sampling box is insulated with polyurethane which is configured to hold the ADS without
allowing movement. Chromeplated spring clips hold the denuders in place. Automatic and manual
control switches allow the sampling box to control the temperature of the ADS. The automatic switch
should be used when the ADS is not in use and when the ADS is sampling for extended periods of time
without constant supervision to prevent low temperature or sudden pressure change exposure of the ADS
(these types of exposure can cause leaks to occur, condensation, or the filters to tear). When sampling,
the ADS should be kept 1 °C above the indoor temperature to prevent condensation. The sampling box
has two connections with the pump timer: the plastic suction hose connected with "Quick-Release"
couplers and the 12-V power cord with a "Quick-Disconnect" coupler. The power cord remains
connected, and the suction hose is disconnected from the box each time the unit is opened. Inside the
box, the hose is connected to the top of the filter pack with a "Quick-Release" coupler. During sampling
the sample box is kept securely closed (see Figure 2).
14.2.2 Allow the pump to warm up for 20-30 min prior to testing so the pump will provide steady
flow during testing.
14.2.3 To check the Heat/Cool cycles, flip one switch from "AUTO" to "MANUAL" and the other
between "COOL" and "HEAT." Check to insure that the fan and heater work, respectively.
14.2.4 With the elutriator still capped, turn on the pump with the switch on the timer. The rotameter
should indicate zero flow. If there is a flow, the assembly pieces need to be recoupled. Run leak check
for 5-10 s. Turn off pump and remove elutriator cap. Record leak rate on Field Test Data Sheet (see
Figure 14).
14.2.5 Attach DGM output to elutriator inlet. Turn on pump. Record start time on Field Test Data
Sheet (see Figure 14). Using a stopwatch, record the time for 20.0 L to pass through the DGM. Record
the DGM temperature and the absolute pressure of the DGM.
14.2.6 Calculate the flow rate as follows:
Qstd = (V/D(Pbar/pstd)Crstd/Tm)(Pc)
where:
rate corrected to standard conditions, 25 °C and 760 mm Hg, L/min.
V = volume of gas pulled through denuder system, L.
T = time required to pull gas through denuder system, minutes.
J»bar = barometric pressure, mm Hg.
Pgt£j = standard barometric pressure, 760 mm Hg.
Tgtcj = standard temperature, 298 °K.
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
Tm = temperature of dry gas meter, °K(=°C + 273).
FC = dry gas meter correction factor, dimensionless.
14.2.7 If the calculated flow rate is not between 9.5 and 10.5 L/min, readjust the flow rate and repeat
Sections 14.2.4 and 14.2.5 until the rate is in the above range. Preliminary studies should be conducted
to obtain an estimate of the concentrations of the species of interest.
14.2.8 Record the flow rate on Field Test Data Sheet.
14.2.9 Remove DGM connection tubing from elutriator inlet. Pump should remain running so that
sampling continues. Higher flow rates may be used for shorter sampling periods. Concentration of the
species of interest in indoor air and the configuration of the sampling equipment, determine the
appropriate flow rates. Sampling at 10 L/min, requires a sampling time of 24 h to collect pollutant
concentrations between 0.02 and 0.83 ug/rrr.
14.3 Sample Shutdown
14.3.1 Attach DGM connection tubing elutriator inlet with pump still running.' Measure flow rate
as in Sections 14.2.5 and 14.2.6. Record flow time, temperature, and pressure on Field Test Data Sheet
(See Figure 14).
14.3.2 Turn off pump. Record time and elapsed time meter reading on log sheet. Remove DGM
connection tubing from elutriator inlet. Remove ADS from the sampling box, cap the ends, and place
the ADS in field-to-lab carrying case for transport to lab. Be careful not to stress the ADS during the
transfer or breakage will result.
Caution: When the ADS is brought from a cold field sampling location to a warm laboratory, loosen the
denuder couplings to prevent thermal expansion from breaking the denuders.
14.4 Corrective Action for Leak Test Failure
[Note: These steps should be followed when failure occurs during testing at the laboratory before
transport to the field and in the field before testing.]
14.4.1 Sampler Leaks. Note the problem on the Field Test Data Sheet. Check assembly of ADS
components. Replace gaskets. Check for proper seating of denuder surfaces. Replace any defective
parts.
14.4.2 Cracked or Chipped Denuders or Elutriator Assemblies. Note problem on Field Test Data
Sheet. Discard defective pieces. Do not try to extract cracked pieces. WARNING-USE CAUTION
WHEN DISASSEMBLING CRACKED GLASSWARE. Pieces may shatter and cause severe cuts. Wear
protective clothing.
14.4.3 Contaminated Blank Solutions. Note problem on Field Test Data Sheet. Follow
parts-cleaning procedures closely. Examine the sampler preparation area for possible sources of
contamination and remove source. Check DDW being used in the solution preparations and extractions.
Fill a clean 25 mL polyethylene extraction bottle with the DDW used in solution preparation and
extraction; send to lab for analysis. If contaminated, correct deionization system.
14.4.4 Flow Rate Disagreement. Note problem on Field Test Data Sheet. Check vacuum gauge
on flow module. If a high vacuum exists, the sampler has become blocked. This blockage may be due
to dust or smoke particles clogging the filters or to obstructions in the system or tubing. Check flow
module. Repair as needed.
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
14.4.5 Inadequate Flow Rate. Note problem on Field Test Data Sheet. Check rotameter on flow
controller. If adequate flow is shown here, a leak exists between the controller and the DGM. If no flow
is shown on rotameter, check vacuum gauge on controller. If no vacuum exists, pump needs repair. If
a high vacuum is shown, an obstruction exists in the system. Check to see that the paper filter dividers
were not accidentally installed with the filters in the filter pack. Check tubing for kinks.
[Note: "typically the pressure drop across the filters should be approximately 1" Hg at 10 L/minflow rate
at sea level. This pressure drop can vary from 1-10 L/min depending on elevation.]
IS. ADS Disassembly
15.1 Remove the ADS from the field-to-lab carrying case using both hands. To prevent stress, hold the
ADS by its ends,
Caution: Do not stress the ADS while removing it from the case.
15.2 Decouple the elutriator-jet assembly from the first denuder-impactor-coupler assembly.
15.3 When using the denuder-impactor, the frit-pin must be removed from the support in the denuder
before removing the frit from the pin. The frit is then extracted from the pfei using pin tool #3 and the
frit extraction tool (see Figure 13). When using the impactor-coupler assembly, the frit is removed from
the coupler seat using pin tool #3 and the "out" frit removal tool (see Figure 13). Put frit in covered dish
and set aside for chemical extraction.
15.4 Remove the denuders from the couplers and cover each end of the denuders with clean end caps
until extraction.
15.5 Label a clean 100 mL polyethylene bottle with the sampler ID number and filter type (i.e., Teflon®
or Nylasorb®, as appropriate) for each of the filters.
15.6 Disassemble the filter pack in a clean, ammonia-free air hood. Clean all hood surfaces and utensils
with methanol. Wearing clean gloves and using clean filter forceps, remove the filters and place each in
its storage (protective) bottle, with the exposed filter surface facing downward, until extraction.
fNote: Place the filters in the properly labeled bottles.]
16. Extraction Procedures
[Special precaution: Samples should be analyzed as soon after collection as possible. The solutions and
extraction procedures must be prepared and performed on the day of pH analysis.
Extraction must take place in a clean, ammonia-free air hood. The extracts must be processed in the
order in which they will be analyzed, so that each sample will have a similar time interval between
extraction and analysis. Denuder extracts and filters should be stored in the refrigerator until just prior
Page 4.2-18 Compendium of Methods for Inorganic Air Pollutants January 1997
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-Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
to analysis. Samples stored longer than 30 days tend to degrade due to bacteria growth and/or losses to
the walls of the extraction vessel.
16.1 Impactor Frit Coating Extraction
16.1.1 Place the impactor (which was removed before denuder extraction) into a small extraction
bottle.
16.1.2 Label the bottle appropriately. Pipet 10 mL of impactor extraction solution into the bottle.
The solution must cover the surface of the impactor frit.
16.1.3 Close the extraction bottle and place in an ultrasonic bath for 30 min.
16.2 Denuder Extraction
[Note: If the denuder was the first denuder ad equipped with the impactor frit-pin support, insert a dean
Teflon® impactor frit-pin without frit in place. Then extract as described below. This procedure is to be
followed for each denuder.]
16.2.1 Cap one end of the denuder. Add 5 mL of DDW with a pipet. Cap other end.
16.2.2 Rotate the denuder to wet all surfaces thoroughly with the water. Remove the cap and pour
the liquid into a clean 25 mL polyethylene extraction bottle.
16.2.3 Repeat this procedure with a second 5 mL of DDW extract (total extract volume is 10 mL,
which is placed into a single bottle).
16.2.4 Replace the extraction bottle cap and label the bottle with the sampler ID number and denuder
number and type (as appropriate).
16.3 Filter Extraction
16.3.1 Teflon® Filter Extraction (for pH analysis followed by ion chromatography (1C) analysis)
[Note: Teflon® is not wet by water; therefore, the filter will float on top of aqueous solutions. Solutions
and extraction procedures must be prepared and performed on the day ofpH analysis. Extraction of the
filters must take place in a clean, ammonia-free, air hood. The filters must be processed in the order in
which they will be analyzed so that each sample will have a similar time interval between extraction and
analysis.]
16.3.1.1 Allow the hood to be flushed with ammonia-free air for at least 5 min before filter
extraction. All of the hood surfaces and extraction utensils must be cleaned with a Kimwipe® moistened
with ethanol.
16.3.1.2 Pipet 3 mL of 0.0001 N perchloric acid (HCIO^) solution into the appropriately labeled
extraction vial (4 mL).
[Note: Use HCIO^ because it inhibits CO^ from dissolving into the solution and keeps the organic
compounds in solutionfrom dissociating. Both these activities can change the ionic strength of solution.]
16.3.1.3 Place the Teflon® filter in the extraction vial. Cap tightly. Store at 5°C in the dark until
ready for analysis.
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
16.3.1.4 When ready for analysis, the filter must be prepared (within the air hood) in the
following manner: Using forceps and gloved hands, lift the filter from the extraction vial. Let the excess
solution drain off into the vial. Holding the filter over the extraction vial, and using an automatic pipet,
apply 100 ± 5 mL of ethanol to the filter. Add the ethanol slowly to ensure that all portions of the
membrane are wet with ethanol. Immerse the filter in the aqueous solution once again. Tap the forceps
against the inside of the vial to remove liquid. Tightly replace cap. Put in ultrasonic bath for 15 min
total, rotating the rack 90° every 5 min.
[Note: Perchloric acid is used in place of potassium chloride, initially, to prevent interference in the
measurements of cations and onions by ion chromatography. Potassium chloride must be added to the
portions of the sample extract that are used for pH analysis (the purpose of the salt, final concentration
0.04 M, is to increase the ionic strength and thus to reduce the time for equilibrium ofthepH electrode
used for measurement). Use the same bottle (freshly opened) of ethanol to extract the Teflon® filters that
are used to prepare suljuric add standards.]
16.3.1.5 When ready for pH analysis, the extracts are prepared in the order of pH measurement.
Inside the air hood, remove the caps from 4 mL extraction vials. Wipe off any drops which may leak
onto the outside of the cup.
16.3.1.6 Using gloved hands and a 1 mL automatic pipet, transfer 1 mL of the extract to each of
two correspondingly labeled 2 mL cups.
[Note: The first 2 mL cup for each extract has the same I.D. # as the 4 mL cup, and the second 2 mL cup
lias the same I.D.ff with a hyphen (-). This system also is used with the working standards.]
16.3.1.7 After transferring the extracts to the 2 mL cups, recap the 4 mL extract cup. Store the
4 mL cups at 5°C in a refrigerator pending sulfate analysis by 1C.
16.3.2 Nylon Filter Extraction.
16.3.2.1 Pipet 10 mL of 1C eluent into the appropriately labeled filter vial or bottle with caps.
/Note: Be sure that the filter lies flat on the bottom of the bottle and that all of the filter is covered by
the extraction solution.]
16.3.2.2 Replace the bottle's cap and put in an ultrasonic bath for 30 min.
16.3.2.3 Store the bottles in a clean (i.e., pollutant free) refrigerator at 5°C until analysis.
17. Ion Chromatography Analysis
[Note: The analytical procedure described here is not the only appropriate procedure available for
quantifying the analytes of interest. An automated system does not have to be used. This particular
analytical procedure was chosen because it is presently used by EPA. Modifications to this procedure
may be required depending on the intended use of the data; however, any modifications made must be
justified to obtain comparable data quality.]
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic ^ Acidic/Basic Constituents
17.1 Standards Preparation
Special Precaution: Storage of these solutions should be no longer than one week. All of the working
standard solutions are used to calibrate the 1C and are made from reagent grade stock. The crystals are
dried overnight in covered petri dishes at 110°C in a vacuum oven prior to preparing the standard
solutions. Any yellowish discoloration of the dried crystals indicates decomposition and crystals should
be discarded.
17.1.1 Sodium Sulfate Stock Solution.
17.1.1.1 In a clean, calibrated, 1 L flask, add 500 mL of DDW.
17.,1.1.2 On weighing paper, weigh out enough reagent (Na2SO4) to make the solution 2000 ppm
concentration. The target weight is 0.7394 g. Record the gross weight.
[Note: Weigh out slightly more than the target weight because of the adherence of the residual crystals
to the weighing paper (the residual left on. the paper is generally between 0.1 mg and 1 g).]
17.1.1.3 Add the reagent crystals to the 500 mL of DDW. Reweigh weighing paper and subtract
weight from the gross weight. The difference is the actual net weight.
17.1.1.4 Using a proportion, calculate the actual volume needed to make the solution 2000 ppm
(see below).
target wt/actual net wt = 500 mL (target)/actual volume
or
actual volume = (500 mL * actual net wt)/target wt
17.1.1.5 Using the appropriate calibrated pipet, add the amount of DDW needed to achieve the
calculated actual volume. Mix well and cover with parafilm.
17.1.2 Sodium Nitrate Stock Solution.
17.1.2.1 In a clean, calibrated, 1 L flask, add 500 mL of DDW.
17.1.2.2 On weighing paper, weigh out enough reagent (NaNO3) to make the solution 2000 ppm
concentration. The target weight is 0.6854 g. Record the gross weight.
[Note: Weigh out slightly more than the target weight because of the adherence of residual crystals to
the weighing paper.]
17.1.2.3 Follow Sections 17.1.1.3 through 17.1.1.5.
17.1.3 Sodium Nitrite Stock Solution.
17.1.3.1 In a clean, calibrated, 1 L flask, add 500 mL of DDW.
17.1.3.2 On weighing paper, weigh out enough reagent (NaNO2) to make the solution 1000 ppm
concentration. The target weight is 0.7499 g. Record the gross weight.
[Note: Weigh out slightly more than the target weight because of the adherence of residual crystals to
the weighing paper.]
17.1.3.3 Follow Sections 17.1.1.3 through 17.1.1.5.
17.1.4 Standard working solutions. The working solutions are made as follows: Add 10 mL each
of the three stock solutions (Na2SO4, NaNO3, and NaNO2) to a 200 mL volumetric flask and dilute to
the mark with DDW. Subsequent dilutions are carried out using a 10 mL volumetric pipet and
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Method 10-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
appropriate flasks. Standards of 20, 10, 5 and 1 ppm Na2SO4 and NaNO3 (and one-half these
concentrations of NaNO2) are prepared to calibrate the 1C.
17.2 Reagent Preparation
fNote; Storage of these reagents should be no longer than 1 week.]
17.2.1 Anion eluent. The anion eluent is a solution of 1.8 yum Na2CO3 and 1.7 jim NaHCOg. A
concentrated solution can be prepared and diluted as needed.
[Note: See Anion Storage Solution]
17.2.1.1 Concentrated Na2CO3 solution (0.36 M). Weigh out 38.156 g of Na2CO3 (MW =
105.99). Dissolve into 1 L of DDW. Store in refrigerator until ready to dilute.
17.2.1.2 Concentrated NaHCO3 solution (0.34 M). Weigh out 28.564 g of NaHCO3 (MW -
84.01). Dissolve into 1 L of DDW. Store in refrigerator until ready to dilute.
17.2.1.3 Dilution of stock solutions. Bring both solutions to room temperature. Accurately pipet
10 mL of each solution into a 2000 mL volumetric flask which has been partially filled with DDW.
Bring to the mark with DDW (1:200 dilution).
17.2.2 Anion regenerant. The regenerant is a 0.025 N H2SO4 solution. VERY CAREFULLY
dispense 2.8 mL of concentrated Ultrex sulfuric acid (36 N) into a graduated cylinder. Partially fill the
regenerant reservoir with DDW (3 L). Slowly add the acid to the regenerant reservoir. Bring to the
mark with DDW (4 L).
(Note: Protective clothing and eye protection should be worn.]
17.2.3 Cation eluent. There are two cation eluents that are used for the analysis of monovalent and
divalent cations. The strong cation eluent is: 48 jim HC1, 4 /*m DAP.HC1, 4 /*m Histidine.HCl (DAP
= Diaminoproprionic acid). The weak eluent consists of 12 /mi HC1, 0.25 /*m DAP.HC1, 0.25 ^m
Histidine.HCl.
17.2.3.1 Strong cation eluent. Weigh 0.560 g DAP and 0.840 g histidine into a 1 L volumetric
flask. Add 48 mL of 1 M HC1 (Ultrex) to the flask. Bring the eluent to the final volume by bringing
to the mark with DDW. Mix thoroughly to dissolve.
17.2.3.2 Weak cation eluent. Place 63 mL of the strong cation eluent in a 1 L flask. Add 9 mL
of 1 M HC1 to the flask. Bring the eluent to the final volume by bringing to the mark with DDW. Mix
thoroughly to dissolve.
17.2.4 Cation regenerant. The cation regenerant consists of 100 pM Tetrabutyl-
ammoniumhydroxide (TBAOH). Place the TBAOH container into a warm water bath to dissolve any
crystals that may have formed. Measure 266.7 mL of the TBAOH (stock reagent is supplied as 1.5 M,
40% in water) into a graduated cylinder. Add the TBAOH to 4 L of DDW.
17.2.5 Anion storage solution. Since the anion columns contain carbonates from the eluent,
protection must be taken against microorganisms that will live on this food source and clog up the
columns. If the columns are not being used for long periods of time (> 2 weeks), a storage solution of
0.1 M NaOH should be pumped into them.
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
17.3 Sample Preparation
17.3.1 Mark the auto sampler vials with the appropriate identification numbers. Place the vials in
an (1C) autosampler tray.
17.3.2 Using clean, calibrated 0.5 mL pipets, transfer the denuder and the remainder of the filter
extracts from the extraction vials to a clean disposable 0.5 mL (1C) autosampler (polyethylene) vial. Fill
the autosampler vial to the line on the side.
[Note: If refrigerated, the contents of the 4 mL extraction vial must be vortex-mixed prior to transfer to
the autosampler vials.]
. 17.3.3 Place black filter caps on top of the vials. Use the tool provided to push the caps into the
vials until they are flush with the top. (see the 1C manual for more detailed instructions).
17.3.4 Wipe away any excess fluid from the top of the vial to avoid contamination from other
samples.
17.3.5 After all of the trays are filled, place them into the left side of the autosampler. The white
dot on the tray indicates the first sample. Press the button labeled RUN/HOLD to the RUN position.
The trays should move until the first sample is under the sampling head. The front panel should indicate
a READY message. Press local/remove switch to remove.
17.4 Basic System Operations - Start-up and Shut-down
17.4.1 Start-up Procedure for Ion Chromatograph.
17.4.1.1 The major components of the Dionex 2020i Ion Chromatography system are illustrated
in Figure 15. Turn helium and nitrogen tanks on by opening the valve on top of each tank. (Pressure
in either tank should not be less than 500 psi. Replace if necessary.) Open valves at the outlet end of
both regulators. Adjust pressure on the nitrogen regulator to 100 psi. Adjust pressure on the helium
regulator to 14 psi.
17.4.1.2 Check the level of eluents and regenerating solutions. Turn the chromatography (CMA)
values for the anion channel switch ON. Verify that the pressure reading on the face of the degassing
unit is 7 psi. Adjust by turning dial next to pressure gauge. Turn the degas switch to HIGH.
17.4.1.3 Turn the eluent reservoir switches, corresponding to the eluents to be degassed, to the
ON position. Let the eluents degas on HIGH for 3-5 min, then turn degas switch to LOW.
17.4.1.4 Select the appropriate program on the gradient pump module using the PROGRAM
switch. (Programs are recalled from memory by first pressing the PROGRAM switch, then the single
digit reference number corresponding to the appropriate program.)
17.4.1.5 Prime the eluent lines.
[Note: All of the eluent lines used during analysis must be primed to remove any air bubbles that may
be present. The selected program identifies which lines are used.]
• Open the gradient pump drawer. Turn the pump to the START position for 10 s, or until a
CLICK is heard. Turn the pump OFF. This step opens the valve to the eluent line displayed
on the front panel.
• Attach a 10 mL syringe to the priming block on the face of the gradient pump module. With
the priming block valve closed, pull the syringe plunger out to the end of the syringe.
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Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents _ Atmospheric Acidic
• Open the priming block valve. The syringe will quickly fill with eluent. Close the valve on
the priming block when the syringe is almost full. Remove syringe from block and discard
collected eluant.
This priming procedure can be repeated if necessary. All of the eluent lines that are to be used during
a day of analysis should be primed at this time.
17.4.1.6 Open the door of the Advanced Chromatography Module. On the back of the door, at
the bottom, is the conductivity detector. Four labeled lines (anion, cation, waste, and cell) are located
next to the cell. The plumbing must be configured according to the type of analysis to be performed.
If anions are being analyzed, attach the ANION line to the CELL line, and the CATION line to the
WASTE line. If cations are being analyzed, attach the CATION line to the CELL line, and the ANION
line to the WASTE line. Attach the line coming from the pump to the correct port on the advanced
Chromatography module. SYSTEM 1 on the left is for anions; SYSTEM 2 on the right is for cations.
If switching from one system to the other, the pump and the lines coming from the pump must be
purged of the original eluent, which is done by disconnecting the pump line from the chromatograph
module, turning the pump on, and running the new eluent into a waste beaker for 2-3 min.]
17.4.1.7 Select the columns to be used (labeled pH or NC^) by pressing the blue button located
below the labels. To verify that the correct columns are being used, press the switch should at least once,
and then set to the appropriate position.
17.4.1.8 Turn the power switch on the autosampler ON (switch is located on the back of the unit,
on the right). The default settings will be displayed on the front panel. Attach the SAMPLE OUT line
from the autosampler to the advanced Chromatography module. The connection should be made to the
port marked SAMPLE of the appropriate system. Turn the pump to START.
17.4.1.9 Turn the conductivity cell ON (switch is located on the gradient pump module). Turn
the REGEN switch for the appropriate system ON. Verify that regenerant is flowing by inspecting the
regenerant waste line which empties into the sink. Open the advanced Chromatography module door and
inspect for leaks at columns, fittings, etc. Shut pump off if leaks are found.
17.4.1.10 Turn stripchart recorder ON. Baseline should stabilize in less than 20 min. If baseline
is not stable, see troubleshooting Section 17.5 for assistance.
17.4.2 Data acquisition start-up. The following is a description of the current data acquisition
program used by the EPA. The program is available (EPA, Atmospheric Chemistry and Physics
Division, Office of Research and Development, Research Triangle Park, NC) and is for IBM or IBM
compatible computers. Other appropriately designed programs may be used to compile the data collected
for any given sampling network. A computer programmed integrator does not need to be used to
compute the data, but is recommended for large sampling networks.
17.4.2.1 Turn on the IBM XT computer. From the C:> prompt, type: cd/cchart, then type:
cchart. This loads the Chromatochart software. Turn switch on relay box to ENABLE, indicator light
could go on.
17.4.2.2 Press F2 to enter the methods development module. Select option number 1 - "select
channel # and load method file." "Select channel # <0> " type 0 or press ENTER to select the default
choice shown in the brackets (in this case 0). "Load method file named" type the name of the appropriate
method, then press ENTER. A directory of all of the current methods in memory can be obtained by
pressing the F2 function key.
Page 4.2-24 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
17.4.2.3 Press F3 to enter the Data Acquisition module. At this point you will be asked to save
the method file. If there has not been any changes to the methods file, it does not need to be saved.
Select option #4 - "Collect Data." Press ENTER to deactivate the method queue. "Load Run Queue
named," type the name of the run queue if one has been created. Type ENTER to deactivate the run
queue.
17.4.2.4 "Total # runs for method < 1 >,". type how many times the method is to be repeated
(total number of samples). "Autoanalyze Data" type Y. "Autosave data to disc" type Y. "Data file
name (xxxxx) change?", type data file name. "Press ENTER to begin methods." Press ENTER only
after the samples have been loaded into the autosampler and the baseline has stabilized.
17.4.2.5 Figure 16 illustrates the chromatograms for each of the samples as output by the
programmed Spectra-Physics integrator. The program used to generate these outputs can be found in the
Appendix of this method. Note that actual output is by individual run. Most information provided here
is optional to the operator.
17.4.3 Calibration of 1C. The instrument should be brought to normal conditions with a warm-up
time of at least 30 min.
17.4.3.1 With the "Reading" light on, check to ensure the flow rate is 1.5 mLs/minute, the fluid
pressure is 600 psi ± 100 psi and the conductivity is constant as measured by offset difference.
17.4.3.2 Fill the 1C vials with the prepared standard solutions and (10, 5 and 1 ppm Na2SO4 and
NaNO3) and pure eluent. This will allow a four-point calibration curve to be made.
[Note: For low-level applications, more standards and blanks may be necessary in order to obtain
accurate reference curves.]
17.4.3.3 Load the four vials into the sample vial holder and place the holder in the automated
sampler tray.
17.4.3.4 The tray is controlled by a Spectra-Physics SP4200 or SP4270 Computer Integrator. Use
the integrators operation manual to begin calibrating. (A typical program in Basic for integrators that
illustrates integrator capability is shown in the Appendix of this procedure.) By using the RUN
command, the analysis and data treatment phases of the calibration are set in motion. Four calibration
standards are run, the chromatograms and peak areas displayed for each run, and the run results for each
anion are fitted to a quadratic curve by a least squares regression calculation. The three curves are plotted
and the correlation coefficients are calculated. The values of the coefficients are normally greater than
0.999, where 1.000 indicates a perfect fit. Values of less than 0.99 indicate the calibration procedure
should be repeated.
[Note: Recalibration should be carried out whenever standard concentrations show consistently high or
low results relative to the calibration curve is compared to the calibration curve from the old standards.
Comparability of points should be within ± 0.1 ppm or ±10%. For standard concentrations of greater
than 1 ppm, comparability will normally be within 5% or better. Old standards are assumed correct
since they are referenced to the entire historical series of previous standard solutions all of which are
comparable.]
11AA System Shut-down.
17.4.4.1 Shut off the pump. Turn the REGEN switch and the conductivity cell to the OFF
position.
17.4.4.2 Switch the eluent degas switch to HIGH.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-25
-------
Method 10-4.2 ChaPter I0:4
Acidic/Basic Constituents Atmospheric Acidic
17.4.4.3 Turn the stripchart recorder OFF. Cap the pen. Press the F10 function key on the
computer. Select option 3 to exit to DOS. Shut off the printer and the computer.
17.4.4.4 Shut the eluent degas system and reservoir switches and the autosampler to the OFF
position. Close the valves on both gas cylinders. Close the regulator valves.
17.5 Basic Troubleshooting
Before proceeding with the troubleshooting guide, make sure the reagents used were prepared correctly
and are not "old."
17.5.1 Unstable Baselines
17.5.1.1 Wavy baseline. The most common reason for a wavy baseline is an air bubble in the
gradient pump. This problem is diagnosed by observing the pump head indicator lights on the gradient
pump module front panel. If the baseline is pulsing in phases with pump pistons, a bubble is usually
present. Other possibilities include a dirty or stuck check valve, piston seal or "O"-ring, as well as an
air bubble in the conductivity cell.
17.5.1.2 Drifting baseline. Steadily increasing or decreasing baselines usually indicate that the
suppressor column is not performing as it should. Parameters to change include the regenerant and eluent
concentrations and flow rates. Check temperature routinely, as changes in temperature can cause drifting.
Balancing these should stabilize the baseline if the suppressor is functioning correctly. The Dionex
manual describes clean-up procedures if the suppressor is believed to be contaminated.
17.5.1.3 High baselines. As with drifting baselines, the parameters to change are eluent and
regenerant concentrations and flow rates. A high baseline usually indicates that there is not enough
baseline suppression; this condition can be controlled by increasing the regenerant flow rate.
17.5.1.4 Low baselines. Low baselines usually indicate that there is too much suppression, which
can be controlled by decreasing the flow of the regenerant.
17.5.2 Backpressure. Variations in system backpressure are common and should not raise concern
UNLESS the pressure change is greater than 200 psi.
17.5.2.1 High backpressure. The system is protected from pressure related damage through the
high and low pressure alarm settings on the front panel of the gradient pump module. If the high
pressure setting is correctly selected (200 psi above normal operating range), the pump will automatically
shut-off if this value is exceeded. The reason for high backpressure is blockage in the system.
Possibilities include loading against a closed valve, a plugged line, contaminated columns, etc. Diagnosis
is done by removing one component of the system and observing how the pressure changes.
17.5.2.2 Low pressure. Low pressure readings usually indicate a leak somewhere in the system.
Carefully check all fittings for leaks. Tighten if necessary.
17.5.3 Flow
17.5.3.1 Regenerant lines. If there is no flow at the waste outlet end of the regenerant line, check
the following:
* Make sure the correct regenerant switch is turned on .
• Verify that the reservoir is not empty
• Make sure the nitrogen tank is turned on
• Check that the regulator is correctly set
17.5.3.2 Eluent lines. If there is no flow at the outlet end of the eluent lines, check the following:
• Check that the pump is on
* Check that the eluent lines are connected to the correct port
17.5.4 Software. Refer to the ChromatoChart manual for detailed information on software problems.
Page 4.2-26 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
18. Ammonia Analysis by Technicon Autoanalysis
Presented in Sections 18.1 and 18.2 are the recipes for the standards and reagents required to analyze the
ammonium ion (NH4+ - or ammonia (NHg)) by Technicon autoanalysis. The prelude of these Sections
briefly describes the TRAACS 800 autoanalyzer and the sample flow through the TRAACS 800 for
NH4+ analysis. This instrument is capable of quantifying, from a single sample, three different species
simultaneously. An aliquot of the sample is taken from an automated sampler by syringe. A splitter
divides the aliquot into the appropriate volumes required for the particular analyses. Each of the volumes
is then transferred to the appropriate analytical cartridge. Sample flow diagrams that illustrate SO4=,
N.C>3~ and NH^"1" analysis can be shown separately and independently of one another. The data
computation (by-computer) and quality assurance protocols, however, can not be readily adapted to
single-channel instruments. These protocols need to be specific to the individual analytical instrument.
In brief, NH^"*" analysis is illustrated in Figure 17. The samples, along with all standards, are taken
from the auto-advance sampler tray by the use of a proportioning pump and automated syringe. Air and
EDTA are first added to the samples and are mixed in the first set of coils. After mixing, phenolate is
added and mixed in the next set of coils. Nitroprusside is then added and mixed, followed by the
addition and mixing of hypochlorite. At this stage, the sample should be a bright blue color. After the
last mixing stage, the sample is sent through a heated bath, followed by another mixing stage. Finally,
the sample is sent through a colorimeter where the results are recorded on a digital printer and stored in
a computer file for further manipulation.
18.1 Standards and Stock Solutions Preparation
/Note: Before discarding the old solution, it should be checked against the fresh solution by comparing
calibration curves on the working solutions prepared from them. Slopes and intercepts are calculated for
each set of standards. The old slope and intercept are used to calculate concentration values from
readings for the new standards. This calculation determines if the old solution has deteriorated or if an
error has been made in preparing the new solution.]
18.1.1 Ammonium Solution Standard (1,000 ftg/mL). Dry ammonium chloride in an oven for 1 h
at 50-60°C and desiccate over silica gel for 1 h. Weigh 2.9470 g ammonium chloride and dissolve in
800 mL DDW. Dilute to 1 L with DDW and mix thoroughly. This solution is stable for 1 y.
18.1.2 Intermediate Ammonium Standards. To make a 100 j^g/mL ammonium standard, pipet
10 mL of ammonium stock standard into a 100 mL volumetric flask. Dilute to volume with DDW and
mix thoroughly. Keep refrigerated. This solution remains stable for 1 month. To make a 10 fig/mL
ammonium standard, pipet 1.0 mL of ammonium stock standard into a 100 mL volumetric flask. Dilute
to volume with DDW and mix thoroughly. This solution remains stable for one week.
18.1.3 Working Ammonium Standards in DDW. Pipet aliquots of the 100 /ig/mL ammonium
intermediate standards with appropriate volumes of nitrate and sulfate intermediate standards into 100 mL
volumetric flasks according to the table below. Dilute to volume with DDW. Prepare fresh daily.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-27
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Standard
A
B
C
D
E
F
G
H
Stock or
intermediate
standard, jtg/niL
1,000
100
100
100
100
100
10
10
Aliquot, mL
40.0
4.0
3.0
2.0
1.0
0.5
2.0
1.0
Concentration,
jt*g/mL
40.0
4.0
3.0
2.0
1.0
0.5
0.2
0.1
18.1.4 Sodium Citrate Stock Solution. Dissolve 294.1 g of sodium citrate in 800 mL DDW.
Dilute to 1 L and mix thoroughly. Store at room temperature.
18.1.5 20% Citric Acid/5% Glycerol Stock Solution. Dissolve 25 g citric acid in 80 mL DDW.
Add 5 mL glycerol and dilute to 100 mL with DDW. Mix thoroughly and store at room temperature.
18.1.6 Sodium Citrate/Citric Acid/Glycerol Working Solution. Pour 100 mL sodium citrate stock
solution into a 1000 mL volumetric flask. Add 20 mL of the 10% citric acid/5% glycerol stock solution
and dilute to volume with DDW. Mix thoroughly and store at room temperature.
[Note: Tills solution mil be used to make ammonium working standards for citric acid/glycerol-
impregnated filter extract analyses.]
18.1.7 Working Ammonium Standards in Sodium Citrate/Citric Acid/Glycerol Working
Solution. Pipet aliquots of the 100 /ig/mL volumetric flasks according to the table in Section 18.1.3.
Dilute to volume with sodium citrate/citric acid/glycerol working solution and mix thoroughly. Prepare
fresh daily.
18.1.8 Potassium Chloride Stock Solution. Dissolve 74.6 g potassium chloride in 800 mL DDW.
Dilute to 1 L with DDW and mix thoroughly. Store at room temperature.
18.1.9 Potassium Chloride Working Solution. Put 100 mL of the potassium chloride stock solution
into a 1000 mL volumetric flask. Dilute to volume with DDW.
18.1.10 Working Ammonium Standards in Potassium Chloride Working Solution. Pipet aliquots
Of the 100 /ig/mL ammonium stock standard or intermediate standards into 100 mL volumetric flasks
according to the table below. Dilute to volume with potassium chloride working solution and mix
thoroughly. Prepare fresh daily.
Page 4.2-28
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Standard
A
B
C
D
E
F
G
H
Stock or
intermediate
standard, /ig/mL
1,000
100
100
100
100
100
10
10
Aliquot, mL
40.0
4.0
3.0
2.0
1.0
0.5
1.0
0.5
Concentration,
/ig/mL
40.0
4.0
3.0
2.0
1.0
0.5
0.1
0.005
18.2 Reagent Preparation
[Note: When reagents are prepared, label the container with the contents, concentration, date prepared,
and the preparer's initials.]
18.2.1 Alkaline Phenol. Add 83.0 g loose crystallized phenol to 800 mL DDW in a 1 L volumetric
flask. Keeping the flask in an ice bath or under tap water, slowly add 96.0 mL 50% sodium hydroxide
solution. Shake the flask while adding the sodium hydroxide. Cool to room temperature, dilute to 1 L
with DDW, and mix thoroughly. Store in an amber glass container. This solution will remain stable for
3 mo, if kept out of direct light.
18.2.2 Sodium Hypochlorite Solution. The amount of sodium hypochlorite solution varies from
batch to batch of sodium hypochlorite (5% commercial grade). Therefore, for each new batch, a base
and gain experiment must be run to adjust the amount of sodium hypochlorite required to obtain the
existing base and gain values. In a 150 mL volumetric flask, dilute 86 mL of 5% sodium hypochlorite
solution to 100 mL with DDW and mix thoroughly. Check base and gain values. Reduce or increase
the amount of sodium hypochlorite to obtain the same base and gain values as the previous sodium
hypochlorite batch. This solution remains stable for 1 day.
18.2.3 Sodium Nitroprusside Solution. Dissolve 1.1 g of sodium nitroprusside in about 600 mL
of DDW, dilute to 1 L with DDW, and mix thoroughly. Store in an amber container and keep in
refrigerator. This solution remains stable for 1 month, if kept out of direct light.
18.2.4 Disodium EDTA Solution. Dissolve 1.0 mL of 50% w/w sodium hydroxide and 41.0 g of
disodium EDTA mix thoroughly. Add 3.0 mL of Brij-35 and mix. Store in plastic container. This
solution will remain stable for 6 months.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-29
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
19. pH Analysis
19.1 Standard and Reagent Preparation
[Note: Each of the standard H2SO4 stock solutions must be prepared fresh the day ofpH analysis.]
19.1.1 Standard H2SO4 Solution.
19.1.1.1 Label seven 25 mL polyethylene stoppered volumetric flasks. Also, label each flask with
the volume of 1 N BSC solution indicated in the following table:
Standard
H9SO4, Flask
No.
1
2
3
4
5
6
7
Volume of
1.000NH2SO4
added to each
flask, /iL
0
25
50
100
200
400
800
Standard
concentration,
10-% Hr>SO4
0
1
2
4
8
16
32
19.1.1.2 Use the 25 jtiL automatic pipet to add 1 N stock H2SO4 to flasks #1-3. Use the 100 /*L
pipet to add 1 N stock H2SC>4 to flasks #4-7. Dilute all flasks to the 25 mL mark with absolute ethanol.
Cap with stoppers or parafilm and mix well.
19.1.2 2 M Potassium Chloride (KC1) Solution.
19.1.2.1 Weigh 149.2 ± 0.1 g of KC1. Add the KC1 to a 2 L flask.
19.1.2.2 Add about 700 mL of DDW water to the flask. Swirl the solution until the KC1 is
completely dissolved.
19.1.2.3 Pour this mixture into a 1 L graduated cylinder. Rinse the flask with a small amount
of water and transfer the rinse into the cylinder. Fill the cylinder to the 1 L mark.
19.1.2.4 Pour the solution from the cylinder into the 1 L polyethylene bottle. Cap and shake the
bottle to mix well. Mark the bottle with date of preparation.
19.1.3 0.1 N Perchloric Acid (HCIO^ Solution.
19.1.3.1 Fill a 1 L graduated cylinder about 1/2 full with DDW. Transfer 10 ± 0.1 mL of
60-62% HC104 into the 1 L cylinder with a 10 mL pipet.
19.1.3.2 Fill the cylinder to the 1 L mark. Pour the solution into the 1 L polyethylene bottle.
19.1.3.3 Cap and shake the bottle to mix well. Mark the date of preparation on the bottle.
19.1.4 0.01 NHC1O4 Solution.
19.1.4.1 Fill a 1 L graduated cylinder about 1/2 full with DDW.
19.1.4.2 Measure 100 mL of the 0.1 N HC1O4 solution with the 100 mL graduated cylinder.
Add solution to the 1 L cylinder.
Page 4.2-30
Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
19.1.4.3 Fill a 1 L cylinder with DDW to the 1 L mark. Pour the solution into the 1 L
polyethylene bottle.
19.1.4.4 Cap and shake the bottle to mix well. Mark the date of preparation on the bottle.
19.1.5 Extraction Solution (ES).
[Note: This solution has the same composition as the solution used to fill the sample vials for Teflon®
filters. It must be prepared fresh on the day ofpH analysis.]
19.1.5.1 Measure 100 ± 10 mL of DDW into a 1 L graduated cylinder. Transfer to a 2 L
erlenmeyer flask.
19.1.5.2 Using a 5 mL calibrated automatic pipet, add 10 ± 0.1 mL of 0.01 N perchloric acid
to flask of water.
19.1.5.3 Mix well and cover with parafilm until ready for use.
19.1.6 EA Solution.
19.1.6.1 Measure 150 ± 2 mL of ES (prepared in Section 18.1.5) into a 250 mL graduated
cylinder. Transfer to a 250 mL erlenmeyer flask.
19.1.6.2 Using a 5 mL graduated cylinder, add 5 ± 0.1 mL of ethanol (from the same fresh bottle
of ethanol that was used to prepare the standards in 18.1.1) to the flask.
19.1.6.3 Again using a 5 mL graduated cylinder, add 3 ± 0.1 mL of 2 M potassium chloride
(KC1) solution to the flask.
19.1.6.4 Mix well and cover with parafilm until ready for use.
19.1.7 Working Standard Test Solutions.
19.1.7.1 Place fourteen-4 mL polystyrene sample cups (as used with Technicon Auto-Analyzer
II system) labeled 1, 1*, 2, 2*...7, 7* into racks. Using the calibrated dispensing pipet bottle, add 3 mL
of ES solution to each 4 mL cup.
19.1.7.2 Using the displacement pipet, add 50 uL of absolute ethanol to each cup. Pour about
3 mL of standard (K^SC^ solution) #1 into a labeled 4 mL cup.
19.1.7.3 Immediately pipet 50 uL of this standard into the 4 mL cups labeled 1 and 1* containing
the ES solution and ethanol.
[Note: This transfer must be done without delay to prevent the standard concentration from increasing
significantly due to evaporation of the ethanol solvent.]
19.1.7.4 Repeat the procedure for each of the other 6 standards. If there is a delay of more than
5 min between the preparation of these mixtures and the next step, put caps on the 4 mL cups.
19.1.7.5 To prepare for analysis, mix each mixture. Then transfer two aliquots from each cup
to 2 mL sample cups. Place cup #1 in a rack. In a second rack place two-2 mL cups labeled 1 and 1-.
Use the 1 mL automatic pipet to mix the contents of 4 mL cup #1 by drawing 1 mL into the pipet tip and
then dispensing it back into the 4 mL cup three times. Use the same pipet to transfer 1 mL of the
mixture to each of the two labeled 2 mL cups. Place caps on the two 2 mL cups. After transferring the
two aliquots to 2 mL cups, rinse the automatic pipet tip in a flask of DDW. Repeat the transfer
procedure for each of the other working standard pairs.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-31
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
19.2 Calibration of pH Meter
The pH meter requires temperature calibration whenever a new electrode is used. Use the manufacture's
procedure in the instrument manual. This calibration should be repeated every 3 months when not in use.
The pH meter is left with the power cord plugged into the AC outlet, the mode control knob is left in
the standby position, the electrode lead is partially disconnected by pressing the plastic ring on its outer
edge, and the combination electrode is immersed in a 4 M KC1 solution (a slit rubber stopper seals the
bottle with the electrode in it). Keep a record of the temperature calibrations in a lab notebook.
19.3 Pre-Analysis Calibration
(Note: Hie pH buffer solutions are not used for any quantitative purpose. They are used to standardize
the electrode and as a diagnostic to verify that the pH measurement system is working as expected before
beginning analysis of the samples.]
19.3.1 Use a pH Analytical Log Form to record all date (see Figure 18). While still in standby
mode, reconnect the electrode lead at the back of the pH meter.
19.3.2 Fill three 4 mL cups with pH 7 buffer. Withdraw the electrode from the 4 M KC1 bottle and
wipe the tip gently with a Kimwipe® to remove the bulk of the solution. Rinse the electrode with one
cup of pH 7 buffer. Do not test pH of the first cup.
19.3.3 Immerse the electrode in the second cup of the pH 7 buffer. Use a small bottle or other
support to hold the cup up to the electrode while waiting for the meter reading to equilibrate.
19.3.4 Test the pH by turning to the pH mode of the meter. Allow the reading to stabilize for at
least 30 s. Record the result on the log for "1st cup."
19.3.5 Turn to standby mode, and then test the last cup of pH 7 buffer. Record the results on the
log for the "2nd cup." If the pH value for the 2nd cup is not 7.00 ± 0.01, adjust the "calib." knob to
obtain a reading of 7.00. Note this adjustment on the log.
19.3.6 Fill three 4 mL cups with pH 4 buffer. With the meter in the standby mode, remove the cup
containing pH 7 buffer, wipe the tip of the electrode gently with a Kimwipe® and then rinse the electrode
with the first cup of pH 4 buffer.
19.3.7 Test the next two cups of pH 4 buffer as above, recording the results on the log. If the pH
value for the 2nd cup is not 4.00 ± 0.01, adjust the "slope" knob to get a reading of 4.00. If the value
for the second cup was not 4.00 ± 0.03, the calibrations at pH 7 and at pH 4 must both be repeated.
19.4 pH Test 0.01 N HCIO4 Solution
(Note: Tlie 0.01 NHCIO^ solution is used to prepare the ES solution, which is used to prepare the EA
solution. The pH value for the EA solution must be 4.09 ± 0.04. If this pH value is not achieved, the
0.01 NHCIO^ solution must be reprepared.]
19A.I Calibrate the pH meter with pH 4 buffer.
19.4.2 Rinse the pH electrode with DDW. Wipe the tip of the electrode with a Kimwipe®.
19.4.3 Fill three 4 mL cups with EA solution. Measure the pH of the test-EA solution as with the
buffer solutions this value must be 4.09 ± 0.04.
Page 4.2-32 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
19.4.4 If the above pH value is not achieved, follow the steps outlined in Sections 18.1.3 - 18.1.6
to reprepare the solutions. Test the pH of the new solutions. Repeat as necessary to obtain a pH of
4.09 ± 0.04.
19.4.5 Leave the electrode immersed in the "2nd cup" with the meter in the standby mode until ready
to start analysis of the working standards.
19.5 Analysis of Working Standard
[Note: Immediately following the EA analysis, start testing the working standards.]
19.5.1 With the pH meter still in the standby mode, remove the last cup from the electrode, gently
wipe the tip with a Kimwipe®, and immerse the electrode into the working standard cup #1.
/Note: Only two cups are available for each working standard (also for filter extracts). Thus, pH
measurement is made for both of the two cups for each sample. Also, the electrode tip is not wiped
between the 1st and 2nd cups of each sample.]
19.5.2 After testing the pH of cup #1, test cup #1-. Record the results of both on the pH Analytical
Log Form.
19.5.3 With the meter in the stand-by mode, remove the #1- sample cup, wipe the electrode with a
Kimwipe®, and test one 2 mL cup of EA solution. Rinse with DDW.
19.5.4 Test a 2nd cup of EA solution; record the results for both cups on the logsheet. Discard the
1st cup of EA, but retain the 2nd cup to be used as the 1st cup for the next EA test.
19.5.5 Continue testing the remainder of the working standards, #1*, 1*-, ... 7, 7-, 7*, 7*-.
Remember that the electrode tip is wiped before and after each pair of test solutions, but not in between
two cups of the same sample.
/Note: If there is trouble obtaining constant pH values, use a magnetic stirrer to keep the contents to be
measured uniform. If employed, ensure that the sample cups are insulated from any temperature increase
of the stirring platform, which may occur during extended use.]
19.5.6 Use the mode control knob in the "temp." position to measure the temperature of the test
solutions every 5-10 samples and record the results on the logsheet.
19.6 Analysis of Filter Extracts
After measuring the pH of the working standards, measure the pH of the filter extracts and record all
results on the log. After all the filter extracts have been tested make an additional test with the EA
solution. At the end make a final test of pH 4 buffer. With the mode control in the standby mode, shut
down the pH meter by disconnecting the electrode lead at the back of the meter, leaving the meter power
cord plugged into the AC line. Immerse the electrode tip in the bottle of 4 M KC1.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-33
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
20. Atmospheric Species Concentration Calculations
The system described in the previous sections collects nitric acid (HNOg), sulfur dioxide (SC^) , ammonia
(NH3), particulate sulfate (SC^), and particulate nitrate (NOg"). The collection of each of these species
is illustrated in Figure 1. Nitric acid and sulfur dioxide gases are collected on denuders one and two.
Some 862 gas is collected on denuder three also. Nitrous acid gas is collected on denuders two and
three. Ammonia gas is collected on denuder four. Particulate sulfate and nitrate are collected on the first
(Teflon)® filter, while some of the particulate nitrate collected on the Teflon® filter evaporates and collects
on the second (nylon) filter. Also collected on the Teflon® filter are fine particles that contain hydrogen
ions (H"*~), though probably not free H+. Hydrogen ions are most likely present in the HgO* form.
The concentration of these H+ ions indicates the atmospheres acid aerosol content. Prepare the Teflon®
filter extracts for pH analysis prior to 1C analysis for the particulate sulfate contents. Special precautions
must be taken to prevent contamination of the Teflon® filters by ammonia before either of the analyses.
20.1 Assumptions of the Annular Denuder System
A number of assumptions are made about the performance of the annular denuder system so that validity
of the calculations presented later in this section will hold true. As discussed in Section 6, significant
interferences need to be considered to make accurate estimations of species concentrations. The
assumptions are as follows:
• The first denuder stage collects 100% of sampled HNO^ as nitrate. (Since the diffusivity of
HNOj is high, diffusion to the side walls is assumed to be very quick.)
• The first denuder stage collects 100% of sampled HNO2 as nitrite, which can oxidize to nitrate.
• The first denuder collects 100% of the SO2 as sulfite, which can oxidize to sulfate.
fNote:_ Before analysis, add hydrogen peroxide (Z^C^ to oxidize the sulfite (SO^~) to sulfate
) to simplify the calculations.]
The amounts of nitrite and nitrate collected on denuder 1 represent amounts of interfering gases,
such as NC>2, collected on denuder 1.
The second denuder stage collects 100% of the sampled ammonia (NHo) as ammonium ion
(NH4+).
The Teflon® filter is 100% efficient for particulate sulfate, nitrate, and ammonia. Particle losses
are less than 1 % on each denuder. This assumption may or may not stand true depending on
the concentrations of the components in the air sampled. Modifications may be needed to avoid
low (or underestimates of) acidic measurements. For .example, another filter stage may need
to be added to accurately account for the particulate ammonia content of the air sampled. If
ammonium nitrate (NH^NO^) was collected on the Teflon® filter, its probability of evaporation
is high. Therefore, a citric acid-impregnated filter downstream would correct for the loss from
the Teflon* filter. Also, interaction of ammonia and sulfuric acid neutralizes the filter and
causes the acidic measurement to be biased. (Again diffusion rules the particle loss assumption;
particles have lower diffusivities than gases.)
The nylon filter collects any nitrate that evaporates from the Teflon® filter.
Page 4.2-34 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
20.2 Calculations Using Results from 1C Analysis
These assumptions lead directly to equations for computing atmospheric concentrations from denuder
measurements.
20.2.1 Analytical results are given at NO-j - in jtg/mL, and SO^= as
20.2.2 The extraction volume was 10 mL (i.e., 0.010L).
20.2.3 Nitrate concentration converted to equivalent nitric acid:
CN03- = [N03- sample - N03- blank ][10 mL][98/62]
CSO4= = [SO4= sample - SO4= blank][10 mL][100/98]
20.3 Calculations Using Results from pH Analysis
Earlier pH determinations have been based on the pH buffer concentrations, the activity of the solution,
and the antilog of the measured pH value. More recent studies have steered away from the issue of
activity by comparing the results of the standards, thus alleviating errors introduced by basing the
activities of ions retained on filters on those retained in solution. The methodology developed from these
more recent studies is described herein. The end results are reported in terms of mass of equivalent of
ions. Appropriate values of accuracy and precision with respect to H+ concentration for this method are
10% and 5%, respectively, for sample pH values in the 4.00 to 7.00 range.
20.3.1 Summary of Method. There are two parts to this methodology: determination of the
"nominal EQ" and determination of the "actual (EQ^)." The nominal EQ is defined as the equivalent
Hg H2SO4/m3 for a nominal 5.76 m3 sample volume (24 h at 4 LPM). The actual EQA is defined as
the equivalent /ig H2SO4/m3 based on the actual sample air volume.
20.3.1.1 Determine the nominal EQ^ as follows:
20.3.1.1.1 To account for the difference between standards prepared with filters and standards
prepared without filters, adjust the measured concentration values for the working standards (without
filters) for each analysis day.
20.3.1.1.2 Calculate the standard curve, using a linear regression of the equivalent of /ig
H^SO^/nv* (for 5.76 m3 volume of sample) for each working standard vs. the adjusted concentration
values for the working standards.
20.3.1.1.3 Use the standard curve to determine EQjsj for each sample filter.
20.3.1.1.4 Calculate the actual air flow rate to determine the actual air sample volume. Divide
the actual air sample volume into EQjsj to determine EQ^.
20.3.1.2 Determine the actual EQ^ as follows:
20.3.1.2.1 The actual sample air volume, V, for each sample is calculated using data from the
field log sheet. This data includes the initial and final elapsed time, the initial rotameter reading, and the
rotameter I.D. No.
20.3.1.2.2 The calibration curve for the given rotameter reading is used to calculate the flow for
the sample (LPM).
20.3.1.2.3 The nominal EQj^ is divided by the calculated flow to give the actual EQ^.
20.3.2 Adjustment for Filter vs. Non-Filter Standards. This adjustment is necessary because
experiments showed that the measured acid concentration from filters doped with H2SO4 stock standards
yielded concentrations, as measured by the difference from EA solution, that were about 3 % lower than
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-35
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
the values found for working standards (prepared without filters from the same stock standards). The
results gave the following relation (by linear regression):
Cf = -0.11 + 0.971 (Cnf)
where:
Cf = difference in units of 10"^ N, calculated using the pH of each filter standard and the pH of EA
tested after that standard.
Cnf = the same difference for non-filter standards or the apparent net strong acid concentration of
For each working standard (non-filter), on a given analysis day, calculate the "apparent net concentration
of H2SC>4M as follows:
Cnf= IQ-PHWS . 10-pHEA
where:
pHWS = measured pH for a working standard (or apparent strong acid concentration for E^SO^j. -
doped filter standards).
pHEA = measured pH for the EA solution (or apparent strong acid concentration for non-filter,
2SC>4 doped standards).
After calculating the Cnf values for each working standard, use equation (1) above to calculate the
adjusted values of Cf for each.
20.3.3 Determination of Standard Curve. For each working standard, the corresponding EQ^j
value (the equivalent of /ig F^SC^/mr [assuming a sample volume of 5.76 m^]) is determined as follows:
EQN = m/5.76 (106 jtg)/g
[Note: 5. 76 is the volume for a sample collected for 24 h at 4 LPM, in m?J
fNote: The analyst may determine whether concentration or mass is calculated here and used to create
the standard curve. If mass is used, a nominal sample air volume is not necessary. The value ofm is
determined as follows:/
m = [1.000] [S/25] [5 x 10'5] [49]
where:
1.000 = concentration of the commercial standard B^SC^, in units of equivalents/L.
S = volume of commercial standard 112804 used to prepare a given stock standard
solution, mL.
25 = volume of each stock standard solution, mL.
Page 4.2-36 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
5 x 10"^ (50 uL) = is the volume of each stock standard solution used to prepare its respective
working standard, L.
49 = equivalent weight of 112804, units of grams/equivalent.
[Note: When the value ofS is 1 mLor greater for a final volume of 25 mL, the standard curve illustrates
non-linearity.]
An example table of the values of the nominal EQ^ for each working standard is shown in Table 3. For
each analysis day, the standard curve should be determined by calculating the linear regression of
vs. Cf, with the result in the following equation:
= intercept + [Cf] [slope]
20.3.4 Determination of Nominal EQjy for Filter Samples. The apparent net strong acid
concentration of each sample filter extract, Cs, is calculated as with the working standards:
Cs = 10'PHS - 10-pHEA
where:
pHS = measured pH of the sample filter extract (or apparent strong acid concentration for sample
filters extracts).
pHEA = measured pH for the EA solution (or apparent strong acid concentration for non-filter,
SO standards).
/Note: The Cs values for the filter extracts are directly comparable to the C* values for the working
standards, since the Cf values have been adjusted for the difference in apparent acid concentration for
tests made with filters and tests made without filters.]
To determine the nominal EQj^ values for filter samples, use the following equation:
EQN = Intercept + [Cg] [Slope]
20.3.5 Determination of Actual EQA. The actual sample air value, V, for each sample is calculated
using the data from the field log sheet. These data include the initial and final elapsed times, the initial
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-37
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
rotameter reading, and the rotameter I.D. No. Use the calibration curve for the given rotameter to
calculate the flow for the sample, in LPM. Calculate the value of V as follows:
V =
where:
F = flow from the calibration curve, LPM.
T = net elapsed time, rain.
Since the nominal EQj^ values were determined assuming a flow of exactly 4 LPM and a net elapsed time
of exactly 24 h, the assumed volume was 5.76 m3; therefore, calculate the value of the "actual EQ^"
by:
EQA = [EQN]/V
where:
= units of jig/m3
Nominal EQj^ as determined by:
EQN = m/5.76 (106 jug/g)
where*
m = [1.000] [S/25] [5 x 10'5] [49].
1.000 = concentration of commercial standard E^SC^, units of equivalents/L.
S = volume of commercial standard H^SC^ used to prepare a given stock standard
solution mL.
25 = volume of each stock standard solution, mL.
5 x 10~^ (50 uL) = volume of each stock standard solution used to prepare its respective working
standard, L.
49 = equivalent weight of E^SO^ units of grams/equivalent.
Proper dilution rates are indicated on Table 4.
21. Variations of Annular Denuder System Usage
As described in Sections 3 and 4, the ADS is used to measure reactive acidic (SGj and HNOg) and basic
(NHg) gases and strong acidity of atmospheric particles found in ambient air. The unique features of the
ADS that separate it from established air monitoring methods are the ability of sampling artifacts to be
eliminated from the collected gases and particles and preservation of die samples for subsequent analysis,
which is accomplished by removing NHg hi the gas stream with a citric acid coated denuder, thus
reducing the probability of the particulate acid sulfates (SO4==) captured on the Teflon® filter from being
neutralized. The ADS configuration described in Section 13 clearly illustrates these unique features. The
elutriator is designed to allow only particles with <2.5 /im diameter into the system. The impactor is
Page 4.2-38 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4 Method IO-4.2
Atmospheric Acidic Acidic/Basic Constituents
designed to reduce the possibility of coarse particle infiltration even further. And finally, the sequence
of the denuders reduces interference of possible chemical reactions that could cause under-or
over-estimations of concentrations to be made. Although this configuration is recommended for
measuring these gases and particulates, the user may wish to measure only one or two of the chemical
species. The following discussion will present possible variations of the ADS to accommodate such
usages.
21.1 Today, the ADS is being used in intercomparison studies to assess NHj concentration differences
indoors and outdoors. The assembly used here consists of an elutriator-impactor assembly, an annular
denuder, and a filter pack assembly. The elutriator-impactor assembly and the annular denuder are both
smaller than those described earlier. The filter pack is available in the smaller size, but an adaptor is also
available to assemble the smaller annular denuder to the larger filter pack assembly. This system is
referred to as the personal sampler (see Figure 20). It is designed for sampling while attached to the shirt
of a worker. The personal sampler can be used to measure other chemical species in indoor air by simply
changing the reactive surface (coating) of the annular denuder or the types of filters used.
21.2 Another variation of ADS application is simultaneous use in parallel with a fine particle sampler.
The fine particle sampler assembly is very similar to the annular denuder assembly. The main difference
is that a flow-straightener tube replaces the annular denuder. The flow-straightener is a shorter version,
1-1/4 to 4" long, of the annular denuder and creates even air flow across the filters to collect particulate
matter. Again the elutriator-impactor assembly and flow-straightener are available in smaller sizes with
accommodating filter pack assemblies. In addition, the ADS carrying and shipping cases as well as the
sampling box can be adjusted to accommodate the ADS and fine particle sampler. The assemblies as they
would appear in the sampling box ready for sampling are illustrated in Figure 19.
21.3 If one has interest in quantitations HNC^ utilizing the ADS, special sampling and analytical
concerns must be addressed. As identified in Section 24, Citation 14, guidance is given for accurate
quantitation of HNC^ in ambient air.
22. Method Safety
This procedure may involve hazardous materials, operations, and equipment. This method does not
purport to address all of the safety problems associated with its use. The user must establish appropriate
safety and health practices and determine the applicability of regulatory limitations prior to the
implementation of this procedure. These practices should be part of the user's SOP manual.
23. Performance Criteria and Quality Assurance (QA)
Required quality assurance measures and guidance concerning performance criteria that should be
achieved within each laboratory are summarized and provided in the following section.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-39
-------
Method IO-4.2 Chapter IO-4
Acidic/Basic Constituents Atmospheric Acidic
23.1 Standard Operating Procedures (SOPs)
23.1.1 SOPs should be generated by the users to describe and document the following activities in
their laboratory: (1) assembly, calibration, leak check, and operation of the specific sampling system and
equipment used; (2) preparation, storage, shipment, and handling of the sampler system; (3) purchase,
certification, and transport of standard reference materials; and (4) all aspects of data recording and
processing, including lists of computer hardware and software used.
23.1.2 Specific instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the monitoring work.
23.2 QA Program
The user should develop, implement, and maintain a quality assurance program to ensure that the
sampling system is operating properly and collecting accurate data. Established calibration, operation,
and maintenance procedures should be conducted regularly and should be part of the QA program.
Calibration procedures provided in Sections 17 and 19, operation procedures in Sections 14 and 17, and
maintenance procedures in Section 17 of this method and the manufacturer's instruction manual should
be followed and included in the QA program. Additional QA measures (e.g., trouble shooting) and
further guidance in maintaining the sampling system are provided by the manufacturer. For detailed
guidance in setting up a quality assurance program, the user is referred to the Code of Federal
Regulations (Section 24, Citation 12) and the U. S. EPA Handbook on Quality Assurance (Section 24,
Citation 13).
24. References
I. Waldman, J. M., Operations Manualfor the Annular Denuder System Used in the U. S. EPA/RTVM
Atmospheric Acidity Study UMPNJ - Robert Wood Johnson Medical School, Piscataway, NJ, August 28,
1987.
2. American Chemical Society Subcommittee on Environmental Chemistry, "Guidelines for Data
Acquisition and Data Quality Evaluation in Environmental Chemistry," Analyt. Chem., Vol.
52:2242-2249, 1980.
3. Sickles, II, J. E., Sampling and Analytical Methods Development for Dry Deposition Monitoring,
Research Triangle Institute Report No. RTI/2823/00-15F, Research Triangle Institute, Research Triangle
Park, NC, July 1987.
4. Forrest, J., and Neuman, L., "Sampling and Analysis of Atmospheric Sulfur Compounds for Isotopic
Ratio Studies," Atmos. Environ., Vol. 7:562-573, 1973.
5. Stevens, R. K., et al., ACGIH Symposium: "Inlets, Denuders and Filter Packs to Measure Acidic
Inorganic Pollutants in the Atmosphere," Aislomer Conference Center, Pacific Grove, CA, February 16,
1986,
Page 4.2-40 Compendium of Methods for Inorganic Air Pollutants January 1997
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Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
TABLE 2. ACCELERATOR JET DIAMETERS AND CORRESPONDING REYNOLDS
NUMBER (RE) FOR SELECTED FLOW RATES TO OBTAIN 2.5 MM AERODYNAMIC
D5Q SEPARATION
How rate,1:.] ,
L/min ••/:
1.0
2.0
5.0
10.0
12.0
15.0
16.7
20.0
Jet diameter, mm
1.55
1.97
2.65
3.33
3.55
3.85
4.00
4.25
Reynolds number (RE)
900
1,400
2,700
4,200
4,700
5,500
6,000
6,600
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-43
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
TABLE 3. SUMMARY OF KEY PROBE SITING CRITERIA FOR ACID AEROSOL
MONITORING STATIONS
Factor
Criteria
Vertical spacing above ground
Representative of the breathing zone and avoiding effects
of obstruction, obstacles, and roadway traffic. Height of
probe intake above ground in general, 2-3 m above
ground and 2-15 m above ground in the case of nearby
roadways.
About 1 m or more above the structure where the
sampler is located.
Horizontal spacing from
obstruction and obstacles
Minimum horizontal separation from obstructions such as
trees is > 20 m from the dripline and 10 m from the
dripline when the trees act as an obstruction.
Distance from sampler inlet to an obstacle such as a
building must be at least twice the height the obstacle
protrudes above the sampler.
If a sampler is located on a roof or other structures,
there must be a minimum of 2 m separation from walls,
parapets, penthouses, etc.
There must be sufficient separation between the sampler
and a furnace or incinerator flue. The separation
distance depends on the height and the nature of the
emissions involved.
Unrestricted airflow
Spacing from roads
Unrestricted airflow must exist in an arc of at least 270
degrees around the sampler, and the predominant wind
direction for the monitoring period must be included in
the 270 degree arc.
A sufficient separation must exist between the sampler
and nearby roadways to avoid the effect of dust re-
entrainment and vehicular emissions on the measured air
concentrations.
Sampler should be placed at a distance of 5-25 m from
the edge of the nearest traffic lane on the roadway
depending on the vertical placement of the sampler inlet
which could be 2-15 m above ground.
Page 4.2-44
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
TABLE 4. DILUTION RATES
[===========
Standard HoSO4
Flask No.
1
2
3
4
5
6
7
=======
Volume of
1.0NH2SO4
Added to Eacn
Flask, mL
0.000
0.025
0.050^
0.100
0.200
0.400
0.800
Equivalent; I
Strong Acid :
Mass Collected
on Filter, >ga
0
4.90
9.80
19.60
39.20
28.40
156.80
,
Equivalent Strong ;
Acid C61lected-on
Filter; ptg/m5
0.00
0.43
0.85
1.70
3.40
6.81
13.61
aBased on 6.2 mL extraction volume.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-45
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
To Pump and
Flow Controller
Analyts
Coating Determined
£r a
fc===3
Filler Pack Assembly, 47 mm J
I J
^J
Coupler with >L~J
Built-in Seal Ring OUT
Annular Denuder, Stainless Steel, >.
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
V"""
Air Flow Jn-t
Coupler with *-L~
Built-in Seal Ring tTTt
Annular Denuder, Stainless Steel, >-
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
I
'o
o
0
?
0
m*
^^--^-— -L_
t
H*. N03-
NH,'
i •
NH,
1
V
1
HCI, HNO,
HNOa, SO,
1
Coupler-Impactor with
Built-in Teflon® Seat Support
Elutriator, with Accelerator Jet,
Glass, Teflon® Coated
vAiri-i
Figure 1. Schematic view of Annular Denuder showing species collected.
Page 4.2-46
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Temperature Control Fan
Field Sampling Box
Heater
Temperature
Control Unit
Heater
Includes:
• Field Sampling Box
• 13" x 7" x 28" Heated and Cooled
• Pump-Timer System, Single Channel
with Mass Flow Controller
• Cyclone
• Annular Denuder
Filter Pack
110Vor220V
Pump-Timer System
Figure 2. Annular Denuder system.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-47
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Teflon Seat Support
Side View
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with Mill
Built-in Seal Ring,
Annular Denuder, Stainless Steel,
Multi-Channel, 242mm length,
Flow Straightener, Teflon® Coated
Coupler with MJULL
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler-lmpactor
with Built-in Teflon®
Seat Support
Elutriator, with Removable
Accelerator Jet, Aluminum,
Teflon® Coated
Annular Denuder Filter Pack
Assembly with Coupler-lmpactor
Shown in line
Air Flow
Page 4.2-50
Figure 5. Side view impactor/coupler assembly.
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO:4 '
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Pin Removal Tool
Impactor Support Pin
and Frit
Viton O-ring
#30 Threads -
Annular Denuder-
Impactor Housing Seat
Annular Denuder-
Impactor (242 mm long)
#30 Threads
Cap
Filter Pack
Assembly, 47 mm
Air Flow
Coupler with
Built-in Seal Ring
Annular Denuder, Glass,
242 mm Length, Flow
Straightener Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder-Impactor,
Glass, 242 mm Length,
Flow Straightener
Teflon® Coated
Impactor Support Pin
Frit
Coupler with
Built-in Seal Ring
Elutriator, with
Accelerator Jet, Glass
Teflon® Coated
Glass Annular Denuder
with Inset Impactor Assembly
Shown in line
Figure 4. Glass Annular Denuder with inset impactor assembly.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 4.2-49
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Quick-Release Plug
Aluminum Filter
Housing Outlet
Spacer, Teflon®
Porous Screen, Stainless
Steel, Teflon® Coated
Nylon Filter
Spacer, Teflon®
Porous Screen, Stainless
Steel, Teflon® Coated
Teflon® Filter
Filter Housing Inlet,
Aluminum Teflon® Coated
Delrin Screw Sleeve
Acid Aerosol Filter Assembly
To Pump and
Flow Controller
Acid Aerosol
Filter
Air Flow
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm Length
Flow Straigtener Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm Length
Flow Straigtener Teflon® Coated
Coupler with IJUt
Built-in Seal Ring
Cyclone, Aluminum
Teflon® Coated, /f
10 Lpm, 2.5 urn cut
Acid Aerosol Filter Assembly
Shown in line
Figure 8. Filter pack assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-53
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Quick-Release Plug
Aluminum Filter
Housing Outlet
Spacer, Teflon®
Porous Screen, Stainless
Steel, Teflon® Coated
Nylon Filter
Spacer, Teflon®
Porous Screen, Stainless
Steel, Teflon® Coated
Teflon® Filter
Filter Housing Inlet,
Aluminum Teflon® Coated
Delrin Screw Sleeve
Acid Aerosol Filter Assembly
To Pump and
Flow Controller
Acid Aerosol
Filter
Air Flow
Coupler with
Built-in Seal Ring [JJJJ
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm Length
Flow Straigtener Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm Length
Flow Straigtener Teflon® Coated
Coupler with SUB,
Built-in Seal Ring
Cyclone, Aluminum
Teflon® Coated,
10 Lpm, 2.5 pm cut K
Acid Aerosol Filter Assembly
Shown in line
Figure 8. Filter pack assembly.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-53
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO4
Atmospheric Acidic
Wall Clamp
Dryer/Cleaner
Bottle
Frit
Thermoplastic Caps with
Teflon Seal Rings and Hose Barbs
Teflon Tubing
Back-to-Back
Connectors
Annular Denucfer,,
Stainless Steel,
Multi-Channel,
242 mm Length;
Flow Straightener,
Teflon® Coated
End Caps
i
Manifold
i
1
Air
Figure 9. Drying train and manifold.
Page 4.2-54
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Temperature Control Fan
Field Sampling Box
Heater
Temperature
Control Unit
Heater
Includes:
• Field Sampling Box
• 13" x 7" x 28" Heated and Cooled
• Pump-Timer System, Single Channel
with Mass Flow Controller
• Cyclone
• Annular Denuder
• Filter Pack
• 110Vor220V
Pump-Timer System
Figure 10. Annular Denuder system with cyclone in heated sampling case.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-55
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Frit Removal Tool,-
Stalnless Steel
Viton O-rlng
Impactor Support Pin
and Frit
Frit -
Frit Holder,
Stainless Steel
Filter Pack
Assembly, 47 mm
Air Flow
Coupler with
Built-in Seal Ring
Annular Denuder, Glass,
242 mm Length; Flow
Straightener Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder-lmpactor,
Glass, 242 mm Length,
Flow Straightener
Teflon® Coated
- Impactor Support Pin
Frit
Coupler with
Built-in Seal Ring
Elutriator, with
Accelerator Jet, Glass
Teflon® Coated
Glass Annular Denuder
with Inset Impactor Assembly
Shown in line-
Figure 11. Frit removal from pin.
Page 4.2-56
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
7
6
I 5
of
I 3
Q
H
HI O
-3 ^
1
0
THEORY OK
2.5micromDfA
CUT PONT
THEORY QUESTIONABLE
DIAMETER
••-- REYNOLDS NO.
-J 1 i
6 8 10 12 14 16 18 20
FLOW RATE, fiter/min
Figure 12. D^Q for acceleration jet (Figure 7A) and
Teflon®-coated cyclone (Figure 7B).
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-57
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Cutaway View
Frit Removal Tool,
Stainless Steel
Coupler-Impactor
with Built-in
Teflon® Seat Support
Coupler-Impactor
Protection Cap
(OUT)
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightenor, Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler-Impactor with .Uiil.
Built-in Teflon® Seat Support
Elutriator, with Removable
Accelerator Jet, Aluminum,
Teflon® Coated
Aluminum and Teflon® Assembly
Shown in line
Figure 13. Side view impactor/coupler assembly with disc removal tools.
Page 4.2-58
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
* Method IO-4.2
Acidic/Basic Constituents
GENERAL
Project:
Site: —
Location:
Date: ;
Location of Sampler:
Sample Code;
Operator:
Mass Flow
Controller No.:
Lab Calibration Date:
Flow Rate Set Point:
Calibrated By:
Rotameter No.:
DGM No.:
EQUIPMENT
Sampler
Citric Acid Denuder No.:
Filter Assembly No.:
Time:
Flow Rate: _
Temperature:
Pressure:
SAMPLING DATA
Time
Stop
Avg. Flow Rate:
Leak Check (Before):
(After):—
Total Sample Vol.:
Flow Maintained Rate:
(±5%)
Time
Flow
- Rate (Q),
L/min
Ambient
Temperature,
• °c
". Barometric
Pressure,.
'mmHg
Relative
'Humidity,
% '
Comments
Figure 14. ADS field test data sheet.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-59
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Separation Mode
Data Mode
Buent
Reservoir
Pump
Sample
Injector
HPICAG4A
Guard Column
HPICAS4A
Anattica!
Column
Micromembrane
Suppressor
Column
Conductivity
Cell
1
Recorder
Electronic
Integrator
Computer
Figure 15. Major components of a commercially available ion chromatographer.
Page 4.2-60
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Denuder 3
(Na2C03)
0«nuder 2
(Na2C03)
a
"c.
Danuder 1
(Na CI)
J
2-°
Solvent HNOj
Front
4-°
t t
5.0 Retention Time
i (Minutes)
SO2
(SOI)
Figure 16. Chromatograms of denuder/filter extract performed by the ion chromatography.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-61
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Filter 2
(Nyfon)
t
tn
o
niter 1
{Teflon)
/v
2.0
Solvent
Front
4.0
} I
(NO,) (SOI)
6.0 Retention Time >•
(Minutes')
Figure 16 (Cont'd). Chromatograms of denuder/filter extract performed by the ion chromatography.
Page 4.2-62
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Wash Water
To Sampler
Heating
Bath
37°C
oonoo _ noonn. nonon nnnnn
Proportioning
Pump
Colorimeter
Wash Water
Air
Sample
EOTA
Phenolate
Nttroprusslde
Hypochlorlte
Water
Sampler
Figure 17. Technicon autoanalyzer flow diagram for ammonia analysis.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-63
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Determination of the Strong Acidity of
Atmospheric Fine-Particles (<2.5 /^m)
Name:
Date: _
LAB:_
Sample I.D.:
Location: —
Constituent
pH 7 Buffer
1
2
3
pH 4 Buffer
1
o
3
EA Solution
1
2
3
Working Standards
1A1
1A2
EA
1B1
1B2
EA
2A1
2A2
Temp.
EA
2B1
2B2
EA
3A1
3A2
EA
Temp.
3B1
3B2
EA
RUN NUMBER
1
:
;
2
3
4
•
5
6
'
•
1
Figure 18. pH Analytical Laboratory Log Form
Page 4.2-64
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
Constituent
4A1
4A2
EA
4B1
4B2
Temp.
EA
5A1
5A2
EA
5B1
5B2
EA
6A1
6A2
Temp.
EA
6B1
6B2
EA
EA
7A1
7A2
EA
7B1
7B2
Temp.
Sample Extracts
A
Al
B
Bl
C
Cl
D
Dl
E
El
EA
Temp.
EA Solution
1
2
3
pH4 Buffer
1
2
3
RUN NUMBER
1
2
3
4
5
6
7
Figure 18 (cont). pH Analytical Laboratory Log Form
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-65
-------
Method IO-4.2
Acidic/Basic Constituents
CUTAWAY VIEW
Chapter IO-4
Atmospheric Acidic
QUICK RELEASE
PLUG
FILTER PACK
FILTER INLET COMPONENT
COUPLER
(TYPICAL)
FLOW STRAIGHTNER
(37mm LONG)
COUPLER/IMPACTOR
ACCELERATION JET
ELUTRIATOR
AIR
Figure 19. Annular Denuder personal sampler.
Page 4.2-66
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring
Flow Straightener,
37 mm length
Coupler-lmpactor with
Built-in Teflon® Seat Support
Elutriator, with Accelerator Jet,
Glass, Teflon® Coated
Air Flow
Cutaway View
© © ©
© a ©
Figure 20. Annular Denuder system with parallel fine particle sampler.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-67
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EPA/625/R-96/010a.
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
SAMPLING AND ANALYSIS
FOR ATMOSPHERIC MERCURY
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
-------
EPA/625/R-96/010a.
Compendium of Methods
for the Determination of
Inorganic Compounds
in Ambient Air
Compendium Method IO-5
SAMPLING AND ANALYSIS
FOR VAPOR AND PARTICLE
PHASE MERCURY UTILIZING
COLD VAPOR ATOMIC
FLUORESCENCE SPECTROMETRY
(CVAFS)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1997
-------
Method IO-5
Acknowledgements
This Method is part of the Compendium of Methods for the Determination of Inorganic Compounds in
Ambient Air (EPA/625/R-96/060a), which was prepared under Contract No. 68-C3-0315, WA No. 2-10,
by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG), and
under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A. Manning, Center
for Environmental Research Information (CERI), and Frank F. McElroy, National Exposure Research
Laboratory (NERL), both in the EPA Office of Research and Development, were the project officers
responsible for overseeing the preparation of this method. Other support was provided by the following
members of the Compendia Workgroup:
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael F. Davis, U.S. EPA, Region 7, KC, KS
• Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
• Frank F. McElroy, U.S. EPA, NERL, RTP, NC
• William T. "Jerry" Winberry, Jr., MRI, Gary, NC
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in the
preparation and review of this methodology.
Author(s)
Gerald Keeler, University of Michigan, Ann Arbor, MI
Jim Barres, University of Michigan, Ann Arbor, MI
Peer Reviewers
Susan Kilmer, Michigan Department of Natural Resources, Lansing, MI
Eric Prestbo, Frontier GeoSciences, Seattle, WA
Anne M. Falke, Frontier GeoSciences, Seattle, WA
Jamie Brown, Supelco Inc., Bellefonte, PA
Alan Zaffird, International Technology Corporation, Cincinnati, OH
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has been
approved for publication as an EPA document. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
ll
-------
Method IO-5
Sampling and Analysis for Vapor and Particle Phase Mercury in
Ambient Air Utilizing Cold Vapor Atomic Fluorescence
Spectrometry (CVAFS)
TABLE OF CONTENTS
1. Scope 5.0-1
2. Applicable Documents 5.0-2
2.1 ASTM Documents 5.0-2
2.2 Other Documents 5.0-2
3. Method Summary 5.0-2
4. Significance 5.0-3
5. Definitions 5.0-4
5.1 Calibration 5.0-4
5.2 Calibration Standard 5.0-4
5.3 Laboratory Duplicates (LD1 and LD2) 5.0-4
5.4 Collocated Samples 5.0-4
5.5 Laboratory Procedural Blank (LRB) 5.0-4
5.6 Field Blank (FB) 5.0-4
5.7 Storage Blank (STB) 5.0-4
5.8 Mercury Standard Stock : 5.0-4
5.9 Precision 5.0-4
5.10 Accuracy 5.0-5
5.11 Detectability 5.0-5
5.12 Completeness 5.0-6
6. Contamination 5.0-6
7. Interferences 5.0-7
8. Safety, Restrictions, and Limitations 5.0-7
9. Facilities, Equipment, and Materials , 5.0-8
9.1 Facilities 5.0-8
9.2 Equipment 5.0-8
9.3 Materials 5.0-9
10. Preparation of Supplies, Adsorbents and Reagents 5.0-10
10.1 Acid Cleaning Procedure 5.0-10
10.2 Preparation of Gold-Coated Bead Traps 5.0-11
10.3 Preparation of Glass Fiber Filters 5.0-12
11. Collection of Ambient Air Samples 5.0-13
11.1 The Sampling Equipment 5.0-13
11.2 Collection of Vapor Phase Hg Samples 5.0-14
11.3 Collection of Particulate Hg Samples 5.0-16
11.4 Sample Storage 5.0-18
111
-------
TABLE OF CONTENTS (continued)
12. Analysis of Ambient Air Samples 5.0-18
12.1 Introduction 5.0-18
12.2 The Analytical System 5.0-19
12.3 Preparation of Reagents and Standards 5.0-19
12.4 Summary of Dual-amalgamation CVAFS Analytical Procedure 5.0-20
12.5 Analysis of Vapor Phase Hg Samples '. . 5.0-21
12.6 Analysis of Hg in Particulate Samples 5.0-22
13. Calculation of Mercury Concentrations in Ambient Air 5.0-25
13.1 Calculation of Vapor Phase Mercury Concentrations 5.0-25
13.2 Calculation of Particle-Phase Mercury Concentration 5.0-26
14. Quality Assurance/Quality Control (QA/QC) 5.0-28
14.1 Personnel Qualifications 5.0-28
14.2 QA/QC Samples 5.0-28
14.3 Precision and Accuracy . 5.0-29
14.4 Performance Criteria 5.0-29
15. References 5.0-30
IV
-------
Chapter IO-5
SAMPLING AND ANALYSIS FOR ATMOSPHERIC MERCURY
Method IO-5
SAMPLING AND ANALYSIS FOR VAPOR AND PARTICLE PHASE MERCURY IN
AMBIENT AIR UTILIZING COLD VAPOR ATOMIC FLUORESCENCE
SPECTROMETRY
1. Scope
1.1 Elemental mercury (Hg) and most of its derivatives are metabolic poisons which bioaccumulate in
aquatic food chains, ultimately reaching concentrations capable of causing neurological and reproductive
damage in terrestrial, as well as, aquatic organisms. Atmospheric Hg, although present only in trace
amounts, has been established as a significant source of Hg to aquatic environments.
1.2 The widespread use of Hg stems largely from its electrical conductivity, high specific gravity, and
fungicidal properties. The major sources of atmospheric Hg include combustion processes (incineration
of medical waste, municipal waste, sewage sludge, and hazardous waste, as well as burning of fossil
fuels), and manufacturing processes (iron and steel production, mining/smelting operations, cement
production, and coke production).-
1.3 Mercury compounds in the atmosphere exist in vapor and particulate forms, preferentially
partitioning into the vapor phase. Mercury species fall within two main categories: inorganic Hg
compounds and organic Hg compounds. The most common form of inorganic Hg is elemental Hg vapor.
Other inorganic Hg forms include mercuric chloride (HgCl2) and mercurous chloride (HgCl). The
organic compounds include those compounds in which Hg is covalently bonded to a carbon atom, as in
the case of methyl and dimethyl Hg.
1.4 Increased focus on atmospheric Hg pollution has resulted from the Clean Air Act Amendments of
1990. Mercury and its compounds are included in the Title III list of hazardous air pollutants and are
subject to standards established under Section 112, including maximum achievable control technology
(MACT). Also, Section 112(c)(6) of the 1990 Amendments mandates that Hg (among others) be subject
to standards that allow for the maximum degree of emission reduction. These standards are to be
promulgated no later than 10 years following the date of enactment. Additionally, within 5 years of the
date of enactment, a list of source categories that account for no less than 90 percent of Hg emissions
must be established.
1.5 As a result of the congressional mandates, the U.S. Environmental Protection Agency (EPA), state,
and local air pollution control agencies are under increased pressure to monitor the trace levels of
mercury in the ambient air. In addition, attempts to identify source/receptor relationships for these
substances and to develop control programs to regulate emissions have been initiated.
1.6 Previous methods used to collect vapor-phase Hg have relied on the rapid amalgamation between
Hg and gold or silver and in some cases the adsorption of Hg onto activated charcoal. Mercury was then
quantified using atomic absorption spectrometry or instrumental neutron activation analysis. These
methods generally required long-duration samples due to higher detection limits. Collection of vapor-
phase Hg was improved with the use of thin gold plating on sand packed in a trap to maximize the
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-1
-------
Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
surface area for collection (Fitzgerald and Gill, 1979). Improvements to analytical detection limits were
also made by employing cold-vapor atomic fluorescence spectrometry (Bloom and Fitzgerald, 1988).
1.7 Previous methods used to collect particulate Hg included trapping particles on quartz wool, which
was susceptible to artifact formation due to the adsorption of vapor-phase Hg. Quartz-wool plugs should
not be utilized for ambient particulate Hg sampling. Additional methods have included air filtration
through quartz fiber filters followed by acid extraction. The acid extraction techniques have, until
recently, been plagued by high Hg concentrations in the acid extraction solutions. Acid extraction can
be utilized as a suitable alternative to the microwave digestion technique in many applications where
precision requirements and detection limits are not limiting factors. Instrumental neutron activation
analysis has also been used to quantify mercury in particulates collected on Teflon® filters (Lamborg et
al., 1994). Microwave digestion has been demonstrated to give equivalent results to INAA on Urban
Particulate Standard Reference Materials.
1.8 This method describes procedures for collection and analysis of vapor phase and particulate Hg,
inorder to provide an EPA-approved, accessible sampling and analytical methodology, for uniform
monitoring of atmospheric mercury levels. These procedures have been used successfully in long-term
regional monitoring programs, as well as short-term intensive studies.
2. Applicable Documents
2.1 ASTM Documents
• D1356 Definition of Terms Related to Atmospheric Sampling and Analysis
• D1357 Practice for Planning the Sampling of the Ambient Atmosphere
2.2 Other Documents
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, EPA-600/9-76-005.
• U. S. Environmental Protection Agency, Quality Assurance Handbook for Air Pollution
Measurement Systems, EPA-600/4-77-027a.
* Scientific Publications of Ambient Air Studies (1-12).
3. Method Summary
[Note: This method for collection and analysis of mercury in ambient air take advantage of the
amalgamating property of mercury to a gold surface. In the following description reference is made to
gold-coated glass beads only. However, other media have been shown to give equivalent results. These
include, but are not limited to, gold-coated sand and a solid gold matrix.]
Page 5.0-2 Compendium of Methods for Inorganic Air Pollutants September 1996
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
3.1 The collection of mercury, from ambient air in the vapor and particulate phase, involves use of gold-
coated bead traps and quartz-fiber filters. The amalgamation process for vapor-phase mercury requires
a flow rate low enough to allow adsorption of the mercury in the air to the gold surface. The
significantly lower levels of particle-phase mercury on the other hand require a much higher flow rate
in order to collect sufficient particle mass for mercury determination. Therefore, separate sampling
systems are needed for the collection of mercury in the vapor and particle phases. Accurate flow
determinations through both sampling systems are critical in providing accurate Hg concentrations in air.
3.2 Vapor-phase Hg is collected using gold-coated glass bead traps. A Teflon® filter pack with a glass
fiber filter is placed in front of the traps to remove particulate material from the air being sampled. Air
is pulled through the vapor-phase sampling system using a mass-flow controlled vacuum pump at a
nominal flow rate of 0.3 Lpm.
3.3 Particle-phase Hg is collected using a glass-fiber filter in an open-faced Teflon® filter pack. Air is
pulled through the particulate sampling system using a vacuum pump at a nominal flow rate of 30 Lpm.
3.4 Determination of vapor- and particle-phase mercury in ambient air is accomplished using cold-vapor
atomic fluorescence spectrometry (CVAFS), more specifically, dual-amalgamation CVAFS. The amount
of vapor-phase mercury collected on a gold-coated bead trap is determined directly by CVAFS. The
sample trap is heated to release the collected mercury. The desorbed mercury is carried in an inert gas
stream (He or Ar) to a second gold-coated bead trap, the analytical trap. The mercury collected on the
analytical trap is then thermally desorbed and carried into the CVAFS analyzer. The resulting voltage
peak is integrated to produce peak area for the sample.
3.5 Determination of Hg in the particle phase requires acid extraction of the glass-fiber filters prior to
analysis. The sample filters are extracted in a nitric acid solution using microwave digestion to yield
"acid-extractable" particulate mercury. The extract is oxidized with BrCl to convert all forms of Hg to
Hg+2. NH2OH • HC1 and SnC12 are added to the extract to reduce the Hg+2 to volatile Hg°. The Hg°
is liberated from the extract by purging with an inert gas (N2) and collected on a gold-coated bead trap.
The amount of mercury collected on the trap is then determined using dual-amalgamation CVAFS.
4. Significance
4.1 The area of toxic air pollutants has been the subject of interest and concern for many years.
Recently the use of receptor models has resolved the elemental composition of atmospheric aerosol into
components related to emission sources. The assessment of human health impacts resulting in major
decisions on control actions by federal, state, and local governments are based on these data.
4.2 Elemental mercury and most compounds of mercury are protoplasmic poisons and, therefore, may
be lethal to all forms of living matter. In general, the organic mercury compounds are more toxic than
mercury vapor or the inorganic compounds. Even small amounts of mercury vapor or many mercury
compounds can produce mercury intoxication when inhaled by man. Acute mercury poisoning, which
can be fatal or cause permanent damage to the nervous system, has resulted from inhalation of from
1,200 to 8,500 fj.g/nr of mercury. The more common chronic poisoning (mercuralism) which also
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-3
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
affects the nervous system is an insidious form in which the patient may exhibit no well-defined
symptoms for months or sometimes years after exposure. The symptoms usually associated with
mercuralism are erethism 9exaggerated emotional response), gingivitis, and muscular tremors. A person
suffering from a mild case of mercury poisoning is usually unaware of the cause of the illness because
the symptoms are psychopathological in nature. Likewise, these ambiguous symptoms may result in an
incorrect diagnosis by a physician. In addition, animals and plants also exhibit a low tolerance to
mercury and its compounds.
5. Definitions
5.1 Calibration—the process of correlating instrument response to known standard units of measure by
regression analysis for the purpose of quantifying unknown samples based on observed instrument
readings.
5.2 Calibration Standard—a solution prepared from a certified mercury standard stock solution which
is used to calibrate instrument response to concentration.
5.3 Laboratory Duplicates (LD1 and LD2)—two aliquots of the same sample treated exactly the same
throughout preparation and analysis. Analyses of laboratory duplicates provide an indication of precision
associated with laboratory procedures.
5.4 Collocated Samples—samples collected from identical sampling systems placed in the field side-by-
side. Collocated samples are collected and analyzed identically and are used to determine overall
sampling and analytical precision.
5.5 Laboratory Procedural Blank (LRB)-a blank trap or filter treated exactly like a sample during
laboratory processing and analysis. The LRB is used to determine the amount of mercury added to
samples from the laboratory environment, reagents, equipment, and handling.
5.6 Field Blank (FB)--a field blank is treated exactly like an ambient sample during sample setup and
removal, but air is not drawn through the field blank. The FB is used to determine the limit of detection
and is site-specific.
5.7 Storage Blank (STB)~a blank created by storing either a gold-coated trap (vapor phase Hg), or a
filter (particle phase Hg) prior to analysis. The STB is used to determine the amount of mercury added
to samples during storage.
5.8 Mercury Standard Stock—a solution containing a certified concentration of mercury obtained from
a commercial source. This standard is used to prepare calibration standards.
5.9 Precision-a measure of the overall uncertainty in a particular measurement. Assessment of
precision requires the analysis of co-located samples.
Page 5.0-4 Compendium of Methods for Inorganic Air Pollutants September 1996
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
Precision is assessed using relative percent difference (RPD) between the collocated samples. The
average precision is reported as the average of the absolute value of the RPD.
(X.
RPD=
(
where:
Xj = concentration from the first collector
X2 = concentration from the second collector
5.10 Accuracy—a measure of the degree to which a measurement or computed value reflects the true
value of analyte present. Accuracy is assessed using standard reference materials (SRM) that have been
processed in a manner identical to the field samples.
Percent recovery, R, is used to assess accuracy from standard reference materials. Recovery is calculated
as:
R = (Measured Mass/Actual Mass) (100)
Certified reference materials for mercury in vapor and paniculate phases are not available, preventing
the assessment of accuracy in these media. Interlaboratory calibrations and sample exchanges are strongly
recommended.
5.11 Detectability—the detection limit is defined as the lowest value of a characteristic that a
measurement process, or a method-specific procedure can reliably discern. Three types of detection
limits include the instrument detection limit (IDL), the method detection limit (MDL), and the system
detection limit (SDL) defined as:
5.11.1 IDL. The smallest signal above background noise that an instrument can detect at a 99
percent confidence level. This value is quantified by direct injection of a spiked blank or other low level
sample (1-5 times the theoretical IDL) into the instrument. The sample does not undergo any sample
processing steps of the analytical methods and is used to provide the detection capabilities of the
instrument.
5.11.2 MDL. The minimum concentration of a substance measured and reported with 99 percent
confidence that the analyte concentration is greater than zero. This is determined from the analysis of
a sample in a given matrix containing the analyte. It is essential that all sample processing steps of the
analytical method be included in the determination of the MDL. In many cases the term "limit of
detection" (LOD) and MDL are used synonymously.
5.11.3 SDL. The minimum concentration of analyte measured in a sample that is detectable and
distinguishable from background noise of the entire data collection system. For Hg analyses, the SDL
is defined as either the mean or 3cr of the field or storage blanks, whichever value is largest.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-5
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
5.12 Completeness
The measure of the number of valid samples (meeting all QA requirements) obtained compared to the
number required to achieve the objectives of the study. Overall completeness is the number of valid
samples compared to the number planned. Laboratory completeness is the number of valid samples
obtained compared to the number analyzed. As with the other date quality attributes, completeness can
be controlled through adherence to analysis protocols in order to minimize contamination and sampling
errors.
Completeness is calculated as:
Completeness = v/(n)(100)
where:
v = number of samples judged valid
n = total number of measurements necessary to achieve project objectives
6. Contamination
6.1 Determination of Hg in atmospheric samples requires the ability to reliably detect very small
(picogram) amounts of mercury. The potential for contamination of ambient samples cannot be
overemphasized.
6.2 Much of the effort required to obtain good data is associated with maintaining the cleanest possible
conditions. Absolute adherence to clean techniques is essential throughout all phases of sample collection,
handling, and analysis.
6.2.1 Class 100 Clean Room-A key element in minimizing exposure of samples to potential
contaminants includes the use of a metal-free Class 100 clean room, which is supplied by HEPA filtered
air that has been passed through charcoal adsorbent to reduce vapor-phase Hg levels. Procedures
conducted in the clean room include the final stages of acid-cleaning for sample containers and supplies,
the extraction and analysis of particulate mercury samples, and storage of ultra-pure reagents.
6.2.2 Preparation of Sampling Supplies to Minimize Contamination-All containers with which the
sample comes into contact are acid-cleaned using the protocol described in this method. Supplies used
to manufacture gold-coated traps for vapor-phase Hg collection and filters used for collection of
particulate Hg are baked prior to use to volatilize Hg. Particle-free gloves are worn during all
manipulations of sample containers and supplies. All acid-cleaned supplies are stored double or triple-
bagged in resealable polyethylene. Containers for gold-coated bead traps and glass fiber filters prepared
for sampling are sealed with Teflon® tape and-bagged.
6.2.3 Minimizing Exposure During Sample ColIection-On-site preparation of filters and traps for
sampling is conducted by trained operators, outdoors to minimize potential particulate contributions.
Sample preparation can also be performed indoors if a Class 100 environment is utilized. During all
phases of sample set-up and removal, the operator wears particle-free gloves and stands downwind of the
sample in order to prevent contamination by shedding particles from clothing or breathing on samples.
Page 5.0-6 Compendium of Methods for Inorganic Air Pollutants September 1996
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Participate Mercury
After sampling, filters and traps are re-sealed in containers using Teflon® tape and bagged in resealable
polyethylene.
6.2.4 Minimizing Exposure During Sample Analysis-All reagents utilized in the analysis of samples
for Hg are highly purified to minimize Hg content. Suggested sources for low-Hg containing reagents
are supplied in this method. Blank levels in reagents are carefully monitored and reagents are replaced
periodically to maintain the lowest levels possible. Particle-free gloves are worn during all phases of
sample analysis. Blanks from extraction vessels for particulate Hg analysis are monitored and analytical
systems are maintained to insure consistent, low detection limits.
7. Interferences
7.1 Types of interferences and the procedures used to resolve them analytically vary depending on the
manufacturer and model of the analytical instrument used. There are no known positive interferences at
the wavelength of 253.7 nm used to excite and measure the fluorescence of Hg atoms using the CVAFS
procedure as described. Suspected negative interferences include polyaromatic hydrocarbons and water
vapor. Excessive water vapor will interfere by quenching the fluorescence signal as the Hg is liberated
from the gold trap. Free halogens also present a hazard to the gold traps resulting in a permanent
destruction of the trap resulting in low values or no response at all.
7.2 Ambient levels of dimethyl mercury, sulfur dioxide, hydrogen sulfide, and nitrogen dioxide do not
interfere with the collection or analysis of mercury vapor when utilizing silver wool techniques. These
compounds have not, however, been thoroughly tested utilizing the gold-coated bead trap technique. It
is the users responsibility to evaluate these compounds when using this methodology.
8. Safety, Restrictions, and Limitations
8.1 The toxicity or carcinogenicity of reagents used in this method have not been fully established. Each
chemical should be regarded as a potential health hazard and exposure to these compounds should be as
low as reasonably achievable. Each laboratory is responsible for maintaining a current awareness file
of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference
file of material data handling sheets should also be available to all personnel involved in the chemical
analysis.
8.2 Mercury compounds are highly toxic if inhaled, swallowed or absorbed through the skin.
Laboratory personnel should use caution and wear gloves when handling standards containing mercury.
8.3 The American Conference of Governmental Industrial Hygienists (ACGIH) has adopted the threshold
limit value (TLV) of 100 /*g/m3 for mercury vapor and inorganic compounds of mercury for an 8-hour
work day. In addition, the ACGIH has established a TLV for organic mercury of 10 pg/m3 for an
8-hour exposure.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-7
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
9. Facilities, Equipment, and Materials
9.1 Facilities
9.1.1 Clean room-Class 100 with down-flow, positive pressure ventilation, and separated dressing
room. Construction materials' must be nonmetallic, preferably plastic or varnished wood attached without
metal fasteners. Metal parts for which no substitute exists must be painted or otherwise sealed. Paints
and varnishes must not contain mercury fungicides or additives. Non-permanent plastic enclosures which
provide HEPA-filtered air at adequate flow rates can also, under many circumstances, provide an
adequate clean environment. These facilities will likely require more strict adherence to maintenance and
cleaning schedules.
9.1.1.1 Adhesive mats, for use at entry points and at work stations to remove dust and dirt from
clean-room boots.
9.1.1.2 Laminar-flow exhaust hood for clean reagent preparation and particulate Hg sample
processing and purging.
9.1.1.3 Clean room suit, hood, boots, and particle free gloves.
9.1.2 Fume hoods - for the acetone and hydrochloric acid soaking steps of the labware cleaning
system.
9.2 Equipment
[Note: Following is a list of the required facilities, equipment, supplies and reagents for sample
preparation, collection, and analysis. The make and model of some of the items are provided although
many of the materials are available from a variety of sources.]
9.2.1 Mercury Analysis System
[Note: Separate CVAFS analysis systems dedicated to measurement of mercury from vapor phase and
particulate samples is recommended since standardization procedures and analytical levels ofHg differ
for the t\vo media.]
9.2.1.1 Cold vapor atomic fluorescence spectrometer (CVAFS).
9.2.1.2 Power conditioner to reduce voltage fluctuations to CVAFS.
9.2.1.3 Integrator.
9.2.1.4 Variable voltage transformers (2) for thermally desorbing traps.
9.2.1:5 Mass flow controller for maintaining constant flow rate of carrier gas through CVAFS.
9.2.1.6 Four-channel programmable circuit controller.
9.2.1.7 Axial fans (2), 30 CFM, for cooling traps.
9.2.1.8 Nickel-chromium wire coils (2) for thermally desorbing gold traps.
9.2.2 Microwave Digestion System
9.2.2.1 Microwave oven equipped with temperature and pressure control system for extracting
particulate Hg samples.
9.2.2.2 Teflon® digestion vessels.
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
9.2.3 Muffle furnace-for baking glass fiber filters, quartz wool, and quartz tubes; capable of heating
to 700°C.
9.2.4 Pumps and Flow Measurement System
9.2.4.1 Sampling box (plastic enclosure, suitable for outdoor conditions, approximately 18x24").
9.2.4.2 Pole for sampling box (1-1/4" galvanized steel pip nominally 10 feet long).
9.2.4.3 Mounting hardware for sampling box.
9.2.4.4 Vinyl tape to cover steel pipe and mounting hardware.
9.2.4.5 Trap heater, custom made.
9.2.4.6 Variable voltage transfer for trap heater.
9.2.4.7 Vacuum pumps, oil-less, brush-less, capable of flow rates of 30 Lpm and 0.3 Lpm with
mass flow controller.
9.2.4.8 Rotameters, calibrated, capable of measuring 0.3 and 30 Lpm.
9.2.4.9 Dry test meter to measure total volume of air for particulate mercury sample.
9.2.5 Freezer for particulate Hg sample storage at -40°C.
9.3 Materials
9.3.1 Supplies for Cleaning Sampling and Analysis Equipment
9.3.1.1 Acetone, reagent grade.
9.3.1.2 Alkaline detergent.
9.3.1.3 Deionized water, high purity, 18.2 M Q cm"1.
9.3.1.4 Concentrated hydrochloric acid, trace metal grade.
9.3.1.5 Concentrated nitric acid, trace metal grade.
9.3.1.6 Water bath capable of maintaining temperature of 80°C.
9.3.1.7 Polyethylene or polypropylene tubs with lids, various sizes.
9.3.1.8 Polyethylene carboys, 20 L with spigot.
9.3.1.9 New, resealable polyethylene bags.
9.3.1.10 Particle-free wipes.
9.3.2 Supplies for Preparation of Gold-Coated Bead Traps
9.3.2.1 Sputter coater with 24 karat gold source.
9.3.2.2 Glass-blowing torch.
9.3.2.3 Tungsten rod for indenting quartz tubes.
9.3.2.4 Borosilicate glass beads (1 mm dia.), acid-washed.
9.3.2.5 Quartz tubes (10 cm length, 7 mm O.D., 5 mm I.D.).
9.3.2.6 Quartz wool.
9.3.2.7 Teflon® heat shrink tubing.
9.3.2.8 Teflon® end plugs, custom made.
9.3.2.9 Rigid plastic tubes with endcaps for gold trap storage.
9.3.2.10 Teflon® tape, V4".
9.3.2.11 Polyethylene tube bags and heat sealer.
9.3.3 Supplies for Preparation of Glass Fiber Filters
9.3.3.1 Glass fiber filters, 47 mm.
9.3.3.2 Ceramic crucible.
9.3.3.3 Teflon® jars for storage of filters.
9.3.3.4 Teflon® tape, 1 in.
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
9.3.4 Supplies for Sample Collection
9.3.4.1 Teflon® filter holders, 47 mm, closed inlet for vapor-phase Hg, open inlet for particle-
phase Hg.
9.3.4.2 Plastic petri dishes, 50 mm, for participate mercury sample filters.
9.3.4.3 Plastic/scalable refrigerator type containers.
9.3.4.4 Teflon® coated forceps.
9.3.4.5 Particle-free gloves.
9.3.4.6 Resealable polyethylene bags.
9.3.4.7 Teflon® tape, 1" and V4".
9.3.4.8 Teflon® tubing, K" O.D.
9.3.4.9 Latex tubing, 1/8" I.D.
9.3.4.10 Polyethylene tubing, 3/8" O.D.
9.3.4.11 Quick connectors.
9.3.4.12 Extension cords.
9.3.5 Supplies for Sample Analysis
9.3.5.1 Carrier gas, argon or helium, ultra-high purity (99.999%).
9.3.5.2 Purge gas, nitrogen, pre-purified (99.998%).
9.3.5.3 Gas tight syringe, 100 /iL.
9.3.5.4 Injection port.
9.3.5.5 Minnert valve and septa for injection port.
9.3.5.6 Glass impinger and bubblers, 30 mL.
9.3.5.7 Pipets, including 1000 /*L, 500 /*L, 250 pL, 100 /nL, and 50 AiL.
9.3.5.8 Glass or Teflon® tubes, Vfc" O.D., 6" long, for soda lime traps
9.3.5.9 Teflon® reducing unions (W to 1A"), for connecting soda lime traps to bubbler exhaust
and gold trap.
9.3.5.10 Concentrated nitric acid (HNC^), highest purity.
9.3.5.11 Concentrated hydrochloric acid (HC1), highest purity.
9.3.5.12 Potassium bromide (KBr).
9.3.5.13 Potassium bromate (KBrO3)
9.3.5.14 Hydroxylamine hydrochloride (NH2OH • HC1)
9.3.5.15 Stannous chloride dihydrate (SnCl2 • 2H2O).
9.3.5.16 1000 /tg/mL mercury standard, NIST traceable.
9.3.5.17 Elemental mercury, liquid, high purity.
9.3.5.18 Constant temperature (± 0.1 °C), circulating water bath.
9.3.5.19 Certified immersion thermometer.
10. Preparation of Supplies, Adsorbents and Reagents
10.1 Acid Cleaning Procedure
[Note: All Teflon® and polyethylene sample bottles, reagent bottles and analytical supplies which will
come into contact with the samples are cleaned using the following procedures.-]
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
[Note: The acids mentioned below may be reused many times. A large volume of each types of add may
be prepared and stored in dedicated polyethylene carboys. Add should be checked for contamination or
replaced regularly.]
10.1.1 Acetone Rinse-sampling and analytical supplies for acid-cleaning by first ringing with reagent
grade acetone in a fume hood.
10.1.2 Detergent Wash-supplies are then washed with a dilute Alconox detergent solution, rinsed
five times with cold tap water followed by three rinses with deionized water.
10.1.3 Heated Hydrochloric Acid Soak-bottles are filled with 3M (250 mL of high purity
concentrated HC1 in 750 mL of D.I. water) trace metal grade HC1 and soaked at 80°C in a water bath
in a fume hood for six hours, then cooled to room temperature, emptied and rinsed three times with
ASTM Type I water. Polyethylene or polypropylene tubs with lids are used to soak small items such as
the filter packs, quartz tubes, Teflon® endplugs, etc..
10.1.4 Short Nitric Acid Soak-bottles and polyethylene tubs of small items are filled with 0.56M
trace metal grade HNC^, soaked at room temperature for 72 hours, emptied, and rinsed three times with
ASTM Type I water.
10.1.5 Long Nitric Acid Soak-bottles and covered tubs with supplies are transferred to the Class 100
clean room, rinsed three times with ASTM Type I water, and filled with 0.56 M, HNO3 and soaked at
room temperature for 7 days. After the soaking period, the bottles & tubs are emptied and rinsed five
times with ASTM Type I water.
10.1.6 Drying Step-all sampling and analytical supplies are dried in the clean room or in a Class 100
acrylic drying cabinet and double or triple bagged before being stored.
10.1.7 Bulk Nitric Acid Soak-supplies that cannot be heated in the HC1 step are soaked in covered
tubs with separately prepared 0.56M HNO3 at room temperature for 7 days, rinsed and dried as described
above.
10.2 Preparation of Gold-Coated Bead Traps
[Note: The following sections detail the steps for construction of gold-coated bead traps for collection
of vapor-phase Hg infield studies. Depending upon the scope of the mercury sampling to be performed,
it may be cost-effective to purchase traps or trap-making supplies from a commercial source.]
10.2.1 Preparation of Gold-Coated Beads and Trap
10.2.1.1 Borosilicate glass beads (1 mm diameter) are coated with a gold plasma generated under
vacuum using a sputter coater. The thickness of the gold coating produced should be approximately
300 angstrom. The operating manual for the sputter coater should be consulted for the appropriate
settings to obtain this thickness.
10.2.1.2 Quartz tubes are indented using a glass-blowing torch. Three radial indentations are
made about 2.5 cm from one end of a 10 centimeter long tube.
10.2.1.3 All components of the gold bead traps are heated in a muffle furnace to remove any Hg
prior to assembling traps. The gold-coated beads are baked at 500°C for one hour, the quartz wool at
600°C for one hour, and the quartz tubes at 700°C for one hour.
10.2.1.4 Teflon® heat-shrink tubing (0.25 in. diameter after shrinking), is cut into 1.25 in. pieces
and acid cleaned with a bulk HNO3 soak (see Section 10.1.7).
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
10.2.2 Construction of Trap
10.2.2.1 A small amount of quartz wool is rolled into a ball and placed in the quartz tube so that
it rests on the indentations forming a short (-0.25 cm) plug. About 0.7 g of the gold-coated beads are
added to the quartz tube on top of the quartz wool. A second ball of quartz wool is placed in the quartz
tube so that it rests on top of the beads. Traps should be packed as tightly as possible without breaking
the quartz wool fibers. Three more radial indentations in the quartz tube are made just beyond the second
quartz wool plug.
[Note: Best results are obtained by maintaining the integrity of the quartz wool fibers when rolling and
compacting the wool into the quartz tube. Also, loosely packed traps may result in air flowing around
the beads and not contacting the gold surfaces.]
10.2.2.2 Teflon® heat-shrink tubing is attached to both ends of the trap so that about half of the
tubing extends from the trap. The Teflon® endplugs are inserted into the Teflon® heat-shrink tubing.
10.2.2.3 Plastic tubes are used as storage containers for each individual trap with endplugs.
10.2.2.4 Each trap is labeled with a unique number to identify and monitor the performance of
the trap.
10.2.3 Trap Conditioning and Testing
10.2.3.1 New traps are 'conditioned' prior to use by drawing air through the trap at 0.3 Lpm for
30 minutes and then 'blanked' by heating the trap to 500°C for five minutes while an inert gas (i.e., He)
flows through the trap at 0.3 Lpm. The conditioning procedure is performed twice prior to testing the
trap.
10.2.3.2 New traps are evaluated for their reproducibility in collecting vapor-phase Hg and for
their blank levels prior to use.
10.2.3.3 Traps to be used in vapor-phase Hg sample collection are prepared by blanking the trap,
Teflon®-taping the endplugs to the trap, placing the trap in the plastic storage tube, heat sealing the tube
in polyethylene, then placing two gold traps for a sample in a resealable polyethylene bag.
10.3 Preparation of Glass Fiber Filters
[Note: Glass fiber filters used for collection of particle-phase Hg samples must be heated prior to me
to release any Hgfrom the filter matrix.]
10.3.1 The glass fiber filters are placed in a clean crucible with a lid and heated in a muffle furnace
at 500 °C for one hour.
10.3.2 After cooling for one hour in the muffle furnace but still hot, the filters are transferred from
the crucible to an acid cleaned Teflon® jar (50 mm diameter) using acid cleaned Teflon® forceps. The
lid to the Teflon® jar is sealed with Teflon® tape, and the jar is triple-bagged and stored hi the clean room
until needed.
10.3.3 Twenty percent of each batch of glass fiber filters used for particle-phase Hg samples and
blanks are kept for preparation of standard addition filters used for CVAFS instrument calibration as
described in Section 12.6.3.
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Participate Mercury
11. Collection of Ambient Air Samples
[Note: A basic concern regarding sample collection is the potential for contamination. Absolute
adherence to clean sampling protocols is essential. This includes, but is not limited to: (1) all supplies
with which samples come into contact must be acid cleaned, (2) all sample containers must be handled
with panicle-free gloved hands at all times, (3) all sample containers must be bagged before and after
sample collection, and (4) the operator must stand downwind of the sample during all phases of sample
installation and removal.
In addition, all sample collection procedures (i.e. loading filters into filter packs) should be conducted
outdoors (in the case that a Class 100 laboratory is unavailable on-site). If atmospheric mercury
sampling is to be performed in locations that experience extreme weather conditions, additional measures
can be taken to provide a 'clean' environment indoors for sample handling. Small laminar-flow hoods
in site trailers have been used with good results for loading and unloading sample filters from filter packs.
This section describes the methods for collection of vapor and particle phase Hg samples. The
configuration of the sampling equipment is described first followed by the specific procedures for
collection of vapor and particle phase Hg, respectively. In the following, the term 'gold trap' is used to
refer to traps made from gold-coated beads, gold-coated sand and/or a solid gold matrix which have been
shown to produce equivalent results.]
11.1 The Sampling Equipment
11.1.1 The pumps used for collection of mercury samples in ambient air should be specially designed
for trace-level pollutant sampling. High efficiency oilless, brushless pumps should be used and protected
from weather (i.e., the pump housing should be well sealed from rain, insulated and heated during the
winter, and fan cooled during the summer).
11.1.2 A fiberglass enclosure is used as the 'sample box' to house the filter packs and gold traps
during sample collection (see Figure 1).
11.1.3 The box is mounted on a pole or tower at least 3 meters above ground level. Galvanized steel
provides sufficient strength to support the sample box in high winds and may be wrapped with vinyl tape
to prevent contamination from the metal surface.
11.1.4 Polyethylene tubing with quick connect couplings are used to connect the vacuum lines from
the pump to the sample box.
11.1.5 For particle-phase mercury, a dry test meter (DTM) is connected to the vacuum line between
the pump and the sample box for direct measurement of the volume of air sampled (in L).
11.1.6 Inside the sample box flexible latex tubing with quick connect couplings are used to connect
the vacuum lines to the filter packs for particle-phase Hg. For vapor-phase Hg a piece of Teflon® tubing
is attached to the end of the flexible latex tubing for connecting to the gold traps during sampling.
11.1.7 Moisture on gold surface interferes with the amalgamation of Hg. Therefore, condensation
during collection of vapor-phase Hg must be prevented. To prevent condensation in the gold traps during
sampling, a heat tube is used to keep the traps above ambient temperature. The heat tube is constructed
from heat tape wrapped around a metal tube, insulated and covered with heat-shrink electrical tubing and
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-13
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
electrical tape. The heat tube assembly is plugged into a variable voltage transformer to provide constant
low heat to warm the trap.
11.1.8 The 47 mm Teflon® filter packs used for collection of vapor- and particle phase Hg are an
assemblage of three main components—a threaded inlet, a filter support base with 1A inch tube ferrule
nut, and a clampdown nut to connect the inlet to the filter holder. For vapor-phase Hg a closed inlet
filter pack with approximately 4" of 1A inch Teflon® tubing is used to extend the air inlet several inches
from the bottom of the sample box. For particle phase Hg an open inlet filter pack is used that protrudes
several inches through the sample box during sampling and a plastic quick connect coupling is used for
connection of the outlet to the vacuum line.
11.1.9 Rotameters calibrated for 0.3 and 30 Lpm are used initially to set the flow rate for vapor and
particle-phase Hg respectively. To prevent potential contamination of the sample by the rotameter,
separate 'flow check' filter packs are attached to the rotameters for this procedure. The flow check filter
packs have closed inlets with quick connect couplings on the inlet tubing for connection to the rotameter.
11.1.10 A field test data sheet (FTDS) is used to record all field activities.
11.2 Collection of Vapor Phase Hg Samples
[Note: Collection of vapor-phase mercury in ambient air takes advantage of the amalgamating property
of mercury to a gold surface. The amalgamation process requires a low flow rate to allow adsorption
of the mercury in the air to the gold surface of the trap. A nominal flow rate of 0.3 Lpm is used to
collect vapor phase Hg onto gold traps. A mass flow controller is employed to ensure a constant flow
rate throughout the sampling period and the flow rate is checked both at the beginning and at the end
of the sampling period with a calibrated rotameter. The volume of air sampled is determined from the
average of the flow rate measurements and the sample duration. To minimize the potential for trap
problems (interferences and condensation) the volume of air sampled should be kept at the minimum
required to accurately quantify vapor-phase Hg. Checks of the flow rate also test for leaks and
obstructions in the vacuum lines.
Vapor phase Hg samples are collected using two gold traps in series as a quality control measure. The
outlet from the first trap ('A' or 'sample' trap) is connected to the inlet of th^second trap ('B' or 'back'
trap) using Teflon® tubing. Any breakthrough from the first trap is collected on the second trap. The
t\vo traps are attached to a Teflon® filter pack containing a glass fiber filter to prevent intrusion of
paniculate matter into the gold traps. Breakthrough can be minimized by limiting the sample volume
collected through the traps.]
11.2.1 Flow check procedure
11.2.1.1 The flow rate through the gold traps is set to 0.3 Lpm before each sample event using
a rotameter calibrated for 0.3 Lpm. To prevent potential contamination of the sample by the rotameter,
a separate flow check filter pack and gold trap are attached to the. rotameter for this procedure. The flow
check glass fiber filter should be replaced regularly but may be reused several times.
11.2.1.2 The sampling pump is allowed to warm up for at least 15 minutes prior to any flow
measurement and/or adjustment.
11.2.1.3 The flow check filter pack and gold trap are placed in the sampling box and the vacuum
line connected to the gold trap. The rotameter is connected to the inlet of the filter pack. After the
system has been allowed to stabilize, the flow rate is adjusted to 0.3 Lpm and is recorded on the FTDS.
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Chapter IO-5 Method IO-5.0
Mercury _ Vapor and Particulate Mercury
The rotameter is disconnected from the filter pack and the gold trap disconnected from the vacuum line.
The flow check filter pack and gold traps are removed from the sampling box.
11.2.2 Sample installation procedure
[Note: During all phases of sample set-up and removal, the operator stands downwind of the sample in
order to prevent contamination by shedding particles from clothing, etc. In addition, particle-free gloves
are worn when handling gold bead traps and prefllters.J
11.2.2.1 An acid cleaned 'sample' filter pack with closed inlet is loaded with a pre-fired glass
fiber filter for each new vapor phase Hg sample to be collected and placed in the sample box.
11.2.2.2 The gold traps are taken from their plastic storage tubes and the endplugs removed.
11.2.2.3 The 'A' trap is connected to the Teflon® tubing from the outlet of the filter pack. A
short piece of acid-cleaned Teflon® tubing is placed in the outlet of the 'A' trap. The 'B' trap is then
attached to the Teflon® tubing.
11.2.2.4 The heat tube assembly is positioned to cover the 'A' trap.
11.2.2.5 To begin the sample, the Teflon® tubing at the end of the vacuum line is attached to the
outlet of the 'B' trap.
11.2.2.6 Start the pump and record the following parameters on the Hg FTDS: data, sampling
location, time, ambient temperature, barometric pressure, relative humidity, mass flow control reading,
flow rate, rotameter reading (if applicable), and gold-trap number. A typical Hg FTDS is documented
in Figure 2.
11.2.2.7 Allow the sampler to operate for the desired time, periodically recording the variables
listed above. Check flow rate at the midpoint of the sampling interval if longer than 4 hours. At the end
of the sampling period, record the parameters listed in Section 11.2.2.6. If the flows at the beginning
and end of the sampling period differ by more than 10 percent, mark the gold-trap cartridge as suspect.
11.2.2.8 Calculate and record the average sample rate for the gold-trap cartridge according to the
following equation:
_ Q! + Q2 * ...QN
Va " N
where:
Qa = Average flow rate in L/minute.
Q!> Q2---QN = F'ow rates determined at beginning, end, and immediate points during sampling.
N = Number of points averaged.
11.2.2.9 Calculate and record the total volumetric flow for the gold-trap cartridge using the
following equation:
v -
m 1,000
where:
O
Vm = Total volume sampled (mj) at measured temperature and pressure.
T = Sampling time = T2 - Tj, minutes
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Method IO-5.0 Chapter IO-5
Vapor and Participate Mercury _ Mercury
T2 = Stop time.
TI — Start time.
11.2.2.10 The total volume (Vg) at standard conditions, 25 °C and 760 mmHg, is calculated from
the following equation:
298
760 273 + tA
where:
Vg = Total sample volume (m^) at standard conditions, 25°C and 760 mmHg.
P^ = Average barometric pressure, mmHg.
t^ = Average ambient temperature, °C.
11.2.3 Sample recovery procedure
[Note: Particle-free gloves are worn during this procedure.]
11.2.3.1 The gold-traps are removed from the sampling box and the endplugs are replaced. The
endplugs are sealed to the traps with Teflon® tape and the traps are returned to their respective plastic
tubes and capped.
11.2.3.2 Labels with unique sample identification numbers are affixed to each tube. The tubes
are sealed in polyethylene bags and returned to the laboratory for analysis.
11.2.3.3 The flow rate is checked after removal of the sample traps and filter pack using the
procedure previously described in Section 11.2.1. The flow rate and any deviations from the standard
operating procedures during removal of the sample must be recorded on the Hg FTDS.
11.2.3.4 The pump is turned off and the glass fiber prefilter is discarded. The Teflon® tubing
connector should be returned to the laboratory for cleaning.
11.3 Collection of Particulate Hg Samples
[Note: Since paniculate Hg occurs at ultra-trace levels in the atmosphere and Hg has a high vapor
pressure, the selection of sampling flow rate and duration must be carefully considered. It is typically
necessary to sample at a flow rate of 30 Lpm for 12-24 hours to collect enough paniculate Hg for
analysis. TJie volume of air sampled is measured directly using a calibrated dry test meter (DIM). In
addition, the flow rate is checked both at the beginning and at the end of the sampling period with a
calibrated rotameter to check for leaks or obstructions in the vacuum lines.]
11.3.1 Flow check procedure
11.3.1.1 The flow rate is checked before each sample event using a rotameter calibrated in the
range of 30 Lpm. To prevent potential contamination of the sample by the rotameter, a separate flow
check filter pack is attached to the rotameter for this procedure. The flow check glass fiber filter should
be replaced regularly but may be reused several times.
11.3.1.2 The sampling pump is allowed to warm up for at least 15 minutes prior to any flow
measurement and/or adjustment.
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Mercury Vapor and Particulate Mercury
11.3.1.3 The flow check filter pack is placed in the sampling box. The outlet is connected to the
vacuum line and the inlet to the rotameter. After the system has been allowed to stabilize, the flow rate
is adjusted to 30 Lpm and is recorded on the FTDS. The flow check filter pack is then disconnected
from the rotameter and vacuum line, and removed from the sampling box.
11.3.2 Sample installation procedure
[Note: During all phases of sample set-up and removal, the operator stands downwind of the sample in
order to prevent contamination by shedding particles from clothing, etc. In addition, particle-free gloves
are worn when handling gold bead traps and prefilters.]
11.3.2.1 An acid cleaned 'sample' filter pack with open cylinder inlet is loaded with a pre-baked
glass fiber filter with the 'fibrous side' up, touching only the edge of the filter with a pair of acid cleaned
Teflon® coated forceps. The filter pack is placed in the sample box.
11.3.2.2 To begin the sample, the vacuum line is connected to the outlet of the sample filter pack.
11.3.2.3 Start the pump and record the following parameters on the Hg Field Test Data Sheet
(FTDS): data, sampling location, time, ambient temperature, barometric pressure, relative humidity, dry
gas meter reading, flow rate, rotameter reading (if applicable), gold-trap number and dry gas meter serial
number. A typical Hg FTDS is documented in Figure 2.
11.3.2.4 Allow the sampler to operate for the desired time, periodically recording the variables
listed above. Check flow rate at the midpoint of the sampling interval if longer than 4 hours. At the end
of the sampling period, record the parameters listed in Section 11.3.2.3. If the flows at the beginning
and end of the sampling period differ by more than 10 percent, mark the filter cartridge as suspect.
11.3.2.5 Calculate and record the average sample rate for the filter cartridge according to the
following equation:
N
where:
Qa = Average flow rate in L/minute.
Qj, Q2-..Qjvj = Flow rates determined at beginning, end, and immediate points during sampling.
N = Number of points averaged.
11.3.2.6 Calculate and record the total volumetric flow for the gold-trap cartridge using the
following equation:
y _ CTXQa)
m 1,000
where:
Vm = Total volume sampled (nr) at measured temperature and pressure.
T = Sampling time = T2 - Tj, minutes
T2 = Stop time.
Tj = Start time.
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Method 10-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
11.3.2.7 The total volume (Vg) at standard conditions, 25°C and 760 mmHg, is calculated from
the following equation:
v -V x ?A s 298
m 760 273 - tA
where:
V = Total sample volume (m^) at standard conditions, 25°C and 760 mmHg.
p^ = Average barometric pressure (mmHg) during sampling.
tA = Average ambient temperature (°C) during sampling.
11.3.3 Sample recovery procedure
[Note: Particle-free gloves are worn during this procedure.]
11.3.3.1 The sample filter is removed from the filter pack and placed in an acid cleaned petri dish
using acid-cleaned Teflon®rcoated forceps, touching only the edge of the filter.
11.3.3.2 The petri dish is sealed with Teflon® tape and a label with a unique sample identification
number is affixed to the cover of the petri dish. The petri dish is double bagged and returned to the
laboratory for analysis.
11.3.3.3 The flow rate is checked after removal of the sample Hg traps using the procedure
previously described in Section 11.3.1. The flow rate and any deviations from the standard operating
procedures during removal of the sample must be recorded on the Hg FTDS.
11.4 Sample Storage
11.4.1 Vapor-phase Hg samples are stored at room temperature (away from heat sources) until
analyzed.
11.4.2 Particle-phase Hg filters are stored in a freezer at -40°C until analyzed.
12. Analysis of Ambient Air Samples
12.1 Introduction
12.1.1 This section describes the methods for analysis of vapor and particle phase Hg samples. Dual-
amalgamation cold vapor atomic fluorescence spectrometry (CVAFS) is used to determine the amount
of Hg collected for both types of samples.
12.1.2 The analytical system is described first followed by the specific procedures for analysis of
vapor and particle phase Hg, respectively.
[Note: In thefollo\ving, the term 'gold trap'is used to refer to traps made from gold-coated beads, gold-
coated sand and/or a solid gold matrix which have been shown to produce equivalent results.]
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
11.3.1.3 The flow check filter pack is placed in the sampling box. The outlet is connected to the
vacuum line and the inlet to the rotameter. After the system has been allowed to stabilize, the flow rate
is adjusted to 30 Lpm and is recorded on the FTDS. The flow check filter pack is then disconnected
from the rotameter and vacuum line, and removed from the sampling box.
11.3.2 Sample installation procedure
[Note: During all phases of sample set-up and removal, the operator stands downwind of the sample in
order to prevent contamination by shedding particles from clothing, etc. In addition, particle-free gloves
are worn when handling gold bead traps and prefilters.]
11.3.2.1 An acid cleaned 'sample' filter pack with open cylinder inlet is loaded with a pre-baked
glass fiber filter with the 'fibrous side' up, touching only the edge of the filter with a pair of acid cleaned
Teflon® coated forceps. The filter pack is placed in the sample box.
11.3.2.2 To begin the sample, the vacuum line is connected to the outlet of the sample filter pack.
11.3.2.3 Start the pump and record the following parameters on the Hg Field Test Data Sheet
(FTDS): data, sampling location, time, ambient temperature, barometric pressure, relative humidity, dry
gas meter reading, flow rate, rotameter reading (if applicable), gold-trap number and dry gas meter serial
number. A typical Hg FTDS is documented in Figure 2.
11.3.2.4 Allow the sampler to operate for the desired time, periodically recording the variables
listed above. Check flow rate at the midpoint of the sampling interval if longer than 4 hours. At the end
of the sampling period, record the parameters listed in Section 11.3.2.3. If the flows at the beginning
and end of the sampling period differ by more than 10 percent, mark the filter cartridge as suspect.
11.3.2.5 Calculate and record the average sample rate for the filter cartridge according to the
following equation:
a N
where:
Qa = Average flow rate in L/minute.
Qj, Q2...QN = Flow rates determined at beginning, end, and immediate points during sampling.
N = Number of points averaged.
11.3.2.6 Calculate and record the total volumetric flow for the gold-trap cartridge using the
following equation:
where:
v _
m 1,000
O
Vm = Total volume sampled (mj) at measured temperature and pressure.
T = Sampling time = T2 - Tj, minutes
T2 = Stop time.
Tj = Start time.
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
11.3.2.7 The total volume (Vs) at standard conditions, 25°C and 760 mmHg, is calculated from
the following equation:
y =Vmx^-x 298
8 m 760 273 + tA
where:
Vs = Total sample volume (m^) at standard conditions, 25°C and 760 mmHg.
p^ = Average barometric pressure (mmHg) during sampling.
t^ = Average ambient temperature (°C) during sampling.
11.3.3 Sample recovery procedure
[Note: Particle-free gloves are -worn during this procedure.]
11.3.3.1 The sample filter is removed from the filter pack and placed in an acid cleaned petri dish
using acid-cleaned Teflon®-coated forceps, touching only the edge of the filter.
11.3.3.2 The petri dish is sealed with Teflon® tape and a label with a unique sample identification
number is affixed to the cover of the petri dish. The petri dish is double bagged and returned to the
laboratory for analysis.
11.3.3.3 The flow rate is checked after removal of the sample Hg traps using the procedure
previously described in Section 11.3.1. The flow rate and any deviations from the standard operating
procedures during removal of the sample must be recorded on the Hg FTDS.
11.4 Sample Storage
11.4.1 Vapor-phase Hg samples are stored at room temperature (away from heat sources) until
analyzed.
11.4.2 Particle-phase Hg filters are stored in a freezer at -40°C until analyzed.
12. Analysis of Ambient Air Samples
12.1 Introduction
12.1.1 This section describes the methods for analysis of vapor and particle phase Hg samples. Dual-
amalgamation cold vapor atomic fluorescence spectrometry (CVAFS) is used to determine the amount
of Hg collected for both types of samples.
12.1.2 The analytical system is described first followed by the specific procedures for analysis of
vapor and particle phase Hg, respectively.
[Note: In thefollo\ving, the term 'gold trap' is used to refer to traps made from gold-coated beads, gold-
coated sand and/or a solid gold matrix which have been shown to produce equivalent results.]
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
12.2 The Analytical System
12.2.1 The analytical system consists of a pair of gold traps in series, a thermal desorption system,
a CVAFS mercury detector, an integrator to convert peak voltage to peak area, and an inert carrier gas
(He or Ar).
12.2.2 The dual-amalgamation technique requires two gold traps in series: a 'sample' trap and an
'analytical' trap. This technique has two main advantages: it virtually eliminates interferences due to
organics and C12 from the sample trap and provides greater analytical precision because the same
analytical trap is being used to introduce the Hg into the detector for all the samples.
12.2.3 The thermal desorption system includes a pair of nickel-chromium coils each with a variable
transformer to regulate the output, a pair of small axial fans to cool the coils and traps quickly, and a
programmable circuit controller to coordinate the trap heating and cooling cycles.
12.2.4 Power supplied to the CVAFS should be stabilized by a power conditioner to reduce line
voltage fluctuations. The instrument is left on continuously to stabilize the UV lamp and maintain
consistency from one day to the next. Operating manuals for the CVAFS instruments describe in detail
the operation and maintenance for the specific analyzer.
12.2.5 The carrier gas should be mass-flow controlled to produce a more consistent peak response.
Ultra-high purity gas should be used and a gold trap placed upstream of the sample and analytical traps
to remove any remaining traces of Hg in the gas.
12.2.6 The vapor phase Hg analytical system requires an injection port and gas-tight syringe (100 jtL)
to introduce Hg standards into the sample train.
12.2.6.1 A small amount (2-3 mL) of liquid metallic Hg in a closed 150 mL flask is sufficient to
generate Hg saturated air above the liquid surface for vapor-phase Hg analysis. The flask is immersed
in a constant temperature (+/-0.1 °C) circulating water bath. A certified immersion thermometer should
be used to monitor the temperature of the air above the mercury in the flask. The temperature of the air
in the flask must be maintained below room temperature otherwise, the Hg will condense on the walls
of the injection apparatus.
12.2.6.2 The gas-tight 100 /*L syringe should rest on top of the flask with the needle portion
protruding through a Minnert valve into the flask air. Hg saturated air from the flask should be drawn
up into the syringe and allowed to equilibrate.
12.2.6.3 An injection port with Minnert valve and Teflon-coated septum are used for injecting Hg
saturated air onto gold traps in the analytical system. The port is placed inline for the calibration process
and then removed.
12.2.6.4 Vapor phase analysis is done outside of the clean room.
12.2.7 The particle-phase Hg analytical system requires an aqueous purging system which consists
of: (i) an acid cleaned glass impinger and bubbler system (30 mL capacity) with Teflon® stopcock, (ii)
a soda lime trap to capture acid gases from the bubbling solution, (iii) gold traps for collection of
volatilized Hg from the extracts, and (iv) N2 carrier gas for the system.
12.3 Preparation of Reagents and Standards
12.3.1 Deionized water-Deionized water, with a resistivity of 18.2 MQ cm"1, is prepared using a
water purification system (e.g., Milli-Q) from a prepurified (reverse osmosis) water source. This purified
water conforms to the standards for ASTM Type I water.
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Method IO-S.O Chapter IO-5
Vapor and Participate Mercury Mercury
12.3.2 Hydrochloric acid-containing low concentrations of Hg are used to prepare BrCI and SnCl2
solutions. EM Science SupraPur® HC1 is recommended.
12.3.3 Bromine Monochloride-(BrCl) is made from high purity potassium bromide (EM Science)
and potassium bromate (Baker). The bromine salts (10.8 g of KBr and 15.2 g of KBrO3) are weighed
using acid cleaned weigh boats and spatulas. In the clean room laminar flow exhaust hood, an acid
cleaned magnetic stir bar is placed in a 1L glass bottle of concentrated, high purity HC1. The KBr is
added while stirring the acid with a magnetic stir plate, and allowed to dissolve completely (approx. 1
hour). The KBrC>3 is then added slowly while stirring. After all of the salts have been added, the
solution is allowed to mix until all visible particles have dissolved (1-2 hours). The solution should be
deep yellow in color. If there is no color (or very faint) then the solution should be remade because the
BrCI has undergone reduction and will not have sufficient strength to oxidize all mercury species to
Hg~*~ . The BrCI is stored at room temperature in the clean room exhaust fume hood.
[Caution: BrCI should always be prepared in an exhausting fume hood because hazardous chlorine (C12)
gas is produced.]
12.3A Hydroxylamine hydroch!oride-(NH2OH • HC1) solution is prepared by dissolving 75.0 g of
NH2OH • HC1 (EM Science) in ASTM Type I water in an acid cleaned 250 mL volumetric flask. The
solution is stored in an opaque Teflon® bottle and refrigerated when not being used.
12.3.5 Stannous chloride-(SnCI2) solution is prepared by placing 200.0 g of SnCl2 • 2H2O (Fluka)
in an acid cleaned 1000 mL volumetric flask. In the clean room laminar flow exhaust fume hood, 100
mL of concentrated, high purity HC1 is slowly added. After most of the SnCl2 has dissolved (it does not
dissolve completely), the solution is brought up to volume with ASTM Type I water. The SnCl2 solution
is stored in an acid cleaned, opaque Teflon® bottle and refrigerated when not being used.
12.3.6 Working mercury standard-solution used for CVAFS instrument calibration is prepared by
sequential dilution of a commercial primary standard of 1000 jug Hg/mL. A secondary standard with a
concentration of 1000 ng Hg/mL is made by adding 100 /*L of the primary standard and 5 mL of BrCI
(see Section 12.4.3) to a 100 mL volumetric flask, and diluting to the 100 mL total volume with ASTM
Type I water. The secondary standard solution is remade at least once per year. The working standard
has a concentration of 2 ng Hg/mL in 1 percent BrCI and is prepared by adding 200 fjiL of the secondary
standard and 1000 jtL of BrCI to a 100 mL volumetric flask and diluting to 100 mL total volume with
ASTM Type I water. All standard solutions are stored in the dark at 5°C.
12.3.7 Nitric acid-(HNC>3) extraction solution (10% HNOg, 1.6 M) is used for microwave digestion
of particulate Hg samples. In the clean room laminar-flow exhausting hood 100 mL of high purity
concentrated HNO3 (EM Science SupraPur®) is slowly added to 750 mL of ASTM Type I water in a
1000 mL volumetric flask. The solution is mixed, allowed to cool, and brought up to 1000 mL with
ASTM Type 1 water. The extraction solution is stored in an acid cleaned repipetting bottle in the clean
room exhaust hood.
12.4 Summary of Dual-amalgamation CVAFS Analytical Procedure
12.4.1 The analytical procedure for detection of mercury using CVAFS includes three main steps.
12.4.2 First, the sample trap is placed in the analytical system and heated to release the collected
mercury. The released mercury is entrained by the gas stream, carried into the analytical trap where it
is amalgamated to the gold surface. Second, the analytical trap is heated to release the mercury which
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
then flows into the CVAFS detector cell. Third, the mercury in the detector cell absorbs UV light and
the resulting fluorescence is converted to a voltage proportional to the amount of Hg detected by a
photomultiplier tube.
12.4.3 An integrator then converts the voltage response to peak area.
12.5 Analysis of Vapor Phase Hg Samples
12.5.1 Injection system calibration
12.5.1.1 The injection system is conditioned before each day of analysis to ensure precise and
reproducible results. The process includes the following steps: (i) condition the syringe by flushing it
three times with Hg saturated air, filling it to capacity, and allowing it to equilibrate for 15 minutes, (ii)
place a new septum in the injection port and condition them both with multiple injections of Hg saturated
air before initiating calibration.
12.5.1.2 The flask should be periodically flushed (approx. once per month) with pre-filtered No
gas in order to displace any oxygen which may oxidize the surface of the liquid mercury and prevent
volatilization. Also, the Minnert valve for the syringe on the flask should be above the level of the water
in the water bath. If water gets into the flask, it should be purged as described above.
12.5.2 CVAFS instrument calibration
12.5.2.1 A calibration curve, generated by injection of different volumes of Hg saturated air onto
a gold trap, must be performed before each analysis. The amounts of Hg injected for the calibration
curve should be tailored to the expected value of the samples to be analyzed. Table 1 shows an example
calibration curve for 24 hour vapor-phase Hg samples consisting of five different amounts of Hg injected:
0, 0.2, 0.4, 0.8 and 1.6 ng of Hg.
12.5.2.2 To generate standard injections for the calibration curve, the conditioned injection port
is placed in the analytical train in front of the gold trap to be used for generating the standard curve
(called the "standard trap"). A specified volume of Hg saturated air is withdrawn from the flask using
the gas tight syringe and injected onto the blanked standard trap through the injection port valve. After
the injection the syringe is returned to the flask and filled to capacity until the next injection. The
temperature of the air in the flask is recorded for each injection to calculate the actual amount of Hg
injected.
12.5.2.3 A calibration curve is performed beginning with a zero point (0 pL) and continuing in
ascending order to the highest amount. The zero point of the calibration curve is generated in the same
manner described above except that no Hg saturated air is injected into the port. The amount of Hg
emitted from the needle tip and the injection apparatus and adsorbed onto the gold trap is called the zero
point (typically between 1-5 pg Hg).
12.5.2.4 The response for each standard injection is obtained by dual-amalgamation CVAFS
described in Section 12.2.
12.5.2.5 At any given temperature the vapor density of Hg can be calculated using the Ideal Gas
Law and the saturation vapor pressure of Hg. A table of vapor densities versus temperature is used to
determine the amount of Hg injected for the volume of each standard injection. Table 1 illustrates the
amount of Hg delivered during a typical injection procedure used to generate a standard curve at a flask
temperature of 16.6°C.
12.5.2.6 The slope of the calibration curve is calculated using linear regression. The 0 jiL
injection response is subtracted from each of the points on the curve. The CVAFS analytical system is
linear and the coefficient of determination (r2) should be 0.999 or better and each of the points on the
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Method 10-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
curve should be predicted by the slope within 5 percent of their actual value. If these criteria are not
met, the specific points that are errant should be repeated and the linear regression recalculated.
12.5.2.7 The injection port and standard trap are removed from the analytical train after
calibration.
12.5.3 Sample Analysis
12.5.3.1 After a satisfactory calibration curve for the CVAFS is obtained, sample traps are
analyzed by dual amalgamation CVAFS as described in Section 12.2.
12.5.3.2 Control standards should be analyzed at regular intervals during the analysis of samples
to detect any drift in the response or change in sensitivity of the CVAFS instrument. Control standards
are generated in the same manner as the calibration standards described above. The volume of Hg
saturated air injected for a control standard should be representative of the Hg concentration of the
samples being analyzed.
12.5.3.3 The predicted value of the control standards should be within 5 % of the calibration curve
before continuing to analyze samples. If subsequent control standards also deviate by more than 5% from
the calibration curve, it is likely that the analyzer sensitivity has changed and a second calibration curve
should be generated. Sample analysis should only continue after recalibration has met the criteria outlined
in 12.5.2.6.
12.6 Analysis of Hg in Particulate Samples
12.6.1 Microwave Digestion System
12.6.1.1 The use of microwave digestion to extract samples for analysis allows rapid heating and
elevated pressures for shorter preparation time in a safer and more consistent manner compared to
traditional procedures.
12.6.1.2 The microwave digestion system must use Teflon® vessels and be capable of monitoring
and controlling pressure and temperature inside the vessels.
12.6.1.3 The microwave should be programmable for the target pressure and temperature, and
for maintaining them for a specified time. The operating manual for the microwave digester should be"
consulted for programming, safety and maintenance of this equipment.
12.6.2 Preparation of Standard Addition and Sample Filters for Extraction
[Note: All preparation of filters for particulate Hg analysis must be performed in a Class 100 dean
room. Filters are removed from storage in a -40°C freezer and allowed to equilibrate to room
temperature in the clean room. Acid-cleaned Teflon® microwave vessels and Teflon^-coated forceps are
needed for the filter preparation. Calibration standards using filter media are prepared at the same time
as the sample filters to be analyzed. The microwave vessels should be labeled with the appropriate
identifier for the contents of each vessel.]
12.6.2.1 Glass fiber filters heated and stored with the sample filters as described in Section 10.3
are used as standard addition filters for calibration of the CVAFS instrument. In the clean room, the
standard filters are placed into acid cleaned microwave vessels using acid cleaned Teflon®-coated forceps.
The filters are spiked with appropriate volumes of the 2 ng/mL Hg working standard to generate a
calibration curve. Table 2 shows the volume of Hg standard added to the filters in the microwave vessels
to produce a typical calibration curve for 24 hour particulate Hg samples. The Hg working standard
solution is pipetted directly onto the filter and absorbed by the filter.
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Chapter IO-5 Method IO-5.0
Mercury ^ Vapor and Particulate Mercury
12.6.2.2 All sample filters to be analyzed should be prepared at the same time and handled
identically according to the following procedures. Each petri dish containing a sample filter is removed
from the sealed polyethylene bag and the Teflon® tape around the dish removed and discarded. The filter
is removed from the petri dish using acid cleaned Tefion®-coated forceps touching only the edge of the
filter to avoid the center area with the collected paniculate matter. The filter is carefully folded into
quarters using two pairs of forceps and placed into the appropriately labeled vessel. The forceps are
cleaned after touching each sample filter by rinsing the tips in acid cleaned glass beakers of 10% HNO3
extraction solution and ASTM Type I water.
12.6.3 Filter Extraction using Microwave Digestion
[Note: The prepared standard and sample filters are handled identically using the following microwave
extraction procedure.]
12.6.3.1 In the clean room exhaust hood, the extraction solution (10% HNO3, 1.6 M) should be
prepared as described in Section 12.3. A calibrated repippetor is used to dispense 20 mL of extraction
solution into each vessel.
12.6.3.2 Each vessel should be weighed both prior to and following the microwave digestion to
ensure no loss of sample extract during the procedure.
12.6.3.3 The prepared vessels can then be removed from the clean room and placed in the
microwave oven for digestion. The pressure and temperature monitoring sensors should be appropriately
attached and the control program initiated. Optimal results for digestion of glass fiber filters for mercury
determination have been obtained by heating the samples at 160°C and 70 psi for 20 minutes.
12.6.3.4 After the microwave digestion procedure is complete, the vessels should be allowed to
cool until the pressure inside the control vessel is about 1-2 psi. then removed from the microwave and
returned to the clean room.
12.6.4 Oxidation of Digested Filters
12.6A.I In the clean room exhaust hood, the vessels are opened carefully and 0.5 mL of BrCl
(see Section 12.3.3) is added to the extract in each vessel to oxidize all of the mercury in solution to
Hg2+.
12.6.4.2 The capped vessels are gently swirled to mix the vessel contents and allowed to react for
a least 1 hour.
12.6.5 Aqueous Purging System
[Note: In the clean room exhaust hood an aqueous purging system is used to volatilize Hg ° from the filter
extraction solution onto gold traps for quantification by CVAFS. The flow rate of the carrier gas through
the purging system should be maintained at 0.5 Lpm.J
12.6.5.1 A soda lime trap is made from an acid cleaned borosilicate glass tube (15 cm long, 15
mm outer diameter) or from Teflon® tubing of similar dimensions. Acid cleaned Teflon® tubing and
compression fittings are used to attach the trap to the impinger exhaust.
12.6.5.2 Before beginning analysis the tube is packed with high purity grade soda lime using a
small amount of glass wool (1/2") as endplugs. The soda lime trap is then conditioned by purging 20
mL of a 5% HC1 solution (0.3 M) for 30 minutes.
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Method 10-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
12.6.5.3 Purging solution is prepared by adding 1 mL SnCl2 (Section 12.3.5) to 20 mL of ASTM
Type I water in a bubbler and purging for 15 minutes to remove any Hg in the solution or purging
system.
12.6.6 Volatilization and Recapture Procedure
[Note: Tlie follo\ving volatiliztion and recapture procedure is used to liberate Hg °from the oxidized filter
extracts and collect it on gold traps for quantification by CVAFS.J
12.6.6.1 A 5 mL aliquot of the oxidized filter extract is pipetted from the Teflon® vessel into 20
mL of the bubbling solution prepared above.
12.6.6.2 To reduce the halogens in the extract, 0.1 mL NH2OH-HC1 (see Section 12.3.4) is
pipetted into the bubbler. The bubbler is swirled briefly to mix the solution and allowed to react for
5 minutes.
12.6.6.3 A blanked gold trap is attached to the end of the soda lime trap connected to the impinger
for collection of mercury from the bubbled solution.
12.6.6.4 To reduce the oxidized mercury in solution to volatile Hg°, 0.5 mL SnCkj is pipetted
into the bubbler which is immediately attached to the impinger and purged onto the gold trap for
7 minutes.
12.6.7 CVAFS Instrument Calibration using Standard Addition Filters
12.6.7.1 A calibration curve, generated using the standard addition filter extracts, must be
performed before each analysis. A calibration curve is performed beginning with the reagent blank (no
Hg standard added to filter) and continuing in ascending order to the highest concentration standard.
12.6.7.2 The volatilization and recapture procedure described in Section 12.6.6 is used to collect
the Hg in solution for each standard addition filter onto gold traps. The amount of Hg volatilized from
the extracts is determined by analysis of the gold trap using dual-amalgamation CVAFS as described in
Section 12.4.
12.6.7.3 The concentration of Hg in the extraction solution for each of the standard addition filters
is determined from the amount of 2 ng/mL mercury standard added to the filter, the total volume of
reagents added, and the volume of solution analyzed. The actual amount of mercury in 5 mL of standard
filter extracts are as shown in Table 2.
12.6.7.4 The slope of the calibration curve is calculated using linear regression. The reagent
blank response is subtracted from each of the points on the curve. The CVAFS analytical system is linear
and the coefficient of determination (r2) should be 0.99 or better and each of the points on the curve
should be predicted by the slope within 10% of their actual value. If these criteria are not met, the
specific points that are errant should be repeated and the linear regression recalculated.
12.6.8 Sample Analysis
12.6.8.1 After a satisfactory calibration curve for the CVAFS is obtained using standard addition
filter extracts, Hg in each sample filter extract is volatilized and recaptured using the procedure described
in Section 12.6.2.
12.6.8.2 The gold traps are analyzed by dual amalgamation CVAFS as described in Section 12.4
to quantify the amount of Hg in the sample filter extract.
12.6.8.3 Control standards should be analyzed at regular intervals during the analysis of samples
to detect any drift in the response or change in sensitivity of the CVAFS instrument. Control standards
are generated in the same manner as the calibration standards described above. The standard addition
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Chapter IO-5 Method IO-5.0
Mercury ^ Vapor and Particulate Mercury
filter used for a control standard should be representative of the Hg concentration of the samples being
analyzed.
12.6.8.4 The control standards response should be within 10% of the calibration curve before
continuing to analyze samples. If subsequent control standards also deviate by more than 10% from the
calibration curve, it is likely that the analyzer sensitivity has changed and a second calibration curve
should be generated. Sample analysis should continue after recalibration.
13. Calculation of Mercury Concentrations in Ambient Air
13.1 Calculation of Vapor Phase Mercury Concentrations
13.1.1 Conversion of vapor phase mercury analysis results to ambient concentrations requires the
results from analysis (samples, blanks and calibration curve) and flow rate and duration data from field
logs. For example calculations see Section 13.1.2.
13.1.1.1 Vapor phase mercury concentrations in ambient air are reported in ng/m3.
13.1.1.2 The amount of mercury collected on a Au-coated bead sample trap (ng Hg) is calculated
from the integrator response for the sample [in Peak Area Units (PAU)] multiplied by the slope of the
calibration curve, which is in ng Hg/PAU.
13.1.1.3 The amount of mercury collected on a Au-coated bead sample trap is blank corrected by
subtracting the average amount of mercury collected on field blank traps. Field blanks are described in
Section 14.2.2.
13.1.1.4 Vapor phase mercury samples are typically collected using 2 Au-coated bead sample traps
in series (the exit from the first trap is connected to the inlet of the second trap). The total amount of
Hg collected for the sample is then calculated by simple addition of the blank corrected amounts of
mercury from the two sample traps.
13.1.1.5 The volume (m3) of air sampled is calculated by multiplying the flow rate through the
sample traps (in cnrVmin.) by the duration of the sample (min.) and converting the product from cm3
to m3.
13.1.1.6 The ambient vapor phase mercury concentration in ng Hg/m3 is calculated from the total
blank corrected ng of Hg for the sample traps divided by the cubic meters of air sampled.
13.1.2 Example Calculation of Ambient Vapor Phase Mercury Concentration
13.1.2.1 An example vapor phase mercury calibration curve is given in Table 3 and discussed in
Section 12.5.2.
13.1.2.2 Calculation of the ng of Hg recovered from two sample traps in series:
Amount of Hg Recovered = Integrator Response x Slope of Calibration Curve
7,135,900 PAU x 1.0585E-7 ng Hg/PAU = 0.755 ng Hg
236,183 PAU x 1.0585E-7 ng Hg/PAU = 0.025 ng Hg
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-25
-------
Method 10-5.0 Chapter IO-5
Vapor and Particulate Mercury _ __ _ Mercury
13.1.2.3 Calculation of the total ng of Hg for the sample:
Total Amount of Hg for sample = £ (Sample ng Hg - Average Field Blank ng Hg)
(0.755 ng Hg - 0.015 ng Hg) + (0.025 ng Hg - 0.015 ng Hg) = 0.750 ng Hg
13.1.2.4 Calculation of the volume of air sampled at a flow rate of 0.3 Lpm and a sample duration
of 24 hours, with average ambient temperature of 20°C and average barometric pressure of 750 mmHg:
Volume of Air Sampled =Flow Rate x Duration
0.3 Lpm x 24 hr. x 1,440 min./24 hr. x 10"3 m3/L = 0.432 m3
13.1.2.5 Correct total sample volume (m3) to standard conditions of 25°C and 760 mmHg:
PA 298
x
273
= 0.432 x 0.9868 x 0.9900
= 0.422 m3 at standard temperature and pressure.
13.1.2.6 Calculation of the vapor phase mercury concentration (ng Hg/m3) for an ambient air
sample at standard temperature and pressure:
Concentration = Total Amount of Hg for Sample / Standard Volume of Air Sampled
0.750 ng Hg / 0.422 m3 = 1.777 ng Hg/m3 at standard temperature and pressure.
13.2 Calculation of Particle-Phase Mercury Concentration
13.2.1 Conversion of particle-phase mercury analysis results to ambient concentrations requires the
results from analysis (samples, blanks and calibration curve) and the volume of air sampled from field
logs. 3
13.2.1.1 Particle-phase mercury concentrations in ambient air are reported in pg/m .
13.2.1.2 The amount of mercury detected for the aliquot of sample analyzed is calculated from
the integrator response [in Peak Area Units (PAU)] for the sample and the reagent blank. The difference
between the sample and reagent blank integrator response is multiplied by the slope of the calibration
curve, which is in pg Hg/ (PAU).
Page 5.0-26 Compendium of Methods for Inorganic Air Pollutants September 1996
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Chapter IO-5 Method IO-5.0
Mercury ^ Vapor and Particulate Mercury
13.2.1.3 The amount of mercury collected on the entire sample filter is calculated by multiplying
the amount of mercury in the aliquot by the ratio of the total extraction volume of 20.5 mL (20 mL of
extraction solution and 0.5 mL of BrCl) to the volume of the aliquot analyzed (5 mL).
13.2.1.4 The volume (m3) of air drawn through the sample filter is calculated from the difference
between the "on" and "off" readings for the Dry Test Meter (DTM) used to measure sample volume and
adjusted by the calibration curve for the DTM display.
13.2.1.5 The particle-phase mercury concentration in pg/m3 is calculated from the amount of
mercury collected on the filter divided by the cubic meters of air sampled.
13.2.2 Example Calculation of Ambient Particle-Phase Mercury Concentration
13.2.2.1 An example particle-phase mercury calibration curve is displayed in Table 4 and
discussed in Section 12.6.7.
13.2.2.2 Calculation of the pg of Hg detected for the aliquot analyzed:
Amount of Hg Detected for Aliquot =
(Sample - Reagent Blank Integrator Response) x (Slope of Calibration Curve)
(7,135,900 PAU - 168,320 PAU) x 9.1091E-5 pg Hg/PAU = 635 pg Hg in aliquot.
13.2.2.3 Calculation of the pg of Hg for the entire sample filter:
Amount of Hg for Filter = (Amount of Hg for Aliquot) x (Extraction Volume /Volume of Aliquot)
(635 pg Hg) x (20.5 mL) / (5 mL) = 2604 pg Hg for filter
13.2.2.4 Calculation of the volume of air sampled from the DTM readings with average ambient
temperature of 20 °C and average barometric pressure of 750 mmHg during sampling:
Volume of Air Sampled = ("Off' - "On" DTM readings) x Slope of DTM Display Calibration
(1075.6 m3 - 1031.3 m3) x 0.975 = 43.2 m3
13.2.2.5 Correct total sample volume (m3) to standard conditions of 25°C and 760 mmHg:
s m 760 273 + tA
= 43.2 m3 x ™ x 298
760 301
= 43.2 x 0.9868 x 0.9900
-i
= 42.2 m at standard temperature and pressure.
13.2.2.6 Calculation of the particle-phase mercury concentration (pg Hg/m3) for an ambient air
sample at standard temperature and pressure:
Concentration = Amount of Hg for Filter / Volume of Air Sampled
2604 pg Hg / 42.2 m3 = 61.706 pg Hg/m3
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-27
-------
Method IO-5.0 Chapter IO-5
Vapor and Participate Mercury Mercury
14. Quality Assurance/Qualify Control (QA/QC)
14.1 Personnel Qualifications
14.1.1 Field operators should be properly trained in the methods for ambient air sample collection
as described in Section 11.
14.1.2 Field operators should routinely collect field blanks and shipping blanks to ensure that clean
handling techniques are consistently employed.
14.1.3 Laboratory analysts should be properly trained in the procedures for analysis of ambient air
samples as described in Section 12.
14.2 QA/QC Samples
14.2.1 Laboratory procedural blanks (LPB) are used to monitor the degree of background
contamination introduced during the laboratory analysis procedures. For analysis of vapor and particle-
phase Hg this blank is equivalent- to the zero-point on the calibration curve and are analyzed before
beginning analysis of samples.
14.2.2 Field Blanks
14.2.2.1 Field blanks are performed to determine the level of sample contamination during all
phases of sample handling, including:
• Sample collection and handling in the field
• Shipment
• Storage
• Sample handling and analysis in the laboratory
14.2.2.2 Field blanks are performed using the same procedures as those described for collecting
samples in Section 11. A minimum frequency of one field blank collected and analyzed per 10 samples
is recommended for each sampling media. Field blank levels less than 2% of the average amount of
mercury collected for a sample can be obtained using the methods described.
14.2.2.3 Vapor phase mercury field blanks are performed by placing the filter pack and attached
gold bead trap in the sampling box as described for a sample, and left in the sample box for 2 minutes
without the vacuum line attached. The vapor phase mercury field blank is removed from the sampling
box as described for a sample and labeled appropriately.
14.2.2 A Particle-phase mercury field blanks are performed by loading a glass fiber filter into the
open-face filter pack as described for a sample. The filter pack is placed in the sampling box for 2
minutes without connecting it to the vacuum line. The particle-phase mercury field blank is removed
from the filter pack as described for a sample and labeled appropriately.
14.2.3 Collocated Samples
14.2.3.1 Collocated samples are used to assess sample variability attributable to:
» Sample collection and handling in the field
* Shipment
• Storage
• Sample handling and analysis in the laboratory
Page 5.0-28 Compendium of Methods for Inorganic Air Pollutants September 1996
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Chapter IO-5 Method IO-5.0
Mercury Vapor and Particulate Mercury
14.2.3.2 Collocated sampling for a minimum of 1 per 20 samples collected is recommended to
properly evaluate variability. Percent differences of less than 10% between collocated samples can be
achieved using the methods described.
14.2.3.3 To collect collocated samples in the field, dual sets of sampling equipment must be used
which are equivalent in all measurable ways.
14.2.4 Shipping Blanks
14.2.4.1 Shipping blanks are performed to determine the level of sample contamination during
shipment and storage of samples, and therefore are only required when supplies and samples are shipped
between a laboratory and a field site.
14.2.4.2 A minimum frequency of one shipping blank collected and analyzed per 10 samples is
recommended for each sampling media when samples are shipped to field sites.
14.2.4.3 Shipping blank levels less than 1 % of the average amount of mercury collected for a
sample can be obtained using the methods described.
14.2.4.4 For a vapor phase mercury shipping blank, a gold trap is sent to the field site and back
to the laboratory for analysis without ever being opened in the field.
14.2.4.5 Particle-phase mercury shipping blanks are performed by loading a glass fiber filter from
the Teflon® storage jar directly into a plastic petri dish. The packaged filter is then sent to the field site
and back to the laboratory for analysis, again without being opened.
14.3 Precision and Accuracy
14.3.1 Precision
14.3.1.1 Collocated samples can be used to assess the overall precision of the method (sampling
and analytical precision). Precision of less than 15% can be achieved for ambient vapor phase and
particle-phase mercury measurements using the methods described.
14.3.1.2 For particle-phase mercury, samples analyzed in duplicate can be used to assess analytical
precision. Analytical precision for the methods described should average less than 10%.
14.3.1.3 For vapor phase mercury, samples can not be analyzed in duplicate. Repeated injections
of vapor phase mercury standards can be used to assess the analytical precisioTwhich should average less
than 5% for the methods described.
14.3.2 Accuracy
14.3.2.1 Accuracy can be assessed using standard reference materials (SRM) that have been
analyzed in a manner identical to the field samples. However, SRMs do not currently exist for ambient
vapor and particle phase mercury.
14.3.2.2 Comparison with other methods of analysis (i.e. neutron activation) or inter-laboratory
comparisons can be used to assess accuracy.
14.4 Performance Criteria
A summary of typical data quality objectives for the determination of mercury concentrations by CVAFS
is illustrated in Table 5.
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-29
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Method IO-5.0 Chapter IO-5
Vapor and Particulate Mercury Mercury
IS. References
1. Bloom, N.S. and Fitzgerald, W.F., "Determination of Volatile Mercury Species at the Picogram
Level by Low-Temperature Gas Chromatography with Cold-Vapor Atomic Fluorescence Detection,"
Anal. Chim. Ada., 208:151, 1988.
2. Burke, J., Hoyer, M., Keeler, G., Scherbatskoy, T., "Wet Deposition of Mercury and Ambient
Mercury Concentrations at a Site in the Lake Champlain Basin," Water, Air, and Soil Pollution, 80:353-
362, 1995.
3. Dumarey, R., Dams, R., and Hoste, J., "Comparison of the Collection and Desorption Efficiency
of Activated Charcoal, Silver, and Gold for the Determination of Vapor phase Atmospheric Mercury,"
Anal. Chem., 57:2638-2643, 1985.
4. Dumarey, R., Temmerman, E., Dams, R. and Hoste, J., "The Accuracy of the Vapor-Injection
Calibration of Mercury by Amalgamation/Cold-Vapour Atomic Absorption Spectromery," Anal. Chim.
Acta., 170:337-340, 1985.
5. Dvonch, J.T., Vette, A.F., Keeler, G.J., Evans, G., and Stevens, R., "An Intensive Multi-Site Pilot
Study Investigating Atmospheric Mercury in Broward County, Florida," Water, Air, and Soil Pollution,
80:169-178, 1995.
6. Fitzgerald, W.F., and Gill, G.A., "Sub-Nanogram Determination of Mercury by Two-Stage Gold
Amalgamation and Gas Phase Detection Applied to Atmospheric Analysis,n Anal. Chem., 15:1714,1979.
7. Keeler, G., Glinsorn, G., and Pirrone, N. "Particulate Mercury in the Atmosphere: It's
Significance, Transport, Transformation and Sources" Water, Air, and Soil Pollution, 80:159-168, 1995.
8. Lamborg, C., Hoyer, M., Keeler, G., Olmez, I., and Huang, X. "Particle-Phase Mercury in the
Atmosphere: Collection/Analysis Method Development and Applications," in Mercury as a Global
Pollutant: Toward Integration and Synthesis, Watras, C. and Huckabee, J. Eds., Lewis Publishers, 1994.
9. Bloom, N.S., "Determination of Pricorgram Levels of Methylmercury by Aqueous Phase Ethylation,
Followed by Cryogenic Gas Chromatography with CFAS" Can. J. Fish Aq. ScL, 46:1131, 1989.
10. Bloom N.S., Prestbo E.M., Hall B. and EJ. von der Geest, "Determination of Total Gaseous Hg
in the Ambient Atmosphere by Collection on lodated Carbon, Hot Acid Digestion and CFAS" Water,
Air and Soil Pollut., 80:1315, 1995.
11. Vermette S., Lindberg S., and N.S. Bloom, "Field Tests for a Regional mercury Deposition
Network - Sampling Design and Preliminary Test Results," Atmos. Envion., 29-: 11, 1995.
Page 5.0-30 Compendium of Methods for Inorganic Air Pollutants September 1996
-------
Chapter IO-5 Method IO-5.0
Mercury ^^ Vapor and Particulate Mercury
12. Prestbo E.M., Liang L., Horvat M., and N.S. Bloom, Recent Advances in the Analytical Techniques
for the Quantification of Mercury and Mercury Compounds in Different Media, USEPA 600-R-92-105
(1992).
January 1997 Compendium of Methods for Inorganic Air Pollutants Page 5.0-31
-------
Method IO-5.0
Vapor and Particulate Mercury
Ghstptetf IO5
Mercury
TABLE 1. AMOUNT OF HG INJECTED FOR A TYPICAL
VAPOR PHASE CALIBRATION CURVE
Volume of Hg Saturated Air
Injected (/iL)
0
20
40
80
160
Amount of Hg Injected
(ng)
0
0.198
0.396
0.793
1,586
Note: Flask temperature = 16.6°C
Vapor density = 9,912 ng/cm3
1 cm3 = 1,000 pL
TABLE 2. AMOUNT OF HG IN 5 mL ALIQUOT
ANALYZED FOR A TYPICAL PARTICLE-PHASE
CALIBRATION CURVE
Volume of 2 ng/mL Hg
Standard Added (>L)
0
200
400
1,000
Amount of Hg in 5 mL
Aliquot Analyzed (pg)
0
97
191
465
Page 5.0-32
Compendium of Methods for Inorganic Air Pollutants September 1996
-------
Chapter IO-5
Mercury
Method IO-5.0
Vapor and Participate Mercury
TABLE 3. EXAMPLE VAPOR PHASE HG CALIBRATION CURVE
Hg Standard
Concentration,
, ngHg
0
0.198
0.396
0.793
1.586
Response, Peak
Area Units
(PAU)
41,193
1,866,300
3,729,482
7,451,226
15,083,592
Response-Zero
Point, Peak Area
Units (PAU)
0
1,825,107
3,688,289
7,410,033
15,042,399
Predicted Value,
ngHg
0
0.193
0.390
0.784
1.592
Percent
Difference from
Standard
-3
-2
-1
0
Slope = 1.0585E-7 ng Hg/PAU
r2 = 0.9999
TABLE 4. EXAMPLE PARTICLE-PHASE HG CALIBRATION CURVE
Hg Standard :;
Concentration,
•. '•'• ngHg •;•;:;"-
0
97
191
465
889
Response, Peak
Area Units
:(PAU)
168,320
1,144,900
2,158,900
5,204,200
9,993,400
Response-Zero
Point, Peak Area
Units (PAU)
0
976,580
1,990,580
5,035,880
9,825,080
Predicted Value,
ngHg
0
89
181
459
895
Percent
Difference from
Standard
0
-8
-5
-1
1
Slope = 9 J091E-5 pg Hg/PAU
r2 = 0.9995
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 5.0-33
-------
Method IO-5.0
Vapor and Particulate Mercury
Chapter IO-5
Mercury
TABLE 5. DATA QUALITY OBJECTIVES FOR MERCURY SAMPLING
AND ANALYSES
QA Criteria
Precision
Accuracy
Completeness
Detectability
Blanks
Calibration
QC Code
LD1/LD2
SRM
SDL
STB
LRB
CLM
LPC
Sample Type
Analytical
MIST certified
reference
solution
All samples
System dection
limit
Storage
Procedural
Multiple point
calibration
Performance
standard
(calibration
standards)
Frequency
15%
5%
Annually
10%
10%
Daily
Every
6 samples
Criteria
RPD <20%
80%0.99
Calculated value within
10% of true value
Control Action
Reanalyze/flag FLD
Reanalyze &/or
recalibrate until
criterial met
Flag BDL
Reanalyze/flag FSTB
Reanalyze/flag FLRB
Reoptimize
instrument. Repeat
calibration
Analyze 2nd control
and recalibrate if
necessary
Page 5.0-34
Compendium of Methods for Inorganic Air Pollutants
September 1996
-------
Chapter IO-5
Mercury
Method IO-5.0
Vapor and Participate Mercury
Secondary
gold-bead
trap
Heated
primary
gold-bead
trap
Pre-filter
Vapor-phase
Hg
Collection
System
Particle-phase
Hg
Collection
System
Polyurethane tubing
Black latextubing
• Open face filter pack for
particulate Hg (glass fiber filter)
Open face filter pack for metals
(Teflon® filter)
Variable transformer box
Figure 1. Ambient sampling system for collection of vapor and particle phase mercury.
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 5.0-35
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Method IO-5.0
Vapor and Particulate Mercury
Chapter IO-5
Mercury
Sampling Vapor and Particle Phase
Mercury in Ambient Air
Project.
Site
Location.
Date
Height above ground.
Operator
Barometric Pressure (mrnHg)
Ambient Temperature (°C)
Rain (Y/N)
Relative Humidity (%)
Before
After
CARTRIDGE INFORMATION
Vapor-phase System
Primary gold-bead "A" trap I.D. Number
Secondary gold-bead "B" trap I.D. Number
Heated primary trap temperature (°C)
Particle-phase System
Filter pack I.D. Number
FIELD DATA INFORMATION
Comments
Clock
Time
(24-hr)
Flow
Check
GO
Vapor-phase System
Mass Flow
Control
Setting
Flow Rate
(Qa>
(Lpm)
Particle-phase Sytem
Dry Gas
Reading
Flow Rate
(Qa>
(Lpm)
1
Total
Sample
Time,
minute
f
Total
Sample
Volume,
L
Figure 2. Field test data sheet (FTDS) for sampling vapor and particle phase mercury in ambient air.
Page 5.0-36
Compendium of Methods for Inorganic Air Pollutants September 1996
•&U.S. GOVERNMENT PRINTING OFFICE: 1997 - 549-001/60I5I
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Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
TABLE 2. ACCELERATOR JET DIAMETERS AND CORRESPONDING REYNOLDS
NUMBER (RE) FOR SELECTED FLOW RATES TO OBTAIN 2.5 MM AERODYNAMIC
D5Q SEPARATION
Flow rate,
L/min.
1.0
2.0
5.0
10.0
12.0
15.0
16.7
20.0
Jet diameter, mm
1.55
1.97
2.65
3.33
3.55
3.85
4.00
4.25
Reynolds number (RE)
900
1,400
2,700
4,200
4,700
5,500
6,000
6,600
January 1997
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-43
-------
Acidic/Basic Constituents
Atmospheric Acidic
TABLE 3. SUMMARY OF KEY PROBE SITING CRITERIA FOR ACID AEROSOL
MONITORING STATIONS
Factor
Criteria
Vertical spacing above ground
Representative of the breathing zone and avoiding effects
of obstruction, obstacles, and roadway traffic. Height of
probe intake above ground in general, 2-3 m above
ground and 2-15 m above ground hi the case of nearby
roadways.
About 1 m or more above the structure where the
sampler is located.
Horizontal spacing from
obstruction and obstacles
Minimum horizontal separation from obstructions such as
trees is > 20 m from the dripline and 10 m from the
dripline when the trees act as an obstruction.
Distance from sampler inlet to an obstacle such as a
building must be at least twice the height the obstacle
protrudes above the sampler.
If a sampler is located on a roof or other structures,
there must be a minimum of 2 m separation from walls,
parapets, penthouses, etc.
There must be sufficient separation between the sampler
and a furnace or incinerator flue. The separation
distance depends on the height and the nature of the
emissions involved.
Unrestricted airflow
Spacing from roads
Unrestricted airflow must exist in an arc of at least 270
degrees around the sampler, and the predominant wind
direction for the monitoring period must be included in
the 270 degree arc.
A sufficient separation must exist between the sampler
and nearby roadways to avoid the effect of dust re-
entrainment and vehicular emissions on the measured air
concentrations.
Sampler should be placed at a distance of 5-25 m from
the edge of the nearest traffic lane on the roadway
depending on the vertical placement of the sampler inlet
which could be 2-15 m above ground.
Page 4.2-44
Compendium of Methods for Inorganic Air Pollutants
January 1997
-------
Method IO-4.2
Acidic/Basic Constituents
Chapter IO-4
Atmospheric Acidic
Acceleration Jet
Elutriator
(a) Glass Assembly
Aluminum •
Elutriator •
Teflon
Acceleration Jet
Air
(b) Aluminum and Teflon Assembly
Acceleration Jet
Removal Tool
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Coupler with
Built-in Seal Ring TTTTT
Annular Oenuder, Stainless Steel,
Multl-Channol, 242 mm length.
Flow Straightenor, Teflon® Coated
IDE,
Coupler with {rrrff
Built-in Seal Ring Li"J
Annular Donudor, Stainless Steel,
Multi-Channel, 242 mm length.
Flow Straightenor, Teflon® Coated
Coupler-lmpactor with ,
Built-in Teflon® Seat Support
Elutriator, with Removable
Accelerator Jet, Aluminum,
Teflon® Coated
Aluminum and Teflon® Assembly
Shown in line
Figure 3. Available elutriator and acceleration jet assemblies.
Page 4.2-48 Compendium of Methods for Inorganic Air Pollutants January 1997
-------
Chapter IO-4
Atmospheric Acidic
Method IO-4.2
Acidic/Basic Constituents
To Pump and
Flow Controller
Filter Pack Assembly, 47 mm
Nylon
Teflon
Coupler with
Air Flow Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler with
Built-in Seal Ring
Annular Denuder, Stainless Steel,
Multi-Channel, 242 mm length,
Flow Straightener, Teflon® Coated
Coupler with
Built-in Seal Ring
NO,', H
NH,, S04
\
^-
m
!DO
1
CD
ID
}
-
TJ
1
o NH,
l~
+rf
O
1
J
/—*
g HCI, HN02,
«" HN03, S02
r i
Cyclone, Aluminum,
Teflon® Coated,
10 Lpm, 2.5 urn cut
January 1997
Fi-ure 6. Schematic view of Annular Denuder with cyclone
adaptor for removal of coarse particles.
.
Compendium of Methods for Inorganic Air Pollutants
Page 4.2-51
-------
Method IO-4.2
Acidic/Basic Constituents
End Cap
Air Flow
Stainless Steel
Sheath, Inner
Concentric Glass
Teflon-Coated
Flow Straightener
End Cap
Annular Denuder
1 mm Annular Space
Cross-Sectional View
Internal Schematic, of Annular Denude
Internal Surface
Teflon-Coated
Page 4.2-52
Figure 7. Internal schematic of Annular Denuder.
Compendium of Methods for Inorganic Air Pollutants
January 1997
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