United States
Environmental Protection
Agency
Office of Research and
Development
Washington, DC 20460
EPA/625/R-96/01 Ob
January 1999
&EPA
Compendium of
Methods for the
Determination of Toxic
Organic Compounds in
Ambient Air
Second Edition
-------
EPA/625/R-96/010b
January 1999
Compendium of Methods
for the
Determination of Toxic Organic
Compounds in Ambient Air
Second Edition
Center for Environmental Research Information
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
Printed on Recycled Paper
-------
DISCLAIMER
The information in this document has been compiled wholly or in part by the
United States Environmental Protection Agency under contract No. 68-C3-0315,
W.A. 3-10 to Eastern Research Group (ERG). The 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.
It is further noted that the test methods compiled here are working compilations
subject to on-going review and update. It is recommended that the reader refer to
the "AMTIC, Air Toxics" section of EPA's OAQPC Technology Transfer
Network web site at http://www.epa.gov/ttn/amtic/airtox.html to obtain the latest
updates, corrections, and/or comments to these test methods.
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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 organic pollutants in ambient air is often difficult, in part because of the
variety of organic substances of potential concern, the variety of potential techniques for sampling
and analysis, and the lack of standardized and documented methods. Consequently, NRMRL has
developed a Second Edition of the Compendium of Methods for the Determination of Toxic Organic
Compounds in Ambient Air to assist Federal, State, and local regulatory personnel in developing and
maintaining necessary expertise and up-to-date monitoring technology for characterizing organic
pollutants in the ambient air. The Compendium contains a set of 17 peer reviewed, standardized
methods for the determination of volatile, semi-volatile, and selected toxic organic pollutants in the
air. The 17 methods in the Second Edition have been compiled from the best elements of methods
developed or used by various research or monitoring organizations and of which EPA has experience
in use of the methodology during various field monitoring programs over the last several years. As
with the previous Compendia of 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 specifically offered with no endorsement for fitness or recommendation for any particular
application.
This publication has been prepared in support of NRMRL's goal to provide 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 Research Laboratory
111
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TABLE OF CONTENTS
Page
Method TO-1: Method for the Determination of Volatile Organic 1-1 through 1-2
Compounds (VOCs) in Ambient Air Using Tenax®
Adsorption and Gas Chromatography/Mass Spectrometry
(GC/MS)
Method TO-2: Method for the Determination of Volatile Organic 2-1 through 2-2
Compounds (VOCs) in Ambient Air by Carbon Molecular
Sieve Adsorption and Gas Chromatography/Mass
Spectrometry (GC/MS)
Method TO-3: Method for the Determination of Volatile Organic 3-1 through 3-2
Compounds in Ambient Air Using Cryogenic Preconcentration
Techniques and Gas Chromatography with Flame lonization
and Electron Capture Detection
Method TO-4A: Determination of Pesticides and Polychlorinated 4A-1 through 4A-44
Biphenyls in Ambient Air Using high Volume Polyurethane
Foam (PUF) Sampling Followed by Gas Chromato-
graphic/Multi-Deteetor Detection (GC/MD)
Method TO-5: Determination of Aldehydes and Ketones in Ambient 5-1 through 5-2
Air Using High Performance Liquid Chromatography (HPLC)
Method TO-6: Determination of Phosgene in Ambient Air Using High 6-1 through 6-2
Performance Liquid Chromatography (HPLC)
7-1 through 7-2
Method TO-7: Method for the Determination of
N-nitrosodimethylamine (NDMA) in Ambient Air Using Gas
Chromatography
Method TO-8: Method for the Determination of Phenol and 8-1 through 8-2
Methylphenols (Cresols) in Ambient Air Using High
Performance Liquid Chromatography
Method TO-9A: Determination of Polychlorinated, Polybrominated 9A-1 through 9A-90
And Brominated/Chlorinated Dibenzo-p-Dioxins And
Dibenzofurans In Ambient Air
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TABLE OF CONTENTS (continued)
Method TO-10A:
Method TO-11 A:
Method TO-12:
Method TO-13A:
Method TO-14A:
Method TO-15:
Method TO-16:
Method TO-17:
Determination Of Pesticides And Polychlorinated
Biphenyls In Ambient Air Using Low Volume Polyurethane
Foam (PUF) Sampling Followed By Gas
Chromatographic/Multi-Detector Detention (GC/MD)
Determination of Formaldehyde in Ambient Air Using ....
Adsorbent Cartridge Followed by High Performance Liquid
Chromatography (HPLC)
Method for the Determination of Non-methane Organic ,..
Compounds (NMOC) in Ambient Air Using Cryogenic
Preeoncentration and Direct Flame lonization Detection
(PDFID)
Determination of Polycyclic Aromatic Hydrocarbons
(PAHs) in Ambient Air Using Gas Chromatographie/Mass
Spectrometry (GC/MS)
Determination Of Volatile Organic Compounds (VOCs) ...
In Ambient Air Using Specially Prepared Canisters With
Subsequent Analysis By Gas Chromatography
Determination of Volatile Organic Compounds (VOCs) . . .
In Air Collected In Specially-Prepared Canisters And
Analyzed By Gas Chromatography Mass Spectrometry
(GC/MS)
Long-Path Open-Path Fourier Transform Infrared
Monitoring Of Atmospheric Gases
Determination of Volatile Organic Compounds in
Ambient Air Using Active Sampling Onto Sorbent Tubes
Page
10A-1 through 10A-32
11A-1 through 11A-51
12-1 through 12-2
13A-1 through 13A-78
14A-1 through 14A-86
15-1 through 15-62
16-1 through 16-40
17-1 through 17-49
VI
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Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-1
Method for the Determination of Volatile Organic Compounds
(VOCs) in Ambient Air Using Tenax® Adsorption and
Gas Chromatography/Mass Spectrometry (GC/MS)
Summary of Method
Compendium Method TO-1 involves drawing ambient air through a cartridge containing
-1-2 grams of Tenax®. Selected VOCs are trapped on the resin, while highly volatile organic
compounds and most inorganic atmospheric constituents pass through the cartridge. The cartridge
is then transferred to the laboratory and analyzed.
For analysis, the cartridge is placed in a heated chamber and purged with an inert gas, which
transfers the VOCs from the cartridge onto a cold trap and subsequently onto the front of the GC
column. The column is first held at low temperature (e.g., -70°C), then the column temperature is
uniformly increased (temperature programmed). The components eluting from the column are
identified and quantified by mass Spectrometry. Component identification is normally accomplished
using a library search routine on the basis of the GC retention time and mass spectral characteristics.
Less sophisticated detectors (e.g., electron capture or flame ionization) may be used for certain
applications, but their suitability for a given application must be verified by the user. Due to the
complexity of ambient air samples, only high resolution (i.e., capillary) GC techniques are considered
to be acceptable in this method.
Sources of Methodology
Method TO-1 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-1 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 1-1
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Method TO-1 VOCs
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.com/prodindex/acrobat/readstep.html
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 1-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-2
Method for the Determination of Volatile Organic Compounds (VOCs)
in Ambient Air by Carbon Molecular Sieve Adsorption and Gas
Chromatography/Mass Spectrometry (GC/MS)
Summary of Method
Compendium Method TO-2 is similar to Compendium Method TO-1 except the adsorbent
is a carbon molecular sieve (CMS) rather than Tenax®. The use of CMS allows some of the more
volatile organics (i.e., vinyl chloride) to be captured and analyzed.
Method TO-2 is suitable for the determination of certain nonpolar VOCs having boiling points
in the range of-15°C to 120°C. The analytical detection limit varies with the analyte. Detection
limits of 0.01 to 1 ppbv are achievable using a 20-liter sample.
Sampling involves drawing ambient air through a cartridge containing ~0.4 g of a CMS
adsorbent. Volatile organic compounds are captured on the adsorbent while major inorganic
atmospheric constituents pass through (or are only partially retained). After sampling, the cartridge
is returned to the laboratory for analysis. Prior to analysis the cartridge is purged with 2 to 3 liters
of pure, dry air (in the same direction as sample flow) to remove adsorbed moisture.
Similar to Compendium Method TO-1, the cartridge is heated to 350° to 400°C, under
helium purge, and the desorbed organic compounds are collected in a specially designed cryogenic
trap. The collected organics are then flash evaporated onto a capillary column GC/MS system (held
at -70°C). The individual components are identified and quantified during a temperature programmed
chromatographic run.
Similar to Compendium Method TO-1, contamination of the CMS, breakthrough, and antifact
formation are potential weaknesses of the methodology. Method TO-2 also involves a single analysis.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 2-1
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Sources of Methodology
Method TO-2 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-2 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader, Acrobat readers are
available from Adobe*, free of charge, at:
http://www.adobe.com/prodindex/acrobat/readstep.html
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 2-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-3
Method for the Determination of Volatile Organic Compounds in
Ambient Air Using Cryogenic Preconcentration Techniques and Gas
Chromatography with Flame ionization and Electron Capture Detection
Summary of Method
Compendium Method TO-3 involves the in situ collection of VOCs having boiling points in
the range of-10° to 200°C in a cryogenic trap constructed of copper tubing packed with glass beads.
The collection trap is submerged in either liquid nitrogen or liquid argon. Liquid argon is highly
recommended because of the safety hazard associated with liquid oxygen. With the sampling valve
in the fill position, an air sample is admitted into the trap by a volume measuring apparatus. In the
meantime, a GC column oven is cooled to a subambient temperature (-50°C) for sample analysis.
Once sample collection is completed, the value is switched so that the carrier gas sweeps the VOCs
in the trap onto the head of the cooled GC column. Simultaneously, the liquid cryogen is removed,
and the trap is heated to assist the sample transfer process. The GC column is temperature
programmed, and the component peaks eluting from the columns are identified and quantified using
flame ionization and/or electron capture detection. Alternative detectors (e.g., photoionization) can
be used as appropriate. An automated system incorporating these various operations as well as the
data processing Function is described in the method. Due to the complexity of ambient air samples,
high resolution (capillary column) GC techniques are recommended. However, when highly selective
detectors (such as the electron capture detector) are employed, packed column technology without
cryogenic temperature programming can be effectively used in some cases.
Sources of Methodology
Method TO-3 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-3 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 3-1
-------
Method TO-3 VOCs
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.com/prodindex/acrobat/readstep.html
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 3-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
EPA/625/R-9&010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-4A
Determination of Pesticides and
Polychlorinated Biphenyls in Ambient
Air Using High Volume Polyurethane
Foam (PUF) Sampling Followed by
Gas Chromatographic/Multi-Detector
Detection (GC/MD)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-4A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/010b), which was prepared under
Contract No. 68-C3-0315, WA No. 3-10, 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, John O. Burckle, and Scott R. Hedges, Center for Environmental Research Information
(CER1), and Frank F, McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of
Research and Development (ORD), were responsible for overseeing the preparation of this method. Additional
support was provided fay 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 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
Heidi Schultz, ERG, Lexington, MA
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Method TO-4 was originally published in April of 1984 as one of a series of peer reviewed methods in
"Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air," EPA 600/4-
89-018. In an effort to keep these methods consistent with current technology, Method TO-4 has been revised
and updated as Method TO-4A in this Compendium to incorporate new or improved sampling and analytical
technologies. In addition, this method incorporates ASTM Method D 4861-94, Standard Practice for
Sampling and Analysis of Pesticides and Potychlorinated Biphenyls in Air,
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)
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
* Ralph Riggin, Battelle Laboratories, Columbus, OH
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Peer Reviewers
Irene D. DeGraff, Supelco, Bellefonte, PA
• Ronald A. Hiles, Indiana University, Bloomington, IN
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Whitaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence during
the development of this manuscript has enabled it's production.
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.
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METHOD TO-4A
Determination of Pesticides and
Poly chlorinated Biphenyls in Ambient
Air Using High Volume Polyurethane
Foam (PUF) Sampling Followed by
Gas Chromatographic/Multi-Detector
Detection (GC/MD)
TABLE OF CONTENTS
Page
1. Scope 4A-1
2. Summary of Method 4A-1
3. Significance 4A-2
4. Applicable Documents 4A-2
4.1 ASTM Standards 4A-2
4,2 EPA Documents 4A-2
4.3 Other Documents 4A-3
5. Definitions 4A-3
6. Interferences 4A-4
7. Safety 4A-4
8. Apparatus 4A-5
8.1 Sampling 4A-5
8.2 Sample Clean-up and Concentration 4A-6
8.3 Sample Analysis 4A-7
9. Equipment and Materials 4A-7
9.1 Materials for Sample Collection 4A-7
9.2 Sample Extraction and Concentration 4A-8
9.3 GC/MS Sample Analysis 4A-8
10. Preparation of PUF Sampling Cartridge 4A-9
10.1 Summary of Method 4A-9
10,2 Preparation of Sampling Cartridge 4A-9
10.3 Procedure for Certification of PUF Cartridge Assembly 4A-10
11. Assembly, Calibration and Collection Using High-Volume Sampling System 4A-11
11.1 Description of Sampling Apparatus , 4A-11
11.2 Calibration of Sampling System 4A-11
in
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TABLE OF CONTENTS (continued)
Page
11.3 Sample Collection 4A-18
12. Sample Extraction Procedure 4A-20
12.1 Sample Extraction 4A-20
12.2 Sample Cleanup , 4A-21
13. Analytical Procedure 4A-22
13.1 Analysis Organochlorine Pesticides by Capillary Gas Chromatography
with Electron Capture Detector (GC/ECD) 4A-22
13.2 Analysis of Organophosphorus Pesticides by Capillary Gas
Chromatography with Flame Photometric or Nitrogen-Phosphorus
Detectors (GC/FPD/NPD) 4A-23
13.3 Analysis of Carbamate and Urea Pesticides by Capillary Gas
Chromatography with Nitrogen-Phosphorus Detector 4A-23
13.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by
High Performance Liquid Chromatography (HPLC) 4A-24
13,5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass
Spectrometry Detection (GC/MS) 4A-24
13.6 Sample Concentration 4A-25
14. Calculations 4A-25
14.1 Determination of Concentration 4A-25
14.2 Equations 4A-25
15. Performance Criteria and Quality Assurance 4A-27
15.1 Standard Operating Procedures (SOPs) 4A-28
15.2 Process, Field, and Solvent Blanks 4A-28
15.3 Method Precision and Bias 4A-28
15.4 Method Safety 4A-29
16. References 4A-29
IV
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METHOD TO-4A
Determination of Pesticides and Poly chlorinated Biphenyls in
Ambient Air Using High Volume Polyurethane Foam (PUF) Sampling
Followed by Gas Chromatographie/Multi-Deteetor
Detection (GC/MD)
1. Scope
1.1 This document describes a method for sampling and analysis of a variety of common pesticides and for
polychlorinated biphenyls (PCBs) in ambient air. The procedure is based on the adsorption of chemicals from
ambient air on polyurethane foam (PUF) using a high volume sampler.
1.2 The high volume PUF sampling procedure is applicable to multicomponent atmospheres containing
common pesticide concentrations from 0.001 to 50 /^g/m3 over 4- to 24-hour sampling periods. The limits of
detection will depend on the nature of the analyte and the length of the sampling period.
1.3 Specific compounds for which the method has been employed are listed in Table 1. The analytical
methodology described in Compendium Method TO-4A is currently employed by laboratories throughout the
U.S. The sampling methodology has been formulated to meet the needs of common pesticide and PCB
sampling in ambient air.
1.4 Compendium Method TO-4 was originally published in 1989 (1). Further updates of the sampling
protocol were published as part of Compendium Method TO-13 (2). The method was further modified for
indoor air application in 1990 (3). In an effort to keep the method consistent with current technology,
Compendium Method TO-4 has incorporated the sampling and analytical procedures in ASTM
Method D4861-94 (4) and is published here as Compendium Method TO-4A.
2. Summary of Method
2.1 A high-volume (~8 cfm) sampler is used to collect common pesticides and PCBs on a sorbent cartridge
containing PUF. Airborne particles may also be collected, but the sampling efficiency is not known (5). The
sampler is operated for 24-hours, after which the sorbent is returned to the laboratory for analysis.
2,2 Pesticides and PCBs are extracted from the sorbent cartridge with 10 percent diethyl ether in hexane and
determined by gas chromatography coupled with an electron capture detector (BCD), nitrogen-phosphorus
detector (NPD), flame photometric detector (FPD), Hall electrolytic conductivity detector (HECD), or a mass
spectrometer (MS). For common pesticides, high performance liquid chromatography (HPLC) coupled with
an ultraviolet (UV) detector or electrochemical detector may be preferable.
2.3 Interferences resulting from analytes having similar retention times during GC analysis are resolved by
improving the resolution or separation, such as by changing the chromatographic column or operating
parameters, or by fractionating the sample by column chromatography.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-1
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Method TO-4A Pesticides/PCBs
3. Significance
3.1 Pesticide usage and environmental distribution are common to rural and urban areas of the United States.
The application of pesticides can cause adverse health effects to humans by contaminating soil, water, air,
plants, and animal life. PCBs are less widely used, due to extensive restrictions placed on their manufacturer.
Ho\vc%rer, human exposure to PCBs continues to be a problem because of their presence in various electrical
products.
3.2 Many pesticides and PCBs exhibit bioaccumulative, chronic health effects; therefore, monitoring the
presence of these compounds in ambient air is of great importance.
3.3 The relatively low levels of such compounds in the environment requires the use of high volume sampling
techniques to acquire sufficient sample for analysis. However, the volatility of these compounds prevents
efficient collection on filter media. Consequently, Compendium Method TO-4A utilizes both a filter and a PUF
backup cartridge which provides for efficient collection of most common pesticides, PCBs, and many other
organics within the same volatility range.
3.4 Moreover, modifications to this method has been successfully applied to measurement of common
pesticides and PCBs in outdoor air (6), indoor air (3) and for personal respiratory exposure monitoring (3).
4. Applicable Documents
4.1 ASTM Standards
• D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis
• D4861-94 Standard Practice for Sampling and Analysis of Pesticides and Poly chlorinated Biphenyls
in Air
• E260 Recommended Practice for General Gas Chromatography Procedures
• E355 Practice for Gas Chromatography Terms and Relationships
• D3686 Practice for Sampling Atmospheres to Collect Organic Compound Vapors (Activated Charcoal
Tube Adsorption Method
• D3687 Practice for Analysis of Organic Compound Vapors Collected by the Activated Charcoal Tube
Adsorption
• D4185 Practice for Measurement of Metals in Workplace Atmosphere by Atomic Absorption
Spectrophotometry
4.2 EPA Documents
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-JO, Second Supplement, U. S. Environmental Protection Agency, EPA 600/4-89-018, March 1989.
• Manual of Analytical Methods for Determination of Pesticides in Humans and Environmental
Standards, U. S. Environmental Protection Agency, EPA 600/8-80-038, June 1980.
Page 4A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
* Compendium of Methods for the Determination of Air Pollutants in Indoor Air: Method IP-8, U. S.
Environmental Protection Agency, EPA 600/4-90-010, May 1990.
4.3 Other Documents
• Code of Federal Regulations, Title 40, Part 136, Method 604
5. Definitions
[Note: Definitions used in this document and in any user-prepared Standard operating procedures (SOPs)
should be consistent -with ASTMD1356, E260, and E355. All abbreviations and symbols are defined -within
this document at point of use.]
5.1 Sampling efficiency (SE)-ability of the sampling medium to trap analytes of interest. The percentage of
the analyte of interest collected and retained by the sampling medium when it is introduced as a vapor in air
or nitrogen into the air sampler and the sampler is operated under normal conditions for a period of time equal
to or greater than that required for the intended use is indicated by %SE.
5.2 Retention efficiency (RE)-ability of sampling medium to retain a compound added (spiked) to it in liquid
solution.
5.3 Retention time (RT)-time to elute a specific chemical from a chromatographic column, for a specific
carrier gas flow rate, measured from the time the chemical is injected into the gas stream until it appears at the
detector.
5.4 Relative retention time (RRT)-a rate of RTs for two chemicals for the same chromatographic column
and carrier gas flow rate, where the denominator represents a reference chemical.
5.5 Method detection limit (MDL)-the minimum concentration of a substance that can be measured and
reported with confidence and that the value is above zero.
5.6 Kuderna-Danish apparatus-the Kuderna-Danish (K-D) apparatus is a system for concentrating materials
dissolved in volatile solvents.
5.7 MS-SIM-the GC is coupled to a mass spectrometer where the instrument is programmed to acquire data
for only the target compounds and to disregard all others, thus operating in the select ion monitoring mode
(SIM). This is performed using SIM coupled to retention time discriminators. The SIM analysis procedure
provides quantitative results.
5.8 Sublimation-the direct passage of a substance from the solid state to the gaseous state and back into the
solid form without any time appearing in the liquid state. Also applied to the conversion of solid to vapor
without the later return to solid state, and to a conversion directly from the vapor phase to the solid state.
5.9 Surrogate standard-a chemically compound (not expected to occur in the environmental sample) which
is added to each sample, blank and matrix spiked sample before extraction and analysis. The recovery of the
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page4A-3
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Method TO-4A Pesticides/PCBs
surrogate standard is used to monitor unusual matrix effects, gross sample processing errors, etc. Surrogate
recovery is evaluated for acceptance by determining whether the measured concentration falls within acceptable
limits.
6. Interferences
6.1 Any gas or liquid chromatographic separation of complex mixtures of organic chemicals is subject to
serious interference problems due to coelution of two or more compounds. The use of capillary or microbore
columns with superior resolution or two or more columns of different polarity will frequently eliminate these
problems, In addition, selectivity may be further enhanced by use of a MS operated in the selected ion
monitoring (SIM) mode as the GC detector. In this mode, co-eluting compounds can often be determined.
6.2 The BCD responds to a wide variety of organic compounds. It is likely that such compounds will be
encountered as interferences during GC/ECD analysis. The NPD, FPD, and HECD detectors are element
specific, but are still subject to interferences. UV detectors for HPLC are nearly universal, and the
electrochemical detector may also respond to a variety of chemicals. Mass spectrometrie analyses will
generally provide positive identification of specific compounds.
6.3 PCBs and certain common pesticides (e.g., chlordane) are complex mixtures of individual compounds
which can cause difficulty in accurately quantifying a particular formulation in a multiple component mixture.
PCBs may interfere with the determination of pesticides.
6.4 Contamination of glassware and sampling apparatus with traces of pesticides or PCBs can be a major
source of error, particularly at lower analyte concentrations. Careful attention to cleaning and handling
procedures is required during all steps of sampling and analysis to minimize this source of error,
6.5 The general approaches listed below should be followed to minimize interferences.
6.5.1 Polar compounds, including certain pesticides (e.g., organophosphorus and carbamate classes) can
be removed by column chromatography on alumina. Alumina clean-up will permit analysis of most common
pesticides and PCBs (7).
6.5.2 PCBs may be separated from other common pesticides by column chromatography on silicic acid
(8,9).
6.5.3 Many pesticides can be fractionated into groups by column chromatography on Florisil (9).
7. Safety
7.1 The toxicity or carcinogencity of each reagent used in this method has not been precisely defined; however,
each chemical compound should be treated as a potential health hazard. From this viewpoint, exposure to these
chemicals must be reduced to the lowest possible level by whatever means available. The laboratory is
responsible for maintaining a current awareness file of Occupational Safety and Health Administration (OSHA)
regulations regarding the safe handling of the chemicals specified in this method. A reference file of material
data handling sheets should also be made available to all personnel involved in the chemical analysis.
Additional references to laboratory safety are available and have been identified for the analyst (10-12).
Page 4A-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
7.2 PCBs have been classified as a known or suspected, human or mammalian carcinogen. Many of the other
common pesticides have been classified as carcinogens. Care must be exercised when working with these
substances. This method does not purport to address all safety problems associated with its use. It is the
responsibility of whoever uses this method to consult and establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use. The user should be thoroughly familiar with
the chemical and physical properties of targeted substances.
7.3 Treat all target analytes as carcinogens. Neat compounds should be weighed in a glove box. Spent
samples and unused standards are toxic waste and should be disposed according to regulations. Regularly
check counter tops and equipment with "black light" for fluorescence as an indicator of contamination.
7.4 The collection efficiency for common pesticides and PCBs has been demonstrated to be greater than 95
percent for the sampling configuration described in the method (filter and backup adsorbent). Therefore, no
field recovery evaluation will occur as part of this procedure.
8. Apparatus
[Note: This method was developed using the PS-1 semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has 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.]
8.1 Sampling
8.1.1 High-volume sampler (see Figure 1). Capable of pulling ambient air through the filter/adsorbent
cartridge at a flow rate of approximately 8 standard cubic feet per minute (scfm) (0.225 std mVmin) to obtain
a total sample volume of greater than 300 scm over a 24-hour period. Major manufacturers are:
• Tisch Environmental, Village of Cleves, OH
• Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
• Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8.1.2 Sampling module (see Figure 2). Metal filter holder (Part 2) capable of holding a 102-mm circular
particle filter supported by a 16-mesh stainless-steel screen and attaching to a metal cylinder (Part 1) capable
of holding a 65-mm O.D. (60-mm I.D.) x 125-mm borosilicate glass sorbent cartridge containing PUF. The
filter holder is equipped with inert sealing gaskets (e.g., polytetrafluorethylene) placed on either side of the
filter. Likewise, inert, pliable gaskets (e.g., silicone rubber) are used to provide an air-tight seal at each end
of the glass sorbent cartridge. The glass sorbent cartridge is indented 20 mm from the lower end to provide
a support for a 16-mesh stainless-steel screen that holds the sorbent. The glass sorbent cartridge fits into Part
1, which is screwed onto Part 2 until the sorbent cartridge is sealed between the silicone gaskets. Major
manufacturers are:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-5
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Method TO-4A Pesticides/PCBs
• Tisch Environmental, Village of Cleves, OH
• Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
• Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
A field portable unit has been developed by EPA (see Figure 3).
8.1,3 High-volume sampler calibrator. Capable of providing multipoint resistance for the high-volume
sampler. Major manufacturers are:
• Tisch Environmental, Village of Cleves, OH
* Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
• Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8,1.4 Ice chest. To hold samples at <4°C or below during shipment to the laboratory after collection.
8.L5 Data sheets. For each sample for recording the location and sample time, duration of sample,
starting time, and volume of air sampled.
8.2 Sample Clean-up and Concentration (see Figure 4).
8.2.1 Soxhlet apparatus extractor (see Figure 4a). Capable of extracting filter and adsorbent cartridges
(2.3" x 5" length), 1,000 mL flask, and condenser, best source.
8.2.2 Pyrex glass tube furnace system. For activating silica gel at 180°C under purified nitrogen gas
purge for an hour, with capability of raising temperature gradually, best source.
8.2.3 Glass vial. 40 mL, best source.
8.2.4 Erlenmeyer flask. 50 mL, best source.
[Note; Reuse of glassware should be minimized to avoid the risk of cross contamination. All glassware that
is used, especially glassware that is reused, must be scrupulously cleaned as soon as possible after use.
Rinse glassware with the last solvent used in it and then with high-purity acetone and hexane. Wash with
hot water containing detergent. Rinse with copious amount of tap water and several portions of distilled
water. Drain, dry, and heat in a muffle furnace at 400 °Cfor 4 hours. Volumetric glassware must not be
heated in a muffle fiirnace; rather, it should be rinsed with high-purity acetone and hexane. After the
glassu'are is dry and cool, rinse it with hexane, and store it inverted or capped with solvent-rinsed aluminum
foil in a clean environment.]
8.2.5 White cotton gloves. For handling cartridges and filters, best source.
8.2,6 Minivials. 2 mL, borosilicate glass, with conical reservoir and screw caps lined with Teflon®-faced
silicone disks, and a vial holder, best source.
8.2.7 Teflon®-coated stainless steel spatulas and spoons. Best source.
8.2.8 Kuderna-Danish (K-D) apparatus (see Figure 4b). 500 mL evaporation flask (Kontes K-570001-
500 or equivalent), 10 mL graduated concentrator tubes (Kontes K570050-1025 or equivalent) with ground-
glass stoppers, and 3-ball macro Snyder Column (Kontes K-570010500, K-50300-0121, and K-569001-219,
or equivalent), best source.
8.2.9 Adsorption column for column chromatography (see Figure 4c). 1-cm x 10-cm with stands.
8.2.10 Glove box. For working with extremely toxic standards and reagents with explosion-proof hood
for venting fumes from solvents, reagents, etc.
Page 4A-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
8.2.11 Vacuum oven. Vacuum drying oven system capable of maintaining a vacuum at 240 torr (flushed
with nitrogen) overnight,
8.2.12 Concentrator tubes and a nitrogen evaporation apparatus with variable flow rate. Best source.
8.2.13 Laboratory refrigerator. Best source.
8.2.14 Boiling chips. Solvent extracted, 10/40 mesh silicon carbide or equivalent, best source.
8.2.15 Water bath. Heated, with concentric ring cover, capable of ±5°C temperature control, best source.
8.2.16 Nitrogen evaporation apparatus. Best source.
8.2,17 Glass wool. High purity grade, best source.
8.3 Sample Analysis
8.3.1 Gas chromatograph (GC). The GC system should be equipped with appropriate detector(s) and
either an isothermally controlled or temperature programmed heating oven. Improved detection limits may be
obtained with a GC equipped with a cool on-column or splitless injector.
8.3.2 Gas chromatographic column. As an example, a 0.32-mm (I.D.) x 3-mm DB-5, DB-17, DB-608,
DB-1701 are available. Other columns may also provide acceptable results.
8.3.3 HPLC column. As an example, a 4.6-mm x 25-cm Zorbax SIL or fiBondpak C-l8. Other columns
may also provide acceptable results.
8.3.4 Microsyringes. 5 jiL volume or other appropriate sizes.
8.3.5 Balance. Mettler balance or equivalent.
8.3.6 All required syringes, gases, and other pertinent supplies. To operate the GC/MS system.
8.3.7 Pipettes, micropipettes, syringes, burets, etc. To make calibration and spiking solutions, dilute
samples if necessary, etc., including syringes for accurately measuring volumes such as 25 uL and 100 uL.
9. Equipment and Materials
9.1 Materials for Sample Collection (see Figure 5)
9.1.1 Quartz fiber filter. 102-millimeter bindless quartz microfiber filter, Whatman Inc., 6 Just Road,
Fairfield, NJ 07004, Filter Type QMA-4.
9.1.2 Polyurethane foam (PUF) plugs (see Figure 5a). 3-inch thick sheet stock polyurethane type
(density .022 g/cm3). The PUF should be of the polyether type used for furniture upholstery, pillows, and
mattresses. The PUF cylinders (plugs) should be slightly larger in diameter than the internal diameter of the
cartridge. Sources of equipment are Tisch Environmental, Village of Cleves, OH; University Research
Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC; Thermo Environmental Instruments, Inc., 8 West Forge
Parkway, Franklin, MA; Supelco, Supelco Park, Bellefonte, PA; and SKC Inc., 334 Valley View Road, Eighty
Four, PA.
9.1.3 Teflon® end caps (see Figure 5a). For sample cartridge. Sources of equipment are Tisch
Environmental, Village of Cleves, OH and University Research Glassware, Chapel Hill, NC.
9.1.4 Sample cartridge aluminum shipping containers (see Figure 5b). For sample cartridge shipping.
Sources of equipment are Tisch Environmental, Village of Cleves, OH and University Research Glassware,
Chapel Hill, NC.
9.1.5 Glass sample cartridge (see Figure 5a). For sample collection. Sources of equipment are Tisch
Environmental, Village of Cleves, OH; Thermo Environmental Instruments, Inc., 8 West Forge Parkway,
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-7
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Method TO-4A Pesticides/PCBs
Franklin, MA; University Research Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC; and Supelco,
Supelco Park, Bellefonte, PA.
9.1.6 Aluminum foil. Best source.
9.1.7 Hexane, reagent grade. Best source.
9.2 Sample Extraction and Concentration
9.2.1 Methylene chloride. Chromatographic grade, glass-distilled, best source,
9.2.2 Sodium sulfate-anhydrous (ACS). Granular (purified by washing with methylene chloride followed
by heating at 400°C for 4 hours in a shallow tray).
9.2,3 Boiling chips. Solvent extracted or heated in a muffle furnace at 450°C for 2 hours, approximately
10/40 mesh (silicon carbide or equivalent).
9.2.4 Nitrogen. High purity grade, best source.
9.2.5 Ether. Chromatographic grade, glass-distilled, best source.
9.2.6 Hexane. Chromatographic grade, glass-distilled, best source.
9.2.7 Dibromobiphenyl. Chromatographic grade, best source. Used for internal standard.
9.2.8 Decafluorobiphenyl, Chromatographic grade, best source. Used for internal standard.
9.2,9 Glass wool. Silanized, extracted with methylene chloride and hexane, and dried.
9.2.10 Diethyl ether. High purity, glass distilled.
9.2.11 Hexane. High purity, glass distilled.
9.2.12 Silica gel. High purity, type 60, 70-230 mesh.
9.2.13 Round bottom evaporative flask. 500 mL, T 24/40 joints, best source.
9.2.14 Capacity soxhlet extractors. 500 mL, with reflux condensers, best source.
9.2.15 Kuderna-Danish concentrator. 500 mL, with Snyder columns, best source.
9.2.16 Graduated concentrator tubes. 10 mL, with 19/22 stoppers, best source.
9.2.17 Graduated concentrator tubes. 1 mL, with 14/20 stoppers, best source.
9.2.18 TFE fluorocarbon tape. 1/2 in., best source.
9.2.19 Filter tubes. Size 40-mm (I.D.) x 80-mm.
9.2.20 Serum vials. 1 mL and 5 mL, fitted with caps lined with TFE fluorocarbon.
9.2.21 Pasteur pipetter. 9 in., best source.
9.2.22 Glass wool. Fired at 500°C, best source.
9.2.23 Alumina. Activity Grade IV, 100/200 mesh.
9.2.24 Glass Chromatographic column. 2-mm I.D. x 15-cm long.
9.2.25 Vacuum oven. Connected to water aspirator, best source.
9.2.26 Die. Best source.
9.2.27 Ice chest. Best source.
9.2.28 Silicic Acid. Pesticide quality, best source.
9.2.29 Octachloronaphthalene (OCN). Research grade, best source.
9.2.30 Florisil. Pesticide quality, best source.
9.3 GC Sample Analysis
9,3.1 Gas cylinders of hydrogen, nitrogen, argon/methane, and helium. Ultra high purity, best source.
9.3.2 Combustion air. Ultra high purity, best source.
Page 4A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs \ Method TO-4A
9.3.3 Zero air. Zero air may be obtained from a cylinder or zero-grade compressed air scrubbed with
Drierite® or silica gel and 5 A molecular sieve or activated charcoal, or by catalytic cleanup of ambient air.
All zero air should be passed through a liquid argon cold trap for final cleanup.
9.3.4 Chromatographic-grade stainless steel tubing and stainless steel fitting. For interconnections,
Alltech Applied Science, 2051 Waukegan Road, Deerfield, IL 60015, 312-948-8600, or equivalent.
[Note: All such materials in contact with the sample, analyte, or support gases prior to analysis should be
stainless steel or other inert metal. Do not use plastic or Teflon® tubing or fittings.]
10. Preparation of PUF Sampling Cartridge
[Note: This method was developed using the PS-J sample cartridge provider by General Metal Works,
Village qfCleves, OH as a guideline. EPA has 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.]
10.1 Summary of Method
10.1.1 This part of Compendium Method TO-4A discusses pertinent information regarding the preparation
and cleaning of the filter, adsorbent, and filter/adsorbent cartridge assembly. The separate batches of filters
and adsorbents are extracted with the appropriate solvent.
10.1.2 At least one PUF cartridge assembly and one filter from each batch, or 10 percent of the batch,
whichever is greater, should be tested and certified clean before the batch is considered for field use.
10.2 Preparation of Sampling Cartridge
10.2.1 Bake the Whatman QMA-4 quartz filters at 400°C for 5 hours before use.
10.2.2 Set aside the filters in a clean container for shipment to the field or prior to combining with the PUF
glass cartridge assembly for certification prior to field deployment.
10.2.3 The PUF plugs are 6.0-cm diameter cylindrical plugs cut from 3-inch sheet stock and should fit,
with slight compression, in the glass cartridge, supported by the wire screen (see Figure 2). During cutting,
rotate the die at high speed (e.g., in a drill press) and continuously lubricate with deionized or distilled water,
Pre-cleaned PUF plugs can be obtained from many of the commercial sources identified in Section 9.1.2.
10.2.4 For initial cleanup, place the PUF plugs in a Soxhlet apparatus and extract with acetone for
16 hours at approximately 4 cycles per hour. When cartridges are reused, use diethyl ether/hexane (10 percent
volume/volume [v/v]) as the cleanup solvent.
[Note: A modified PUF cleanup procedure can be used to remove unknown interference components of the
PUF blank. This method consists of rinsing 50 times with toluene, acetone, and diethyl ether/hexane (5 to
10 percent v/v), followed by Soxhlet extraction. The extracted PUF is placed in a vacuum oven connected
to a water aspirator and dried at room temperature for approximately 2 to 4 hours (until no solvent odor
is detected). Alternatively, they may be dried at room temperature in an air-tight container with circulating
nitrogen (zero grade). Place the clean PUF plug into a labeled glass sampling cartridge using gloves and
forceps. Wrap the cartridge with hexane-rinsed aluminum foil and placed in a jar fitted with TFE
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-9
-------
Method TO-4A Pesticides/PCBs
fluoroearbon-lined caps. The foil wrapping may also be marked for identification using a blunt probe. The
extract from the Soxhlet extraction procedure from each batch may be analyzed to determine initial
cleanliness prior to certification.]
10.2.5 Fit a nickel or stainless steel screen (mesh size 200/200) to the bottom of a hexane-rinsed glass
sampling cartridge to retain the PUF adsorbents, as illustrated in Figure 2. Place the Soxhlet-extracted,
vacuum-dried PUF (2,5-cm thick by 6.5-cm diameter) on top of the screen in the glass sampling cartridge using
polyester gloves,
10.2.6 Wrap the sampling cartridge with hexane-rinsed aluminum foil, cap with the Teflon® end caps,
place in a cleaned labeled aluminum shipping container, and seal with Teflon® tape. Analyze at least I PUF
plug from each batch of PUF plugs using the procedure described in Section 10.3, before the batch is
considered acceptable for field use. A blank level of <10 ng/plug and filter for single component compounds
is considered to be acceptable. For multiple component mixtures (e.g., PCBs), the blank level should be
-------
Pesticides/PCBs Method TO-4A
flask and its lower joint into the concentrator tube with 5 mL of hexane. A 5-mL syringe is recommended for
this operation.
[Note: The solvent may have to be exchanged to another solvent to meet the requirements of the analytical
procedure selected for the target analytes.]
10.3.7 Concentrate the extract to 1 mL and analyze according to Section 13.
10.3.8 Acceptable levels of common pesticides must be less than 10 ng for each pair of filter and adsorbent
assembly analyzed. For multiple component mixtures (e.g., PCBs), the blank level should be less than 100 ng
for each pair of filter and adsorbent. Once certified clean, the cartridges can be shipped to the field without
being chilled.
11. Assembly, Calibration and Collection Using High-Volume Sampling System
[Note: This method was developed using the PS-1 semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has 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 necessaiy if another commercially available sampler
is selected.]
11.1 Description of Sampling Apparatus
The entire sampling system is diagrammed in Figure 1. This apparatus was developed to operate at a rate of
4 to 10 scfin (0.114 to 0.285 std rrrVmin) and is used by EPA for high-volume sampling of ambient air. The
method write-up presents the use of this device.
The sampling module (see Figure 2) consists of a filter and a glass sampling cartridge containing the PUF
utilized to concentrate common pesticides and PCBs from the air. A field portable unit has been developed by
EPA (see Figure 3).
11.2 Calibration of Sampling System
Each sampler should be calibrated (1) when new, (2) after major repairs or maintenance, (3) whenever any
audit point deviates from the calibration curve by more than 7 percent, (4) before/after each sampling event,
and (5) when a different sample collection media, other than that which the sampler was originally calibrated
to, will be used for sampling.
11.2.1 Calibration of Orifice Transfer Standard. Calibrate the modified high volume air sampler in the
field using a calibrated orifice flow rate transfer standard. Certify the orifice transfer standard in the laboratory
against a positive displacement rootsmeter (see Figure 6). Once certified, the recertification is performed rather
infrequently if the orifice is protected from damage. Recertify the orifice transfer standard performed once per
year utilizing a set of five multiple resistance plates.
[Note: The set of five multihole resistance plates are used to change the flow through the orifice so that
several points can be obtained for the orifice calibration curve. The following procedure outlines the steps
to calibrate the orifice transfer standard in the laboratory.]
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page4A-ll
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Method TO-4A __ Pesticides/PCBs
11.2.1.1 Record the room temperature (T, in °C) and barometric pressure (Pb in mm Hg) on the Orifice
Calibration Data Sheet (see Figure 7). Calculate the room temperature in K (absolute temperature) and record
on Orifice Calibration Data Sheet.
T1inK = 2730+T1in°C
1 1.2.1.2 Set up laboratory orifice calibration equipment as illustrated in Figure 6. Check the oil level
of the rootsmeter prior to starting. There are 3 oil level indicators, 1 at the clear plastic end and 2 site glasses,
1 at each end of the measuring chamber.
1 1.2.1.3 Check for leaks by clamping both manometer lines, blocking the orifice with cellophane tape,
turning on the high volume motor, and noting any change in the rootsmeter's reading. If the rootsmeter's
reading changes, there is a leak in the system. Eliminate the leak before proceeding. If the rootsmeter's reading
remains constant, turn off the hi-vol motor, remove the cellophane tape, and unclamp both manometer lines.
1 1 .2.1 .4 Install the 5-hole resistance plate between the orifice and the filter adapter.
1 1.2.1.5 Turn manometer tubing connectors 1 turn counter-clockwise. Make sure all connectors are
open.
11.2.1.6 Adjust both manometer midpoints by sliding their movable scales until the zero point
corresponds \vith the meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on
tubing connectors. (If additional liquid is required for the water manometer, remove tubing connector and add
clean water.)
11.2.1.7 Turn on the high volume motor and let it run for 5 minutes to set the motor brushes. Turn the
motor off. Insure manometers are set to zero. Turn the high volume motor on.
1 1 .2.1.8 Record the time, in minutes, required to pass a known volume of air (approximately 200 to
300 ftj of air for each resistance plate) through the rootsmeter by using the rootsmeter's digital volume dial and
a stopwatch.
11.2.1.9 Record both manometer readings-orifice water manometer (AH) and rootsmeter mercury
manometer (A?) on Orifice Calibration Data Sheet (see Figure 7).
[Note: aH is the sum of the difference from zero (0) of the two column heights.]
11.2.1.10 Turn off the high volume motor.
11.2.1.11 Replace the 5-hole resistance plate with the 7-hole resistance plate.
11.2.1.12 Repeat Sections 1 1.2. 1 .3 through 11.2.1.11.
11.2.1.13 Repeat for each resistance plate. Note results on Orifice Calibration Data Sheet (see
Figure 7). Only a minute is needed for warm-up of the motor. Be sure to tighten the orifice enough to
eliminate any leaks. Also check the gaskets for cracks.
[Note: The placement of the orifice prior to the rootsmeter causes the pressure at the inlet of the rootsmeter
to be reduced below atmospheric conditions, thus causing the measured volume to be incorrect. The volume
measured by the rootsmeter must be corrected.]
Page4A-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs __ Method TO-4A
11.2.1.14 Correct the measured volumes on the Orifice Calibration Data Sheet:
P - AP T,
V = V (
Vstd Vra v
std ra
rst
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Method TO-4A ; Pesticides/PCBs
* The sampler and the orifice transfer standard are calibrated to standard volumetric flow rate units (scfin
or scmm).
« An orifice transfer standard with calibration traceable to MIST is used.
« A "UH tube water manometer or equivalent, with a 0- to 16-inch range and a maximum scale division
of 0.1 inch, will be used to measure the pressure in the orifice transfer standard.
• A Magnehelic gauge or equivalent, with a 9- to 100-inch range and a minimum scale division of 2 inches
for measurements of the differential pressure across the sampler's orifice is used,
• A thermometer capable of measuring temperature over the range of 32° to 122°F (0° to 50°C)to±2°F
(±1°C) and referenced annually to a calibrated mercury thermometer is used.
• A portable aneroid barometer (or equivalent) capable of measuring ambient barometric pressure between
500 and 800 mm Hg (19.5 and 31.5 in. Hg) to the nearest mm Hg and referenced annually to a
barometer of known accuracy is used.
* Miscellaneous handtools, calibration data sheets or station log book, and wide duct tape are available.
11.2.2.1 Set up the calibration system as illustrated in Figure 8. Monitor the airflow through the
sampling system with a venturi/Magnehelic assembly, as illustrated in Figure 8. Audit the field sampling
system once per quarter using a flow rate transfer standard, as described in the EPA High Volume-Sampling
Method, 40 CVR 50, Appendix B. Perform a single-point calibration before and after each sample collection,
using the procedures described in Section 11.2.3.
11.2.2.2 Prior to initial multi-point calibration, place an empty glass cartridge in the sampling head and
activate the sampling motor. Fully open the flow control valve and adjust the voltage variator so that a sample
flow rate corresponding to 110 percent of the desired flow rate (typically 0.20 to 0.28 nrVmin) is indicated on
the Magnehelic gauge (based on the previously obtained multipoint calibration curve). Allow the motor to
warm up for 10 minutes and then adjust the flow control valve to achieve the desire flow rate. Turn off the
sampler. Record the ambient temperature and barometric pressure on the Field Calibration Data Sheet (see
Figure 9).
11.2.2.3 Place the orifice transfer standard on the sampling head and attach a manometer to the tap on
the transfer standard, as illustrated in Figure 8. Properly align the retaining rings with the filter holder and
secure by tightening the three screw clamps. Connect the orifice transfer standard by way of the pressure tap
to a manometer using a length of tubing. Set the zero level of the manometer or Magnehelic. Attach the
Magnehelic gauge to the sampler venturi quick release connections. Adjust the zero (if needed) using the zero
adjust screw on face of the gauge.
11.2.2.4 To leak test, block the orifice with a rubber stopper, wide duct tape, or other suitable means.
Seal the pressure port with a rubber cap or similar device. Turn on the sampler.
Qcnitlon: Avoid running the sampler for too long 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 life of the motor.
11.2.2.5 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 on the sampler's Magnehelic.
Leaks are usually caused either by damaged or missing gaskets by cross-threading and/or not screwing sample
cartridge together tightly. All leaks must be eliminated before proceeding with the calibration. When the
sample is determined to be leak-free, turn off the sampler and unblock the orifice. Now remove the rubber
stopper or plug from the calibrator orifice.
11.2.2.6 Turn the flow control valve to the fully open position and turn the sampler on. Adjust the flow
control valve until a Magnehelic reading of approximately 70 in. is obtained. Allow the Magnehelic and
Page4A-14 Compendium of Methods far Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
manometer readings to stabilize and record these values on the orifice transfer Field Calibration Data Sheet
(see Figure 9).
11.2.2.7 Record the manometer reading under Yl and the Magnehelic reading under Y2 on the Field
Calibration Data Sheet, For the first reading, the Magnehelic should still be at 70 inches as set above.
11.2.2.8 Set the Magnehelic to 60 inches by using the sampler's flow control valve. Record the
manometer (Yl) and Magnehelic (Y2) readings on the Field Calibration Data Sheet (see Figure 9).
11.2.2.9 Repeat the above steps using Magnehelic settings of 50, 40, 30, 20, and 10 inches.
11.2.2.10 Turn the voltage variator to maximum power, open the flow control valve, and confirm that
the Magnehelic reads at least 100 inches. Turn off the sampler and confirm that the Magnehelic reads zero.
11.2.2.11 Read and record the following parameters on the Field Calibration Data Sheet. Record the
following on the calibration data sheet:
Data, job number, and operator's signature;
* Sampler serial number;
• Ambient barometric pressure; and
* Ambient temperature.
11.2.2.12 Remove the "dummy" cartridge and replace with a sample cartridge.
11.2.2.13 Obtain the Manufacturer High Volume Orifice Calibration Certificate.
11.2.2.14 If not performed by the manufacturer, calculate values for each calibrator orifice static
pressure (Column 6, inches of water) on the manufacturer's calibration certificate using the following equation:
^H(P/760)(298/[Ta + 273])
where:
Pa = the barometric pressure (mm Hg) at time of manufacturer calibration, mm Hg
Ta= temperature at time of calibration, °C
11.2.2.15 Perform a linear regression analysis using the values in Column 7 of the manufacturer High
Volume Orifice Calibration Certificate for flow rate (Qsltt) as the "X" values and the calculated values as the
Y values. From this relationship, determine the correlation (CC1), intercept (Bl), and slope (Ml) for the
Orifice Transfer Standard.
11.2.2.16 Record these values on the Field Calibration Data Sheet (see Figure 9).
11.2.2.17 Using the Field Calibration Data Sheet values (see Figure 9), calculate the Orifice Manometer
Calculated Values (Y3) for each orifice manometer reading using the following equation:
Y3 Calculation
Y3 = [Y1(P./760)(298/{T. + 273})]17'
11.2.2.18 Record the values obtained in Column Y3 on the Field Calibration Data Sheet (see Figure 9).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-15
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Method TO-4A Pesticides/PCBs
11.2.2.19 Calculate the Sampler Magnehelic Calculate Values (Y4) using the following equation:
Y4 Calculation
Y4 = [Y2(P/760)(298/{T. + 273})]'/J
11.2.2.20 Record the value obtained in Column Y4 on the Field Calibration Data Sheet (see Figure 9).
11.2.2.21 Calculate the Orifice Flow Rate (XI) in scm, using the following equation:
XI Calculation
Y3 - Bl
XI =
Ml
11.2.2.22 Record the values obtained in Column XI, on the Field Calibration Data Sheet (see Figure 9).
11.2.2.23 Perform a linear regression of the values in Column XI (as X) and the values in Column Y4
(as Y). Record the relationship for correlation (CC2), intercept (B2), and slope (M2) on the Field Calibration
Data Sheet.
11.2.2.24 Using the following equation, calculate a set point (SP) for the manometer to represent a
desired flow rate:
Set point (SP) = [(Expected Pa)/(Expeeted Ta)(Tstd/Pstd)][M2 (Desired flow rate) + B2f
where:
P, = Expected atmospheric pressure (?„), mm Hg
T, = Expected atmospheric temperature (Ta),, °C
M2 = Slope of developed relationship
B2 = Intercept of developed relationship
Tstd = Temperature standard, 25 °C
P«d = Pressure standard, 760 mm Hg
11.2.2.25 During monitoring, calculate a flow rate from the observed Magrtehelic reading using the
following equations:
Y5 = [Average Magnehelic Reading (AH) (P/Ta)(TMd/Pstd)fJ
X2 - Y5 - B2
M2
where:
Y5 = Corrected Magnehelic reading
X2 = Instant calculated flow rate, scm
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Pesticides/PCBs Method TO-4A
11.2.2.26 The relationship in calibration of a sampling system between Orifice Transfer Standard and
flow rate through the sampler is illustrated in Figure 10.
11.2.3 Single-Point Audit of the High Volume Sampling System Utilizing Calibrated Orifice Transfer
Standard
Single point calibration checks are required as follows:
• Prior to the start of each 24-hour test period.
• After each 24-hour test period. The post-test calibration check may serve as the pre-test calibration
check for the next sampling period if the sampler is not moved.
* Prior to sampling after a sample is moved.
For samplers, perform a calibration check for the operational flow rate before each 24-hour sampling event
and when required as outlined in the user quality assurance program. The purpose of this check is to track the
sampler's calibration stability. Maintain a control chart presenting the percentage difference between a
sampler's indicated and measured flow rates. This chart provides a quick reference of sampler flow-rate drift
problems and is useful for tracking the performance of the sampler. Either the sampler log book or a data sheet
will be used to document flowcheck information. This information includes, but is not limited to, sampler and
orifice transfer standard serial number, ambient temperature, pressure conditions, and collected flow-check
data.
In this subsection, the following is assumed:
• The flow rate through a sampler is indicated by the orifice differential pressure;
• Samplers are designed to operate at an actual flow rate of 8 scfin, with a maximum acceptable flow-rate
fluctuation range of ±10 percent of this value;
* The transfer standard will be an orifice device equipped with a pressure tap. The pressure is measured
using a manometer; and
* The orifice transfer standard's calibration relationship is in terms of standard volumetric flow rate (QsUi).
11.2.3.1 Perform a single point flow audit check before and after each sampling period utilizing the
Calibrated Orifice Transfer Standard (see Section 11.2.1).
11.2.3,2 Prior to single point audit, place a "dummy" glass cartridge in the sampling head and activate
the sampling motor. Fully open the flow control valve and adjust the voltage variator so that a sample flow
rate corresponding to 110 percent of the desired flow rate (typically 0.19 to 0.28 m3/min) is indicated on the
Magnehelic gauge (based on the previously obtained multipoint calibration curve). Allow the motor to warm
up for 10 minutes and then adjust the flow control valve to achieve the desired flow rate. Turn off the sampler.
Record the ambient temperature and barometric pressure on the Field Test Data Sheet (see Figure 11).
11.2.3.3 Place the flow rate transfer standard on the sampling head.
11.2.3.4 Properly align the retaining rings with the filter holder and secure by tightening the 3 screw
clamps. Connect the flow rate transfer standard to the manometer using a length of tubing.
11.2.3.5 Using tubing, attach 1 manometer connector to the pressure tap of the transfer standard. Leave
the other connector open to the atmosphere.
11.2.3.6 Adjust the manometer midpoint by sliding the movable scale until the zero point corresponds
with the water meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on tubing
connectors. (If additional liquid is required, remove tubing connector and add clean water.)
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Method TO-4A Pesticides/PCBs
11,2,3.7 Turn on high-volume motor and let run for 5 minutes.
11.2.3.8 Record the pressure differential indicated, AH, in inches of water, on the Field Test Data Sheet.
Be sure stable &H has been established.
11.2.3.9 Record the observed Magnahelic gauge reading, in inches of water, on the Field Test Data
Sheet Be sure stable ^M has been established.
11.2.3.10 Using previous established Orifice Transfer Standard curve, calculate Qra (see
Section 11.2.2.23).
11.2.3.11 This flow should be within ±10 percent of the sampler set point, normally, 8 ft3. If not,
perform a new multipoint calibration of the sampler.
11,2.3.12 Remove flow rate transfer standard and dummy adsorbent cartridge.
11.3 Sample Collection
11.3.1 General Requirements
11.3.1.1 The sampler should be located in an unobstructed area, at least 2 meters from any obstacle to
air flow. The exhaust hose should be stretched out in the downwind direction to prevent recycling of air into
the sample head.
11.3.1.2 All cleaning and sample module loading and unloading should be conducted in a controlled
environment, to minimize any chance of potential contamination.
11.3.1,3 When new or when using the sampler at a different location, all sample contact areas need to
be cleared. Use triple rinses of reagent grade hexane contained in Teflon® rinse bottles. Allow the solvent to
evaporate before loading the PUF modules.
11.3.2 Preparing Cartridge for Sampling
11.3.2.1 Detach the lower chamber of the cleaned sample head. While wearing disposable, clean, lint-
free nylon, or powder-free surgical gloves, remove a clean glass adsorbent module from its shipping container.
Remove tire Teflon® end caps. Replace the end caps in the sample container to be reused after the sample has
been collected.
11.3.2.2 Insert the glass module into the lower chamber and tightly reattach the lower chambers to the
module.
11.3.2.3 Using clean rinsed (with hexane) Teflon-tipped forceps, carefully place a clean conditioned
fiber filter atop the filter holder and secure in place by clamping the filter holder ring over the filter. Place the
aluminum protective cover on top of the cartridge head. Tighten the 3 screw clamps. Ensure that all module
connections are tightly assembled. Place a small piece of aluminum foil on the ball-joint of the sample
cartridge to protect from back-diffusion of semi-volatile into the cartridge during transporting to the site.
[Note: Failure to do so could result in airflow leaks at poorly sealed locations which could affect sample
representativeness J
11.3.2.4 Place in a carrying bag to take to the sampler.
11.3.3 Collection
11.3.3,1 After the sampling system has been assembled, perform a single point flow check as described
in Sections 11.2.3.
11.3.3.2 With the empty sample module removed from the sampler, rinse all sample contact areas using
reagent grade hexane in a Teflon® squeeze bottle. Allow the hexane to evaporate from the module before
loading the samples.
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Pesticides/PCBs Method TO-4A
11.3.3.3 With the sample cartridge removed from the sampler and the flow control valve fully open, turn
the pump on and allow it to warm-up for approximately 5 minutes.
11.3.3.4 Attach a "dummy" sampling cartridge loaded with the exact same type of filter and PUF media
to be used for sample collection.
11.3.3.5 Turn the sampler on and adjust the flow control valve to the desired flow as indicated by the
Magnehelic gauge reading determined in Section 11.2.2.24. Once the flow is properly adjusted, take extreme
care not to inadvertently alter its setting.
11.3.3.6 Turn the sampler off and remove the "dummy" module. The sampler is now ready for field use.
11.3.3.7 Check the zero reading of the sampler Magnehelic. Record the ambient temperature,
barometric pressure, elapsed time meter setting, sampler serial number, filter number, and PUF cartridge
number on the Field Test Data Sheet (see Figure 11). Attach the loaded sampler cartridge to the sampler.
11.3.3.8 Place the voltage variator and flow control valve at the settings used in Section 11.3.2, and the
power switch. Activate the elapsed time meter and record the start time. Adjust the flow (Magnehelic setting),
if necessary, using the flow control valve.
11.3.3.9 Record the Magnehelic reading every 6 hours during the sampling period. Use the calibration
factors (see Section 11.2.2.24) to calculate the desired flow rate. Record the ambient temperature, barometric
pressure, and Magnehelic reading at the beginning and during sampling period.
11.3.4 Sample Recovery
11.3.4.1 At the end of the desired sampling period, turn the power off. Carefully remove the sampling
head containing the filter and adsorbent cartridge. Place the protective "plate" over the filter to protect
cartridge during transport to clean recovery area. Also, place a piece of aluminum foil around the bottom of
adsorbent sampler head.
11.3.4.2 Perform a final calculated sampler flow check using the calibration orifice, as described in
Section 11.3.2. If calibration deviates by more than 10 percent from initial reading, mark the flow data for that
sample as suspect and inspect and/or remove from service, record results on Field Test Data Sheet, Figure 11.
11.3.4.3 Transport adsorbent sampler head to a clean recovery area.
11.3.4.4 While wearing disposable lint free nylon or powder-free surgical gloves, remove the PUF
cartridge from the lower module chamber and lay it on the retained aluminum foil in which the sample was
originally wrapped.
11.3.4.5 Carefully remove the glass fiber filter from the upper chamber using clean Teflon®-tipped
forceps.
11.3.4.6 Fold the filter in half twice (sample side inward) and place it in the glass cartridge atop the
PUF.
11.3.4.7 Wrap the combined samples in the original hexane rinsed aluminum foil, attached Teflon® end
caps and place them in their original aluminum sample container. Complete a sample label and affix it to the
aluminum shipping container.
11.3.4.8 Chain-of-custody should be maintained for all samples. Store the containers under dry ice and
protect from UV light to prevent possibly photo-decomposition of collected analytes. If the time span between
sample collection and laboratory analysis is to exceed 24 hours, refrigerate sample at 4°C.
11.3.4.9 Return at least 1 field filter/PUF blank to the laboratory with each group of samples. Treat
a field blank exactly as the sample except that no air is drawn through the filter/adsorbent cartridge assembly.
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Method TO-4A Pesticides/PCBs
11,3.4,10 Ship and store field samples chilled (<4°) (blue ice is acceptable) until receipt at the analytical
laboratory, after which they should be refrigerated at less than or equal to 4°C, Extraction must be performed
within 7 days of sampling and analysis within 40 days of extraction.
12. Sample Extraction Procedure
[Pfotc: Sample extraction should be performed under a properly ventilated hood.]
12.1 Sample Extraction
12.1.1 All samples should be extracted within 1 week after collection. All samples should be stored at
<4°C until extracted.
12.1.2 All glassware should be washed with a suitable detergent; rinsed with deionized water, acetone, and
hcxanc; rinsed again with deionized water; and fired in an oven (500°C).
12.1.3 Prepare a spiking solution for determination of extraction efficiency. The spiking solution should
contain one or more surrogate compounds that have chemical structures and properties similar to those of the
analytcs of interest. Octachloronaphthalene (OCN) and dibutylchlorendate have been used as surrogates for
determination of organochlorine pesticides by GC with an BCD. Tetrachloro-m-xylene and decachlorobiphenyl
can also be used together to insure recovery of early and late eluting compounds. For organophosphate
pesticides, tributylphosphate or triphenylphosphate may be employed as surrogates. The surrogate solution
should be prepared so that addition of 100 ^L into the PUF plug results in an extract containing the surrogate
compound at the high end of the instrument's calibration range. As an example, the spiking solution for OCN
is prepared by dissolving 10 mg of OCN in 10 mL of 10% acetone in n-hexane, followed by serial dilution n-
hexanc to achieve a final spiking solution of OCN is 1
[Note; Use the recoveries of the surrogate compounds to monitor for unusual matrix effects and gross
sample processing errors. Evaluate surrogate recovery/or acceptance by determining whether the measured
concentration falls within the acceptance limits of 60-120 percent.]
12.1.4 The extracting solution (10% diethyl ether/hexane) is prepared by mixing 1800 mL of freshly
opened hexane and 200 mL of freshly opened diethyl ether (preserved with ethanol) to a flask.
12.1.5 All clean glassware, forceps, and other equipment to be used should be rinsed with 10% diethyl
ctlicr/ hcxanc and placed on rinsed (10% diethyl ether/hexane) aluminum foil until use. The condensing towers
should also be rinsed with 10% diethyl ether/hexane. Then add 700 mL of 10% diethyl ether/hexane to the
1,000 mL round bottom flask and add up to three boiling granules.
12.1.6 Using precleaned (i.e., 10% diethyl ether/hexane Soxhlet extracted) cotton gloves, the filter/PUF
cartridge is removed from the sealed container, the PUF removed from the glass cartridge, and the filter/PUF
together are placed into the 300 mL Soxhlet extractor using prerinsed forceps.
12.1.7 Before extraction begins, add 100 (iL of the OCN solution directly to the top of the PUF plug.
[Nola; Incorporating a known concentration of the solution onto the sample provides a quality assurance
check to determine recovery efficiency of the extraction and analytical processes.]
12.1.8 Connect the Soxhlet extractor to the 1,000 mL boiling flask and condenser. Wet the glass joints
with 10% diethyl ethcr/hexane to ensure a tight seal between the fittings. If necessary, the PUF plug can be
Page 4A-20 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
adjusted using forceps to wedge it midway along the length of the siphon. The above procedure should be
followed for all samples, with the inclusion of a blank control sample.
12.1.9 The water flow to the condenser towers of the Soxhlet extraction assembly should be checked and
the healing unit turned on. As the samples boil, the Soxhlet extractors should be inspected to ensure that they
are filling and siphoning properly (4 to 6 cycles/hour). Samples should cycle for a minimum of 16 hours.
12.1.10 At the end of the extracting process (minimum of 16 hours), the heating unit is turned off and the
sample cooled to room temperature.
12.1.11 The extracts are then concentrated to 5 mL using a Kuderna-Danish (K-D) apparatus. The K-D
is set up, assembled with concentrator tubes, and rinsed. The lower end of the filter tube is packed with glass
wool and filled with sodium sulfate to a depth of 40 mm. The filter tube is then placed in the neck of the K-D.
The Soxhlet extractors and boiling flasks are carefully removed from the condenser towers and the remaining
solvent is drained into each boiling flask. Sample extract is carefully poured through the filter tube into the
K-D. Each boiling flask is rinsed three times by swirling hexane along the sides. Once the sample has drained,
the filter tube is rinsed down with hexane. Each Snyder column is attached to the K-D and rinsed to wet the
joint for a tight seal. The complete K-D apparatus is placed on a steam bath and the sample is evaporated to
approximately 5 mL.
[Note: Do not allow samples to evaporate to dryness.]
Remove sample from the steam bath, rinse the Snyder column with a minimum of hexane, and allow to cool.
Adjust sample volume to 10 mL in a concentrator tube, close with a glass stopper, and seal with TFE
fluorocarbon tape. Alternatively, the sample may be quantitatively transferred (with concentrator tube rinsing)
to prescored vials and brought up to final volume. Concentrated extracts are stored at <4°C until analyzed.
Analysis should occur no later than 40 days after sample extraction.
12.2 Sample Cleanup
12.2.1 If only polar compounds are sought, an alumina cleanup procedure is appropriate. Before cleanup,
the sample extract is carefully reduced to 1 mL using a gentle stream of clean nitrogen.
12.2.2 A glass chromatographic column (2-mm I.D. x 15-cm long) is packed with alumina (7), activity
grade IV, and rinsed with approximately 20 mL of n-hexane. The concentrated sample extract is placed on
the column and eluted with 10 mL of n-hexane at a rate of 0.5 mL/minute. The eluate volume is adjusted to
exactly 10 mL and analyzed as per Section 13.
12.2.3 If both PCBs and common pesticides are sought, alternate cleanup procedures (8,9) may be required
(i.e., silicic acid).
12.2.4 Finally, class separation and improved specificity can be achieved by column clean-up and
separation on Florisil (9).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-21
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Method TO-4A Pesticides/PCBs
13. Analytical Procedure
13.1 Analysis of Organochlorine Pesticides by Capillary Gas Chromatography with Electron Capture
Detector (GC/ECD)
[Note: Organochlorine pesticides, PCBs and many nonchlorinated pesticides are responsive to electron
capture detection (see Table I). Most of these compounds can be analyzed at concentration of I to 50 ng/mL
by CC'ECD. The following procedure is appropriate. Sampling and analytical methods that have been used
to determine pesticides and PCBs collected from air using a modification of this methodology have been
published (14-22),]
13.1.1 Select GC column (e.g., 0.3-mtn by 30-m DB-5 column) and appropriate GC conditions to separate
the target analytes. Typical operating parameters for this column with splitless injection are: Carrier gas-
chromatography grade helium at a flow rate of 1 to 2 mL/min and a column head pressure of 7 to 9 psi (48 to
60 kPa); injector temperature of 250°C; detector temperature of 350°C; initial oven temperature of 50°C held
for 2.0 min., ramped at 15°C/min to I50°C for 8 min, ramped at 10°C/min to 295°C then held for 5 min;
purge time of 1.0 min, A typical injection volume is 2 to 3 ^L.
13.1.2 Remove sample extract from refrigerator and allow to warm to room temperature.
13.1.3 Prepare standard solution from reference materials of known purity. Analytically pure standards
of Organochlorine pesticides and PCBs are available from several commercial sources.
13.1.4 Use the standard solutions of the various compounds of interest to determine relative retention times
(RRTs) to an internal standard such as p,p'-DDE, aldrin or octachloronaphthalene. Use 1 to 3-/iL injections
or other appropriate volumes.
13.1.S Determine detector linearity by injecting standard solutions of three different concentrations
(amounts) that bracket the range of analyses. The calibration is considered linear if the relative standard
deviation (RSD) of the three response factors for the three standards is 20 percent or less.
13.1.6 Calibrate the system with a minimum of three levels of calibration standards in the linear range.
Tlic low standard should be near the analytical method detection limit. The calibration is considered linear if
the relative standard deviation (RSD) of the three response factors for the three standards is 20 percent or less.
The initial calibration should be verified by the analysis of a standard from an independent source. Recovery
of 85 to 115 percent is acceptable. The initial calibration curve should be verified at the begining of each day
and after every ten samples by the analysis of the midpoint standard; an RPD of 15% or less is acceptable for
continuing use of the initial calibration curve.
13.1,7 Inject 1 to 3 /^L of sample extract. Record volume injected to the nearest 0.05 ^L.
13.1.8 A typical BCD response for a mixture of single component pesticides using a capillary column is
illustrated in Figure 12. If the response (peak height or area) exceeds the calibration range, dilute the extract
and reanalyze.
13.1.9 Quantify PCB mixtures by comparison of the total heights or areas of GC peaks (minimum of five)
with the corresponding peaks in the best-matching standard. Use Aroclor 1242 for early-eluting PCBs and
cither Aroclor 1254 or Aroclor 1260 as appropriate for late-eluting PCBs,
13.1.10 If both PCBs and Organochlorine pesticides are present in the same sample, use column
chromatographie separation on silicic acid (8,9) prior to GC analysis.
13.1.11 If polar compounds are present that interfere with GC/ECD analysis, use column chromatographie
cleanup or alumina (7), activity grade FV, in accordance with Section 12.2.
Page 4A-22 Compendium of Methods far Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs __ Method TO-4A
13.1.12 For confirmation use a second GC column such as DB-608. All GC procedures except GC/MS
require second column confirmation.
13.1.13 For improved resolution use a capillary column such as an 0.25-mm I.D. x 30-m DB-5 with
0.25 ^m film thickness. The following conditions are appropriate.
• Helium carrier gas at 1 mL/min.
• Column temperature program, 90 ° C (4 min)/ 1 6 ° C/min to 1 54 ° C/4 ° C/min to 270 ° C .
• Detector, 63Ni ECD at 350°C.
• Make up gas, nitrogen, or 5% methane/95% argon at 60 mL/min.
• Splitless injection, 2 ^L maximum.
• Injector temperature, 220°C.
13.1.14 Class separation and improved specificity can be achieved by column chromatographic separation
on Florisil (9).
13.1.15 A Hall electrolytic conductivity detector (HECD) operated in the reductive mode may be
substituted for the ECD for improved specificity. Sensitivity, however, will be reduced by at least an order
of magnitude.
13.2 Analysis of Organophosphorus Pesticides by Capillary Gas Chromatography with Flame
Photometric or Nitrogen-Phosphorus Detectors (GC/FPD/NPD)
[Note: Organophosphorus pesticides are responsive to flame photometric and nitrogen-phosphorus (alkali
flame ionization) detection. Most of these compounds can be analyzed at concentrations of 50 to 500 ng/mL
using either of these detectors.]
13.2.1 Procedures given in Section 13.1.1 through 13.1.9 and Section 13.1.13 through 13.1.14 apply,
except for the selection of surrogates.
13.2.2 Use tributylphosphate, triphenylphosphate, or other suitable compound(s) as surrogates to verify
extraction efficiency and to determine RRTs.
13.3 Analysis of Carbamate and Urea Pesticides by Capillary Gas Chromatography with Nitrogen-
Phosphorus Detector
13.3.1 Trazine, carbamate, and urea pesticides may be determined by capillary GC (DB-5, DB-17, or
DB-1701 stationary phase) using nitrogen-phosphorus detection or MS-SIM with detection limits in the 0.05
to 0.2 ^L/mL range. Procedures given in Section 13.1.1 through 13.1.9 and Section 13.1.13 through 13.1.14
apply, except for the selection of surrogates, detector, and make up gas.
13.3.2 Thermal degradation may be minimized by reducing the injector temperature to 200° C. HPLC may
also be used, but detection limits will be higher (1 to 5 /ug/mL).
13.3.3 N-methyl carbamates may be determined using reverse-phase high performance liquid
Chromatography (HPLC) (C-18) (Section 13.4) and post-column derivization with o-phthaldehyde and
fluorescence detection (EPA Method 53 1). Detection limits of 0.01 to 0. 1 ^g/mL can be achieved.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-23
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Method TO-4A Pesticides/PCBs
13.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by High Performance Liquid
Chromatography (HPLC)
[Note: Many carbamate pesticides, urea pesticides, pyrethrins, phenols, and other polar pesticides maybe
analyzed by high HPLC with fixed or variable wavelength UVdetection. Either reversed-phase or normal
phase chromatography may be used. Detection limits are 0.2 to 10 &g/mL of extract.]
13.4.1 Select HPLC column (i.e., Zorbax-SIL, 46-mm I.D. x 25-cm, or //-Bondapak CIS,
3.9-mm x 30-cm, or equivalent).
13.4.2 Select solvent system (i.e., mixtures of methanol or acetonitrile with water or mixtures of heptane
or hexane with isopropanoi).
13.4.3 Follow analytical procedures given in Sections 13.1.2 through 13.1.9.
13.4.4 If interferences are present, adjust the HPLC solvent system composition or use column
ehromatographic clean-up with silica gel, alumina, or Florisil (9).
13.4.5 An electrochemical detector may be used to improve sensitivity for some ureas, carbonates, and
phcnolics. Much more care is required in using this detector, particularly in removing dissolved oxygen from
the mobile phase and sample extracts.
13.4.6 Chlorophenol (di- through penta-) may be analyzed by GC/ECD or GC/MS after derivatization with
pentafluorobenzylbromide (EPA Method 604).
13.4.7 Chlorinated phenoxyaeetic acid herbicides and pentachlorophenol can be analyzed by GC/ECD or
GC/MS after derivatization with diazomethane (EPA Method 515), DB-5 and DBJ-17G1 columns (0.25-mm
I.D. x 30-m) at 60 to 300°C/4°C per min have been found to perform well.
13.5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass Spectrometry Detection
(GC/MS)
[Note: A mass spectrometer operating in the selected ion monitoring mode is usejulfor confirmation and
identification of pesticides.]
13.5.1 A mass spectrometer operating in select ion monitoring (SIM) mode can be used as a sensitive
detector for multi-residue dctenmination of a wide variety of pesticides. Mass spectrometers are now available
that provide detection limits comparable to nitrogen-phosphorus and electron capture detectors.
13.5.2 Most of the pesticides shown in Table 1 have been successfully determined by GC/MS-SIM.
Tjpical GC operating parameters are as described in Section 13.1.1.
13.5.3 The mass spectrometer is typically operated using positive ion electron impact ionization (70 eV).
Other instrumental parameters are instrument specific.
13.5.4 p-Tcrphenyl-di4 is commonly used as a surrogate for GC/MS analysis.
13.5.5 Quantification is typically performed using an internal standard method. 1,4-Dichlorobenzene,
naphthalene-dg, acenaphthene-d]0, phenanthrene-djo, chrysene-di2 and perylene-dl2 are commonly used as
internal standards. Procedures given in Section 13.1.1 through 13.1.9 and Section 13.1.13 through 13.1.14
apply, except for the selection of surrogates, detector, and make up gas.
13.5.6 Sec ASTM Practice D 3687 for injection technique, determination of relative retention times, and
other procedures pertinent to GC and HPLC analyses.
Page 4A-24 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pestkides/PCBs Method TO-4A
13.6 Sample Concentration
13.6.1 If concentrations are too low to detect by the analytical procedure of choice, the extract may be
concentrated to 1 mL or 0.5 tnL by carefully controlled evaporation under an inert atmosphere. The following
procedure is appropriate.
13.6.2 Place K-D concentrator tube in a water bath and analytical evaporator (nitrogen blow-down)
.apparatus. The water bath temperature should be from 25°C to 50°C.
13.6.3 Adjust nitrogen flow through hypodermic needle to provide a gentle stream.
13.6.4 Carefully lower hypodermic needle into the concentrator tube to a distance of about 1 cm above
the liquid level.
13.6.5 Continue to adjust needle placement as liquid level decreases.
13.6.6 Reduce volume to slightly below desired level.
13,6.7 Adjust to final volume by carefully rinsing needle tip and concentrator tube well with solvent
(usually n-hexane).
14. Calculations
14.1 Determination of Concentration
14.1.1 The concentration of the analyte in the extract solution can be taken from a standard curve where
peak height or area is plotted linearly against concentration in nanograms per milliliter (ng/mL). If the detector
response is known to be linear, a single point is used as a calculation constant.
14.1.2 From the standard curve, determine the nanograms of analyte standard equivalent to the peak height
or area for a particular compound.
14.1.3 Ascertain whether the field blank is contaminated. Blank levels should not exceed 10 ng/sample
for organochlorine pesticides or 100 ng/sample for PCBs and other pesticides. If the blank has been
contaminated, the sampling series must be held suspect.
14.2 Equations
14,2.1 Quantity of the compound in the sample (A) is calculated using the following equation:
A xV\
A = 1000
x Vi J
where:
A = total amount of analyte in the sample, ng.
A., = calculated amount of material injected onto the chromatograph based on calibration
curve for injected standards, ng.
Ve = final volume of extract, mL.
V; = volume of extract injected, /J.L.
1000 = factor for converting microliters to milliliters.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page4A-25
-------
Method TO-4A Pesticides/PCBs
14.2.2 The extraction efficiency (EE) is determined from the recovery of surrogate spike as follows:
EE(%) = — [100]
where:
EE = extraction efficiency, %
S = amount of spike recovered, ng.
S, = amount of spike added to plug, ng.
The extraction efficiency (surrogate recovery) must fall between 60-120% to be acceptable.
14.2.3 The total volume of air sampled under ambient conditions is determined using the following
equation:
n
V rr x P)
Z-F \i; A *• \)
v = lii
1000 L/m3
where:
V,= total volume of air sampled, m3.
T, = length of sampling segment between flow checks, min.
F, = average flow during sampling segment, L/min.
14.2.4 The air volume is corrected to EPA standard temperature (25 °C) and standard pressure (760 mm
Hg) as follows:
V -V
298K
760 mm Hg tA
where:
V, = volume of air at standard conditions (25 °C and 760 mm Hg), std. m3.
Vt = total volume of air sampled, m3.
Pb = average ambient barometric pressure, mm Hg.
Pw = vapor pressure of water at calibration temperature, mm Hg.
tA = average ambient temperature, °C + 273.
14.2.S If the proper criteria for a sample have been met, concentration of the compound in a standard cubic
meter of air sampled is calculated as follows:
C,(ng/std. m3) =
(A)
-------
Pesticides/PCBs Method TO-4A
If it is desired to convert the air concentration value to parts per trillion (ppt) in dry air at standard
temperature and pressure (STP), the following conversion is used:
ppt = 0.844 (CJ
The air concentration can be converted to parts per trillion (v/v) in air at STP as follows:
(24.45) (Ca)
pptv =
(MW)
where:
MW = molecular weight of the compound of interest, g/g-mole.
14.2.6 If quantification is performed using an internal standard, a relative response factor (RRF) is
calculated by the equation:
RRF =
where:
Is = integrated area of the target analyte peak, counts.
Iis = integrated area of the internal standard peak, counts.
Cis = concentration of the internal standard, ng///L.
Cs = concentration of the analyte, nj
14.2.7 The concentration of the analyte (CJ in the sample is then calculated as follows:
3 (RRF)(lis)
where:
Is = integrated area of the target analyte peak, counts.
RRF = relative response factor (see Section 14.2.7).
15. Performance Criteria and Quality Assurance
[Note: This section summarizes required quality assurance (QA) measures and provides guidance
concerning performance criteria that should be achieved within each laboratory.]
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-27
-------
Method TO-4A Pesticides/PCBs
15.1 Standard Operating Procedures (SOPs)
15.1.1 Users should generate SOPs describing the following activities accomplished in their laboratory;
(1) assembly, calibration, and operation of the sampling system, with make and model of equipment used; (2)
preparation, purification, storage, and handling of sampling cartridges, (3) assembly, calibration, and operation
of the analytical system, with make and model of equipment used; and (4) all aspects of data recording and
processing, including lists of computer hardware and software used.
15.1.2 SOPs should provide specific stepwise instructions and should be readily available to, and
understood by, the laboratory personnel conducting the work,
15,2 Process, Field, and Solvent Blanks
15.2.1 One filter/PUF cartridge from each batch of approximately twenty should be analyzed, without
shipment to the field, for the compounds of interest to serve as a process blank.
15.2.2 During each sampling episode, at least one filter/PUF cartridge should be shipped to the field and
returned, without drawing air through the sampler, to serve as a field blank.
15.2.3 Before each sampling episode, one PUF plug from each batch of approximately twenty should be
spiked with a known amount of the standard solution. The spiked plug will remain in a sealed container and
will not be used during the sampling period. The spiked plug is extracted and analyzed with the other samples.
This field spike acts as a quality assurance check to determine matrix spike recoveries and to indicate sample
degradation.
15.2.4 During the analysis of each batch of samples, at least one solvent process blank (all steps conducted
but no filter/PUF cartridge included) should be carried through the procedure and analyzed.
15.2.5 Levels for process, field and solvent blanks should not exceed 10 ng/sample for single components
or 100 ng/sample for multiple component mixtures (i.e., for organochlorine pesticides and PCBs).
15.3 Method Precision and Bias
15.3.1 Precision and bias in this type of analytical procedure are dependent upon the precision and bias
of tire analytical procedure for each compound of concern, and the precision and bias of the sampling process.
15.3.2 Several different parameters involved in both the sampling and analysis steps of this method
collectively determine the precision and bias with which each compound is detected. As the volume of air
sampled is increased, the sensitivity of detection increases proportionately within limits set by: (a) the retention
efficiency for each specific component trapped on the polyurethane foam plug, and (b) the background
interference associated with the analysis of each specific component at a given site sampled. The sensitivity
of detection of samples recovered by extraction depends on: (a) the inherent response of the particular GC
detector used in the determinative step, and (b) the extent to which the sample is concentrated for analysis. It
is the responsibility of the analyst(s) performing the sampling and analysis steps to adjust parameters so that
the required detection limits can be obtained.
15.3.3 The reproducibility of this method for most compounds for which it has been evaluated has been
determined to range from ±5 to ±30% (measured as the relative standard deviation) when replicate sampling
cartridges are used (N>5). Sample recoveries for individual compounds generally fall within the range of 90
to 110%, but recoveries ranging from 65 to 125% are considered acceptable.
Page 4A-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
15.4 Method Safety
15.4.1 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.
15.4.2 It is the users responsibility to consult and establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to the implementation of this procedure. This should
be part of the users SOP manual.
16. References
1. Riggin, R, M., Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air, U. S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory, Quality
Assurance Division, Research Triangle Park, NC, EPA-600/4-84-041, April 1984.
2. Winberry, W. T. Jr., et al., "Determination of Benzo(a)Pyrene and Other Polynuclear Aromatic
Hydrocarbons (PAHs) in Ambient Air Using Gas Chromatographic (GC) and High Performance Liquid
Chromatographic (HPLC) Analysis: Method TO-13," in Compendium of Methods for the Determination of
Toxic Organic Compounds in Ambient Air, Second Supplement, U. S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Quality Assurance Division, Research Triangle Park, NC,
EPA-600/4-89-018, March 1989.
3. Winberry, W. T. Jr., et al., "Determination of Organochlorine Pesticides in Indoor Air: Method IP-8," in
Compendium of Methods for the Determination of Air Pollutant in Indoor Air, U. S. Environmental
Protection Agency, Research Triangle Park, NC, EPA-600/4-90-010, May 1990.
4. "Standard Practice for Sampling and Analysis of Pesticides and Polychlorinated Biphenyls in Air," Annual
Book of ASTM Standards, Method D4861-94, ASTM, Philadelphia, PA.
5. Lewis, R,, and MacLeod, K., "Portable Sampler for Pesticides and Semi-Volatile Industrial Organic
Chemicals in Air," Anal, Chem., Vol. 54, 1982, pp. 310-315.
6. Winberry, W. T. Jr., et al., "Determination of Organochlorine Pesticides in Ambient Air Using Low Volume
Polyurethane Foam (PUF) Sampling with Gas Chromatography/Electron Capture Detector (GC/ECD):
Method TO-10, in Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air, Second Supplement, U. S. Environmental Protection Agency, Research Triangle Park, NC,
EPA-600/4-89-018, March 1989.
7. Lewis, R,, and Brown, A., and Jackson, M., "Evaluation of Polyurethane Foam for Sampling of Pesticides,
Polychlorinated Biphenyls and Polychlorinated Napththalenes in Ambient Air," Anal. Chem., Vol. 49, 1977,
pp. 1668-1672.
8. Armour, J., and Burke, J., "Method for Separating Polychlorinated Biphenyls from DDT and Its Analogs,"
Journal of the Association of Official Analytical Chemists, Vol. 53, No. 4, 1970, pp. 761-768.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-29
-------
Method TO-4A : Pesticides/PCBs
9. Manual of Analytical Methods for the Analysis of Pesticides in Human and Environmental Samples, U.
S. Environmental Protection Agency, Research Triangle Park, NC, EPA-600/8-80-03S, June 1980 (NTIS No.
PB82-208752).
10. Carcinogens - Working with Carcinogens, Department of Health, Education, and Welfare, Public Health
Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No.
77-206, August 1977,
11. OSHA Safety and Health Standards, General Industry, (29CFR1910), Occupational Safety and Health
Administration, OSHA, 2206, Revised, January 1976.
12, "Safety in Academic Chemistry Laboratories," American Chemical Society Publication, Committee on
Chemical Safety, 3rd Edition, 1979.
13. Kogan, V., Kuhlman, M., Coutant, R., and Lewis, R., "Aerosol Filtration in Sorbent Beds," Journal of
the Air and Waste Management Association, Vol. 43, 1993, pp. 1367-1373.
14. Lewis, R., and Lee, R., "Air Pollution from Pesticide Sources, Occurrences and Dispersion," in: Air
Pollution from Pesticides and Agricultural Processes, Lee, R., Editor, CRC Press, Boca Raton, FL, 1976,
pp. 51-94.
15. Lewis, R., "Problem Associated with Sampling for Semi-Volatile Organic Chemicals in Air," in
Proceedings of the 1986 EPA/APCA Symposium on Measurement of Toxic Air Pollutants, Air and Waste
Management Association, Pittsburgh, PA, 1986, pp. 134-145.
16. Camann, D., Harding, J., and Lewis, R., "Trapping of Particle-Associated Pesticides in Indoor Air by
Polyurethane Foam and Evaporation of Soil Track-In as a Pesticide Source," in: Indoor Air '90, Vol. 2,
Walkinshaw, D., Editor, Canada Mortgage and Housing Corp., Ottawa, 1990, pp. 621-626.
17. Marplc, V., Rubow, K., Turner, W., and Spengler, J., "Low Flow Rate Sharp Cut Impactors for Indoor
Air Sampling Design and Calibration," Journal of the Air Pollution Control Association. Vol. 37, 1987,
pp. 1303-1307.
18. Hsu, J., Wheeler, H., Camann, D., Shatterberg, H., Lewis, R., and Bond, A., "Analytical Methods for
Detection of Non-Occupational Exposure to Pesticides," Journal ofChromatographic Science, Vol. 26, 1988,
pp. 181-189.
19. Lewis, R. G., and Jackson, M. D., "Modification and Evaluation of a High-Volume Air Sampler for
Pesticides and Semi-Volatile Industrial Organic Chemicals," Anal, Chem., 54, 592-594, 1982.
20. Lewis, R. G., Jackson, M. D., and MacLeod, K. E., "Protocol for Assessment of Human Exposure to
Airborne Pesticides," U, S. Environmental Protection Agency, Research Triangle Park, NC, EPA-600/2-80-
180, May 1980.
Page 4A-30 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-4A
21. Riggin, R. M., Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds
in Ambient Air, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA-600/4-83-027,
June 1983.
22. Longbottom, J. E., and Lichtenberg, J. J., "Methods for Organic Chemical Analysis of Municipal and
Industrial Wastewater," U. S. Environmental Protection Agency, Cincinnati, OH, EPA-600/4-82-057, May
1982.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-31
-------
Method TO-4A
Pesticides/FCBs
TABLE 1. COMPOUNDS FOR WHICH PROCEDURE HAS BEEN TESTED1
Compound
Alachlor
Aldrin
Allethrin
Aroclor 1242
Aroclor 1254
Aroclor 1260
Atrazine
Bcndiocarb
BHC (a- and p-Hexachlorocyclohexanes)
Captan
Carbaryl
Carbofuran
Chlordane, technical
Chlorothatonil
Chlorotoluron
Chlorpyritos
2,4-D esters and salts
Dacihal
p,p-'DDT
p,p-'DDE
Diazinon
Dicloran
Dicldrin
Dicofol
Dierotophos
Diuron
Ethyl parathion
Fenvalerate
Fluomcturon
Recommended
Analysis* ..-.
GC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/NPD
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/NPD or FPD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
HPLC/UV
HPLC/UV
Compound
Folpet
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Lindane (y-BHC)
Linuron
Malathion
Methyl parathion
Methoxychlor
Metolachlor
Mexacarbate
Mirex
Monuron
Trans-nonachlor
Oxychlordane
PentachJorobenzene
Pentaehlophenol
Permethrin (cis and trans)
o-Phenylphenol
Phorate
Propazine
Propoxur (Baygon)
Pyrethrin
Resmethrin
Ronnel
Simazine
Terbuthiuron
Trifluralin
Recommended
Analysis
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
GC/NPD or FPD
GC/NPD or FPD
GC/FCD
GC/ECD
GC/FCD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
GC/NPD
HPLC/UV
HPLC/UV
HPLC/UV
GC/ECD
HPLC/UV
HPLC/UV
GC/ECD
1 The following recommendations are specific for that analyte for maximum sensitivity.
1 GC = gas chromatography; ECD = electron capture detector, FPD = flame photometric detector; HPLC = high performance
liquid chromatography; NPD = nitrogen-phosphorus detector; UV = ultraviolet absorption detector; GC/MS = gas
chrotnatography/mass spectrometry may also be used.
Page 4A-32
Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs
Method TO-4A
Magnehlic Gauge
0-100 in. •
Exhaust Duct
(Sin. x 10ft)
Sampling Head
(see Figure 3)
Voltage Variator
Elapsed Time
Meter
7-Day Timer
Figure 1. Typical high volume air sampler for monitoring common pesticides and PCBs.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 4A-33
-------
Method TO-4A
Pestlcides/PCBs
C
Air Flow
Particle Fitter
Particle Filter
Support
• Assembled
Sampling
Module
Air Flow
Exhaust
•. «„» v v *•
if * >. • •
% v ',i *il
; \-. * <, ,
>. ». V rf
. v > y -.
!«.*» v V *
Filter Retaining Ring
Silicone Gasket
102-mm
Quartz-fiber
Filter
-Filter Support Screen
Filter Holder (Part 2)
Silicone Gasket
Glass Cartridge
Retainlnct Screen
Sorbent
Retaining Screen
Silicone Gasket
Cartridge
He-Idler
(Part 1)
Figure 2. Typical absorbent cartridge assembly for sampling common pesticides and PCBs.
Page 4A-34
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pesticides/PCBs
Method TO-4A
Exhaust Hose
4" Diameter Pullflex
Filter and Support
PUF Adsorbent
Cartridge and Support
Quick Release Connections
for Module
Quick Release Connections
for Magnahelic Gage
Row Control Valve
Elapsed Time Indicator
Figure 3. Portable high volume air sampler developed by EPA.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 4A-35
-------
Method TO-4A
Pesticides/PCBs
Water In
Saxhlet
Extraction
Tub* ond
Thimble
Water Out
Flask
(a) Soxhlet Extraction Apparatus
with Allihn Condenser
3 Ball Macro
Synder Column
500 ml
Evaporator
Flask
10 mL
Concentrator
Tube
(b) Kuderna-Dariish (K-D) Evaporator
with Macro Synder Column
Disposable 6 inch
Pasteur Pipelte
3
^
t
Inches
v. S
^-7T~%
^CiLiIi«*
<*^s
X!';-;- J^v
m^i i Gfom Sodiufti Sulfotc
^, 10 Grom Silica
Gel Slurry
*ft'-;.:-:~-f}^ — moss wool Plug
(c) Silico Gel Clean-up Column
Figure 4. Apparatus used for sample clean-up and extraction.
Page 4A-36
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pesticides/PCBs
Method TO-4A
Glass PUF Cartridge with
Stainless Steel Screens
,64mm O.D..
CM
en
in
en
Glass
Cartridge
End Cap
PUF Plug
End Cap
5a. Glass PUF cartridge, plug, and end caps.
Accessories
Teflon Sealing Caps PUF Insert
with O-rings for
capping PUF Sampler
1
Aluminum Canister for Shipping
and Storage of the PUF Sampler
5b. PUF shipping container.
Figure 5. Glass PUF cartridge (5a) and shipping container
(5b) for use with high-volume sampling systems.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 4A-37
-------
Method TO-4A
Pesticides/PCBs
Mercury
Monometer
o o o o o o
Barometer
Thermometer
Filter Adapter
Rpotsmeter
High Volume Motor
Resistance Plates
Figure 6. Positive displacement rootsmeter used to calibrate orifice transfer standard.
Page 4A-38
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 4A-39
r
]
(
]
i
s
A
COMPENDIUM METHOD TO-4A
ORIFICE CALIBRATION DATA SHEET
Ti Name
Ji rmnHg
Drifice No.
Date
Rootsmeter No.
'r.
] Plants
'. Tioles)
5
7
10
13
18
Air Y/o|uiae \ ; •
. Measured by' :
: Rootsmeter V^ .'
•(R3)
200
200
300
300
300
J:
5.66
5.66
8.50
8.50
8.50
: . •„* '.' ' \'
5wt3itwSiQ
: Volume, :
Factors: (R3)(0.02
Calculation Equations:
1 y _ \T ( I \t *A\
ivhere:
Tstd =
pstd =
J- Qstd =
* ffl ^ p ^^ rp
296°K
760.0 mm Hg
IT
Air Volume
Through:
#(miH)
ooo m \ _
•fcSSi,
; Hg> .
m.3 and (in.
Pressure
Drop .•
. AOJOSS •
Orifice, ••' :
• ;.. 'Ftdwiate',' .
,- ^ _„ . xiriin ri£v
hTtrl 9S a i . . ° I — nirv
ngj zD.t { ) mn
in. Hg
':' Y. - axis. . . -: •
-;^ ;:-:
iHg
i
Figure 7. Orifice calibration data sheet.
s
1
w
1
a
i.
-------
Method TO-4A
Pesticides/PCBs
Shutoffvalvts
~ Manometer
0-18 in.
Magnehelte gauge
0 -100 in.
Elapsed time
meter
Exhaust duct
Figure 8. Field calibration configuration of the high-volume sampler
for common pesticides and PCBs.
Page 4A-40
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pesticides/PCBs
Method TO-4A
COMPENDIUM METHOD TO-4A
FIELD CALIBRATION DATA SHEET FOR SAMPLER CALIBRATION
Sampler ID:
Sampler Location:
High Volume Transfer Orifice Data:
Correlation Coefficient (CC1):
(CC2):
Intercept (Bl):
(B2):
Calibration Orifice ID:
Job No.:
Slope (Ml):
(M2):
Calibration Date:
Time:
Calibration Ambient Temperature: °F
Calibration Ambient Barometric Pressure:
Calibration set point (SP):
CALIBRATOR'S SIGNATURE
."Hg.
mmHg
SAMPLER CALIBRATION
Actual values from calibration
Orifice
manometer,
inches
(Yl)
Monitor
Magnehelic.,
inches
(Y2)
70
60
50
40
30
20
10
Calibrated values
Orifice
manometer
(Y3)
Monitor
Magnehelic
(Y4)
Calculated value
orifice flow, scm
(XI)
Definitions
Yl = Calibration orifice reading, in. H2O
Y2 = Monitor Magnehelic reading, in. H2O
Pa = Barometric pressure actual, mm Hg
Bl = Manfacturer's Calibration orifice Intercept
Ml = Manufacturer's Calibration orifice manometer
slope
Y3 = Calculated value for orifice manometer
= [Yl(Pa/760)(298/{Ta
Y4 = Calculated value for Magnehelic
= [Y2(Pa/760)(298/{Ta + 273})]*
XI = Calculated value orifice flow, scm
Y3-B1
Ml
Pstd = Barometric pressure standard, 760 mm Hg
Ta = Temperature actual, °C
T5ld = Temperature standard, 25°C
Figure 9. Orifice transfer standard field calibration data sheet.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 4A-41
-------
Method TO-4A
Pesticides/PCBs
Y4
(•H20adj.)
Y1
CH20)
—II Manometer
0-18ia
Bapaedtfme
malar
Linear regression of X1 (scmm) vs. Y4
Calculate B2 and M2
». Y3
("hfcOadj.)
X1
(scmm)
Y5 = [avg. mag. Ah (F^ ^298/760)]
X2
(scmm)
Y5-B2
M2
Figure 10. Relationship between orifice transfer standard and flow rate through sampler.
Page 4A-42
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-4A
Sampler I.D. No.:
Lab PUF Sample No.:
Sample location:
COMPENDIUM METHOD TO-4A
FIELD TEST DATA SHEET
GENERAL INFORMATION
Operator:
Other:
PUF Cartridge Certification Date:
Date/Time PUF Cartridge Installed:
Elapsed Timer:
Start
Stop
Diff.
Sampling
Start
Ml
M2
Bl
B2
Barometric pressure ("Hg)
Ambient Temperature (°F)
Rain
Sampling time
Start .
Stop
DiflF.
Stop
Yes.
No
.Yes.
No
Audit flow check within ±10 of set point
Yes
No
TIME
Avg.
TEMP
BAROMETRIC
PRESSURE
MAGNEHEUC
READING
CALCULATED
FLOW RATE
(scrani)
READ BY
Comments
Figure 11. Field test data sheet.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 4A-43
-------
Method TO-4A
Pesticides/PCBs
OPERATING CONDITIONS
Column Type;
DB-5 0.32 capillary,
0.25 um film thickness
Dlbutyichlor«iidat«
Column Temperature Program: 90'C(4min)/16'C per min lo
154"C/4'C per min lo 27CTC.
Detector:
Carrier Gas:
Mak« Up Gas;
Electron Capture
Helium at 1 mL/m'm.
5% Methane/95% Argon at 60 mL/mln.
Heptachlor
Undone
Aldrin
II I
Cndrin
Dietdrin
Methoxychlor
p,p'DDT
TIME
Figure 12. Chromatogram showing a mixture of single component pesticides determined
by GC/ECD using a capillary column.
Page 4A-44
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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EPA/625/R-96/010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-5
Determination of Aldehydes and Ketones in Ambient Air Using
High Performance Liquid Chromatography (HPLC)
Summary of Method
Compendium Method TO-5 involves drawing ambient air through a midget impinger
containing 10 mL of 2N HC1/0.05% 2,4-dinitrophenylhydrazine (DNPH reagent) and 10 mL of
isooctane. Aldehydes and ketones readily form stable 2,4-dinitrophenylhydrazones (DNPH
derivatives).
After sampling, the impinger solution is placed in a screw-capped vial having a Teflon®-lined
cap and returned to the laboratory for analysis. The DNPH derivatives are recovered by removing
the isooctane layer, extracting the aqueous layer with 10 mL of 70/30 hexane/methylene chloride, and
combining the organic layers.
The combined organic layers are evaporated to dryness under a steam of nitrogen and the
residue dissolved in methanol. The DNPH derivatives are determined using reversed phase HPLC
with an ultraviolet (UV) adsorption detector operated at 370 nm.
Sources of Methodology
Method TO-5 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-5 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 5-1
-------
Method TO-S Carbonyl(s)
http://www.epa.gov/ttn/amtic/airtox.html
Methods TO-1 to TO-13 are now posted in the portable document format (PDF),
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.com/prodindex/acrobat/readstep.htnil
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 5-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-6
Determination of Phosgene in Ambient Air Using
High Performance Liquid Chromatography (HPLC)
Summary of Method
Compendium Method TO-6 involves drawing an air sample through a midget impinger
containing 10 mL of 2% aniline/toluene (2/98 by volume). Phosgene readily reacts with aniline to
form carbanilide (1,3-diphenylurea), which is stable indefinitely. After sampling, the impinger
contents are transferred to a screw-capped vial having a Teflon-lined cap and returned to the
laboratory for analysis. The solution is taken to dryness by heating to 60 °C on an aluminum heating
block under a gentle stream of pure nitrogen gas. The residue is dissolved in 1 mL of acetonitrile.
Carbanilide is determined in the acetonitrile solution using reverse-phase HPLC with an ultraviolet
(UV) absorbance detector operating at 254 nm. Precision for phosgene spiked into a clean air stream
is ±15-20% relative standard deviation. Recovery is quantitative within that precision, down to less
than 3 ppbv.
Sources of Methodology
Method TO-6 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-6 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 6-1
-------
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.eoin/prodindex/acrobat/readstep.html
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 6-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-7
Method for the Determination of N-nitrosodimethylamine (NDMA)
in Ambient Air Using Gas Chromatography
Summary of Method
Compendium Method TO-7 involves drawing ambient air through a Thermosorb/N adsorbent
cartridge at a rate of approximately 2 L per minute for an appropriate period of time. Breakthrough
has been shown not to be a problem with total sampling volumes of 300 L (i.e., 150 minutes at 2 L
per minute) or less. The selection of Thermosorb/N adsorbent over Tenax® GC, was due, in part,
to recent laboratory studies indicating artifact formation on Tenax® from the presence of oxides of
nitrogen in the sample matrix.
After sampling, the cartridge is plugged and returned to the laboratory for analysis. In the
laboratory, the cartridge is pre-eluted with 5 mL of methylene chloride (in the same direction as
sample flow) to remove interferences. Residual methylene chloride is removed by purging the
cartridge with air in the same direction. The cartridge is then eluted, in the reverse direction, with
2 mL of acetone. This eluate is collected in a screw-capped vial and refrigerated until analysis.
NDMA is determined by GC/MS using a Carbowax 20M capillary column, NDMA is quantified from
the response of the m/e 74 molecular ion using an external standard calibration method.
Sources of Methodology
Method TO-7 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium, Method TO-7 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone; 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 7-1
-------
Method TO-7 NDMA
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.com/prodindex/acrobat/readstep.hitml
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 7-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-8
Method for the Determination of Phenol and Methylphenols (Cresols)
in Ambient Air Using High Performance Liquid Chromatography
Summary of Method
Compendium Method TO-8 involves drawing ambient air through two midget impingers, each
containing 15 mL of 0.1 N NaOH. The phenols are trapped as phenolates. The impinger solutions
are placed in a vial with a Teflon®-lined screw cap and returned to the laboratory for analysis. The
solution is cooled in an ice bath and adjusted to a pH <4 by addition of 1 mL of 5% sulfuric acid
(V/V). The sample is adjusted to a final volume of 25 mL with distilled water. The phenols are
determined using reverse-phase HPLC with either ultraviolet (UV) absorption detection at 274 nm,
electrochemical detection, or fluorescence detection. In general, the UV detection approach should
be used for relatively clean samples.
Sources of Methodology
Method TO-8 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium. Method TO-8 is contained in the original Compendium of
Methods for the Determination of Toxic Organic Compounds in Ambient Air, EP A-600/4-89-017,
which may be purchased in hard copy from: National Technical Information Service, 5285 Port
Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E-Mail:
info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-methods
may also be available from various commercial sources.
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtox.html
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 8-1
-------
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader, Acrobat readers are
available from Adobe®, free of charge, at:
http://www.adobe.coin/prodindex/acrobat/readstep.htinl
and are required to read Acrobat (PDF) files. Readers are available for Windows,
Macintosh, and DOS.
Page 8-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
EPA/625/R-96/010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-9A
Determination Of Polychlorinated,
Polybrominated And
Brominated/Chlorinated
Dibenzo-p-Dioxins And Dibenzofurans In
Ambient Air
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-9A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/010b), which was prepared under
Contract No. 68-C3-0315, WA No. 3-10, 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, John Burckle, and Scott Hedges, Center for Environmental Research Information
(CERI), and Frank F. McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of
Research and Development, were responsible for overseeing the preparation of this method. 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 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
* Heidi Schultz, ERG, Lexington, MA
William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Method TO-9 was originally published in March of 1989 as one of a series of peer reviewed methods in the
second supplement to "Compendium of Methods for the Determination of Toxic Organic Compounds in
Ambient Ait;" EPA 600/4-89-018. In an effort to keep these methods consistent with current technology,
Method TO-9 has been revised and updated as Method TO-9A in this Compendium to incorporate new or
improved sampling and analytical technologies.
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)
Bob Harless, U.S. EPA, NERL, RTF, NC
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
• Gil Radolovich, Midwest Research Institute, KC, MO
« Mark Horrigan, Midwest Research Institute, KC, MO
Peer Reviewers
Audrey E. Dupuy, U.S. EPA, NSTL Station, MS
* Greg Jungclaus, Midwest Research Institute, KC, MO
Stan Sleva, TRC, RTF, NC
Robert G. Lewis, U.S. EPA, NERL, RTF, NC
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Whitaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence
during the development of this manuscript has enabled it's production.
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 TO-9A
Determination Of Poly chlorinated, Polybrominated And Brominated/Chlorinated
Dibenzo-p-Dioxins And Dibenzofurans In Ambient Air
TABLE OF CONTENTS
Page
1. Scope 9A-1
2. Summary of Method , , 9A-2
3. Significance 9A-3
4. Safety , 9A-3
5, Applicable Documents 9A-4
5.1 ASTM Standards 9A-4
5,2 EPA Documents 9A-4
5.3 Other Documents 9A-5
6. Definitions 9A-5
7. Interferences And Contamination 9A-9
8. Apparatus 9A-9
8.1 High-Volume Sampler . 9A-9
8.2 High-Volume Sampler Calibrator 9A-9
8.3 High Resolution Gas Chromatograph-High Resolution Mass Spectrometer-Data
System (HRGC-HRMS-DS) 9A-10
9. Equipment And Materials 9A-10
9.1 Materials for Sample Collection 9A-10
9.2 Laboratory Equipment 9A-11
9.3 Reagents and Other Materials 9A-11
9.4 Calibration Solutions and Solutions of Standards Used in the Method 9A-12
10. Preparation Of PUF Sampling Cartridge 9A-12
10.1 Summary of Mediod 9A-12
10.2 Preparation of Sampling Cartridge 9A-13
10.3 Procedure for Certification of PUF Cartridge Assembly 9A-13
10.4 Deployment of Cartridges for Field Sampling 9A-14
11. Assembly, Calibration And Collection Using Sampling System 9A-14
11.1 Description of Sampling Apparatus 9A-14
11.2 Calibration of Sampling System 9A-15
11.3 Sample Collection 9A-21
in
-------
TABLE OF CONTENTS (continued)
Page
12. Sample Preparation , 9A-23
12.1 Extraction Procedure for Quartz Fiber Filters and PUF Plugs 9A-23
12.2 Cleanup Procedures 9A-23
12.3 Glassware Cleanup Procedures 9A-25
13. HRGC-HRMS System Performance 9A-25
13.1 Operation of HRGC-HRMS 9A-25
13.2 Colum Performance 9A-26
13,3 SIM Cycle Time 9A-26
13.4 Peak Separation 9A-26
13.5 Initial Calibration 9A-26
13.6 Criteria Required for Initial Calibration 9A-27
13.7 Continuing Calibration 9A-28
14. HRGC-HRMS Analysis And Operating Parameters 9A-28
14.1 Sample Analysis 9A-28
14.2 Identication Criteria 9A-29
14.3 Quantification 9A-29
14.4 Calculations 9A-30
14.5 Method Detection Limits (MDLs) 9A-31
14.6 2,3,7,8-TCDD Toxic Equivalents 9A-31
15. Quality Assurance/Quality Control (QA/QC) 9A-32
16. Report Format 9A-33
17. References 9A-34
IV
-------
METHOD TO-9A
Determination Of Polychlorinated, Polybrominated And
Brominated/Chlorinated Dibenzo-p-Dioxins
And Dibenzofurans In Ambient Air
1. Scope
1.1 This document describes a sampling and analysis method for the quantitative determination of
polyhalogenated dibenzo-p-dioxins and dibenzofurans (PHDDs/PHDFs) in ambient air, which include the
polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenzo-p-dioxins
and dibenzofurans (PBDDs/PBDFs), and bromo/chloro dibenzo-p-dioxins and dibenzofurans
(BCDDs/BCDFs). The method uses a high volume air sampler equipped with a quartz-fiber filter and
polyurethane foam (PUF) adsorbent for sampling 325 to 400 m3 ambient air in a 24-hour sampling period.
Analytical procedures based on high resolution gas chromatography-high resolution mass spectrometry
(HRGC-HRMS) are used for analysis of the sample.
1.2 The sampling and analysis method was evaluated using mixtures of PHDDs and PHDFs, including the
2,3,7,8-substituted congeners (1,2). It has been used extensively in the U.S. Environmental Protection
Agency (EPA) ambient air monitoring studies (3,4) for determination of PCDDs and PCDFs.
1.3 The method provides accurate quantitative data for tetra- through octa-PCDDs/PCDFs (total
concentrations for each isomeric series).
1.4 Specificity is attained for quantitative determination of the seventeen 2,3,7,8-substituted PCDDs/PCDFs
and specific 2,3,7,8-substituted PBDD/PBDF and BCDD/BCDF congeners.
1.5 Minimum detection limits (MDLs) in the range of 0.01 to 0.2 picograms/meter3 (pg/m3) can be achieved
for these compounds in ambient air.
1.6 Concentrations as low as 0.2 pg/m3 can be accurately quantified.
1.7 The method incorporates quality assurance/quality control (QA/QC) measures in sampling, analysis, and
evaluation of data.
1.8 The analytical procedures also have been used for the quantitative determination of these types of
compounds in sample matrices such as stack gas emissions, fly ash, soil, sediments, water, and fish and
human tissue (5-9).
1.9 The method is similar to methods used by other EPA, industry, commercial, and academic laboratories
for determining PCDDs and PCDFs in various sample matrices (10-25). This method is an update of the
original EPA Compendium Method TO-9, originally published in 1989 (26).
1.10 The method does not separately quantify gaseous PHDDs and PHDFs and particulate-associated
PHDDs and PHDFs because some of the compounds volatilize from the filter and are collected by the PUF
adsorbent. For example, most of the OCDD is collected by the filter and most of the TCDDs are collected
by the PUF during sampling. PCDDs/PCDFs may be distributed between the gaseous and particle-adsorbed
phases in ambient air. Therefore, the filter and PUF are combined for extraction in this method.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-1
-------
Method TO-9A Dioxins and Furans
1.11 The sampling and analysis method is very versatile and can be used to determine other brominated and
brominated/chlorinated dioxins and furans in the future when more analytical standards become available
for use in the method. A recent modification of the sample preparation procedure provides the capability
required to determine PCDDs, PCDFs, PCBs, and PAHs in the same sample (27).
2. Summary of Method
2.1 Quartz-fiber filters and glass adsorbent cartridges are pre-cleaned with appropriate solvents and dried
in a clean atmosphere. The PUF adsorbent plugs are subjected to 4-hour Soxhlet extraction using an
oversized extractor to prevent distortion of the PUF plug. The PUF plugs are then air dried in a clean
atmosphere and installed in the glass cartridges. A 50 microliter (/uL) aliquot of a 16 picogram/microliter
(pg/tuL) solution of 37Cl4-2,3,7,8-TCDD is spiked to the PUF in the laboratory prior to field deployment.
(Different amounts and additional I3C,2-labeIed standards such as 13C12-1,2,3,6,7,8-HxCDF may also be used
if desired.) The cartridges are then wrapped in aluminum foil to protect from light, capped with Teflon®
end caps, placed in a cleaned labeled shipping container, and tightly sealed with Teflon® tap until needed.
2.2 For sampling, the quartz-fiber filter and glass cartridge containing the PUF are installed in the
high-volume air sampler.
2.3 The high-volume sampler is then immediately put into operation, usually for 24 hours, to sample 325
to 400 m3 ambient air.
[Note: Significant losses were not detected when duplicate samplers were operated 7 days and sampled
2660 tn3 ambient air (1-4).]
2.4 The amount of ambient air sampled is recorded at the end of the sampling session. Sample recovery
involves placing the filter on top of the PUF. The glass cartridge is then wrapped with the original aluminum
foil, capped with Teflon® end caps, placed back into the original shipping container, identified, and shipped
to the analytical laboratory for sample processing.
2.5 Sample preparation typically is performed on a "set" of 12 samples, which consists of 9 test samples,
a field blank, a method blank, and a matrix spike.
2.6 The filter and PUF are combined for sample preparation, spiked with 9 13C12-labeled PCDD/PCDF and
4 PBDD/PBDF internal standards (28), and Soxhlet extracted for 16 hours. The extract is subjected to an
acid/base clean-up procedure followed by clean-up on micro columns of silica gel, alumina, and carbon. The
extract is then spiked with 0.5 ng 13C,2-1,2,3,4-TCDD (to determine extraction efficiencies achieved for the
l3C,2-Iabeled internal standards) and then concentrated to 10 /uL for HRGC-HRMS analysis in a 1 mL conical
reactivial.
2.7 The set of sample extracts is subjected to HRGC-HRMS selected ion monitoring (SIM) analysis using
a 60-m DB-5 or 60-m SP-2331 fused silica capillary column to determine the sampler efficiency, extraction
efficiency, and the concentrations or the MDLs achieved for the PHDDs/PHDFs (28). Defined identification
criteria and QA/QC criteria and requirements are used in evaluating the analytical data. The analytical
results along with the volume of air sampled are used to calculate the concentrations of the respective tetra-
Page 9A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Dioxins and Furans Method TO-9A
through octa-isomers, the concentrations of the 2,3,7,8-chlorine or -bromine substituted isomers, or the
MDLs. The concentrations and/or MDLs are reported in pg/m3. The EPA toxicity equivalence factors
(TEFs) can be used to calculate the 2,3,7,8-TCDD toxicity equivalents (TEQs) concentrations, if desired
(18).
3. Significance
3.1 The PHDDs and PHDFs may enter the environment by two routes: (1) manufacture, use and disposal
of specific chemical products and by-products and (2) the emissions from combustion and incineration
processes. Atmospheric transport is considered to be a major route for widespread dispersal of these
compounds in stack gas emissions throughout the environment. The PCDDs/PCDFs are found as complex
mixtures of all isomers in emissions from combustion sources. The isomer profiles of PCDDs/PCDFs found
in ambient air are similar to those found in combustion sources. Isomer profiles of PCDDs/PCDFs related
to chemical products and by-products are quite different in that only a few specific and characteristic isomers
are detectable, which clearly indicate they are not from a combustion source.
3.2 The 2,3,7,8-substituted PCDDs/PCDFs are considered to be the most toxic isomers. Fortunately, they
account for the smallest percentage of the total PCDD/PCDF concentrations found in stack gas emissions
from combustion sources and in ambient air. The 2,3,7,8-tetrachIorodibenzo-p-dioxin (2,3,7,8-TCDD), 1
of 22 TCDD isomers and the most toxic member of PCDDs/PCDFs, is usually found as a very minor
component in stack gas emissions (0.5 to 10 percent of total TCDD concentration) and is seldom found in
ambient air samples. All of the 2,3,7,8-substituted PCDDs/PCDFs are retained in tissue of life-forms such
as humans, fish, and wildlife, and the non 2,3,7,8-substituted PCDDs/PCDFs are rapidly metabolized and/or
excreted.
3.3 Attention has been focused on determining PHDDs/PHDFs in ambient air only in recent years. The
analyses are time-consuming, complex, difficult, and expensive. Extremely sensitive, specific, and efficient
analytical procedures are required because the analysis must be performed for very low concentrations in the
pg/m3 and sub pg/m3 range. The MDLs, likewise, must be in the range of 0.01 to 0.2 pg/m3 for the results
to have significant meaning for ambient air monitoring purposes. The background level of total
PCDDs/PCDFs detected in ambient air is usually in the range of 0.5 to 3 pg/m3, and the PBDFs is in the
range of 0.1 to 0.2 pg/m3 (2,3,14). Because PCDDs/PCDFs, PBDDs/PBDFs, and BCDDs/BCDFs can be
formed by thermal reactions, there has been an increasing interest in ambient air monitoring, especially in
the vicinities of combustion and incineration processes such as municipal waste combustors and resource
recovery facilities (19,20). PBDDs/PBDFs can be created thermally (22,23), and they may also be formed
in certain chemical processes (21). BCDDs/BCDFs have been detected in ash from combustion/incineration
processes (9). The sampling and analysis method described here can be used in monitoring studies to
accurately determine the presence or absence of pg/m3 and sub pg/m3 levels of these compounds in ambient
air (26,27).
4. Safety
4.1 The 2,3,7,8-TCDD and other 2,3,7,8-chlorine or bromine substituted isomers are toxic and can pose
health hazards if handled improperly. Techniques for handling radioactive and infectious materials are
applicable to 2,3,7,8-TCDD and the other PFfDDs and PHDFs. Only highly trained individuals who are
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-3
-------
Method TO-9A Dioxins and Furans
thoroughly versed in appropriate laboratory procedures and familiar with the hazards of 2,3,7,8-TCDD
should handle these substances. A good laboratory practice involves routine physical examinations and
blood checks of employees working with 2,3,7,8-TCDD. It is the responsibility of the laboratory personnel
to ensure that safe handling procedures are employed.
4.2 The toxicity or carcinogenicity of the other penta-, hexa-, hepta-, and octa-PHDDs/PHDFs with chlorine
or bromine atoms in positions 2,3,7,8 are known to have similar, but lower, toxicities. However, each
compound should be treated as a potential health hazard and exposure to these compounds must be
minimized.
4.3 While the procedure specifies benzene as the extraction solution, many laboratories have substituted
toluene for benzene (28). This is due to the carcinogenic nature of benzene. The EPA is presently studying
the replacement of benzene with toluene.
4.4 A laboratory should develop a strict safety program for working with these compounds, which would
include safety and health protocols; work performed in well ventilated and controlled access laboratory;
maintenance of current awareness file of OSHA regulations regarding the safe handling of chemicals
specified in the method; protective equipment; safety training; isolated work area; waste handling and
disposal procedures; decontamination procedures; and laboratory wipe tests. Other safety practices as
described in EPA Method 613, Section 4, July 1982 version, EPA Method 1613 Revision A, April 1990,
Office of Water and elsewhere (29,30).
5. Applicable Documents
5.1 ASTM Standards
• Method D1365 Definitions of Terms Relating to Atmospheric Sampling and Analysis.
• Method E260 Recommended Practice for General Gas Chromatography Procedures.
• Method E355 Practice for Gas Chromatography Terms and Relationships.
5.2 EPA Documents
• Quality Assurance HandbookforAir Pollution Measurement Systems, Volume II, U.S. Environmental
Protection Agency, EPA 600/R-94-038b, May 1994.
• Protocol for the Analysis of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin by High Resolution Gas
Chromatography-High Resolution Mass Spectrometry, U. S. Environmental Protection Agency,
EPA 600/40-86-004, January 1986.
• "Evaluation of an EPA High Volume Air Sampler for Poly chlorinated Dibenzo-p-Dioxins and
Polychlorinated Dibenzofurans," undated report by Battelle under Contract No. 68-02-4127, Project
Officers Robert G. Lewis and Nancy K. Wilson, U. S. Environmental Protection Agency, Research
Triangle Park, North Carolina.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air:
Method TO-9, Second Supplement, U. S. Environmental Protection Agency, EPA 600/4-89-018,
March 1989.
• Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds in Ambient
Air, U. S. Environmental Protection Agency, EPA 600/4-83-027, June 1983.
Page 9A-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Dioxins and Furans Method TO-9A
* "Analytical Procedures and Quality Assurance for Multimedia Analysis of Polychlorinated Dibenzo-p-
Dioxins and Dibenzofurans by High Resolution Gas Chromatography - Low Resolution Mass Spectro-
metry," U. S. Environmental Protection Agency/OSW, SW-846, RCRA 8280 HRGC-LRMS, January
1987.
• "Analytical Procedures and Quality Assurance for Multimedia Analysis of Polychlorinated Dibenzo-p-
Dioxins and Dibenzofurans by High Resolution Gas Chromatography - High Resolution Mass
Spectrometry," U.S. Environmental Protection Agency/OSW, SW-846, RCRA 8290 HRGC-HRMS, June
1987.
« Harless, R., "Analytical Procedures and Quality Assurance Plan for the Determination of PCDDs and
PCDFs Ambient Air near the Rutland, Vermont Municipal Incinerator," Final Report, U. S.
Environmental Protection Agency, AREAL, RTP, NC, 1988.
« Feasibility of Environmental Monitoringand Exposure Assessment for a Municipal Waste Combustor:
Rutland, Vermont Pilot Study, U.S. Environmental Protection Agency, EPA 600/8-91/007, March 1991.
* "Method 23, Determination of Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Dibenzofurans
(PCDFs) from Stationary Sources." Federal Register, Vol. 56, No. 30, February 13, 1991.
* Method 1613 Tetra- through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC-HRMS,
U. S. Environmental Protection Agency, Office of Solid Waste, Washington, DC, April 1990.
5.3 Other Documents
* "Operating Procedures for Model PS-1 Sampler," Graseby/General Metal Works, Inc., Village of
Cleves, OH 45002 (800-543-7412).
• "Chicago Air Quality: PCB Air Monitoring Plan, Phase 2," IEAP/APC/86-011, Illinois Environmental
Protection Agency, Division of Air Pollution Control, April 1986.
• "Operating Procedures for the Thermo Environmental Semi-volatile Sampler," Thermo Environmental
Instruments, Inc. (formerly Wedding and Associates), 8 West Forge Parkway, Franklin, MA 02038 (508-
520-0430).
6. Definitions
[Note: Definitions used in this document and any user-prepared Standard Operating Procedures (SOPs)
should be consistent with those used in ASTMD1356. All abbreviations and symbols are defined within this
document at the point of first use.]
6.1 Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)—
compounds that contain from 1 to 8 chlorine atoms, resulting in a total of 75 PCDDs and 135 PCDFs. The
structures are shown in Figure 1. The numbers of isomers at different chlorination levels are shown in
Table 1. The seventeen 2,3,7,8-substituted PCDDs/PCDFs are shown in Table 2.
6.2 Polybrominated dibenze-p-dioxins (PBDDs) and polybrominated dibenzofurans (PBDFs)
compounds that have the same structure and contain from 1 to 8 bromine atoms, resulting in a total of 75
PBDDs and 135 PBDFs. The structures and isomers are the same as those of the PCDDs/PCDFs shown in
Figure 1 and Tables 1 and 2.
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Method TO-9A Dioxins and Furans
6.3 Brominatcd/chlorinated dibenzo-p-dioxins (BCDDs) and bnominated/chlorinated dibenzofurans
(BCDFs)—compounds with the same structures and may contain from 1 to 8 chlorine and bromine atoms,
resulting in 1550 BCDD congeners and 3050 BCDF congeners.
6.4 Polylmlogcnatcd dibenzo-p-dioxins (PHDDs) and polyhalogenated dibenzofurans (PHDFs)—
dibenzo-p-dioxins and dibenzofurans substituted with 1 or more halogen atoms.
6.5 Isomer—compounds having the sample number and type of halogen atoms, but substituted in different
positions. For example, 2,3,7,8-TCDD and 1,2,3,4-TCDDare isomers. Additionally, there are 22 isomers
that constitute the homologues of TCDDs.
6.6 Isomeric group—a group of dibenzo-p-dioxins or dibenzofurans having the same number of halogen
atoms. For example, the tetra-chlorinated dibenzo-p-dioxins.
6.7 Internal Standard—is an isotopically-labeled analog that is added to all samples, including method
blanks (process and field) and quality control samples, before extraction. They are used along with response
factors to measure the concentration of the analytes. Nine PCDD/PCDF and 4 PBDD/PBDF internal
standards are used in this method. There is one for each of the chlorinated dioxin and furan isomeric groups
with a degree of halogenation ranging from four to eight, with the exception of OCDF.
6.8 High-Resolution Calibration Solutions (see Table 3)—solutions in tridecane containing known
amounts of 17 selected PCDDs and PCDFs, 9 internal standards (l3C12-labeled PCDDs/PCDFs), 2 field
standards, 4 surrogate standards, and 1 recovery standard. The set of 5 solutions is used to determine the
instrument response of the unlabeled analytes relative to the 13C12-labeled internal standards and of the I3C12-
labelcd internal standards relative to the surrogate, field and recovery standards. Different concentrations and
other standards may be used, if desired. Criteria for acceptable calibration as outlined in Section 13.5 should
be met in order to use the analyte relative response factors.
6.9 Sample Fortification Solutions (see Table 4)—solutions (in isooctane) containing the l3C12-labeled
internal standards that are used to spike all samples, field blanks, and process blanks before extraction.
Brominated standards used only when desired.
6.10 Recovery Standard Solution (see Table 5)—Recovery Standard Solution (see Table 5)—an isooctane
solution containing the 13C12-1,2,3,4-TCDD (13CI2-2,3,7,8,9-HxDD optional) recovery standards that are
added to the extract before final concentration for HRGC-HRMS analysis to determine the recovery
efficiencies achieved for the 13C12-labeled internal standards.
6.11 Air Sampler Field Fortification Solution (see Table 6)—an isooctane solution containing the 37C14-
2,3,7,8-TCDD standard that is spiked to the PUF plugs prior to shipping them to the field for air sampling.
6.12 Surrogate Standard Solution (see Table 7)—an isooctane solution containing 4 l3C12-labeled
standards that may be spiked to the filter or PUF prior to air sampling, to the sample prior to extraction, or
to the sample extract before cleanup or before HRGC-HRMS analysis to determine sampler efficiency
method efficiency or for identification purposes (28). Other standards and different concentrations may be
used, if desired.
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Dioxins and Furans Method TO-9A
6.13 Matrix Spike aud Method Spike Solutious (see Table 8)—isooctane solutions of native (non-labeled)
PCDDs and PCDFs and PBDDs and PBDFs that are spiked to a clean PUF prior to extraction.
6.14 Sample Set—consists of nine test samples, field blank, method blank, and matrix spiked with native
PHDDs/PHDFs. Sample preparation, HRGC-HRMS analysis, and evaluation of data is performed on a
sample set.
6.15 Lab Control Spike—standard that is prepared during sample preparation and that contains exactly the
same amounts of all of the labeled and unlabeled standards that were used in extraction and cleanup of the
sample set for HRGC-HRMS analysis.
6.16 Field Blank—consists of a sample cartridge containing PUF and filter that is spiked with the filed
fortification solution, shipped to the field, installed on the sampler, and passively exposed at the sampling
area (the sampler is not operated). It is then sealed and returned to the laboratory for extraction, cleanup,
and HRGC-HRMS analysis. It is treated in exactly the same manner as a test sample. A field blank is
processed with each sampling episode. The field blank represents the background contributions from passive
exposure to ambient air, PUF, quartz fiber filter, glassware, and solvents.
6.17 Laboratory Method Blank—represents the background contributions from glassware, extraction and
cleanup solvents. A Soxhlet extractor is spiked with a solution of 13C12-labeled internal standards, extracted,
cleaned up, and analyzed by HRGC-HRMS in exactly the same manner as the test samples.
6.18 Solvent Blank—an aliquot of solvent (the amount used in the method) that is spiked with the
13C12-labeled internal standards and concentrated to 60 /uL for HRGC-HRMS analysis. The analysis provides
the background contributions from the specific solvent.
6.19 GC Column Performance Evaluation Solution (see Table 9)—a solution containing a mixture of
selected PCDD/PCDF isomers, including the first and last chromatographic eluters for each isomeric group.
Used to demonstrate continued acceptable performance of the capillary column and to define the
PCDD/PCDF retention time windows. Also includes a mixture of tetradioxin isomers that elute closest to
2,3,7,8-TCDD.
6.20 QA/QC Audit Samples—samples of PUF that contain known amounts of unlabeled PCDDS and
PCDFs. These samples are submitted as "blind" test samples to the analytical laboratory. The analytical
results can then be used to determine and validate the laboratory's accuracy, precision and overall analytical
capabilities for determination of PCDDs/PCDFs.
6.21 Relative Response Factor—response of the mass spectrometer to a known amount of an analyte
relative to a known amount of a labeled internal standard.
6.22 Method Blank Contamination—the method blank should be free of interferences that affect the
identification and quantification of PHDDs and PHDFs. A valid method blank is an analysis in which all
internal standard signals are characterized by S/N ratio greater than 10:1 and the MDLs are adequate for the
study. The set of samples must be extracted and analyzed again if a valid method blank cannot be achieved.
6.23 Sample Rerun—additional cleanup of the extract and reanalysis of the extract.
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Method TO-9A Dioxins and Furans
6.24 Extract Reanalysis—analysis by HRGC-HRMS of another aliquot of the final extract.
6.25 Mass Resolution Check—a standard method used to demonstrate a static HRMS resolving power of
10,000 or greater (10 percent valley definition).
6.26 Method Calibration Limits (MCLs)—for a given sample size, a final extract volume, and the lowest
and highest calibration solutions, the lower and upper MCLs delineate the region of quantitation for which
the HRGC-HRMS system was calibrated with standard solutions.
6.27 HRGC-HRMS Solvent Blank—a 1 or 2 ^L aliquot of solvent that is analyzed for tetra- through octa-
PCDDs and PCDFs following the analysis of a sample that contains high concentrations of these compounds.
An acceptable solvent blank analysis (free of PHDDs/PHDFs) should be achieved before continuing with
analysis of the test samples.
6.28 Sampler Spike (SS)—a sampler that is spiked with known amounts of the air sampler field fortification
solution (see Table 6) and the matrix spike solutions (see Table 8) prior to operating the sampler for 24 hours
to sample 325-400 std m3 ambient air. The results achieved for this sample can be used to determine the
efficiency, accuracy and overall capabilities of the sampling device and analytical method.
6.29 Collocated Samplers (CS)—two samplers installed close together at the same site that can be spiked
with known amounts of the air sampler field fortification solution (see Table 6) prior to operating the
samplers for 24 hours to sample 325-400 std m3 ambient air. The analytical results for these two samples
can be used to determine and evaluate efficiency, accuracy, precision, and overall capabilities of the sampling
device and analytical method.
6.30 Congener—a term which refers to any one particular member of the same chemical family. As an
example, there are 75 congeners of chlorinated dibenzo-p-dioxins. A specific congener is denoted by unique
chemical notations. For example, 2,4,8,9-tetrachlorodibenzofuran is referred to as 2,4,8,9-TCDF.
6.31 Homologue—a term which refers to a group of structurally related chemicals that have the same degree
of chlorination. For example, there are eight homologues of CDDs, monochlorinated through
octochlorinated. Notation for homologous classes is as follows:
Class '.'..
Dibenzo-p-dioxin
Dibenzofiiran
No. of halogens
1
2
3
4
5
6
7
8
1 through 8
Acronym
D
F
Acronym
M
D
Tr
T
Pe
Hx
Hp
O
CDDs and CDFs
Example
2,4-DCDD
1,4,7,8-TCDD
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Dioxins and Furans Method TO-9A
7. Interferences And Contamination
7.1 Any compound having a similar mass and mass/charge (m/z) ratio eluting from the HRGC column within
± 2 seconds of the PHDD/PHDF of interest is a potential interference. Also, any compound eluting from the
HRGC column in a very high concentration will decrease sensitivity in the retention time frame. Some
commonly encountered interferences are compounds that are extracted along with the PCDDs and PCDFs
or other PHDDs/PHDFs, e.g., polychlorinated biphenyls (PCBs), methoxybiphenyls, polychlorinated
diphenylethers, polychlorinated naphthalenes, DDE, DDT, etc. The cleanup procedures are designed to
eliminate the majority of these substances. The capillary column resolution and mass spectrometer resolving
power are extremely helpful in segregating any remaining interferences from PCDDs and PCDFs. The
severity of an interference problem is usually dependent on the concentrations and the mass spectrometer
and chromatographic resolutions. However, polychlorinated diphenylethers are extremely difficult to resolve
from PCDFs because they elute in retention time windows of PCDFs, and their fragment ion resulting from
the loss of 2 chlorine atoms is identical to that of the respective PCDF. For example, the molecular ions of
hexachlorodiphenylethers must be monitored to confirm their presence or absence in the analysis for TCDFs.
This requirement also applies to the other PCDFs and PBDFs.
7.2 Since very low levels of PCDDs and PCDFs must be determined, the elimination of interferences is
essential. High purity reagents and solvents must be used, and all equipment must be scrupulously cleaned.
All materials, such as PUF, filter solvents, etc., used in the procedures are monitored and analyzed frequently
to ensure the absence of contamination. Cleanup procedures must be optimized and performed carefully to
minimize the loss of analyte compounds during attempts to increase their concentrations relative to other
sample components. The analytical results achieved for the field blank, method blank, and method spike in
a "set" of samples is extremely important in evaluating and validating the analytical data achieved for the
test samples.
8. Apparatus
[Note: This method was developed using the PS-1 semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has 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.]
8.1 High-Volume Sampler (see Figure 2). Capable of pulling ambient air through the filter/adsorbent
cartridge at a flow rate of approximately 8 standard cubic feet per minute (scfm) (0.225 std m3\min) to obtain
a total sample volume of greater than 325 scm over a 24-hour period. Major manufacturers are;
Tisch Environmental, Village ofCleves, OH
Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8.2 High-Volume Sampler Calibrator. Capable of providing multipoint resistance for the high-volume
sampler. Major manufacturers are:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-9
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Method TO-9A Dioxins and Furans
Tisch Environmental, Village of Cleves, OH
Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
- Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8.3 High Resolution Gas Chromatograph-High Resolution Mass Spectrometer-Data System
(HRGC-HRMS-DS)
8.3.1 The GC should be equipped for temperature programming and all of the required accessories, such
as gases and syringes, should be available. The GC injection port should be designed for capillary columns.
Splitless injection technique, on-column injections, or moving needle injectors may be used. It is important
to use the same technique and injection volume at all times.
8.3.2 The HRGC-HRMS interface, if used, should be constructed of fused silica tubing or all glass or
glass lined stainless steel and should be able to withstand temperatures up to 340°C. The interface should
not degrade the separation of PHDD/PHDF isomers achieved by the capillary column. Active sites or cold
spots in the interface can cause peak broadening and peak tailing. The capillary column should be fitted
directly into the HRMS ion source to avoid these types of problems. Graphite ferrules can adsorb
PHDDs/PHDFs and cause problems. Therefore, Vespel® or equivalent ferrules are recommended.
8.3.3 The HRMS system should be operated in the electron impact ionization mode. The static resolving
power of the instrument should be maintained at 10,000 or greater (10% valley definition). The HRMS
should be operated in the selected ion monitoring (SIM) mode with a total cycle time of one second or less.
At a minimum, the ions listed in Tables 10,11, and 12 for each ofthe select ion monitoring (SIM) descriptors
should be monitored. It is important to use the same set of ions for both calibration and sample analysis.
8.3.4 The data system should provide for control of mass spectrometer, data acquisition, and data
processing. The data system should have the capability to control and switch to different sets of ions
(descriptors/mass menus shown in Tables 10, 11, and 12) at different times during the HRGC-HRMS SIM
analysis. The SIM traces/displays of ion signals being monitored can be displayed on the terminal in real
time and sorted for processing. Quantifications are reported based on computer generated peak areas. The
data system should be able to provide hard copies of individual ion chromatograms for selected SIM time
intervals, and it should have the capability to allow measurement of noise on the baseline. It should also have
the capability to acquire mass-spectral peak profiles and provide hard copies of the peak profiles to
demonstrate the required mass resolution.
8.3.5 HRGC columns, such as the DB-5 (28) and SP-2331 fused silica capillary columns, and the
operating parameters known to produce acceptable results are shown in Tables 13 and 14. Other types of
capillary' columns may also be used as long as the performance requirements can be successfully
demonstrated.
9. Equipment And Materials
9.1 Materials for Sample Collection (see Figure 3a)
9.1.1 Quartz fiber filter. 102 millimeter bindless quartz microfiber filter, Whatman International Ltd,
QMA-4.
9.1.2 Polyurcthane foam (PUF) plugs. 3-inch thick sheet stock polyurethane type (density
0.022 g/cm3). The PUF should be ofthe polyether type used for furniture upholstery, pillows, and mattresses.
The PUF cylinders (plugs) should be slightly larger in diameter than the internal diameter ofthe cartridge.
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Dioxins and Furans Method TO-9A
Sources of equipment are Tisch Environmental, Village of Cleves, OH; University Research Glassware, 116
S. Merritt Mill Road, Chapel Hill, NC; Thermo Environmental Instruments, Inc., 8 West Forge Parkway,
Franklin, MA; Supelco, Supelco Park, Bellefonte, PA; and SKC Inc., 334 Valley View Road, Eighty Four,
PA (see Figure 3b).
9.1.3 Teflon® end caps. For sample cartridge. Sources of equipment are Tisch Environmental, Village
of Cleves, OH; and University Research Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC (see
Figure 3b).
9,1,4 Sample cartridge aluminum shipping containers. For sample cartridge shipping. Sources of
equipment are Tisch Environmental, Village of Cleves, OH; and University Research Glassware, 116 S.
Merritt Mill Road, Chapel Hill, NC (see Figure 3b).
9.1.5 Glass sample cartridge. For sample collection. Sources of equipment are Tisch Environmental,
Village of Cleves, OH; Thermo Environmental Instruments, Inc., 8 West Forge, Parkway, Franklin, MA; and
University Research Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC (see Figure 3b).
9.2 Laboratory Equipment
9.2.1 Laboratory hoods.
9.2.2 Drying oven.
9.2.3 Rotary evaporator. With temperature-controlled water bath.
9.2.4 Balances.
9.2.5 Nitrogen evaporation apparatus.
9.2,6 Pipettes. Disposal Pasteur, 150-mm long x 5-mm i.d.
9,2.7 Soxhlet apparatus. 500-mL.
9.2.8 Glass funnels.
9.2.9 Desiccator.
9.2.10 Solvent reservoir. 125-mL, Kontes, 12.35-cm diameter.
9.2.11 Stainless steel spoons and spatulas.
9.2.12 Glass wool. Extracted with methylene chloride, stored in clean jar.
9.2.13 Laboratory refrigerator.
9.2.14 Chromatographic columns.
9.2.15 Perfluorokerosenes.
9.3 Reagents and Other Materials
9.3.1 Sulfuric acid. Ultrapure, ACS grade, specific gravity 1.84, acid silica.
9.3.2 Sodium hydroxide. Potassium hydroxide, reagent grade, base silica.
9.3.3 Sodium sulfate.
9.3.4 Anhydrous, reagent grade.
9.3.5 Glass wool. Silanized, extracted with methylene chloride and hexane, and dried.
9.3.6 Diethyl ether. High purity, glass distilled.
9.3.7 Isooctane. Burdick and Jackson, glass-distilled.
9,3.8 Hexane. Burdick and Jackson, glass-distilled.
9.3.9 Toluene. Burdick and Jackson, glass-distilled, or equivalent.
9.3.10 Methylene chloride. Burdock and Jackson, chromatographic grade, glass distilled.
9.3.11 Acetone. Burdick and Jackson, high purity, glass distilled.
9.3.12 Tridecane. Aldrich, high purity, glass distilled.
9.3.13 Isooctane. Burdick and Jackson, high purity, glass distilled.
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Method TO-9A Dioxins and Furans
9.3.14 Alumina. Acid, pre-extracted (16-21 hours) and activated.
93.15 Silica gel. High purity grade, type 60, 70-230 mesh; extracted in a Soxhlet apparatus with
methylene chloride (see Section 8.18) for 16-24 hours (minimum of 3 cycles per hour) and activated by
heating in a foil-covered glass container for 8 hours at 130°C.
9.3.16 18 percent Carbopack C/Celite 545.
9.3.17 Methanol. Burdick and Jackson, high purity, glass distilled.
9.3.18 Nonane. Aldrich, high purity, glass distilled.
9.3.19 Benzene. High purity, glass distilled.
9.4 Calibration Solutions and Solutions of Standards Used in the Method
9.4.1 HRGC-HRMS Calibration Solutions (see Table 3). Solutions containing 13CI2-labeled and
unlabeled PCDDs and PCDFs at known concentrations are used to calibrate the instrument. These standards
can be obtained from various commercial sources such as Cambridge Isotope Laboratories, 50 Frontage
Road, Andover, MA 01810, 508-749-8000.
9.4.2 Sample Fortification Solutions (see Table 4). An isooctane solution (or nonane solution)
containing the 13C12-labeled PCDD/PCDF and PBDD/PBDF internal standards at the listed concentrations.
The internal standards are spiked to all samples prior to extraction and are used to measure the concentration
of the unlabeled native analytes and to determine MDLs.
9.4.3 Recovery Standard Spiking Solution (see Table 5). An isooctane solution containing
"C,2-1,2,3,4-TCDD at a concentration of 10 pg/y^L. Additional recovery standards may be used if desired.
9.4.4 Sampler Field Fortification Solution (see Table 6). An isooctane solution containing 10 pg/^uL
J7C!4-2,3,7,8-TCDD.
9.4.5 Surrogate Standards Solution (see Table 7). An isooctane solution containing the four
l3C,2~labeied standards at a concentration of 100 pg//uL.
9.4.6 Matrix/Method Spike Solution (see Table 8). An isooctane solution containing the unlabeled
PCDDs/PCDFs and PBDDs/PBDFs at the concentrations listed.
[Note: All PHDD/PHDF solutions listed above should be stored in a refrigerator at less than or equal to
4 °C in the dark. Exposure of the solutions to light should be minimized.]
9.4.7 Column Performance Evaluation Solutions (see Table 9). Isooctane solutions of first and last
chromatographic eluting isomers for each isomeric group of tetra- through octa-CDDs/CDFs. Also includes
a mixture of tetradioxin isomers that elute closest to 2,3,7,8-TCDD.
10. Preparation Of PUF Sampling Cartridge
10.1 Summary of Method
10.1.1 This part of the procedure discusses pertinent information regarding the preparation and cleaning
of the filter, adsorbents, and filter/adsorbent cartridge assembly. The separate batches of filters and
adsorbents are extracted with the appropriate solvent.
10.1.2 At least one PUF cartridge assembly and one filter from each batch, or 10 percent of the batch,
whichever is greater, should be tested and certified before the batch is considered for field use.
10.1.3 Prior to sampling, the cartridges are spiked with surrogate compounds.
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Dioxins and Furans Method TO-9A
10.2 Preparation of Sampling Cartridge
10.2.1 Bake the quartz filters at 400°C for 5 hours before use.
10.2.2 Set aside the filters in a clean container for shipment to the field or prior to combining with the
PUF glass cartridge assembly for certification prior to field deployment.
10.2.3 The PUF plugs are 6.0-cm diameter cylindrical plugs cut from 3-inch sheet stock and should fit,
with slight compression, in the glass cartridge, supported by the wire screen (see Figure 2). During cutting,
rotate the die at high speed (e.g., in a drill press) and continuously lubricate with deionized or distilled water.
Pre-cleaned PUF plugs can be obtained from commercial sources (see Section 9.1.2).
10.2.4 For initial cleanup, place the PUF plugs in a Soxhlet apparatus and extract with acetone for
16 hours at approximately 4 cycles per hour. When cartridges are reused, use diethyl ether/hexane (5 to
10 percent volume/volume [v/v]) as the cleanup solvent.
[Note; A modified PUF cleanup procedure can be used to remove unknown interference components of the
PUF blank. This method consists of rinsing 50 times with toluene, acetone, and diethyl ether/hexane (5 to
10 percent v/v), followed by Soxhlet extraction. The extracted P UF is placed in a vacuum oven connected
to a water aspirator and dried at room temperature for approximately 2 to 4 hours (until no solvent odor
is detected). The extract from the Soxhlet extraction procedure from each batch may be analyzed to
determine initial cleanliness prior to certification.]
10.2.5 Fit a nickel or stainless steel screen (mesh size 200/200) to the bottom of a hexane-rinsed glass
sampling cartridge to retain the PUF adsorbents, as illustrated in Figure 2. Place the Soxhlet-extracted,
vacuum-dried PUF (2.5-cm thick by 6.5-cm diameter) on top of the screen in the glass sampling cartridge
using polyester gloves.
10.2.6 Wrap the sampling cartridge with hexane-rinsed aluminum foil, cap with the Teflon® end caps,
place in a cleaned labeled aluminum shipping container, and seal with Teflon® tape. Analyze at least 1 PUF
plug from each batch of PUP plugs using the procedures described in Section 10.3, before the batch is
considered acceptable for field use. A level of 2 to 20 pg for tetra-,penta-, and hexa- and 40 to 150 pg for
hepta- and octa-CDDs similar to that occasionally detected in the method blank (background contamination)
is considered to be acceptable. Background levels can be reduced further, if necessary. Cartridges are
considered clean for up to 30 days from date of certification when stored in their sealed containers.
10.3 Procedure for Certification of PUF Cartridge Assembly
10.3.1 Extract 1 filter and PUF adsorbent cartridge by Soxhlet extraction and concentrate using a
Kuderna-Danish (K-D) evaporator for each lot of filters and cartridges sent to the field.
10.3.2 Assemble the Soxhlet apparatus. Charge the Soxhlet apparatus with 300 mL of the extraction
solvent (10 percent v/v diethyl ether/hexane) and reflux for 2 hours. Let the apparatus cool, disassemble it,
and discard the used extraction solvent. Transfer the filter and PUF glass cartridge to the Soxhlet apparatus
(the use of an extraction thimble is optional).
[Note: The filter and adsorbent assembly are tested together in order to reach detection limits, to minimize
cost and to prevent misinterpretation of the data. Separate analyses of the filter and PUF would not yield
useful information about the physical state of most of the PHDDs and PHDFs at the time of sampling due
to evaporative losses from the filter during sampling.]
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Method TO-9A Dioxins and Furans
10.3,3 Add 300 mL of diethyl ether/hexane (10 percent v/v) to the Soxhlet apparatus. Reflux the sample
for 18 hours at a rate of at least 3 cycles per hour. Allow to cool; then disassemble the apparatus.
10.3.4 Assemble a K-D concentrator by attaching a 10-mL concentrator tube to a 500-mL evaporative
flask.
10.3.5 Transfer the extract by pouring it through a drying column containing about 10 cm of anhydrous
granular sodium sulfate and collect the extract in the K-D concentrator. Rinse the Erlenmeyer flask and
column with 20 to 30 mL of 10 percent diethylether/hexane to complete the quantitative transfer.
10.3.6 Add 1 or 2 clean boiling chips and attach a 3-ballSnyder column to the evaporative flask. Pre-wet
the Snyder column by adding about 1 mL of the extraction solvent to the top of the column. Place the K-D
apparatus on a hot water bath (50°C) so that the concentrator tube is partially immersed in the hot water, and
the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the
apparatus and the water temperature as required to complete the concentration in one hour. At the proper
rate of distillation, the balls of the column will actively chatter but the chambers will not flood with
condensed solvent. When the apparent volume of liquid reaches approximately 5 mL, remove the K-D
apparatus from the water bath and allow it to drain and cool for at least 5 minutes. Remove the Snyder
column and rinse the flask and its lower joint into the concentrator tube with 5 mL of hexane. A 5-mL
syringe is recommended for this operation.
10.3.7 Concentrate the extract to 1 mL, cleanup the extract (see Section 12.2.2), and analyze the final
extract using HRGC-HRMS.
10.3.8 The level of target compounds must be less than or equal to 2 to 20 pg for tetra-, penta-, and hexa-
and 40 to 150 pg for hepta- and octa-CDDs for each pair of filter and adsorbent assembly analyzed is
considered to be acceptable,
10.4 Deployment of Cartridges for Field Sampling
10.4.1 Prior to field deployment, add surrogate compounds (i.e., chemically inert compounds not
expected to occur in an environmental sample) to the center bed of the PUF cartridge, using a microsyringe.
The surrogate compounds (see Table 3) must be added to each cartridge assembly.
10.4.2 Use the recoveries of the surrogate compounds to monitor for unusual matrix effects and gross
sampling processing errors. Evaluate surrogate recovery for acceptance by determining whether the
measured concentration falls within the acceptance limits.
11. Assembly, Calibration And Collection Using Sampling System
(Note: Tins method was developed using the PS-I semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has 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.]
11.1 Description of Sampling Apparatus
The entire sampling system is diagrammed in Figure 1. This apparatus was developed to operate at a rate
of 4 to 10 scfm (0.114 to 0.285 std mVmin) and is used by EPA for high-volume sampling of ambient air.
The method write-up presents the use of this device.
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Dioxins and Furans _ Method TO-9A
The sampling module (see Figure 2) consists of a filter and a glass sampling cartridge containing the PDF
utilized to concentrate dioxins/furans from the air. A field portable unit has been developed by EPA (see
Figure 4).
11.2 Calibration of Sampling System
Each sampler should be calibrated (1) when new, (2) after major repairs or maintenance, (3) whenever any
audit point deviates from the calibration curve by more than 7 percent, (4) before/after each sampling event,
and (5) when a different sample collection media, other than that which the sampler was originally calibrated
to, will be used for sampling.
11.2.1 Calibration of Orifice Transfer Standard. Calibrate the modified high volume air sampler in
the field using a calibrated orifice flow rate transfer standard. Certify the orifice transfer standard in the
laboratory against a positive displacement rootsmeter (see Figure 5). Once certified, the recertification is
performed rather infrequently if the orifice is protected from damage. Recertify the orifice transfer standard
performed once per year utilizing a set of five multiple resistance plates.
[Note: The set of five multihole resistance plates are used to change the flow through the orifice so that
several points can be obtained for the orifice calibration curve. The following procedure outlines the steps
to calibrate the orifice transfer standard in the laboratory.]
11.2.1.1 Record the room temperature (T, in °C) and barometric pressure (Pb in mm Hg) on the Orifice
Calibration Data Sheet (see Figure 6). Calculate the room temperature in K (absolute temperature) and
record on Orifice Calibration Data Sheet.
11.2.1.2 Set up laboratory orifice calibration equipment as illustrated in Figure 5. Check the oil level
of the rootsmeter prior to starting. There are 3 oil level indicators, 1 at the clear plastic end and 2 site
glasses, 1 at each end of the measuring chamber.
11.2.1.3 Check for leaks by clamping both manometer lines, blocking the orifice with cellophane tape,
turning on the high volume motor, and noting any change in the rootsmeter's reading. If the rootsmeter's
reading changes, there is a leak in the system. Eliminate the leak before proceeding. If the rootsmeter's
reading remains constant, turn off the hi-vol motor, remove the cellophane tape, and unclamp both
manometer lines.
11.2.1.4 Install the 5-hole resistance plate between the orifice and the filter adapter.
11.2.1.5 Turn manometer tubing connectors 1 turn counter-clockwise. Make sure all connectors are
open.
11.2.1.6 Adjust both manometer midpoints by sliding their movable scales until the zero point
corresponds with the meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on
tubing connectors. (If additional liquid is required for the water manometer, remove tubing connector and
add clean water.)
11.2.1.7 Turn on the high volume motor and let it run for 5 minutes to set the motor brushes. Turn
the motor off. Insure manometers are set to zero. Turn the high volume motor on.
11.2.1.8 Record the time, in minutes, required to pass a known volume of air (approximately 200 to
300 ft3 of air for each resistance plate) through the rootsmeter by using the rootsmeter's digital volume dial
and a stopwatch.
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Method TO-9A Dioxins and Furans
11.2.1.9 Record both manometer readings-orifice water manometer (^H) and rootsmeter mercury
manometer (A?) on Orifice Calibration Data Sheet (see Figure 6).
[Note: &H is the sum of the difference from zero (0) of the two column heights.]
11.2.1.10 Turn off the high volume motor.
11.2.1.11 Replace the 5-hole resistance plate with the 7-hole resistance plate.
11.2.1.12 Repeat Sections 11.2.1.3 through 11.2.1.11.
11.2.1.13 Repeat for each resistance plate. Note results on Orifice Calibration Data Sheet (see
Figure 6). Only a minute is needed for warm-up of the motor. Be sure to tighten the orifice enough to
eliminate any leaks. Also check the gaskets for cracks.
[Nats: The placement of the orifice prior to the rootsmeter causes the pressure at the inlet of the rootsmeter
to be reduced below atmospheric conditions, thus causing the measured volume to be incorrect. The volume
measured by the rootsmeter must be corrected.]
11.2.1.14 Correct the measured volumes on the Orifice Calibration Data Sheet:
P - A? T..
V = V (— V S"S
Vstd Vm v p A T )
rstd * a
where:
V,ld = standard volume, std m3
Vra = actual volume measured by the rootsmeter, m3
P, = barometric pressure during calibration, mm Hg
^P = differential pressure at inlet to volume meter, mm Hg
PItd = 760 mm Hg
T. = ambient temperature during calibration, K.
11.2.1.15 Record standard volume on Orifice Calibration Data Sheet.
11.2.1.16 The standard flow rate as measured by the rootsmeter can now be calculated using the
following formula:
Q - ^
^
where:
Qltd = standard volumetric flow rate, std mVmin
0 = elapsed time, min
11.2.1.17 Record the standard flow rates to the nearest 0.01 std mVmin.
11.2.1.18 Calculate and record J&.H (P^^(298/7^ value for each standard flow rate.
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Dioxins and Furans Method TO-9A
11.2.1.19 Plot each ./AH (P1/Pstd)(298/T1) value (y-axis) versus its associated standard flow rate
(x-axis) on arithmetic graph paper and draw a line of best fit between the individual plotted points.
[Note: This graph will be used in the field to determine standard flow rate.]
11.2.2 Calibration of the High Volume Sampling System Utilizing Calibrated Orifice Transfer
Standard
For this calibration procedure, the following conditions are assumed in the field:
• The sampler is equipped with an valve to control sample flow rate.
• The sample flow rate is determined by measuring the orifice pressure differential, using a magnehelic
gauge.
• The sampler is designed to operate at a standardized volumetric flow rate of 8 fVVmin (0.225 mVmin),
with an acceptable flow rate range within 10 percent of this value.
• The transfer standard for the flow rate calibration is an orifice device. The flow rate through the
orifice is determined by the pressure drop caused by the orifice and is measured using a "U" tube
water manometer or equivalent.
• The sampler and the orifice transfer standard are calibrated to standard volumetric flow rate units
(scfm or scmm).
• An orifice transfer standard with calibration traceable to NIST is used.
• A "U" tube water manometer or equivalent, with a 0- to 16-inch range and a maximum scale division
of 0.1 inch, will be used to measure the pressure in the orifice transfer standard.
• A magnehelic gauge or equivalent, with a 9- to 100-inch range and a minimum scale division of
2 inches for measurements of the differential pressure across the sampler's orifice is used.
• A thermometer capable of measuring temperature over the range of 32° to 122°F(0° to50°C)to±2°F
(±1 °C) and referenced annually to a calibrated mercury thermometer is used.
• A portable aneroid barometer (or equivalent) capable of measuring ambient barometric pressure
between 500 and 800 mm Hg (19.5 and 31.5 in. Hg) to the nearest mm Hg and referenced annually
to a barometer of known accuracy is used.
• Miscellaneous handtools, calibration data sheets or station log book, and wide duct tape are available.
11.2.2.1 Monitor the airflow through the sampling system with a venturi/Magnehelic assembly, as
illustrated in Figure 7. Set up the calibration system as illustrated in Figure 7. Audit the field sampling
system once per quarter using a flow rate transfer standard, as described in the EPA High Volume-Sampling
Method, 40 CVR 50, Appendix B. Perform a single-point calibration before and after each sample collection,
using the procedures described in Section 11.2.3.
11.2.2.2 Prior to initial multi-point calibration, place an empty glass cartridge in the sampling head
and activate the sampling motor. Fully open the flow control valve and adjust the voltage variator so that
a sample flow rate corresponding to 110 percent of the desired flow rate (typically 0.20 to 0.28 m3/min) is
indicated on the Magnehelic gauge (based on the previously obtained multipoint calibration curve). Allow
the motor to warm up for 10 minutes and then adjust the flow control valve to achieve the desire flow rate.
Turn off the sampler. Record the ambient temperature and barometric pressure on the Field Calibration Data
Sheet (see Figure 8).
11.2.2.3 Place the orifice transfer standard on the sampling head and attach a manometer to the tap
on the transfer standard, as illustrated in Figure 7. Properly align the retaining rings with the filter holder
and secure by tightening the three screw clamps. Connect the orifice transfer standard by way of the pressure
tap to a manometer using a length of tubing. Set the zero level of the manometer or magnehelic. Attach the
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-17
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Method TO-9A Dioxins and Furans
magnehelic gauge to the sampler venturi quick release connections. Adjust the zero (if needed) using the
zero adjust screw on face of the gauge.
11.2.2.4 To leak test, block the orifice with a rubber stopper, wide duct tape, or other suitable means.
Seal the pressure port with a rubber cap or similar device. Turn on the sampler.
Caution: Avoid running the sampler from too long 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 life of the motor,
11.2,2.5 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 on the sampler's magnehelic.
Leaks are usually caused either by damaged or missing gaskets by cross-threading and/or not screwing
sample cartridge together tightly. All leaks must be eliminated before proceeding with the calibration. When
the sample is determined to be leak-free, turn off the sampler and unblock the orifice. Now remove the
rubber stopper or plug from the calibrator orifice.
11.2.2.6 Turn the flow control valve to the fully open position and turn the sampler on. Adjust the
flow control valve until a Magnehelic reading of approximately 70 in. is obtained. Allow the Magnehelic
and manometer readings to stabilize and record these values on the Field Calibration Data Sheet (see
Figure 8).
11.2.2.7 Record the manometer reading under Y1 and the Magnehelic reading under Y2 on the Field
Calibration Data Sheet. For the first reading, the Magnehelic should still be at 70 inches as set above.
11.2.2.8 Set the magnehelic to 60 inches by using the sampler's flow control valve. Record the
manometer (Y I) and Magnehelic (Y2) readings on the Field Calibration Data Sheet.
11.2.2.9 Repeat the above steps using Magnehelic settings of 50,40, 30, 20, and 10 inches.
11.2.2.10 Turn the voltage variator to maximum power, open the flow control valve, and confirm that
the Magnehelic reads at least 100 inches. Turn off the sampler and confirm that the magnehelic reads zero.
11.2.2.11 Read and record the following parameters on the Field Calibration Data Sheet. Record the
following on the calibration data sheet:
Data, job number, and operator's signature;
» Sampler serial number;
* Ambient barometric pressure; and
• Ambient temperature.
11.2.2.12 Remove the "dummy" cartridge and replace with a sample cartridge.
11.2.2.13 Obtain the Manufacturer High Volume Orifice Calibration Certificate.
11.2.2.14 If not performed by the manufacturer, calculate values for each calibrator orifice static
pressure (Column 6, inches of water) on the manufacturer's calibration certificate using the following
equation:
jAH(Pa/760)(298/[Ta + 273])
where:
P, = the barometric pressure (mm Hg) at time of manufacturer calibration, mm Hg
T, = temperature at time of calibration, °C
11.2.2.15 Perform a linear regression analysis using the values in Column 7 of the manufacturer High
Volume Orifice Calibration Certificate for flow rate (QSTD) as the "X" values and the calculated values as
the Y values. From this relationship, determine the correlation (CC1), intercept (B1), and slope (M1) for the
Orifice Transfer Standard.
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Dioxins and Furans Method TO-9A
11.2.2.16 Record these values on the Field Calibration Data Sheet (see Figure 8).
11.2.2.17 Using the Field Calibration Data Sheet values (see Figure 8), calculate the Orifice
Manometer Calculated Values (Y3) for each orifice manometer reading using the following equation:
Y3 Calculation
Y3 - [Yl(P/760)(298/{Ta + 273})]'/J
11.2.2.18 Record the values obtained in Column Y3 on the Field Calibration Data Sheet (see Figure 8).
11.2.2.19 Calculate the Sampler Magnehelic Calculate Values (Y4) using the following equation:
Y4 Calculation
Y4 = [Y2(P/760)(298/{Ta + 273})]*
11.2.2.20 Record the value obtained in Column Y4 on the Field Calibration Data Sheet (see Figure 8).
11.2.2.21 Calculate the Orifice Flow Rate (XI) in scm, using the following equation:
XI Calculation
Y3 - Bl
XI =
Ml
11.2.2.22 Record the values obtained in Column XI, on the Field Calibration Data Sheet (see
Figure 8).
11.2.2.23 Perform a linear regression of the values in Column XI (as X) and the values in Column Y4
(as Y). Record the relationship for correlation (CC2), intercept (B2), and slope (M2) on the Field Calibration
Data Sheet.
11.2.2.24 Using the following equation, calculate a set point (SP) for the manometer to represent a
desired flow rate:
Set point (SP) = [(Expected Pa)/(Expected Ta)(Ts(d/Pstd)][M2 (Desired flow rate) + B2]2
where:
Pa = Expected atmospheric pressure (Pa), mm Hg
Ta = Expected atmospheric temperature (Ta), °C
M2 = Slope of developed relationship
B2 = Intercept of developed relationship
Tstd = Temperature standard, 25 °C
Psld = Pressure standard, 760 mm Hg
11.2.2.25 During monitoring, calculate a flow rate from the observed Magnehelic reading using the
following equations:
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Method TO-9A Dioxins and Furans
Y5 = [Average Magnehelic Reading (AH) (Pa/Ta)(Tstd/Pstd)]'''
Y5 - B2
X2 =
M2
where:
Y5 = Corrected Magnehelic reading
X2 = Instant calculated flow rate, scm
11.2.2.26 The relationship in calibration of a sampling system between Orifice Transfer Standard
and flow rate through the sampler is illustrated in Figure 9.
11.2.3 Single-Point Audit of the High Volume Sampling System Utilizing Calibrated Orifice
Transfer Standard
Single point calibration checks are required as follows:
• Prior to the start of each 24-hour test period.
• After each 24-hour test period. The post-test calibration check may serve as the pre-test calibration
check for the next sampling period if the sampler is not moved.
• Prior to sampling after a sample is moved.
For samplers, perform a calibration check for the operational flow rate before each 24-hour sampling event
and when required as outlined in the user quality assurance program. The purpose of this check is to track
the sampler's calibration stability. Maintain a control chart presenting the percentage difference between a
sampler's indicated and measured flow rates. This chart provides a quick reference of sampler flow-rate drift
problems and is useful for tracking the performance of the sampler. Either the sampler log book or a data
sheet will be used to document flowcheck information. This information includes, but is not limited to,
sampler and orifice transfer standard serial number, ambient temperature, pressure conditions, and collected
flow-check data.
In this subsection, the following is assumed:
• The flow rate through a sampler is indicated by the orifice differential pressure;
• Samplers are designed to operate at an actual flow rate of 8 scfm, with a maximum acceptable flow-
rate fluctuation range of ±10 percent of this value;
• The transfer standard will be an orifice device equipped with a pressure tap. The pressure is measured
using a manometer; and
• The orifice transfer standard's calibration relationship is in terms of standard volumetric flow rate
11.2.3.1 Perform a single point flow audit check before and after each sampling period utilizing the
Calibrated Orifice Transfer Standard (see Section 1 1.2.1).
1 1.2.3.2 Prior to single point audit, place a "dummy" glass cartridge in the sampling head and activate
the sampling motor. Fully open the flow control valve and adjust the voltage variator so that a sample flow
rate corresponding to 1 10 percent of the desired flow rate (typically 0.19 to 0.28 mVmin) is indicated on the
Magnehelic gauge (based on the previously obtained multipoint calibration curve). Allow the motor to warm
up for 10 minutes and then adjust the flow control valve to achieve the desired flow rate. Turn off the
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Dioxins and Furans Method TO-9A
sampler. Record the ambient temperature and barometric pressure on a Field Test Data Sheet (see
Figure 10).
11.2.3.3 Place the flow rate transfer standard on the sampling head.
11.2.3.4 Properly align the retaining rings with the filter holder and secure by tightening the 3 screw
clamps. Connect the flow rate transfer standard to the manometer using a length of tubing.
11.2.3.5 Using tubing, attach 1 manometer connector to the pressure tap of the transfer standard.
Leave the other connector open to the atmosphere.
11.2.3.6 Adjust the manometer midpoint by sliding the movable scale until the zero point corresponds
with the water meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on tubing
connectors. (If additional liquid is required, remove tubing connector and add clean water.)
11.2.3.7 Turn on high-volume motor and let run for 5 minutes.
11.2.3.8 Record the pressure differential indicated, AH, in inches of water, on the Field Test Data
Sheet. Be sure stable AH has been established.
11.2.3.9 Record the observed Magnahelic gauge reading, in inches of water, on the Field Test Data
Sheet. Be sure stable AM has been established.
11.2.3.10 Using previous established Orifice Transfer Standard curve, calculate Q^ (see
Section 11.2.2.23).
11.2.3.11 This flow should be within ±10 percent of the sampler set point, normally, 8 ft3. If not,
perform a new multipoint calibration of the sampler.
11.2.3.12 Remove Flow Rate Transfer Standard and dummy adsorbent cartridge.
11.3 Sample Collection
11.3.1 General Requirements
11.3.1.1 The sampler should be located in an unobstructed area, at least 2 meters from any obstacle
to air flow. The exhaust hose should be stretched out in the downwind direction to prevent recycling of air
into the sample head.
11.3.1.2 All cleaning and sample module loading and unloading should be conducted in a controlled
environment, to minimize any chance of potential contamination.
11.3.1.3 When new or when using the sampler at a different location, all sample contact areas need
to be cleared. Use triple rinses of reagent grade hexane or methylene chloride contained in Teflon® rinse
bottles. Allow the solvents to evaporate before loading the PUF modules.
11.3.2 Preparing Cartridge for Sampling
11.3.2.1 Detach the lower chamber of the cleaned sample head. While wearing disposable, clean, lint-
free nylon, or powder-free surgical gloves, remove a clean glass adsorbent module from its shipping
container. Remove the Teflon® end caps. Replace the end caps in the sample container to be reused after
the sample has been collected.
11.3.2.2 Insert the glass module into the lower chamber and tightly reattach the lower chambers to the
module.
11.3.2.3 Using clean rinsed (with hexane) Teflon-tipped forceps, carefully place a clean conditioned
fiber filter atop the filter holder and secure in place by clamping the filter holder ring over the filter. Place
the aluminum protective cover on top of the cartridge head. Tighten the 3 screw clamps. Ensure that all
module connections are tightly assembled. Place a small piece of aluminum foil on the ball-joint of the
sample cartridge to protect from back-diffusion of semi-volatile into the cartridge during transporting to the
site.
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Method TO-9A Dioxins and Furans
[Note: Failure to do so could result in airflow leaks at poorly sealed locations which could affect sample
representativeness.]
11.3.2.4 Place in a carrying bag to take to the sampler.
11.3.3 Collection
11.3.3.1 After the sampling system has been assembled, perform a single point flow check as described
in Sections 11.2.3.
11.3.3.2 With the empty sample module removed from the sampler, rinse all sample contact areas
using reagent grade hexane in a Teflon® squeeze bottle. Allow the hexane to evaporate from the module
before loading the samples.
11.3.3.3 With the sample cartridge removed from the sampler and the flow control valve fully open,
turn the pump on and allow it to warm-up for approximately 5 minutes.
11.3.3.4 Attach a "dummy" sampling cartridge loaded with the exact same type of filter and PUF
media to be used for sample collection.
11.3.3.5 Turn the sampler on and adjust the flow control valve to the desired flow as indicated by the
Magnehelic gauge reading determined in Section 11.2.2.24. Once the flow is properly adjusted, take extreme
care not to inadvertently alter its setting.
11.3.3.6 Turn the sampler off and remove both the "dummy" module. The sampler is now ready for
field use.
11.3.3.7 Check the zero reading of the sampler Magnehelic. Record the ambient temperature,
barometric pressure, elapsed time meter setting, sampler serial number, filter number, and PUF cartridge
number on the Field Test Data Sheet (see Figure 10). Attach the loaded sampler cartridge to the sampler.
11.3.3.8 Place the voltage variator and flow control valve at the settings used in Section 11.3.2, and
the power switch. Activate the elapsed time meter and record the start time. Adjust the flow (Magnehelic
setting), if necessary, using the flow control valve.
11.3.3.9 Record the Magnehelic reading every 6 hours during the sampling period. Use the calibration
factors (see Section 11.2.2.23) to calculate the desired flow rate. Record the ambient temperature, barometric
pressure, and Magnehelic reading at the beginning and during sampling period.
11.3.4 Sample Recovery
11.3.4.1 At the end of the desired sampling period, turn the power off. Carefully remove the sampling
head containing the filter and adsorbent cartridge to a clean area.
11.3.4.2 While wearing disposable lint free nylon or surgical gloves, remove the PUF cartridge from
the lower module chamber and lay it on the retained aluminum foil in which the sample was originally
wrapped.
11.3.4.3 Carefully remove the glass fiber filter from the upper chamber using clean Teflon®-tipped
forceps.
11.3.4.4 Fold the filter in half twice (sample side inward) and place it in the glass cartridge atop the
PUF.
11.3.4.5 Wrap the combined samples in the original hexane rinsed aluminum foil, attached Teflon®
end caps and place them in their original aluminum sample container. Complete a sample label and affix it
to the aluminum shipping container.
11.3.4.6 Chain-of-custody should be maintained for all samples. Store the containers at <4°C and
protect from light to prevent possibly photo-decomposition of collected analytes. If the time span between
sample collection and laboratory analysis is to exceed 24 hours, refrigerate sample.
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Dioxins and Furans Method TO-9A
11.3.4.7 Perform a final calculated sample flow check using the calibration orifice, as described in
Section 11.3.2. If calibration deviates by more than 10 percent from the initial reading, mark the flow data
for that sample as suspect and inspect and/or remove from service.
11.3.4.8 Return at least 1 field filter/PUF blank to the laboratory with each group of samples. Treat
a field blank exactly as the sample except that no air is drawn through the filter/adsorbent cartridge assembly.
11.3.4.9 Ship and store samples under ice (<4°C) until receipt at the analytical laboratory, after which
it should be refrigerated at less than or equal to 4°C. Extraction must be performed within seven days of
sampling and analysis within 40 days after extraction.
12. Sample Preparation
12.1 Extraction Procedure for Quartz Fiber Filters and PUF Plugs
12.1.1 Take the glass sample cartridge containing the PUF plug and quartz fiber filter out of the shipping
container and place it in a 43-mm x 123-mm Soxhlet extractor. Add 10 /^L of 13C12-labeled sample
fortification solution (see Table 4) to the sample. Put the thimble into a 50 mm Soxhlet extractor fitted with
a 500 mL boiling flask containing 275 mL of benzene.
[Note: While the procedure specifies benzene as the extraction solution, many laboratories have substituted
toluene for benzene because of the carcinogenic nature of benzene (28), The EPA is presently studying the
replacement of benzene with toluene.]
12.1.2 Place a small funnel in the top of the Soxhlet extractor, making sure that the top of the funnel is
inside the thimble. Rinse the inside of the corresponding glass cylinder into the thimble using approximately
25 mL of benzene. Place the extractor on a heating mantel. Adjust the heat until the benzene drips at a rate
of 2 drops per second and allow to flow for 16 hours. Allow the apparatus to cool.
12.1.3 Remove the extractor and place a 3-bulb Snyder column onto the flask containing the benzene
extract. Place on a heating mantel and concentrate the benzene to 25 mL (do not let go to dryness). Add
100 ml of hexane and again concentrate to 25 mL. Add a second 100 mL portion of hexane and again
concentrate to 25 mL.
12.1.4 Let cool and add 25 mL hexane. The extract is ready for acid/base cleanup at this point.
12.2 Cleanup Procedures
12.2.1 Acid/Base Cleanup. Transfer the hexane extract to a 250 mL separatory funnel with two 25-mL
portions of hexane. Wash the combined hexane with 30 ml of 2 N potassium hydroxide. Allow layers to
separate and discard the aqueous layer. Repeat until no color is visible in the aqueous layer, up to a
maximum of 4 washes. Partition the extract against 50 ml of 5% sodium chloride solution. Discard the
aqueous layer. Carefully add 50 mL of concentrated sulfuric acid. Shake vigorously for 1 minute, allow
layers to separate, and discard the acid layer. Repeat the acid wash until no color is visible in the aqueous
layer, up to a maximum of 4 washes. Partition the extract against 50 ml of 5% sodium chloride solution.
Discard the aqueous layer. Transfer the hexane through a 42-mm x 160-mm filter funnel containing a plug
of glass wool and 3-cm of sodium sulfate into a 250-mL Kuderna-Danish (KD) concentrator fitter with a
15-mL catch tube. Rinse the filter funnel with two 25 mL portions of hexane. Place a 3-bulb Snyder column
on the KD concentrator and concentrate on a steam bath to 1-2 mL. The extract is ready for the alumina
column cleanup at this point, but it can be sealed and stored in the dark, if necessary. An extract that
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Method TO-9A Dioxins and Furans
contains obvious contamination, such as yellow or brown color, is subjected to the silica column cleanup
prior to the alumina cleanup.
12.2.2 Silica Column Preparation. Gently tamp a plug of glass wool into the bottom of a 5.75-inch
(14.6 cm) disposable Pasteur pipette. Pour prewashed 100-200 mesh Bio-Sil®A (silica gel) into the pipette
until a height of 3.0 cm of silica gel is packed into the column. Top the silica gel with 0.5 cm of anhydrous
granular sodium sulfate. Place columns in an oven set at 220°C. Store columns in the oven until ready for
use, at least overnight. Remove only the columns needed and place them in a desiccator until they have
equilibrated to room temperature. Use immediately.
12.2.3 Silica Column Cleanup. Position the silica column over the alumina column so the eluent will
drip onto the alumina column. Transfer the 2 mL hexane extract from the Acid/Base Cleanup onto the silica
column with two separate 0.5-mL portions of hexane. Elute the silica column with an additional 4.0 mL of
hexane. Discard the silica column and proceed with the alumina column cleanup at the point where the
column is washed with 6.0 mL of carbon tetrachloride.
12.2.4 Alumina Column Preparation. Gently tamp a plug of glass wool into the bottom of a 5.75-inch
(14.6 cm) disposable Pasteur pipette. Pour WOELM neutral alumina into the pipette while tapping the
column with a pencil or wooden dowel until a height of 4.5 cm of alumina is packed into the column. Top
the alumina with a 0.5 cm of anhydrous granular sodium sulfate. Prewash the column with 3 mL
dichloromethane. Allow the dichloromethane to drain from the column; then force the remaining
dichloromethane from the column with a stream of dry nitrogen. Place prepared columns in an oven set at
225°C. Store columns in the oven until ready for use, at least overnight. Remove only columns needed and
place them in a desiccator over anhydrous calcium sulfate until they have equilibrated to room temperature.
Use immediately.
12.2.5 Alumina Column Cleanup. Prewet the alumina column with 1 mL of hexane. Transfer the
2 mL hexane extract from acid/base cleanup into the column. Elute the column with 6.0 mL of carbon
tetrachloride and archive. Elute the column with 4.0 mL of dichloromethane and catch the eluate in a 12- mL
distillation receiver. Add 3 yuL tetradecane, place a micro-Snyder column on the receiver and evaporate the
dichloromethane just to dryness by means of a hot water bath. Add 2 mL of hexane to the receiver and
evaporate just to dryness. Add another 2-mL portion of hexane and evaporate to 0.5 mL. The extract is
ready for the carbon column cleanup at this point.
12.2.6 Carbon Column Preparation. Weigh 9.5 g of Bio-Sil®A (100-200 mesh) silica gel, which has
been previously heated to 225 °C for 24 hours, into a 50-mL screw cap container. Weigh 0.50 g of Amoco
PX-21 carbon onto the silica gel cap and shake vigorously for 1 hour. Just before use, rotate the container
by hand for at least 1 minute. Break a glass graduated 2.0-mL disposal pipette at the 1.8 mL mark and fire
polish the end. Place a small plug of glass wool in the pipette and pack it at the 0.0 mL mark using two small
solid glass rods. Add 0.1 mL of Bio-Sil®A 100-200 mesh silica gel. If more than 1 column is to be made
at a time, it is best to add the silica gel to all the columns and then add the carbon-silica gel mixture to all
columns. Add 0.40 mL of the carbon silica gel mixture to the column; the top of the mixture will be at the
0.55-mL mark on the pipette. Top the column with a small plug of glass wool.
12.2.7 Carbon Column Cleanup. Place the column in a suitable clamp with the silica gel plug up. Add
approximately 0.5 mL of 50 percent benzene-methylene chloride (v/v) to the top of the column. Fit a 10 mL
disposable pipette on the top of the carbon column with a short piece of extruded teflon tubing. Add an
additional 9.5 mL of the 50 percent benzene-methylene chloride. When approximately 0.5 mL of this solvent
remains, add 10 mL of toluene. After all the toluene has gone into the column, remove the 10-mL reservoir
and add at least 2.0 mL of hexane to the column. When approximately 0.1 mL of the hexane is left on the
top of the column, transfer the sample extract onto the column with a Pasteur pipette. Rinse the distillation
receiver column that contained the extract with two separate 0.2 mL portions of hexane and transfer each
rinse onto the column. Allow the top of each transfer layer to enter the glass wool before adding the next
Page 9A-24 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Dioxiiis and Furans Method TO-9A
one. When the last of the transfer solvent enters the glass wool, add 0,5 mL of methylene chloride, replace
the 10-mL reservoir, and add 4.5 mL of methylene chloride to it. When approximately 0.5 mL of this solvent
remains, add 10 mL of 50 percent benzene-methylene chloride. When all this solvent has gone onto the
column, remove the reservoir, take the column out of the holder and rinse each end with toluene, turn the
column over, and put it back in the holder. All previous elution solvents are archived. Place a suitable
receiver tube under the column and add 0.5 mL of toluene to the top of the column. Fit the 10 mL reservoir
on the column and add 9.5 mL of toluene to it. When all toluene has eluted through the column and has been
collected in the receiving tube, add 5 mL of tetradecane and concentrate to 0.5 mL using a stream of nitrogen
and water bath maintained at 60°C. Transfer the toluene extract to a 2.0 mL graduated Chromofiex® tube
with two 0.5-mL portions of benzene. Add 0.5 ng of 13C,2-1,2,3,4-TCDD and store the extracts in the dark
at room temperature. Concentrate the extract to 30 juL using a stream of nitrogen at room temperature just
prior to analysis or shipping. Transfer the extracts that are to be shipped to a 2 mm i.d. x 75 mm glass tube
that has been fire sealed on one end with enough benzene to bring the total volume of the extract to 100 jwL.
Then fire seal other end of the tube.
12.3 Glassware Cleanup Procedures
In this procedure, take each piece of glassware through the cleaning separately except in the oven baking
process. Wash the 100-mL round bottom flasks, the 250 mL separatory funnels, the KD concentrators, etc.,
that were used in the extraction procedures three times with hot tap water, two times with acetone and two
times with hexane. Then bake this glassware in a forced air oven that is vented to the outside for 16 hours
at 450°C. Clean the PFTE stopcocks as above except for the oven baking step. Rinse all glassware with
acetone and hexane immediately before use.
13. HRGC-HRMS System Performance
13.1 Operation of HRGC-HRMS
Operate the HRMS in the electron impact (El) ionization mode using the selected ion monitoring (SIM)
detection technique. Achieve a static mass resolution of 10,000 (10% valley) before analysis of a set of
samples is begun. Check the mass resolution at the beginning and at the end of each day. (Corrective actions
should be imp lemented whenever the resolv ing power does not meet the requirement.) Chromatography time
required for PCDDs and PCDFs may exceed the long-term stability of the mass spectrometer because the
instrument is operated in the high-resolution mode and the mass drifts of a few ppm (e.g., 5 ppm in mass)
can have adverse effects on the analytical results. Therefore, a mass-drift correction may be required. Use
a lock-mass ion for the reference compound perfluorokerosene (PFK) to tune the mass spectrometer. The
selection of the SIM lock-mass ions of PFK shown in the descriptors (see Tables 10,11 and 12) is dependent
on the masses of the ions monitored within each descriptor. An acceptable lock-mass ion at any mass
between the lightest and heaviest ion in each descriptor can be used to monitor and correct mass drifts.
Adjust the level of the reference compound (PFK) metered inside the ion chamber during HRGC-HRMS
analyses so that the amplitude of the most intense selected lock-mass ion signal is kept to a minimum. Under
those conditions, sensitivity changes can be more effectively monitored. Excessive use of PFK or any
reference substance will cause high background signals and contamination of the ion source, which will
result in an increase in "downtime" required for instrument maintenance.
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Method TO-9A DioxJns and Furans
Tune the instrument to a mass resolution of 10,000 (10% valley) at m/z 292.9825 (PFK). By using the peak
matching unit (manual or computer simulated) and the PFK reference peak, verify that the exact m/z
392.9761 (PFK) is within 3 parts per million (ppm) of the required value.
Document the instrument resolving power by recording the peak profile of the high mass reference signal
(m/z 392.9761) obtained during the above peak matching calibration experiment by using the low mass PFK
ion at m/z 292.9825 as a reference. The minimum resolving power of 10,000 should be demonstrated on the
high mass ion while it is transmitted at a lower accelerating voltage than the low mass reference ion, which
is transmitted at full voltage and full sensitivity. There will be little, if any, loss in sensitivity on the high
mass ion if the source parameters are properly tuned and optimized. The format of the peak profile
representation should allow for computer calculated and manual determination of the resolution, i.e., the
horizontal axis should be a calibrated mass scale (amu or ppm per division). Detailed descriptions for mass
resolution adjustments are usually found in the instrument operators manual or instructions.
13.2 Column Performance
After the HUMS parameters are optimized, analyze an aliquot of a column performance solution containing
the first and last eluting compounds (see Table 9), or a solution containing all congeners, to determine and
confirm SIM parameters, retention time windows, and HRGC resolution of the compounds. Adjustments
can be made at this point, if necessary. Some PeCDFs elute in the TCDD retention time window when using
the 60 m DB-5 column. The PeCDF masses can be included with the TCDD/TCDF masses in Descriptor
1. Include the PeCDD/PeCDF masses with the TCDD/TCDF masses when using the 60 m SP-2331 polar
column. The HRGC-HRMS SIM parameters and retention time windows can be rapidly and efficiently
determined and optimized by analysis of a window defining solution of PCDDs/PCDFs using one mass for
each isomer for the complete analysis of terra- through octa- compounds, as illustrated in Figure 11.
13.3 SIM Cycle Time
The total time for each SIM cycle should be 1 second or less for data acquisition, which includes the sum
of the mass ion dwell times and ESA voltage reset times.
13.4 Peak Separation
Chromatographic peak separation between 2,3,7,8-TCDD and the co-eluting isomers should be resolved with
a valley of 25% or more (see Figure 12).
13.5 Initial Calibration
I
After the HRGC-HRMS SIM operating conditions are optimized, perform an initial calibration using the 5
calibration solutions shown in Table 3. The quantification relationships of labeled and unlabeled standards
are illustrated in Tables 15, 16, 17, and 18. Figures 13 through 22 represent the extracted ion current profiles
(EICP) for specific masses for 2,3,7,8-TCDF, 2,3,7,8-TCDD and other 2,3,7,8-substituted PCDF/PCDD
(along with their labeled standards) through OCDF and OCDD respectively.
(Note: Other solutions containing fewer or different congeners and at different concentrations may also be
used for calibration purposes.]
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Dioxins and Furans __ Method TO-9A
Referring to Tables 10, 11, or 12, calculate (1) the relative response factors (RRFs) for each unlabeled
PCDD/PCDF and PBDD/PBDF [RJRF (I)] relative to their corresponding 13C12-labeled internal standard and
(2) the RRFs for the 13C12-Iabeled PCDD/PCDF and PBDD/PBDF internal standards [RRF (II)] relative to
37Cl4-2,3,7,8-TCDD recovery standard using the following formulae;
Ax
RRF(I)
(Q XA.)
v^- '
(A. xQ )
RRF(II) = — - - —
(Q. xA )
VX: '
where:
Ax = the sum of the integrated ion abundances of the quantitation ions (see Tables 10,
11 or 12) for unlabeled PCDDs/PCDFs, and PBDDs/PBDFs and
BCDDs/BCDFs.
Ais = the sum of the integrated ion abundances of the quantitation ions for the
13C12-labeled internal standards (see Table 10, 11 or 12).
[Note: Other nC,2-labeled analytes may also be used as the recovery standard(s)]
Ars = the integrated ion abundance for the quantitation ion of the 37Cl4-2,3,7,8-TCDD
recovery standard.
Qis = the quantity of the 13C12-labeled internal standard injected, pg.
Qx = the quantity of the unlabeled PCDD/PCDF analyte injected, pg.
Qrs = the quantity of the 37Cl4-2,3,7,8-TCDD injected, pg.
RRF(I) and RRF(II) = dimensionless quantities. The units used to express Qis and Qx must be the
same.
[Note: I3C I2-1,2,3,7,8-PeBDF is used to determine the response factor for the unlabeled 2,3,7,8~substituted,
PeBDD, HxBDF and HxBDD.J
Calculate the average RRFs for the 5 concentration levels of unlabeled and "C12- labeled PCDDs/PCDFs and
PBDDs/PBDFs for the initial calibration using the following equation:
=== RRF 1+RRF2+RRF3+RRF4+RRFS
RRF=
5
13.6 Criteria Required for Initial Calibration
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Method TO-9A Dioxins and Furans
The analytical data must satisfy certain criteria for acceptable calibration. The isotopic ratios must be within
the acceptable range (see Tables 19 and 20). The percent relative standard deviation for the response factors
should be less than the values presented in Table 21. The signal-to-noise ratio for the '3C12-labeled standards
must be 10:1 or more and 5:1 or more for the unlabeled standards.
13.7 Continuing Calibration
Conduct an analysis at the beginning of each day to check and confirm the calibration using an aliquot of the
calibration solution. This analysis should meet the isotopic ratios and signal to noise ratios of the criteria
stated in Section 13.6 (see Table 21 for daily calibration percent difference criteria). It is good practice to
confirm the calibration at the end of the day also. Calculate the daily calibration percent difference using
the following equation.
RRF -RRF
%RRF = -g— x 100
RRF
= the relative response factor for a specific analyte in the continuing calibration standard.
14, HRGC-HRMS Analysis And Operating Parameters
14,1 Sample Analysis
Sample Analysis. An aliquot of the sample extract is analyzed with the HRGC-HRMS system using the
instrument parameters illustrated in Tables 13 and 14 and the SIM descriptors and masses shown in
Tables 10, 11, and 12. A 30-m SE-54 fused silica capillary column is used to determine the concentrations
of total tetra-, penta-, hexa-, hepta- and octa-CDDs/CDFs and/or to determine the minimum limits of
detections (MLDs) for the compounds. If the tetra-, penta-, and hexa-CDDs/CDFs were detected in a sample
and isomer specific analyses are required, then an aliquot of the sample extract is analyzed using the 60 m
SP-2331 fused silica capillary column to provide a concentration for each 2,3,7,8-substituted PCDD/PCDF
and concentrations for total PCDDs and PCDFs also.
[Note.: Other capillary columns such as the DB-5, SE-30, and DB-225 may be used if the performance
satisfies the specifications for resolution of PCDDs/PCDFs, The SE-54 column resolves the four HpCDF
isomers, Arc HpCDD isomers, OCDF and OCDDfor isomer specific analysis. It does not resolve the tetra-,
penta-, and hexa-2,3,7,8-substituted isomers. The SE-54 column is used for the analysis ofPBDDs and
PBDFs.J
Isomer specificity for all 2,3,7,8-substituted PCDDs/PCDFs cannot be achieved on a single HRGC capillary
column at this time. However, many types of HRGC capillary columns are available and can be used for
these analyses after their resolution capabilities are confirmed to be adequate using appropriate standards.
Two HRGC columns shown in Table 13 have been used successfully since 1984 (27,28). The 60-m DB-5
provides an efficient analysis for total concentrations of PCDDs/PCDFs, specific isomers (total tetra-, penta-,
hexa-CDDs/CDFs, four HpCDF isomers, two HpCDD isomers, OCDD and OCDF), PBDDs/PBDFs, and/or
determination of MDLs. The 60 m SP-2331 column provides demonstrated and confirmed resolution of
Page 9A-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Dioxins and Furans Method TO-9A
2,3,7,8-substituted tetra-, penta-, and hexa-PCDDs/PCDFs (14). The descriptors and masses shown in Tables
10, 11 and 12 must be modified to take into account the elution of some of the PeCDDs and PeCDFs in the
tetra retention time window using the SP-233 Icolumn.
14,2 Identication Criteria
Criteria used for identification of PCDDs and PCDFs in samples are as follows:
• The integrated ion abundance ratio M/(M+2) or (M+2)/(M+4) shall be within 15 percent of the
theoretical value. The acceptable ion abundance ranges are shown in Tables 19 and 20.
« The ions monitored for a given analyte, shown in Tables 10, 11, and 12, shall reach their maximum
within 2 seconds of each other.
* The retention time for the 2,3,7,8-substituted analytes must be within 3 seconds of the corresponding
'3C,2-IabeIed internal standard, surrogate, or alternate standard.
« The identification of 2,3,7,8-substituted isomers that do not have corresponding l3C,2-labeled standards
is done by comparison to the analysis of a standard that contains the specific congeners. Comparison
of the relative retention time (RRT) of the analyte to the nearest internal standard with reference (i.e.,
within 0.005 RRT time units to the comparable RRTs found in the continuing calibration or literature).
• The signal-to-noise ratio for the monitored ions must be greater than 2.5.
• The analysis shall show the absence of polychlorinated diphenyl- ethers (PCDPEs), Any PCDPEs that
co-elute (± 2 seconds) with peaks in the PCDF channels indicates a positive interference, especially
if the intensity of the PCDPE peak is 10 percent or more of the PCDF.
Use the identification criteria in Section 14.2 to identify and quantify the PCDDs and PCDFs in the sample.
Figure 23 illustrates a reconstructed EICP for an environmental sample, identifying the presence of
2,3,7,8-TCDF as referenced to the labeled standard.
14.3 Quantification
The peak areas of ions monitored for 13C12-Iabeled PCDDs/PCDFs and 37Cl4-2,3,7,8-TCDD, unlabeled
PCDDs/PCDFs, and respective relative response factors are used for quantification. The 37C14~2,3,7,8-
TCDD, spiked to extract prior to final concentration, and respective response factors are used to determine
the sample extraction efficiencies achieved for the nine BC12-labeled internal standards, which are spiked
to the sample prior to extraction (% recovery). The I3C,2-labeled PCDD/PCDF internal standards and
response factors are used for quantification of unlabeled PCDDs/PCDFs and for determination of the
minimum limits of detection with but one exception: I3Cn-OCDD is used for OCDF. Each I3C12-labeled
internal standard is used to quantify all of the PCDDs/PCDFs in its isomeric group. For example, I3C12-
2,3,7,8-TCDD and the 2,3,7,8-TCDD response factor are used to quantify all of the 22 tetra-chlorinated
isomers. The quantification relationships of these standards are shown in Tables 15, 16, 17, and 18. The
37Cl4-2,3,7,8-TCDD spiked to the filter of the sampler prior to sample collection is used to determine the
sampler retention efficiency, which also indicates the collection efficiency for the sampling period.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-29
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Method TO-9A Pioxins and Furans
14.4 Calculations
14,4.1 Extraction Efficiency. Calculate the extraction efficiencies (percent recovery) of the 9 13C12-
labeled PCDD/PCDF or the 3 13C,2-labeled PBDD/PBDF internal standards measured in the extract using
the formula:
[A. xQ xlOO]
IS rs
[Q,sxArsxRRF(II)]
where:
%R,$ = percent recovery (extraction efficiency).
Ai$ - Hie sum of the integrated ion abundances of the quantitation ions (see Tables 10,11 or 12)
for the 13C12-labeled internal standard.
Ara = the sum of the integrated ion abundances of the quantitation ions (see Table 10, 11 or 12)
for the 37C14- or "C12-labeled recovery standard; the selection of the recovery standard(s)
depends on the type of homologues.
Q,, — quantity of the 13Ci2-labeled internal standard added to the sample before extraction, pg,
Qn - quantity of the "C14- or 13C12-labeled recovery standard added to the sample extract before
HRGC-HRMS analysis, pg.
RRF(II) = calculated mean relative response factor for the labeled internal standard relative to the
appropriate labeled recovery standard.
14.4.2 Calculation of Concentration. Calculate the concentration of each 2,3,7,8-substituted
PCDD/PCDF, other isomers or PBDD/PBDF that have met the criteria described in Sections 14.2 using the
following formula:
[A *Q. ]
x-i _ L X ^1SJ
* = [A.sXVstdxRRF(I)]
where:
Cx= concentration of unlabeled PCDD/PCDF, PBDD/PBDF or BCDD/BCDF congeners), pg/m3.
A,= the sum of the integrated ion abundances of the quantitation ions (see Table 11,12or 13) for
the unlabeled PCDDs/PCDFs, or PBDDs/PBDFs or BCDFs.
A,,= the sum of the integrated ion abundances of the quantitation ions (see Table 11,12or 13)for
the respective l3C12-labeled internal standard,
Ql$ = quantity of the 13C12-labeled internal standard added to the sample before extraction, pg.
V,,d = standard volume of air, std m3.
RRF(I) = calculated mean relative response factor for an unlabeled 2,3,7,8-substituted PCDD/PCDF
obtained in Section 13.4.
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Pioxins and Furans Method TO-9A
14.5 Method Detection Limits (MDLs)
The ambient background levels of total PCDDs/PCDFs are usually found in the range of 0.3 to 2,9 pg/m3.
Therefore, the MDLs required to generate meaningful data for ambient air should be in the range of 0.02 to
0.15 pg/m3 for tetra-, penta-, and hexa-CDDs/CDFs. Trace levels, 0.05 to 0.25 pg/m3, of HpCDDs and
OCDD are usually detected in the method blank (background contamination).
An MDL is defined as the amount of an analyte required to produce a signal with a peak area at least 2.5 x
the area of the background signal level measured at the retention time of interest. MDLs are calculated for
total PHDDs/PHDFs and for each 2,3,7,8-substituted congener. The calculation method used is dependent
upon the type of signal responses present in the analysis. For example:
• Absence of response signals of one or both quantitation ion signals at the retention time of the 2,3,7,8-
substituted isomer or at the retention time of non 2,3,7,8-substituted isomers. The instrument noise
level is measured at the analyte's expected retention time and multiplied by 2.5, inserted into the
formula below and calculated and reported as not detected (ND) at the specific MDL.
• Response signals at the same retention time as the 2,3,7,8-substituted isomers or the other isomers that
have a S/N ratio in excess of 2.5:1 but that do not satisfy the identification criteria described in 14.2
are calculated and reported as ND at the elevated MDL and discussed in the narrative that
accompanies the analytical results. Calculate the MDLs using the following formula:
[2.5 x A x Q ]
MDL = ——g—
[A. x V , x RRF]
L is std J
where:
MDL = concentration of unlabeled PHDD/PHDF, pg/m3.
Ax = sum of integrated ion abundances of the quantitation ions (see Table 10, 11 or 12) for the
unlabeled PHDDs/PHDFs which do not meet the identification criteria or 2.5 x area of noise
level at the analyte's retention time.
Ais = sum of the integrated ion abundances of the quantitation ions (see Table 10, 11, or 12) for
the I3C12-labeled internal standards.
Qh = quantity of the '3CI2-labeled internal standard spiked to the sample prior to extraction, pg.
Vstd = standard volume of ambient air sampled, std m3.
RRF = mean relative response factor for the unlabeled PHDD/PHDF,
14.6 2,3,7,8-TGDD Toxic Equivalents
Calculate the 2,3,7,8-TCDD toxic equivalents of PCDDs and PCDFs present in a sample according to the
method recommended by EPA and the Center for Disease Control (18). This method assigns a 2,3,7,8-TCDD
toxicity equivalency factor (TEF) for each of the seventeen 2,3,7,8-substituted PCDDs/PCDFs (see Table
22). The 2,3,7,8-TCDD equivalent of the PCDDs and PCDFs present in the sample is calculated by the
respective TEF factors times their concentration for each of the compounds listed in Table 22. The exclusion
of the other isomeric groupings (mono-, di-, and tri-chlorinated dibenzodioxins and dibenzofurans) does not
mean that they are non-toxic. Their toxicity, as known at this time, is much less than the toxicity of the
compounds listed in Table 22. The above procedure for calculating the 2,3,7,8-TCDD toxic equivalents is
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-31
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Method TO-9A Dioxins and Furans
not claimed to be based on a thoroughly established scientific foundation. The procedure, rather, represents
a "consensus recommendation on science policy." Similar methods are used throughout the world.
15. Quality Assurance/Quality Control (QA/QC)
15.1 Certified analytical standards were obtained from Cambridge Isotope Laboratories, 50 Frontage Road,
Andover, MA 01810, 508-749-8000.
15.2 Criteria used for HRGC-HRMS initial and continuing calibration are defined in Sections 13.5 and 13.6.
15.3 Analytical criteria used for identification purposes are defined In Section 14.2.
15,4 All test samples, method blanks, field blanks, and laboratory control samples are spiked with 13C,2~
labeled internal standards prior to extraction.
15.5 Sample preparation and analysis and evaluation of data are performed on a set of 12 samples, which
may consist of 9 test samples, field blank, method blank, fortified method blank, or a laboratory control
sample.
15.6 Method evaluation studies were performed to determine and evaluate the overall method capabilities
(1,2).
15.7 The 13C|2-1,2,3,4-TCDD solution is spiked to filters of all samplers, including field blanks, immediately
prior to operation or is spiked to all PUF plugs prior to shipping them to the field for sampling to determine
and document the sampling efficiency.
15.8 Minimum equipment calibration and accuracy requirements achieved are illustrated in Table 23.
15.9 QA/QC requirements for data:
Criteria Requirements
The data shall satisfy all indicated identification criteria Discussed in Section 14.2
Method efficiency achieved for 13C12-labeled tetra-, penta-, hexa- 50 to 120%
CDDs/CDFs and PBDDs/PBDFs
Method efficiency achieved for 13C12-labeled HpCDD and OCDD 40 to 120%
Accuracy achieved for PHDDs and PHDFs 70 to 130%
in method spike at 0.25 to 2.0 pg/m3
concentration range
Precision achieved for duplicate method spikes or QA samples ± 30%
Sampler efficiency achieved for I3CI2-1,2,3,4-TCDD 50 to 120%
Method blank contamination Free of contamination that would
interfere with test sample results.
Method detection limit range 0.02 to 0.25 pg/m3
for method blank and field blank (individual isomers)
Page 9A-32 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Dioxins and Furans Method TO-9A
16, Report Format
The analytical results achieved for a set of 12 samples should be presented in a table such as the one shown
in Table 24. The analytical results, analysis, QA/QC criteria, and requirements used to evaluate data are
discussed in an accompanying analytical report. The validity of the data in regard to the data quality
requirements and any qualification that may apply is explained in a clear and concise manner for the user's
information.
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Method TO-9A Dioxins and Furans
17. References
I. Harless, R. L. et al., "Evaluation of Methodology for Determination of Polyhalogenated Dibenzo-p-
Dioxins and Dibenzofurans in Ambient Air," in Proceedings of the 1991 EPA/A&WMA International
Symposium on Measurement of Toxic and Related Air Pollutants, U. S. Environmental Protection Agency,
Research Triangle Park, NC 27711, EPA-600/9-91-018, May 1991.
2. Harless, R. L., et al., "Evaluation of a Sampling and Analysis Method for Determination of
Polyhalogenated Dibenzo-p-Dioxins and Dibenzofurans in Ambient Air," in Proceedings of the llth
International Symposium on Chlorinated Dioxins and Related Compounds, U. S. Environmental Protection
Agency, Research Triangle Park, NC 27711, EPA-600/D-91 -106; Chemosphere, Vol. 25, (7-10): 1317-1322,
Oct-Nov 1992.
3. Smith-Mullen, C., et al., Feasibility of Environmental Monitoring and Exposure Assessment for a
Municipal Waste Combustor, Rutland, Vermont Pilot Study, U. S. Environmental Protection Agency,
Research Triangle Park, NC 27711, EPA-600/8-91-007, March 1991.
4. Harless, R, L., et al., Sampling and Analysis for Polychlorinated Dibenzo-p-Dioxins and Dibenzojurans
in Ambient Air, U. S. Environmental Protection Agency, Research Triangle Park, NC 27711, EPA-600/D-9-
172, May 1990.
5. Harless, R. L. et al., Analytical Procedures and Quality Assurance Plan for the Analysis of2,3,7,8-TCDD
in Tier 3-7 Samples of the U. S. EPA National Dioxin Study, U. S. Environmental Protection Agency,
Research Triangle Park, NC 27711, EPA-600/3-85-019, May 1986.
6, Harless, R. L. etal., Analytical Procedures andQuality Assurance Plan for the Analysis of'Tetra Through
Octa Chlorinated Dibenzo-p-Dioxins and Dibenzofurans in Tier 4 Combustion and Incineration Processes,
U, S. Environmental Protection Agency, Research Triangle Park, NC 27711, Addendum to EPA-600/3-85-
019, May 1986.
7. Albro, P.W., et al., "Methods for the Quantitative Determination of Multiple Specific Polychlorinated
Dibenzo-p-Dioxins and Dibenzofuran Isomers in Human Adipose Tissue in the Parts-Per-Trillion Range.
An Interiaboratory Study," Anal Chem., Vol.57:2717-2725, 1985.
8. O'Keefe, P. W., et al., "Interiaboratory Validation of PCDD and PCDF Concentrations Found in
Municipal Incinerator Emissions," Chemosphere, Vol. 18:185-192, 1989.
9. Harless, R. L., et al., "Identification of Bromo/Chloro Dibenzo-p-Dioxins and Dibenzofurans in Ash
Samples," Chemosphere, Vol. 18:201-208, 1989.
10. Lafleur, L.E., and Dodo, G. H,, "An Interiaboratory Comparison of Analytical Procedures for the
Measurement of PCDDs/PCDFs in Pulp and Paper Industry Solid Wastes," Chemosphere, Vol. 18:77-84,
1989.
Page 9A-34 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Dioxins and Furans Method TO-9A
11. Patterson, D, G. et al., "Levels of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in Workers
Exposed to 2,3,7,B-TCDD," American Journal of Industrial Medicine, Vol. 16:135-146, 1989.
12. Lamparski, L. L. and Nestrick, T. J, "Determination of Tetra-, Hexa-, Hepta-and Octa-chlorodibenzo-p-
dioxin isomers in Paniculate Samples at Parts-Per-Trillion Levels," Anal. Chem., Vol. 52:2045-2054,1980.
13. Rappe,C,, "Analysis of Polychlorinated Dioxins and Furans," Environ. Sci. Technol.,VoL 18:78A-90A,
1984.
14. Rappe,C.,etaI., "Identification of PCDDs and PCDFs in Urban Air," Chemosphere, Vol. 17:3-20,1988.
15. Tondeur, Y., et al., "Method 8290: An Analytical Protocol for the Multimedia Characterization of
Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans by High Resolution Gas Chromatography/High
Resolution Mass Spectrometry," Chemosphere, Vol. 18:119-131, 1989.
16. "Method 23, Method for Measurement of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans from
Stationary Sources," Federal Register, Vol. 56(30):5758-5770, February 13, 1991.
17. "Method 1613: Tetra- through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC-
HRMS," Federal Register, Vol. 56(26:)5098-5122, February 7, 1991.
18. Interim Procedures/or Estimating Risks Associatedwith Exposures to Mixtures of Chlorinated Dibenzo-
p-Dioxins and Dibenzofurans (CDDs/CDFs), U. S. Environmental Protection Agency, Research Triangle
Park, NC 27711, EPA-625/3-89-OI6, March 1989.
19. Tiernan, T., et al., "PCDD/PCDF in the Ambient Air of a Metropolitan Area in the U.S.," Chemosphere,
Vol. 19:541-546, 1989.
20. Hunt, G., "Measurement of PCDDs/PCDFs in Ambient Air," J. Air Pollut. Control Assoc., Vol. 39:330-
331, 1989.
21. "40 CFR Parts 707 and 766, Polyhalogenated Dibenzo-p-Dioxins and Dibenzofurans: Testing and
Reporting Requirements: Final Rule," Federal Register, Vol. 52 (108):21412-21452, June 5, 1987.
22. Buser, H., "Polybrominated Dibenzo-p-Dioxins and Dibenzofurans: Thermal reaction products of
polybrominated diphenyl ether flame retardants," Environ. Sci. TechnoL, Vol. 20:404-408, 1988.
23. Sovocol, G. W., et al., "Analysis of Municipal Incinerator Fly Ash for Bromo and Bromo/Chloro
Dioxins, Dibenzofurans, and Related Compounds," Chemosphere, Vol. 18:193-200, 1989.
24. Lewis, R. G., et al., Modification and Evaluation of a High-Volume Air Sampler for Pesticides and
Semivolatile Industrial Organic Chemicals," Anal. Chem., Vol. 54:592-594, 1982.
25. Lewis, R. G., et al., "Evaluation of Polyurethane Foam for Sampling Pesticides, Polychlorinated
Biphenyls and Polychlorinated Naphthalenes in Ambient Air," Anal. Chem., Vol. 49:1668-1672, 1977.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-3S
-------
Method TO-9A Dioxins and Furans
26. Winberry, W. T., Jr., et al., Compendium of Methods/or the Determination of Toxic Organic Compounds
in Ambient Air, Second Supplement, Method TO-9, U. S. Environmental Protection Agency, Research
Triangle Park, NC 27711, EPA 600/4-89-018, March 1989.
27. "Analysis of Air Samples for PCDDs, PCDFs, PCBs, and PAHs in Support of the Great Lakes
Deposition Project," Draft Report, Midwest Research Institute, 425 Volker Boulevard, Kansas City, MO,
MR! Project No. 3103-A, April 1990.
28. Boggess, K.E., "Analysis of Air Samples for PCDDs, PCDFs, PCBs and PAHs in Support of the Great
Lakes Deposition Project," Final Report, Midwest Research Institute, 425 Volker Boulevard, Kansas City,
MO, MRI Project No. 3103-A, April 1993.
29. "Working with Carcinogens," NIOSH, Publication 77-206, August 1977.
30. "Safety- in the Academic Chemistry Laboratories," ACS Committee on Chemical Safety, 1979.
Page 9A-36 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Dioxins and Furans
Method TO-9A
TABLE 1. NUMBER OF POLYCHLORINATED DIBENZO-P-DIOXIN AND
DIBENZOFURAN (PCDD/PCDF) CONGENERS
No. of Chlorine Atoms
1
2
3
4
5
6
7
8
Total
No. of PCDD Isomers
2
10
14
22
14
10
2
1
75
No. of PCDF Isomers
4
16
28
38
28
16
4
1
135
[Note: This also applies for the polybrominated dibenzo-p-dioxins and dibemofurans
(PBDDs/PBDFs).]
TABLE 2. LIST OF 2,3,7,8-CHLORINE
SUBSTITUTED PCDD/PCDF CONGENERS
PCDDs
2,3,7,8-TCDD
1,2,3,7,8-PeCDD
1,2,3,4,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,4,6,7,8-HpCDD
1,2,3,4,6,7,8,9-OCDD
PCDFs
2,3,7,8-TCDF
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
1,2,3,4,6,7,8,9-OCDF
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-37
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Method TO-9A
Dioxins and Furans
TABLE 3. COMPOSITIONS OF THE INITIAL CALIBRATION SOLUTIONS OF
LABELED AND UNLABELED PCDDS AND PCDFS
Compound Solution No.
Concentrations {pg/yuL)
1
2
3
4
5
Unlabclcd Analytes
2,3,7,8-TCDD
2,3,7,8-TCDF
1,2,3,7,8-PeCDD
1,2,3,7,8-PcCDF
2,3,4,7,8-PeCDF
1,2,3,4,7,8-HxCDD
1,2,3.6,7,8-HxCDD
1.2,3,7,8,9-HxCDD
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
l,2,3J,8,9-HxCDF
2,3,4,6,7,8-HxCDD
1,2,3,4,6,7,8-HpCDD
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
OCDD
OCDF
0,5
0.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
5.0
5.0
1
1
5
5 •
5
5
5
5
5
5
5
5
5
5
5
10
10
5
5
25
25
25
25
25
25
25
25
25
25
25
25
25
50
50
50
50
250
250
250
250
250
250
250
250
250
250
250
250
250
500
500
100
100
500
500
500
500
500
500
500
500
500
500
500
500
500
1000
1000
Internal Standards
l}C,r2,3,7,8-TCDD
"CI2-l,2,3,7,8-PeCDD
"C,,-l, 2,3.6 J,8-HxCDD
"C,2-l,2,3,4,6,7,8-HpCDD
13C,2-OCDD
l3C,r2,3,7,8-TCDF
100
100
100
100
200
100
100
100
100
100
200
100
100
100
100 •
100
200
100
100
100
100
100
200
100
100
100
100
100
200
100
Page 9A-38
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxins and Furans
Method TO-9A
TABLE 3. (continued)
Compound Solution No.
l3C,rl,2,3,7,8-PeCDF
BC1,-l>2,3>4,?,8-HxCDF
!3C,rl,2,3,4,6,7,8-HpCDF
Concentrations (pg//*L)
1
100
100
100
2
100
100
100
3
100
100
100
4
100
100
100
5
100
100
100
Surrogate Standards
l3C,i-2,3,4,7,8-PeCDF
13C12-l,2,3,4,?,8-HxCD
'3e,rl,2,3,6,7,8-HxCDF
"Cn-l,2,3,6,l$,9-HpCD
60
60
60
60
80
80
80
80
100
100
100
100
Field Standards
"Cl4-2,3,7,8-TCDD
l3C|2-l,2,3,7,8,9-HxCDD
100
100
100
100
100
100
120
120
120
120
140
140
140
140
100
100
100
100
Recovery Standard
13C!2-l,2,3,4-TCDD
50
50
50
50
50
[Note: Standards specified in EPA Method 1613 can also be used in this method.]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-39
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Method TO-9A
Dioxins and Furans
TABLE 4. COMPOSITION OF THE SAMPLE
FORTIFICATION SOLUTIONS
Analyte
Chlorinated Internal Standards
13C12-233,7,8-TCDD
13C12-l,2,3,7,8-PeCDD
13C12-l,2,3,6,7,8-HxCDD
13C 12- 1 ,2,3 ,4,6,7, 8-HpCDD
13C12-OCDD
13CI2-2,3,7,8-TCDF
13Cl2-l,2,3,7,8-PeCDF
I3Cl2-l,2,3,4,7,8-HxCDF
13C,rlA3,4,6,7,8-HpCDF
Brominated Internal Standards
13Cl12-2,337,8-TBDD
13C12-2,3,7,8-TBDF
13C12-l,2,3,7,8-PeBDF
Concentration (pg/juL)
100
100
100
100
100
100
100
100
100
0.86
0.86
0.86
Page 9A-40
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxins and Furans
Method TO-9A
TABLE 5. COMPOSITION OF RECOVERY
STANDARD SOLUTION
Analyte
Concentration (pg/^L)
Recovery Standard
13C,2-1,2,3,4-TCDD
10
TABLE 6. COMPOSITION OF AIR SAMPLER FIELD
FORTIFICATION STANDARD SOLUTION
Analyte
Concentration
Field Fortification Standard
37,
'C14-2,3S7,8-TCDD
10
TABLE 7. COMPOSITION OF SURROGATE STANDARD SOLUTION
Analyte
Surrogate Standards
13C,2-ls2,354,7,8-HxCDD
13C12-2,3,4,7,8-PeCDF
13C12-l,2,3,6,7,8-HxCDF
!3CI2- 1 ,2,3,4,7,8,9-HpCDF
Concentration (pg/juL)
100
100
100
100
January 1999
Compendium of Methods for Toxic Organic Air Pottutants
Page 9A-41
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Method TO-9A
Dioxins and Furans
TABLE 8. COMPOSITION OF MATRIX AND METHOD SPIKE AND METHOD
SPIKE SOLUTIONS OF PCDDS/PCDFS AND PBDDS/PBDFS"
Analyte
Native PCDDs and PCDFs
2,3,7,8-TCDD
2,3,7,8-TCDF
1,2,3,7,8-PeCDD
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
1,2,3,4,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
1,2,3,4,6,7,8-HpCDD
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
OCDD
OCDF
Concentration
(pg^L)
1
i
5
5
5
5
5
5
5
5
5
5
5
5
5
10
10
Analyte
Native PBDDs and PBDF
2,3,7,8-TBDD
2,3,7,8-TBDF
1,2,3,7,8-PeBDD
1,2,3,7,8-PeBDF
1,2,3,4,7,8-HxBDD
1,2,3,4,7,8-HxBDF
Concentration
(pg/^L)
s
1
1
5
5
5
5
'Solutions at different concentrations and those containing different congeners may also be used.
Page 9A-42
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxins and Furaiis
Method TO-9A
TABLE 9. HRGC-HRMS COLUMN PERFORMANCE EVALUATION SOLUTIONS
• . - . - - "- -
Congener
' '--•'•" ' First Elated :" ••-"--•
LastEluted
SE-54 Column GC Retention Time Window Defining Standard"
TCDF
TCDD
PeCDF
PeCDD
HxCDF
HxCDD
HpCDF
HpCDD
OCDF
OCDD
1,3,6,8-
1,3,6,8-
1,3,4,6,8-
1,2,4,7,9-
1,2,3,4,6,8-
1,2,4,6,7,9-
1,2,3,4,6,7,8-
1,2,3,4,6,7,9-
OCDF
OCDD
1,2,8,9-
1,2,8,9-
1,2,3,8,9-
1,2,3,8,9-
1,2,3,4,8,9-
1,2,3,4,6,7-
1,2,3,4,7,8,9-
1,2,3,4,6,7,8-
SE-54 TCDD Isomer Specificity Test Standard11
1,2,3,4-TCDD
1,4,7,8-TCDD
2,3,7,8-TCDD
SP-233 1 Column TCDF Isomer Specificity Test Standard0
2,3,4,7-TCDF
2,3,7,8-TCDF
1,2,3,9-TCDF
aA solution containing these congeners and the seventeen 2,3,7,8-substituted congeners may also be used for
these purposes.
bA solution containing the 1,2,3,4,-TCDD and 2,3,7,8-TCDD may also be used for this purpose.
"Solution containing all tetra- through octa-congeners may also be used for these purposes.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-43
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Method TO-9A
Dioxius and Furans
TABLE 10. DESCRIPTORS, MASSES, M/Z TYPES, AND ELEMENTAL COMPOSITIONS
OF THE PCDDS AND PCDFS
Descriptor
Number
1
2
Accurate
Mass
292.9825
303,9016
305,8987
315.9419
317.9389
319.8965
321.8936
327.8847
330.9792
331.9368
333.9339
375.8364
339.8597
341.8567
351.9000
353.8970
354.9792
355.8546
357.8516
367.8949
369,8919
409,7974
m/z Type
Lock
M
M+2
M
M+2
M
M+2
M
QC
M
M+2
M+2
M+2
M+4
M+2
M+4
Lock
M+2
M+4
M+2
M+4
M+2
Elemental Composition
C,F,,
C12 H4 35C14 0
CI2H435C13"C1O
I3C12 H4 3SC14 O
I3C,2 H4 "C13 "Cl O
C,2H4«C1402
C,2 H4 "CI3 "Cl O2
C12 H4 J7C14 Oz
C,FI3
»C,2 H4 35C14 02
13CW H4 35CI3 "Cl O2
C,2 H4 3SC1S 37C1 0
C,2 Hj 35C14 37C1 O
C12 H3 35C13 37C12 0
"Cij H3 3SC14 37C1 0
"C12 H, "C13 "C12 O
C9F,3
CI2 H3 J5C14 37C1 02
C12H335C1337C]2O2
"C,2 H3 35C14 "Cl O2
I3C,2 H3 3SCI3 "C12 02
CI2 H3 «C16 "Cl O
Compound2
PFK
TCDF
TCDF
TCDF3
TCDF3
TCDD
TCDD
TCDD"
PFK
TCDD3
TCDD3
HxCDPE
PeCDF
PeCDF
PeCDF3
PeCDF3
PFK
PeCDD
PeCDD
PeCDD4
PeCDD4
HpCDPE
Primary
m/z
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Page 9A-44
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxlus and Furans
Method TO-9A
TABLE 10. (continued)
Descriptor""
Number
3
4
Accurate
Mass
373.8208
375.8178
383.8639
385.8610
389.8157
391.8127
392.9760
401.8559
403.8529
430.9729
445.7555
407.7818
409.7789
417.8253
419.8220
423.7766
425.7737
430.9729
435.8169
437.8140
479.7165
m/z Type
M+2
M+4
M
M+2
M+2
M+4
Lock
M+2
M+4
QC
M+4
M+2
M+4
M
M+2
M+2
M+4
Lock
M+2
M+4
M+4
Elemental Composition
Cn H2 35C1S "Cl O
C« H2 "C14 "C12 O
I3CI2 H2 "C16 0
"CI2 H2 35C15 "Cl O
Cn H2 "C15 "Cl O2
C,2 H2 "C14 "C12 O2
Cj F15
13C,2 H2 35C15 "Cl O2
13CI2 H2 "C14 37C12 O2
C»FI3
CtjH235Cl637Cl20
C12H»C1637C10
C,2 H "Cl, "C12 0
I3C,2 H 35C17 O
13C12 H 35C16 37C1 O
c,2 H «ei6 37ci o2
C,2 H 35C1S 37C12 02
Cj F|7
"C,2 H 3SC16 37C1 Oj
13C12 H 35C15 37C12 O2
C12 H "Cl, 37C12 O
Compound2
HxCDF
HxCDF
HxCDF3
HxCDF3
HxCDD
HxCDD
PFK
HxCDD3
HxCDD3
PFK
OCDPE
HpCDF
HpCDF
HpCDF3
HpCDF3
HpCDD
HpCDD
PFK
HpCDD3
HpCDD3
NCDPE
Primary
m/z
Yes
Yes
Yes
Yes
Yes
Yes
Yes
.
Yes
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-4S
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Method TO-9A
Dioxins and Furans
TABLE 10. (continued)
Descriptor
Number
5
Accurate
Mass
441.7428
442,9728
443.7399
457.7377
459.7348
469,7779
471.7750
513.6775
m/z Type
M+2
Lock
M+4
M+2
M+4
M+2
M+4
M+4
Elemental Composition
C12 35C17 "Cl O
CIQ F,,
C12"C16"CI20
Cn 3SG17 "Cl O2
C12MC16"C1202
13C1235C1737C1O2
13CI2«a6"CI202
C12 "Cl, "C12 O
Compound2
OCDF
PFK
OCDF
OCDD
OCDD
OCDD3
OCDD5
DCDPE
Primary
m/z
Yes
Yes
Yes
'Nuclidic masses used:
11=1.007825 C =12.00000 13C = 13.003355 F= 18.9984
O-15.994915 "Cl = 34.968853 "Cl = 36,965903
'Compound abbreviations:
Polvchlorinated dibenzo-p-dioxins
TCDD = Tetrachlorodibcnzo-p-dioxin
PcCDD = Pentachlorodibcnzo-p-dioxin
HxCDD = Hexachlorodibenzo-p-dioxin
HpCDD = Heptachlorodibenzo-p-dioxin
OCDD = Octachlorodibenzo-p-dioxin
Polvchlorinated dibenzofurans
TCDF = Tetrachlorodibenzofuran
PeCDF = Pentachlorodibenzofuran
HxCDF= Hexachlorodibenzofuran
HpCDF = Heptachlorodibenzofuran
'Labeled compound
'There is only one m/z for "Cl4-2,3,7,8-TCDD (recovery standard).
Polychlorinated diphenvl ethers
HxCDPE = Hexachlorodiphenyl ether
HpCDPE = Heptachlorodiphenyl ether
OCDPE = Octachlorodiphenyl ether
NCDPE = Nonachlorodiphenyl ether
DCDPE = Decachlorodiphenyl ether
Lock mass and QC compound
PFK = Perfluorokerosene
Page 9A-46
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dloxiiis and Furans
Method TO-9A
TABLE 11, DESCRIPTORS, M/Z TYPES, EXACT MASSES AND ELEMENTAL
COMPOSITIONS OF THE PBDDS AND PBDFS
Descriptor
Number
1
2
Accurate
Mass'
327.8847
330,9792
331.9368
333.9339
417.825
419.822
466.973
481.698
483.696
485.694
492.970
493.738
495.736
497.692
499.690
501.689
509.733
511.731
565.620
643.530
Ion Type
M
QC
M
M+2
M
M+2
:••••• :Elertiental
Cofhposition .
C12H437C1<02
C7F13
CI2H4MC1402
C12 H4 35C13 "Cl O2
I3CI2 H 35C17 O
I3CI2 H "C16 "Cl 0
QC
M+2
M+4
M+6
C12 H4 '9Br3 "BrO
C12 H4 "Br2 "Br2 O
C12H47*Br8IBr3O
LOCK MASS
M+2
M+4
M+2
M+4
M+6
M+2
M+4
M+6
M+6
13C12 H4 TOBr3 "Br O
13CI2 H4 T9Br2 !1Br2 O
CI2H479Br381BrO2
C12 H, 79Br2 "Br2 O2
C,2 H4 7»Br 81Br3 O
13C12H4T9Br3"Br02
13CI2 H4 79Br2 8lBr2 O2
C12 H5 7»Br2 "Br, O
C12 H4 79Br3 81Brj O
Compound2
TCDD4
PFK
TCDD3
TCDD3
HpCDF1
HpCDF1
PFK
TBDF
TBDF
TBDF
PFK
TBDF3
TBDD3
TBDD
TBDD
TBDD
TBDD3
TBDD3
PeBDPO
HxBDPO
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-47
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Method TO-9A
Dioxins and Furans
TABLE 11. (continued)
Descriptor
Number
3
Accurate
Mass1
469.778
471.775
559,608
561.606
563.604
566.966
573.646
575.644
575.603
577.601
579.599
589.641
591.639
616.963
Ion Type
M+2
M+4
M+2
M+4
M+6
Elemental
Composition
"CI2 S5CI, "Cl O2
13CI2 35C16 "Cl 02
Ci2 H3 79Br4 81Br O
C12 H3 79Br3 "Br2 O
C,2 H, 79Br2 "Br3 O
LOCK MASS
M+4
M+6
M+2
M+4
M+6
M+4
M+6
IJC12 H3 "Br, "Br2 O
"CI2 H3 wBr2 8iBr, O
C12 H3 79Br4 8!Br O2
C,2 H3 "Br, "Br2 O2
C,j H3 "Br2 81Br3 O2
IJC12 H3 "Br, "Br2 O2
»Cl2H379Br3s'Br202
QC
Compound2
OCDD5
OCDD3
PeBDF
PeBDF
PeBDF
PFK
PeBDF3
PeBDF3
PeBDD
PeBDD
PeBDD
PeBDD3
PeBDD3
PFK
Page 9A-48
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxins and Furans
Method TO-9A
TABLE 11. (continued)
Descriptor
Number
4
Accurate
Mass1
643.530
721.441
616.963
639.517
641.514
643.512
655.511
657.509
659,507
666.960
721.441
801.349
Ion Type
M+6
M+6
QC
M+4
M+6
M+8
M+4
M+6
M+8
LOCK
MASS
M+6
M+8
Elemental
Composition
C12 H4 79Br3 81Br3 O
C,2 H, "Br4 "Br, O
C,2 H2 7»Br4 "Br2 O
C,2 H2 79Br3 "Br3 O
C,2 H, "Br2 "Br4 O
C12 H2 "Br4 81Br2 O2
CI2 H2 "Br3 8IBr3 O2
C12 Hj 79Br2 81Br4 O2
C,2 H3 "Br4 81Br} O
C12 H2 79Br4 "Br4 O
Compound2
HxBDPO
HpBDPO
PFK
HxBDF
HxBDF
HxBDF
HxBDD
HxBDD
HxBDD
PFK
HpBDPO
OBDPO
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-49
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Method TO-9A
Dioxins and Furans
TABLE 11. (continued)
Descriptor
Number
5
Accurate
Mass1
717.427
719.425
721.423
733.422
735.420
737.418
754.954
770.960
801.349
816.951
879.260
865.958
Ion Type
M+4
M+6
M+8
M+4
M+6
M+4
.'•" V'El&hfjerital :: .. "" : " . - " :
Composition
C12 H "Br5 8IBr2 O
C,2 H 7'Br4 8lBr3 O
C12 H 79Br, !'Br4 O
CI2H79Br5"Brj02
CI2 H 79Br4 g'Brj O2
C12H7'Br3!lBr4O2
QC
LOCK MASS ALTERNATE
M+8
C12 H2 7'Br« "Br4 O
LOCK MASS
M+8
CI2 H "Brs 81Br4 O
QC ALTERNATE
Compound2'
HpBDF
HpBDF
HpBDF
HpBDD
HpBDD
HpBDD
PFK
HpTriazine
OBDPO
PFK
NBDPO
HpTriazine
'Nuclidic masses used: H= 1.007825
0=15.994915
"F= 18.9984
Compound abbreviations:
Polvbromoinated dibenzo-p-dioxins
TBDD = Tetrabromodibenzo-p-dioxin
PeBDD = Pentabromodibenzo-p-dioxin
HxBDD = Hexabromodibenzo-p-dioxin
HpBDD = Heptabromodibenzo-p-dioxin
OBDD = Octabromodibenzo-p-dioxin
Polvbromoinated dibenzofiirans
TBDF = Tetrabromodibenzoruran
PcBDF = Pcntabromodibenzofuran
HxBDF = Hexabromodibenzofuran
HpBDF = Heptabromodibenzofbran
OBDF = Octabromodibenzofuran
'Labeled Compound
4Therc is only one m/z for "CI4-2378-TCDD (recovery standard).
C= 12.000000 "C= 13.003355
= 78.91834 SIBr = 80.91629
Polvbromoinated diphenvl ethers
HxBDPE = Hexabromodiphenyl ether
HpBDPE = Heptabromodiphenyl ether
OBDPE = Oetabromodiphenyl ether
NBDPE = Nonabromodiphenyl ether
DBDPE = Decabromodiphenyl ether
PFK. = Perfluorokerosene
HpTriazine = Tris-(perfluoroheptyi)-s-Triazine
Page 9A-SO
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxins and Furans
Method TO-9A
TABLE 12. DESCRIPTORS, MASSES, M/Z TYPES, AND ELEMENTAL COMPOSITIONS
OF THE BCDDS AND BCDFS
.' Descriptor
Number
1
Accurate
mass1
315.942
317.939
327.885
330.979
331.937
333.934
347.851
349.849
363.846
365.844
m/z Type
M
M+2
M
Lock
M
M+2
M
M+2
M
M+2
Elemental Composition
"C,2 H4 35C14 O
C,2 H4 35C13 "Cl 0
C12 H4 "C14 02
C7F13
»CI2 H4 »C14 02
"C12 H4 3iCl3 "Cl 02
C,2 H4 35C13 "Br 0
C12H4.35Cl237ClTOBrO
C12 H4 35C13 79Br 02
C,2H435Cl217Cl79BrOj'
Compound^
TCDF"
TCDF"
TCDD3
PFK
TCDD4
TCDD4
Br C13 DF
BrCl3DF
Br C13 DD
Br CI, DD
Primary
m/z
Yes
Yes
Yes
Yes
Yes
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-51
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Method TO-9A
Dioxins and Furans
TABLE 12. (continued)
Descriptor
Number
2
Accurate
mass1
351.900
353.897
354.979
367.895
369.892
381.812
383.809
397.807
399.804
m/z Type
M-t-2
M+4
Lock
M+2
M-t-4
M
M+2
M
M+2
Elemental Composition
13C,2 H3 "C15 O
IJC,2 H3 "C14 "C1 0
C9F3
"caH,»aioI
I3CI2 Hj MC14 37C1 02
C,2 Hj 35C14 79Br O
C12 H3 3SClj "CI "Br O
CI2 H3 3SC14 "Br O2
C12 H3 "a, "Cl "Br O2
: ^Compound2 .:
PeCDF4
PeCDF4
PFK
PeCDD4
PeCDD"
Br C14 DF
Br C14 DF
Br C14 DD
Br C14 DD
Primary
m/z
Yes
Yes
Yes
'Nuclidic masses used:
H= 1.007825 C= 12.00000
0 = 15.994915 35C1 = 34.968853
F= 18.9984 79Br = 78.91834
^Compound abbreviations:
Polvchlorinated dibenzo-p-dioxins
TCDD = Tetrachlorodibenzo-p-dioxin
PcCDD = Pentachlorodibenzo-p-dioxin
HxCDD = Hexachlorodibenzo-p-dioxin
HpCDD = Heptachlorodibenzo-p-dioxin
OCDD = Octachlorodibenzo-p-dioxin
Polvchlorinated dibenzofurans
TCDF = Tetrachlorodibenzofuran
PcCDF - Pcntachlorodibenzofuran
HxCDF = liexachlorodibenzofuran
HpCDF = Heptachiorodibenzoftiran
3There is only one m/z for J7Cl4-2,3,7,8-TCDD (recovery standard).
4Labeled compound
"C = 13.003355
"Cl = 36.965903
81Br = 80.91629
Brominated/Chlorinated
dibenzo-p-dioxins and dibenzoflirans
BrQ3DD = Bromotrichloro dibenzo-p-dioxin
BrCl4DD = Bromotetrachloro dibenzo-p-dioxin
BrCljDF = Bromotrichloro dibenzofuran
BrCl4DF = Bromotetrachloro dibenzofuran
Lock mass and OC compound
PFK = Perfluorokerosene
Page 9A-52
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxins and Furans
Method TO-9A
TABLE 13. HRGC OPERATING CONDITIONS
Column Type
Length (m)
i.d. (mm)
Film Thickness Gum)
Carrier Gas
Carrier Gas Flow (mL/min)
Injector temperature (°C)
Injection Mode .
Initial Temperature (°C)
Initial Time (min)
Rate 1 (°C/min)
Temperature (°C)
Hold Time (min)
Rate 2 (deg. C/min)
Temperature (°C)
Hold Time (min)
Rate 2 (deg. C/min)
Final Temperature (°C)
Hold Time (min)
DB-5
60
0.25
0.25
Helium
1-2
290
Splitless
200
2
5
220
16
5
235
7
5
330
5
SE-S4
30
0.25
0.25
Helium
1-2
308
SP-2331
60
0.25
0.20
Helium
1-2
308
< — Moving needle — >
170.0
7.0
8.0
300.0
150.0
7.0
10.0
250.0
TABLE 14. HRMS OPERATING CONDITIONS
Electron impact
ionization
Mass resolution
Analysis
Exact masses monitored
25-70 eV
> 10,000 (10% Valley Definition)
Selected ion monitoring (SIM)
Masses shown in Tables 10, 11, 12
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 9A-53
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Method TO-9A
Dioxins and Furans
TABLE 15. UNLABELED AND LABELED
ANALYTE QUANTIFICATION RELATIONSfflPS
Analyte
2,3,7,8-TCDD
Other TCDDs
"CV2,3,7,8-TCDD
1,2,3,7,8-PeCDD
Other PeCDDs
1,2,3,4,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
Other HxCDDs
1,2,3,4,6,7,8-HpCDD
Other HpCDDs
OCDD
2,3,7,8-TCDF
Other TCDFs
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
Other PeCDFs
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
Other HxCDFs
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
Other HpCDFs
OCDF
: Internal Standard
: . - ; -Used .During Quantification
l3C12-2,3,7,8-TCDD
"C12-2,3,7,8-TCDD
'3Cir2,3,7,8-TCDD
"Cn-l,2,3,l,B-PeCDD
13C,rl,2,3,7,8-PeCDD
13C,2-l,2,3,6,7,8-HxCDD
1JC,rl,2,3,6,7,8-HxCDD
l3C,2-l,2,3,6,7,8-HxCDD
13C,2-l,2,3,6,7,8-HxCDD
"C,2-l, 2,3,4,6,7 ^,8-HpCDD
13C,rl,2,3,4,6,7,8-HpCDD
l3Ci2-OCDD
13C,r2,3,7,8-TCDF
13CI2-2,3,7,8-TCDF
1JC12-l,2,3,7,8-PeCDF
13C,rl,2,3,7,8-PeCDF
"Cn-l,2,3,7,8-PeCDF
13C,rl,2,3,4,7,8-HxCDF
"C12-l,2,3,4,7,8-HxCDF
"C12-l,2,3,4,7,8-HxCDF
"C12-l ,2,3,4,7,8-HxCDF'
"C,r 1 ,2,3,4,7,8-HxCDF
"C,2- 1,2,3,4,6,7,8-HpCDF
l3Cirl,2,3,4,6,7,8-HpCDF
"Cu-l,2,3,4,6,l,B-EpCDF
»CI2-OCDD
Page 9A-54
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxins and Furans
Method TO-9A
TABLE 16. INTERNAL STANDARD'S QUANTIFICATION
RELATIONSHIPS
Internal Standard
13C12-2,3,7,8-TCDD
13C12-l,2,3,7,8-PeCDD
13CI2-l,2,3,6,7,8-HxCDD
"CI2-I,2,3,4,6,7,8-HpCDD
13C12-OCDD
13C12-2,3,7,8-TCDF
'3Ci2-i,2,3,7,8-PeCDF
I3C12-l,2,3,4,7,8-HxCDF
13C,2- 1 ,2,3,4,6,7,8-HpCDF
Standard Used During Percent
Recovery Determination"
13C,2-1,2,3,4-TCDD
13C12-1,2,3,4-TCDD
13C12-l,2,3,7,8,9-F£xCDD
t3C12-l,2,3,7,8,9-HxCDD
13Cirl,2,3,7,8,9-HxCDD
13C12-1,2,3,4-TCDD
13C12-1,2,3,4-TCDD
13C 12- 1 ,2,3 ,7,8,9-HxCDD
'3C,2-l,2,3,7,8,9-HxCDD
Surrogate standards shown in Table 7 may also be used.
TABLE 17. SURROGATE/ALTERNATE STANDARDS
QUANTIFICATION RELATIONSHIPS
13r ?
*-12 Z
13c12-i
"c,2-i
I3r i
Surrogate Standard
,3,4,7,8-PeCDF
,2,3,4,7,8-HxCDD
,2,3,6,7,8-HxCDF
,2,3,4,7,8,9-HpCDF
Standard Used During Percent
Recovery Determination
13C12-l,2,3,7,8-PeCDF
I3C,2-l,2,3,6,7,8-HxCDD
13C12-l,2,3,4,7,8-HxCDF
!3C12-l,2,3,4,6,7,8-HpCDF
[Note: Other surrogate standards may be used instead]
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-55
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Method TO-9A
Dioxins and Furans
TABLE 18. QUANTIFICATION RELATIONSHIPS OF THE
CARBON-LABELED STANDARDS AND THE ANALYTES
Analytes
2,3,7,8-TBDD
2,3,?,8-TBDF
1,2,3,7,8-PeBDD
1,2,3,7,8-PeBDF
2,3,4,7,8-PeBDF
1,2,3,4,7,8-HxBDD
Quantification Standard
•::.:::.-\::-.-:. . .. ...... " - - • •
nC,2-2,3,7,8-TBDD
"C,2-2,3,7,8-TBDF
13C,r 1,2,3,7,8-PeBDD
"C12- 1,2,3,7,8-PeBDF
13C,r 1,2,3,7,8-PeBDF
"Cn-l, 2,3,7, 8-PeBDD
[Note: O.5 ng "Clf2,3,7t8-TCDD spiked to the extract prior to final
concentration to 60 ^L was used to determine the method efficiency (%
recovery of the l3Cn-labeled PBDDs/PBDFs),
• Additional 2,3,7.8-substituted PBDDs/PBDFs are now commercially
available.
• Retention Index for the PBDDs/PBDFs were published by Sovocool,
etai, Chemosphere 16, 221-114, 1987; and Donnelly, et at.,
Biomedical Environmental Mass Spectrometrv, 14, pp. 465-472,
1987.]
TABLE 19. THEORETICAL ION ABUNDANCE RATIOS AND CONTROL
LIMITS FOR PCDDS AND PCDFS
No. of Chlorine
Atoms
42
5
6
63
7
74
8
m/z's Forming
Ratio
M/M+2
M+2/M+4
M+2/M+4
M/M+2
M+2/M+4
M/M+2
M+2/M+4
Theoretical
Ratio :"."
0.77
1.55
1.24
0,51
1.04
0,44
0.89
Control Limits'
• :. ..:Lowftfv '.' ,'.-C; '.,..,' tipper: ...."•• ••'• "'•
0.65
1.32
1.05
0.43
0.88
0.37
0.76
0.89
1.78
1.43
0.59
1.20
0.51
1.02
'Represent ± 15% windows around the theoretical ion abundance ratios.
'Does not apply to 37Cl4-2,3,7,8-TCDD (cleanup standard).
3Uscd for "C,,-HxCDF only.
'Used for IJC,rllpCDF only.
Page 9A-S6
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxins and Furans
Method TO-9A
TABLE 20. THEORETICAL ION ABUNDANCE RATIOS AND CONTROL
LIMITS FOR PBDDS AND PBDFS
Number of
Bromine Atoms
4
4
5
5
6
6
7
7
Ion Type
M+2/M+4
M+4/M+6
M+2/M+4
M+4/M+6
M+4/M+6
M+6/M+8
M+4/M+6
M+6/M+8
Theoretical
Ratio
0.68
1.52
0.51
1.02
0.77
1.36
0.61
1.02
Control Limits
Lower
0.54
1.22
0.41
0.82
0.62
1.09
0.49
0.82
Upper
0.82
1.82
0.61
1.22
0.92
1.63
0.73
1.22
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-57
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Method TO-9A
Dioxins and Furans
TABLE 2 i. MINIMUM REQUIREMENTS FOR INITIAL AND DAILY CALIBRATION
RESPONSE FACTORS
Compound
Relative Response Factors
Initial Calibration RSD
Daily Calibration % Difference
Unlabclcd Analytes
2,3,7,8-TCDD
2.3,7,8-TCDF
1,2,3,7,8-PcCDD
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
1,2,4,5,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3.7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
1, 2,3,4,6,7,8-! IpCDD
1,2,3,4,6,7,8-HpCDF
OCDD
OCDF
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
30
25
25
25
25
25
25
25
25
25
25
25
25
25
25
25
30
Internal Standards
,,Cu-2,3,7,8-TCDD
»etrl,2,3,7,8-PeCDD
"C,,-l,2,3,6,7,8-HxCDD
"C,r 1 ,2,3,4,6,7,8-HpCDD
25
30
25
30
25
30
25
30
Page 9A-58
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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DVoxins and Furans
Method TO-9A
TABLE 21. (continued)
Compound
!3C,rOCDD
13C12-2,3,7,8-TCDF
IJC|2-I,2,3,7,8-PeCDF
13C12- 1 ,2,3,4,7,8-HxCDF
13C12-l,2,3,4,6,7,8-HpCDF
Relative Response Factors
Initial Calibration RSD
30
30
30
30
30
Daily Calibration % Difference
30
30
30
30
30
Surrogate Standards
37Cl4-2,3>7,8-TCDD
13C12-2,3,4,7,8-PeCDF
13CI2-l,2,3,4,7,8-HxCDD
1JC12-l,2,3,4,7,8-HxCDF
13Cu-l,2,3,4,7,8,9-HpCDF
25
25
25
25
25
25
25
25
25
25
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-59
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Method TO-9A
Dioxins and Furans
TABLE 22. 2,3,7,8-TCDD EQUIVALENT FACTORS (TEFS)1
FOR THE POLYCHLORINATED DIBENZODIOXINS
AND POLYCHLORINATED DIBENZOFURANS
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Compound
2,3,7,8-TCDD
1,2,3,7,8-PeCDD
1,2,3,4,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,4,6,7,8-HpCDD
OCDD
2,3,4,7,8-TCDF
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
OCDF
-•^'^"^'^fWK.^'-^f.
1,00
0.50
0.1
0.1
0.1
0,01
0.001
0.10
0.05
0.5
0.1
0.1
0.1
0.1
0.01
0.01
0.001
'Interim procedures for Estimating Risks associated with
Exposures to mixtures of Chlorinated Dibenzo-p-Dioxins and
Dibenzofurans (CDDs/CDFs), WPA-625/3-89-016, March 1989.
[Note: The same TEFs are assigned to the PBDDs/PBDFs and
" BCDDs/BCDFs.J
Page 9A-60
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Dioxins and Furans
Method TO-9A
TABLE 23. MINIMUM SAMPLING EQUIPMENT CALIBRATION AND
ACCURACY REQUIREMENTS
Equipment
Sampler
Acceptance limits
Indicated flow rate =
true flow rate ±10%.
Frequency and method of
measurement
Calibrate with certified
transfer standard on
receipt, after maintenance
on sampler, and any time
audits or flow checks
deviate more than ±10%
from the indicated flow
rate or +10% from the
design flow rate.
Action if require-
ments are not met
Recalibrate
Associated equipment
Sampler on/off timer
Elapsed-time meter
Flowrate transfer
standard (orifice
device)
±30 min/24 hour
±30 min/24 hour
Check at receipt for
visual damage
Check at purchase and
routinely on sample-
recovery days
Compare with a standard
time-piece of known
accuracy at receipt and at
6-month intervals
Recalibrate annually
against positive
displacement standard
volume meter
Adjust or replace
Adjust or replace
Adopt new calibration
curve
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-61
-------
Method TO-9A
Dioxins and Furans
TABLE 24. FORMAT FOR TABLE OF ANALYTICAL RESULTS
IDENTIFICATION
AIR SAMPLER EFFICIENCY (% RECOVERY)
MC,,-I,2,3,4,-TCDD
METHOD EFFICIENCY (% RECOVERY)
"C|r2,3,7,8-TCDF
"€,2-2,3,7,8-^00
"Cu-l^.S.T.S-PcCDF
"C,s-l,2,3,7,8-PeCDD
l3C,,-I,2,3,4,7,8-HxCDF
"C,,-I,2,3,6,7,8-HxCDD
"C,,-1.2,3,4,6,7,8-HpCDD
"C.j-OCDD
CONCENTRATIONS DETECTED or MDL (pg/m3)
TCDDs (TOTAL)'
2,3,7,8-TCDD
PcCDDs (TOTAL)
1.2,3,7,8-PcCDD
HxCDDs (TOTAL)
1.2,3,4,7,8-HxCDD
I.2,3,6,7,8-IL\CDD
1,2,3,7,8,9-MxCDD
MpCDDs (TOTAL)
1,2,3,4,6,7,8-HpCDD
Page 9A-62
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Dioxins and Furans
Method TO-9A
TABLE 24. (continued)
IDENTIFICATION
OCDD
TCDFs (TOTAL)
2,3,7,8-TCDF
PeCDFs (TOTAL)
1,2,3,7,8-PeCDF
2,3,4,7,8-PeCDF
HxCDFs (TOTAL)
1,2,3,4,7,8-HxCDF
1,2,3,6,7,8-HxCDF
1,2,3,7,8,9-HxCDF
2,3,4,6,7,8-HxCDF
HpCDFs (TOTAL)
1,2,3,4,6,7,8-HpCDF
1,2,3,4,7,8,9-HpCDF
OCDF
'(TOTAL) = AH congeners, including the 2,3,7,8-substituted congeners.
ND = Not detected at specified minimum detection limit (MDL).
[Note: Please refer to text for discussion and qualification that must accompany the results.]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-63
-------
Method TO-9A
Dioxins and Furans
Figure 1. Dibenzo-p-dioxin and dibenzoftiran structures.
Page 9A.-64 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Dioxins and Furaus
Method TO-9A
Magnehlic Gauge
0-100 in. -
Exhaust Duct
(6 in, x 10 ft)
Sampling Head
see Figure 3)
Voltage Variator
Elapsed Time
Meter
7-Day Timer
Figure 2. Typical dioxins/fiiran high volume air sampler.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-65
-------
Method TO-9A
Dioxins and Furans
Air Flow
Particle Fitter
Particle Filter
Support
• Assembled
Sampling
Module
Air Flow
Exhaust
Filter Retaining Ring
Silicons Gasket
102-inm
Quartz-fiber
Filter
Filter Support Screen
Filter Holder (Part 2)
Silicone Gasket
Class Cartridge
Retalnlna Screen
Sorbent
Retaining Screen
Silicone Gasket
Cartridge
Holder
(Part 1)
Figure 3a. Typical absorbent cartridge assembly for sampling dioxin/furans.
Page 9A-66
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxins and Furans
Method TO-9A
Glass PDF Sampler with
Stainless Steel Screens
64mm P.P.
.Glass
Cartridge
End Cap
PUF Plug
End Cap
(1) Glass PUF cartridge, plug, and end caps
Accessories
Teflon Sealing Caps PUF Insert
with O-rings for
capping PUF Sampler
(2) PUF shipping container.
Aluminum Canister for Shipping
and Storage of the PUF Sampler
Figure 3b. Typical glass PUF cartridge (1) and shipping container
(2) for use with hi-vol sampling systems.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-67
-------
Method TO-9A
Dioxins and Furans
4" Diameter Pullflex
Filter and Support
PUF Adsorbent
Cartridge and Support
Quick Release Connections
for Module
Quick Release Connections
for Magnahelic Gage
Flow Control Valve
Elapsed Time Indicator
Figure 4. Portable high volume air sampler developed by EPA.
Page 9A-68
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Dioxins and Furans
Method TO-9A
Mercury
Monomeler
Borometer
Thermometer
Filter Adopter
Rootsmeter
High Volume Motor
Resistonce Ploles
Figure 5. Positive displacement rootsmeter used to calibrate orifice transfer standard.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-69
-------
2s-
w
1
e
5
1
I
1
!
f
1-
fe
i5
i5
1
§• -
$
a
SB
3
,-*
r
- ]
]
<
i
/>
COMPENDIUM METHOD TO-9A
ORIFICE CAIIBRATION DATA SHEET
1% Name
i
Pi : mmHe
Drifice No.
Date
lootsmeter No.
Resistance
' Wants
$lo« of
holes) •
5
7
10
13
18
Calculation E
I. V^ =
where:
SIo
T} HMO
stu
J- Qstd =
Air Volume
Measaredby
Rootsmeter Vg^ '
...^
200
200
300
300
300
:^>
5.66
5.66
8.50
8.50
8.50
Factors1
xjuations:
P, - AP TV.
V ( l V **
7«).0 mm Hg
v
~i~
Standard
. (shlia3)
(R3)(0.02
)
Fig
Tiawfor
Air Volume
to Bass
$ (min)
832 mS -
°-5* r/
R3
ure6. Orifi
Rooteroeter
Differential,
d* (aan
Hg) .
m3 and (in.
ce calibratior
. Drop
Orifice,; ,
H^O)'.,
x-Axis
Howrate,
• ' C^M ($tel
Wrt ^/I f1®3* %} - mtr
to. Hg
i data sheet.
Y-axis
u!!*
iHg
|;
o
a
3
a
5*
1
1-
-------
Dioxins and Furans
Method TO-9A
Sampling head
tt
Calibrated
orifice
Shutoff valves
Magnehefc gauge
0-100 in.
Manometer
0-18 in.
Pipe fitting (1/2 in.)
^ . rrrrj-r,, , ,*^, £{,rr. ,
Elapsed time
meter
Exhaust duct
Figure 7. Field calibration configuration of the dioxin/ftiran sampler.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-71
-------
Method TO-9A
Dioxins and Furans
COMPENDIUM METHOD TO-9A
FIELD CALIBRATION DATA SHEET DIOXIN/FURAN SAMPLER CALIBRATION
Sampler ID:
Sampler Location:
High Volume Transfer Orifice Data:
Correlation Coefficient (CC1):
(CC2):
Intercept (Bl):
(B2):
Calibration Orifice ID:
Job No.:
Slope (Ml):
(M2):
Calibration Date:
Time:
Calibration Ambient Temperature: °F
Calibration Ambient Barometric Pressure:
Calibration set point (SP):
CALIBRATOR'S SIGNATURE
"Hg.
mm Hg
SAMPLER CALIBRATION
Actual values from calibration
Orifice
manometer,
inches
(Yl)
Monitor
maguehelie,
inches
(Y2)
70
60
50
40
30
20
10
Calibrated values
Orifice
manometer
(Y3)
Monitor
magnehelle
(Y4)
Calculated value
orifice flow, scm
Definitions
Yl = Calibration orifice reading, in. H2O
Y2 = Monitor magnehelic reading, in. H2O
P, = Barometric pressure actual, mm Hg
Bl = Manfacturer's Calibration orifice Intercept
Ml = Manufacturer's Calibration orifice
manometer slope
Y3 = Calculated value for orifice manometer
= [Y l(Pa/760)(298/{Ta + 273})f
Y4 = Calculated value for magnehelic
= [Y2(Pa/760)(298/{f a + 273})]*
XI = Calculated value orifice flow, scm
= Y3-B1
Ml
P^ = Barometric pressure standard, 760 mm Hg
T, = Temperature actual, °C
Tstd = Temperature standard, 25° C
Figure 8. Orifice transfer field calibration data sheet.
Page 9A-72
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Dioxiiis and Furans
Method TO-9A
f H,O) adj.
Lfnear regression of X1 (serum) vs. Y4
1
Calculate BS and M2
i
Y8-82
X2 = —
(scinm) M2.
Y5 p. [svg, msg. «i h
Figure 9. Relationship between orifice transfer standard and flow rate through sampler.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 9A-73
-------
Method TO-9A
Dioxins and Furans
Sampler I.D. No.:
Lab PUF Sample No.:.
Sample location:
COMPENDIUM METHOD TO-9A
FIELD TEST DATA SHEET
GENERAL INFORMATION
Operator:
Other:
PUF Cartridge Certification Date:
Date/Time PUF Cartridge Installed:
Elapsed Timer:
Start
Stop
,:'. Diff.
Sampling
Start
Ml
M2
Bl
B2
Barometric pressure ("Hg)
Ambient Temperature (°F)
Rain
Sampling time
Start
Stop
Diff.
Stop
Yes
No '
Yes
'NO '
Audit flow check within ± 10 of set point
Yes
No
TIME
Avg.
TEMP
BAROMETRIC
PRESSURE
MAGNEHEL1C
READING
CALCULATED
FLOW RATE
(scnun)
READ BY
Comments
Figure 10. Field test data sheet.
Page 9A-74
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
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5-
I
a
3
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PS
I
3"
5?
MR
10QS
so;
60J
aoi
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lae
1008
HO;
60J
40.:
20J
0"
>i/Z
IDOi
60,]
SO;
20:
n:
•us
MM
looa
80J
so:
«DJ
aoJ
0"
= 903.9016.
33
26: dQ
n l t3(8,o* TCDP |
n • /
' 2?be ' ' 30ioo SiSoo iaSoi JiSoo
= $15.94151
33
|
1
/
zs'ob ' ' ' ialaa ' ailoi ' ' ' 32!oo ' ' ' Jslo-o "
= 319.9985;
30:30
fl " '
'
I \
23:00 -JOtOO 31s 00 32?0"0 33 iC5
— 331 ,9@SS 1
' isloo ' ' ' soSoe ' ' ' jiloo ' ' ' 32!« ' ' ' asSoo '
:39 Jg
1 ;, J5.15
- i
\ \
V / v. ^
J4!oo ' ' Islw 35ioi
'(
i
3S
I
\
V
34:00 35sOQ 36jOO
i
'l
i
2,3,73-TCOO'lji A 3G
ft
m
An 1 J
/ u V V /
" 34'ob ' ' 35:06 " ' ' 36:00
t
i
34- SS
rt«CXZ,3,7,&-TCDD|
'
J^
' J4SOO ' ' ' 35sOO ' ' 35sW '
:4S
H,2,«,&-TCDF|
1
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3V:Q6
i?!«6 ' ' '^
•-51
JU.SAS.TCODj
'
f
V
3?:OD
57:00
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Li. 487
12.6S7
L1.7B7
:fl.3E6
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3.4E7
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L2.0B7
L1.3E7
L5.7B5
•o.oso
,.2,957
b.337
Li.im
L1.2E7
L5.8S€
:O.OEO
F2.7g7
^.Ltt?
L1.6K7
Ll.lE7
LS-3RS
•O.OEO
Tims
65
D
a
3
Figure 11. Chromatograms showing the window defining mix. First and last eluting PCDF and PCDD isomer in each group
are shown above the respective internal quantification standard (IQS).
-------
f
85
e
3
I
a
I
100*
80j
60J
40J
20.;
di
ME
10 Oft
80;
40'
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10 Oi
?PJ
SOJ
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RJIJj
I'OCi
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..M-I
37 121
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37laD SSsOO 39;0d 40JOO 4lsO
-S51JOOOI
41
3?!CO 38-100 39:00 4flloO 4ilD
:=a55.854Sf|
39; 48
1,S,4,7,9-PeCD!}'A
r -.70(340 1
" *" *•* 'l
3? i 00 33 * 00 -^$ bOO 40*00 4JI s y
0 42;
-------
2
o
I
^
I
I
I
I
I
Me =373.8207
lOClSj 46jl.$ . 5i?06 ,..8.9127
80J
OTJ
40J
20J
OJ
ll '
LW.6.8-HXCDF,
; V _
46:99
-------
I
§
I
8-
a
a
§
WZ = 407^810;
2001
aoj
coi
20J
o,
100%
60J
40J
ft:
M(2 = 425.77S? I
iaas
80J
id
1005
»0.;
60J
5d:0d
54:00
5400
SSrOfi
55:00
55:00
S5:SD
54iOO
1
ft ^7
• l\ ' ' ' fc
A
U.
:D
6rO« 5?Tob 58:00
1
La.
_7.
0
6:00' 57«00 SfcsOO
i
1
;&4,el7,B-HpCDD ,
b,
=.2,
Ll.
-0
esOO . 53-Od ' 58:00
\
:-1,2,3,4.B,7,8-KpCDD,'
^
L2-
•n
s!oo ' ' 57! 06 ' 5«'oo
1B7
SB7
DEO
Time
me
556
9fiS
aia
rime
937
5B7
317
2S7
010
SB«
526
OEO
O
c.
>"3
O
O
o'
63
a
a
VO
vo
Figure 11. (continued)
-------
p
63
I
I
I
I
M/Z = 31 9,8965!
lOOi
SOJ
aoj
70-
60J
soJ
40J
30J
20J
10J
9'
35-01
2,3,7,8,-TCDDl \ 36
30:36 1
| 1,S,6,e-TCDD-
II i I I I 1 1 2 3 Q»T^ OD *
I I i 5 ^ 7 /I 23_B«TCDDI[l i 1 * ' i^'t/irfi
ill
11 I v I J
SI
31-00 ' 32:00 ' ' ' 33^00 3«-00 ' 35^00 ' ' ' 36(00^ 37^00 38^00
2.9B7
L2.6S7
L2.0B7
L1.7B7
LI.4ET
Ll.2E7
L8 . 6E6
L5.BER
L2 . 9B6
:O.OBO
M/Z = 331.9366|
iOCA
90J
six:
70J
«OJ
so'
aoJ
30 j
20J
10J
3
53 2 , 7S7
C-2,3,7,8-TCDDi f.2.4E7
31 100 32-lo6 ittioo 34:00 35:QQ 36lo6 37:00 38:00
L2.1E7
U-9E7
LI -SET/
L1.3E7
L1.1B7
L8.0B6
L5-3B6
.O.OBO -
83
P
a.
n
B
in
Figure 12. HRGC-HRMS column performance mix showing acceptable separation of 2,3,7,8-TCDD
from the adjacent isomers.
I
a.
3
-------
2s
'O
00
o
I
I
S1
I
I
Si
g
S3
VO
f,VZ.3CS'.9C16|'
60-
40;
0;^-.
atsoo
I'OOii
aoj
H
40;
0;
27
00
100!
aoJ
20:
OJ
a? oo 28loo
M/Z=317.8988
1001
BO.
60:
40;
20;
0:
* '
4.1X5
L3.31S
L2.5D5
11.7B5
V .^_; ;^r.7
38:00 " ' ' 29-W ' ' " ioloi ' " ' 31:00 ' ' ' 32la6 " ' 33sQtt ' ' ' 34:00 ' ^JSlOO ' ' 3S:00 Tliae
I
_S.73S
U,S25
L3.4IS
13.3B3
it .115
_,_^_I_, r___. , , , , , , ,4.C-OBO
asioo ' ' ' is5oo ' " ' ioJoO ' ' " illOD "' 3i!o6 " ilsOO '"' ' 34:00 ' ' ' 3S:00 ' ' ' 3«!«0 ' Time
! ,.3.91?
:-2,3,7,a-TCDF'.
_^ /-,--,-•-. .... , , i ••"»'• fft-niM
"Jsloi^" ' ' 30:00^' ' ' 31JOO * 32100 33s'o6 " ' ' 3«!09 ' JSsOO ' 36:00 Tiw*
,-3.727
13.9H5
-.2.287
; v
33-00
.7.33$
.0.030
Figure 13. Extracted ion current profiles (EICP) for 2,3,7,8-TCDF and labeled standard.
2
»-
»•*
o
a
I
s
a
31'
2
i
-------
Sr
B
o
5'
I
•8
I
:WZ = 319.886$ -,
1002:
8PJ
60J
aoj
20 j
oj
27
J
u
1 II 2,3.7^-TCDD
'
-> ^JL
06 asioo 29loo ioioo 31-00 si-oo s'sToo iiloo islnn seloo
3 . SE5
L2.6K5
L2.0B5
Ll.3B5
.6- SEW
-0.030
Time
WZ= 321.8836 |
1004
eoJ
6DJ
40;
30:
o-
27
iooa
fiOJ
69J
40:
20:
q:
27
i •
1
1 I
, „ .^'-; w. r i - -
00 2£;00 29: 00 3QiQO 33. -OO 32:00 33 :00 3 4; 00 35: OO 36: 00
°**1-WWv
J)
1^1.2.3.4-TCDD
/ U
.1
»1>2378-TCC>D'
V
00 28 1 00 29*00 i<):00 31:00 32:00 33-! 00 34:DD 35:00 36; 00
r4.3BS
L3.5B5
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L8.6S4
:Q.OEO
ICime
2.1ET7
L1.7E7
j.l.2£T7
-8.3B6
_4.1B6
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WZ= 933.9339',
1009
80-
eo:
20:
0:
27
1
/ \J
^
00 28:00 29:00 3Q;00 31:00 32:00 33:00 34:00 35:00 3G:QO
-2.737
.2 . 2B7
:.1.6B7
-5.4K6
D.OZO
Tine
=
•*)
1
Figure 14. Extracted ion current profiles (HLCP) for 2,3,7,8-TCDD and labeled standard.
I
3
3
-------
I
n
\o
J&-
do
N>
D
o
1
•Q
a
S*
a'
3
,0
1
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R.
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80:
:
vU-
40:
20:
Oz
.«-.
'»%3i7.S-P*COP
J
'jTJOO 38:00 39lOO'
M/Z =341,8568!
10M
SOJ
6ft:
40:
apj
o:
1
17; 00 33:00 33s 00
200|
80;
SB;
40l
20J
0=
MC.'1AS,WeCDF
j
I
1
37:00 38:90 39-QO
M/H = 353.8970;
iOOlj
80;
fio.:
SOJ
JO:
ft"
,
/
j
'3?{QO '38:00 " 29:00
i
A
I
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ft '
1
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i
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ll.OSS
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i
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i
V / I
L4.2E7
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• 0. OBO
40:00 41 '00 42:00 Time
1 (T3-aB7
*
>\
-
i ;
^ ' v
:.2.7l1
12.037
Ll.417
U.8R6
.0.080
"dOiOO" ' ' ' *41;00 42:00" ' TiBic
Figure 15. Extracted ion current profiles (ELCP) for 2,3,7,8-substituted PeCDF and labeled standard.
S
r»
&
o
a.
H
9
2
O
i*
Sfi
»
B
CL
S5
9
en
-------
fr
a
I
I
i
c
I
I
I
• \
M/Z =i 355-BS46 i
1004
BD;
60:
40:
20:
0:
•,
"
i
n 1
1,2^,7,8-PeCDD 1
2-8R5
:.2.236
:
-l.TK?
1 -
1 •}•
1 L5
-------
3?
s
rs
o
I
TO
a
a.
R"
I
I
I
a
a
S?
40;
20J
•WZ.
1.004
80;
60;
40J
o-
10 09
80J
soj
40;
20J
0'
ME
80;
60:
ao:
0;
.'373.8207.
' 43$00 ' ' 44:00
=375.8178
•-"S1" "'"'
1,V* < *S -V «t f
43:00 44: 00
-3aS,86<0 i
* 43iQ3 * ^4JOO
45 00
46sOO
; v.
ts0|J
"wioo
4? l
d7sOO
47o»
L4.5S6
LJ.1E6
L2.1E6
U.OE6
O.OEO
:2.eas
L1.7BG
la.-nss
.-.O.OBO
12.2E7
Ll-lBT
LS.5B6
.0,OBJ
Tine
-5.0S7
-3.0B7
•-O.OIO
Tioe
o
o,
H
q
5*
Si
3
e,
Figure 17. Extracted ion current profiles (EICP) for 2,3,7,8-substituted HxCDF and labeled standard.
a
-------
B
£0
so
so
8-
rj
3»
a
»
S3
•8
VO
o
• NIZ
20J
o'
5s373,820T :
1i2347,i
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-------
Method TO-9A
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EPA/625iU-96/OlOb
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-10A
Determination Of Pesticides And
Polychlorinated Biphenyls In Ambient
Air Using Low Volume Polyurethane
Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector
Detection (GC/MD)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-10A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/0 lOb), which was prepared under Contract
No. 68-C3-Q315, WA No. 3-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research
Grpip, Inc. (ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A.
Manning, John Burekle, and Scott Rl Hedges, Center for Environmental Research Information (CERI), and Frank
F. McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of Research and
Development (ORD), were responsible for overseeing the preparation of this method. Additional support was
provided by other members of the Compendia Workgroup, which include:
John Burckle, U.S. EPA, ORD, Cincinnati, OH
• James L. Cheney, Corps of Engineers, Omaha, NB
Michael 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 ATMcCtamy, U.S. EPA, NERL, RTF, NC
Frank F. McElroy, U.S. EPA, NERL, RTF, NC
* Heidi Schultz, ERG, Lexington, MA
William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Method TO-10 was originally published in March of 1989 as one of a series of peer reviewed methods in the
second supplement to "Compendium of Methods for the Determination of Toxic Organic Compounds in
Ambient Air," EPA 600/4-89-018. In an effort to keep these methods consistent with current technology,
Method TO-10 has been revised and updated as Method TO-10A in this Compendium to incorporate new or
improved sampling and analytical technologies. In addition, this method incorporates ASTM Method D 4861-94,
Standard Practice for Sampling and Analysis of Pesticides and Polychlorinated Biphenyls in Air.
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)
t RobertG. Lewis, U.S. EPA, NERL, RTF, NC
Peer Reviewers
F . William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Irene D. DeGraff, Supelco, Bellefonte, PA
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Whitaker, and Kathy Johnson
of Midwest Research Institute's Administrative Services staff whose dedication and persistence during the
development of this manuscript has enabled it's production.
! ' J !
DISCLAIMER
Th/s Compendium has bean sub/acted to the Agency's pear and administrative review, and it has been
approved for publication as an SPA document. Mention of trade namos or commercial products does not
constitute endorsement or recommendation for use.
-------
METHOD TO-10A
Determination Of Pesticides And Polychlorinated Biphenyls In Ambient
Air Using Low Volume Polyurethane Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector Detection (GC/MD)
TABLE OF CONTENTS
Page
1. Scope IOA-1
2. Summary of Method IOA-1
3. Significance 10A-2
4. Applicable Documents 10A-2
4.1 ASTM Standards 10A-2
4,2 EPA Documents 10A-2
4.3 Other Documents 10A-3
5. Definitions 10A-3
6. Interferences 10A-3
7. Equipment and Materials 10A-4
7.1 Materials for Sample Collection 10A-4
7.2 Equipment for Analysis 10A-5
7.3 Reagents and Other Materials 10A-5
8. Assembly and Calibration of Sampling System 10A-6
8.1 Description of Sampling Apparatus 10A-6
8.2 Calibration of Sampling System 10A-6
9. Preparation of PUF Sampling Cartridges 10A-6
10. Sampling 10A-7
11. Sample Extraction Procedure 10A-8
11.1 Sample Extraction 10A-8
11.2 Sample Cleanup 10A-9
ui
-------
TABLE OF CONTENTS (continued)
12. Analytical Procedure .................... , ................. . ......... ......... 10A-10
12. 1 Analysis of OrganochJorine Pesticides by Capillary Gas Chromatography with
Electron Capture Detector (GC/ECD) ............... . ..... . ...... . .......... 10A-10
12.2 Analysis of Organophosphorus Pesticides by Capillary Gas Chromatography
with Flame Photometric or Nitrogen-Phosphorus Detectors (GC/FPD/NPD) ........ 10A-1 1
12.3 Analysis of Carbamate and Urea Pesticides by Capillary Gas Chromatography
with Nitrogen-Phosphorus Detector ............................... ......... 10A-1 1
12.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by High
Performance Liquid Chromatography (HPLC) ..... ................. . ......... 10A-1 1
12.5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass
Spectrometry Detection (GC/MS) ............. . ............. . .............. 10A-12
12.6 Sample Concentration [[[ 10A-12
13. Calculations %v ..... . ................... . ................................... 10A-13
13.1 Determination of Concentration ......................... . ........ ..... .... 10A-13
14. Sampling and Retention Efficiencies ............................................ 10A-15
14.1 General ......................... . ..................................... 10A-15
14.2 Determining SE [[[ 10A-15
15. Performance Criteria and Quality Assurance ...................................... 10A-17
15.1 Standard Operating Procedures (SOPs) .... ....................... . ......... 10A-17
15.2 Process, Field, and Solvent Blanks ............ . .................. . ......... 10A-17
15.3 Sampling Efficiency and Spike Recovery ... ................................. 10A-17
, 15.4 Method Precision and Bias ............................................... 1QA-18
15.5 MethodSafety ...... . ................................ . ....... . ......... 10A-18
-------
METHOD TO-10A
Determination Of Pesticides And Polychloriniated Biphenyls In Ambient
Air Using Low Volume Polyurethane Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector (GC/MD) Detection
1. Scope
1.1 This document describes a method for sampling and analysis of a variety of common pesticides and for
polycHorinated biphenyls (PCBs) in ambient air. The procedure is based on the adsorption of chemicals from
ambient air on polyurethane foam (PUF) or a combination of PUF and granular sorbent using a low volume
.sampler.
1.2 The low volume PUF sampling procedure is applicable to multicomponent atmospheres containing common
pesticide concentrations from 0.001 to 50 ^g/m3 over 4- to 24-hour sampling periods. The limits of detection
will depend on the nature of the analyte and the length of the sampling period.
1.3 Specific compounds for which the method has been employed are listed in Table 1. The analytical
methodology described in Compendium Method TO- 10A is currently employed by laboratories throughout the
U.S. The sampling methodology has been formulated to meet the needs of common pesticide and PCB sampling
in ambient air.
1.4 Compendium Method TO-10 was originally published in 1989. The method was further modified for indoor
air application in 1990. In an effort to keep the method consistent with current technology, Compendium
Method TO-10 has incorporated ASTM Method 134861-94 (1) and is published here as Compendium
Method TO-10A.
2. Summary of Method
2.1 A low-volume (1 to 5 L/minute) sample is used to collect vapors on a sorbent cartridge containing PUF or
PUF in combination with another solid sorbent Airborne particles may also be collected, but the sampling
efficiency is not known (2).
13, Pesticides and other chemicals are extracted from the sorbent cartridge with 5 percent diethyl ether in hexane
and determined by gas chromatography coupled with an electron capture detector (ECD), nitrogen-phosphorus
detector (NPD), flame photometric detector (FPD), Hall electrolytic conductivity detector (HECD), or a mass
spectrometer (MS). For common pesticides, high performance liquid chromatography (HPLC) coupled with an
ultraviolet (UV) detector or electrochemical detector may be preferable. This method describes the use of an
electron capture detector.
2.3 Interferences resulting from analytes having similar retention times during GC analysis are resolved by
improving the resolution or separation, such as by changing the chromatographic column or operating parameters,
or by fractionating the sample by column chromatography.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-1
-------
Method TO-10A Pestieides/PCBs
3. Significance
3.1 Pesticide us;age and environmental distribution are common to rural and urban areas of the United States.
The application of pesticides can cause potential adverse health effects to humans by contaminating soil, water,
air, plants, and animal life. However, human exposure to PCBs continues to be a problem because of their
presence in the environment.
3.2 Many pesticides and PCBs exhibit bioaccumulative, chronic health effects; therefore, monitoring the presence
of these compounds in ambient air is of great importance.
3.3 Use of a portable, low volume PUF sampling system allows the user flexibility in locating the apparatus.
The user can place the apparatus in a stationary or mobile location. The portable sampling apparatus may be
positioned in a vertical or horizontal stationary location (if necessary, accompanied with supporting structure).
Mobile positioning of the system can be accomplished by attaching the apparatus to a person to test air in the
individual's breathing zone.
3.4 Moreover, this method has been successfully applied to measurement of common pesticides in outdoor air,
indoor air and for personal respiratory exposure monitoring (3).
4. Applicable Documents
4.1 ASTM Standards
* D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis
• D4861-94 Standard Practice for Sampling and Analysis of Pesticides and Polychlorinated Biphenyls
in Air
• • E260 Recommended Practice for General Gas Chromatography Procedures
? • E355 Practice for Gas Chromatography Terms and Relationships
• D3686 Practice for Sampling Atmospheres to Collect Organic Compound Vapors (Activated Charcoal
Tube Adsorption Method
• D3687 Practice for Analysis of Organic Compound Vapors Collected by the Activated Charcoal Tube
",. Adsorption
"•" • D4185 Practice for Measurement of Metals in Workplace Atmosphere by Atomic Absorption
. Spectrophotometry
&• i:It' "if ' • :1 - '
4.2 EPA Documents
* Compendium of Methodsfor the Determination of'Toxic Organic Compounds in Ambient'Air: Method
TO-10, Second Supplement, U, S. Environmental Protection Agency, EPA 600/4-89-018, March 1989.
• Manual of Analytical Methods for Determination of Pesticides in Humans and Environmental
Standards t U. "S. Environmental Protection Agency, EPA 600/8-80-038, June 1980.
* Compendium of Methods for the Determination of Air Pollutants in Indoor Air: Method IP-8, U. S.
Environmental Protection Agency, EPA 600/4-90-010, May 1990.
Page 10A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
PesticMes/FCBs Method TO-10A
4.3 Other Documents
• Code of Federal Regulations, Title 40, Part 136, Method 604
5. Definitions
{Note: Definitions used in this document and in any user-prepared Standard operating procedures (SOPs)
should be consistent with ASTM Dl 356, E260, and E355. All abbreviations and symbols are defined within
this document at point of use.]
5.1 Sampling efficiency (SE)-abUity of the sampling medium to trap analytes of interest. The percentage of
the analyte of interest collected and retained by the sampling medium when it is introduced as a vapor in air or
nitrogen into the air sampler and the sampler is operated under normal conditions for a period of time equal to
or greater than that required for the intended use is indicated by %SE.
5.2 Retention efficiency (KE)-ability of sampling medium to retain a compound added (spiked) to it in liquid
solution.
5.3 Static retention efficiency-ability of the sampling medium to retain the solution spike when the sample
cartridge is stored under clean, quiescent conditions for the duration of the test period.
5.4 Dynamic retention efficiency (REJ-ability of the sampling medium to retain the solution spike when air
or nitrogen is drawn through the sampling cartridge under normal operating conditions for the duration of the test
period. The dynamic RE is normally equal to or less than the SE.
5.5 Retention time (RT)-time to elute a specific chemical from a chromatographic column, for a specific carrier
gas flow rate, measured from the time the chemical is injected into the gas stream until it appears at the detector.
5.6 Relative retention time (RRT)-a rate of RTs for two chemicals for the same chromatographic column and
carrier gas flow rate, where the denominator represents a reference chemical.
5.7 Surrogate standard-a chemically inert compound (not expected to occur in the environmental sample) that
is added to each sample, blank, and matrix-spiked sample before extraction and analysis. The recovery of the
surrogate standard is used to monitor unusual matrix effects, gross sample processing errors, etc. Surrogate
recovery is evaluated for acceptance by determining whether the measured concentration falls within acceptable
limits.
6. Interferences
6.1 Any gas or liquid chromatographic separation of complex mixtures of organic chemicals is subject to serious
interference problems due to coelution of two or more compounds. The use of capillary or microbore columns
with superior resolution or two or more columns of different polarity will frequently eliminate these problems.
hi addition, selectivity may be further enhanced by use of a MS operated in the selected ion monitoring (SIM)
mode as the GC detector. In this mode, co-eluting compounds can often be determined.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-3
-------
Method TO-lOA [ Pesticides/PCBs
6,2 The BCD responds to a wide variety of organic compounds. It is likely that such compounds will be
encountered as interferences during GC/ECD analysis. The NPD, FPD, and HECD detectors are element specific,
but are still subject to interferences. UV detectors for HPLC are nearly universal, and the electrochemical
detector may also respond to a variety of chemicals. Mass spectrometric analyses will generally provide positive
identification of specific compounds.
|
63 PCBs and certain organochlorine pesticides (e.g., chlordane) are complex mixtures of individual compounds
which can cause difficulty in accurately quantifying a particular formulation in a multiple component mixture.
PCBs may interfere with the determination of pesticides.
6.4 Contamination of glassware and sampling apparatus with traces of pesticides or PCBs can be a major source
of .error, particularly at lower anafyte concentrations. Carefiil attention to cleaning and handling procedures is
required during all steps of sampling and analysis to minimize this source of error.
6.5 The general approaches listed below should be followed to minimize interferences.
;:;: ' "*' : lli':i • ' '*'••
6.5.1 Polar compounds, including certain pesticides (e.g., organophosphorus and carbamate classes) can be
removed by column chromatography on alumina. Alumina clean-up will permit analysis of most organochlorine
pesticides and PCBs (4).
6.5.2 PCBs may be separated from other organochlorine pesticides by column chromatography on silicic acid
(5,6).
. 6.53 Many pesticides can be fractionated into groups by column chromatography on Florisil (6).
7. Equipment and Materials
7.1 Materials for Sample Collection
7.1.1 Continuous-Flow Sampling Pump (see Figure 1). The pump should provide a constant air flow
C
-------
Pesticides/PCBs Method TO-10A
7.1.4 Particle Filter. The collection efficiency of PUF for small-diameter (0.1 to I /^m) airborne particles
is only about 20% (7). However, most pesticides and PCBs exist in air tinder steady-state conditions primarily
as vapors (8). Most partieulate-associated pesticides or PCBs, if any, will also tend to be vaporized from filters
after collection (9). Collocated sampling with and without a quartz-fiber pre-filter has yielded indistinguishable
results for a broad spectrum of pesticides and PCBs found in indoor air (10).
7.1.4.1 An open-face filter may be attached to the sampling cartridge by means of a union for 1-in.
(25.4-mm) tubing.
7.1.4.2 A 32-mm diameter quartz microfiber filter (e.g., Palifelex® type 2500 QAT-UP) is placed in the
open end of the union and supported by means of a screen or perforated metal plate [e.g., a 304-stainless steel
disk, 0.0312-in. (OJ-mm) thick with 1/16-in. (1.6-mm) diameter round perforations at 132 holes per in.2
(20 holes/cm2), 41% open area.]. A 32-mm Viton® 0-ring is placed between the filter and outer nut to effect
a seal (see Figure 3). This filter holder is available from Supelco Park, Bellefonte, PA; SKC, 334 Forty Eight,
PA; and other manufacturers.
7.13 Size-Selective Impactor Inlet. A size-selective impactor inlet with an average particle-size cut-point
of 2.5 f*m or 10 ^m mean diameter at a sampling rate of 4 L/min may be used to exclude nonrespirable airborne
partjculate matter (11). This inlet, particle filter support, sampling cartridge holders are available commercially
from Supelco, Supelco Park, Bellefonte, PA; SKC, 334 Forty Eight, PA and University Research Glassware
(URG), Chapel Hill, NC.
7.1.6 Tenax-TA, 60/80 mesh, 2,6-diphenyIphenylene oxide polymer. Commercially available from
Supelco, Supelco Park, Bellefonte, PA and SKC, 334 Forty Eight, PA.
7.2 Equipment for Analysis
7.2.1 Gas Chromatograph (GQ. The GC system should be equipped with appropriate detector(s) and
either an isothermaliy controlled or temperature programmed heating oven. Improved detection limits may be
obtained with a GC equipped with a cool on-column or splitless injector.
7.2.2 Gas Chromatographic Column. As an example, a 0.32 mm (I.D.) x 30 m DB-5, DB-17, DB-608,
and DB-1701 are available. Other columns may also provide acceptable results.
7.2.3 HPLC Column. As an example, a 4.6-mm x 25-cm Zorbax SIL or ^Bondpak C-18. Other columns
may also provide acceptable results.
7.2.4 Microsyringes. 5 f^L volume or other appropriate sizes.
7.3 Reagents and Other Materials
7.3.1 Round Bottom Flasks. 500 mL, T 24/40 joints, best source.
7.3.2 Capacity Soxhlet Extractors. 300 mL, with reflux condensers, best source.
7.33 Kuderna-Danish Concentrator. 500 mL, with Snyder columns, best source.
7.3.4 Graduated Concentrator Tubes. 10 mL, with 19/22 stoppers, best source.
7.3,5 Graduated Concentrator Tubes. 1 mL, with 14/20 stoppers, best source.
7.3.6 TFE Fluorocarbon Tape. 1/2 in., best source.
7.3.7 Filter Tubes. Size 40 mm (I.D.) x 80 mm.
73.8 Serum Vials. 1 mL and 5 mL, fitted with caps lined with TFE fluorocarbon.
73.9 Pasteur Pipettes. 9 in., best source.
73.10 Glass Wool. Fired at 500 °C, best source.
73.11 Boiling Chips. Fired at 500°C, best source..
7.3.12 Forceps. Stainless steel, 12 in., best source.
73.13 Gloves. Latex or precleaned (5% ether/hexane Soxhlet extracted) cotton.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-5
-------
Method TO-10A ; Pesticides/PCBs
7.3.14 Steam Bath.
7.3.15 Heating Mantles. 500 mL.
73.16 Analytical Evaporator. Nitrogen blow-down.
73.17 Acetone. Pesticide quality.
73.18 n-Hexane. Pesticide quality.
73.19 Diethyl Ether. Preserved with 2% ethanol.
73.20 Sodium Sulfate. Anhydrous analytical grade.
73.21 Alumina. Activity Grade IV, 100/200 mesh.
73.22 Glass Chromatographie Column. 2-mm I.D. x 15-em long.
7.3.23 Soxhlet Extraction System. Including Soxhlet extractors (500 and 300 mL), variable voltage
transformers, and cooling water source.
73.24 Vacuum Oven. Connected to water aspirator.
73.25 Die.
73.26 Ice Chest
73.27 SUicic Acid. Pesticide grade.
73.28 Octachloronaphthalene (OCN). Research grade.
73.29 FlorisU. Pesticide grade.
8. Assembly and Calibration of Sampling System
8.1 Description of Sampling Apparatus
8.1.1 A typical sampling arrangement utilizing a personal air pump is shown in Figure 1. This method is
designed to use air sampling pumps capable of pulling air through the sampling cartridge at flow rates of 1 to
5 L/min. The method writeup presents the use of this device.
8,1.2 The sampling cartridge (see Figure 2) consists of a glass sampling cartridge in which the PUF plug or
PUF/Tenax® TAr"sandwich" is retained.
8.2 Calibration of Sampling System
8,2,1 Air flow through the sampling system is calibrated by the assembly shown in Figure 4. All air sampler
must be calibrated in the laboratory before and after each sample collection period, using the procedure described
below.
8.2.2 For accurate calibration, attach the sampling cartridge in-line during calibration. Vinyl bubble tubing
or other means (e.g., rubber stopper or glass joint) may be used to connect the large end of the cartridge to the
calibration system. Refer to ASTM Practice D3686 or D4185, for procedures to calibrate small volume air
pumps. :
i : i "1 >
9. .Preparation of PUF Sampling Cartridges
9.1 The PUF adsorbent is white and yellows upon exposure to light. The "yellowing" of1 PUF will not affect its
ability to collected pesticides or PCBs.
9.2 For initial cleanup and quality assurance purposes, the PUF plug is placed in a Soxhlet extractor and
extracted with acetone for 14 to 24 hours at 4 to 6 cycles per hour.
Page 10 A-o" Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pesticldes/PCBs Method TO-10A
[Note: If commercially pre-extracted PUFplugs are used, extraction with acetone is not required.]
Follow with a 16-hour Soxhlet extraction with 5% diethyl ether in n-hexane. When cartridges are reused, 5%
diethyl ether in n-hexane can be used as the cleanup solvent
93 Place the extracted PUF in a vacuum oven connected to a water aspirator and dry at room temperature for
2 to 4 hours (until no solvent odor is detected). Alternatively, they may be dried at room temperature in an air-
tight container with circulating nitrogen (zero grade). Place the clean PUF plug into a labeled glass sampling
cartridges using gloves and forceps. Wrap the cartridges with liexane-rinsed aluminum foil and placed in jars
fitted with TFE fluorocarbon-Iined caps. The foil wrapping may also be marked for identification using a blunt
probe.
9.4 Granular sorbents may be combined with PUF to extend the range of use to compounds with saturation vapor
pressures greater than 10"4 kPa (6). A useful combination trap can be assembled by "sandwiching" 0.6 g of
Tenax-TA between two 22-mm I.D. x 3.8-cm pre-cleaned PUF plugs, as shown in Figure 2, Cartridge b. The
Tenax-TA should be pre-extracted as described in Section 9.2. This trap may be extracted, vacuum dried, and
removed without unloading it.
9.5 Analyze at least one assembled cartridge from each batch as a laboratory blank before the batch is
acceptable. A blank level of <10 ng/plug for single component compounds is considered to be acceptable. For
multiple component mixtures (e.g., PCBs), the blank level should be <100 ng/plug.
9.6 After cleaning, cartridges are considered clean up to 30 days when stored in sealed containers. Certified clean
cartridges do not need to be chilled when shipping to the field.
10. Sampling
[Note,: After the sampling system has been assembled and calibrated as per Section 8, it can be used to collect
air samples as described below. The prepared sample cartridges should be used within 30 days of
certification and should be handled only with latex or precleaned cotton gloves.]
10.1 Carefully remove the clean sample cartridge from the aluminum foil wrapping (the foil is returned to jars
for later use) and attached to the pump with flexible tubing. The sampling assembly is positioned with the intake
downward or in horizontal position. Locate the sampler in an unobstructed area at least 30 meters from any
obstacle to air flow. The PUF or PUF/XAD-2 cartridge intake is positioned 1 to 2 m above ground level.
Cartridge height above ground is recorded on the Compendium Method TO-lOA field test data sheet (FTDS),
as illustrated in Figure 5.
10.2 After the PUF cartridge is correctly inserted and positioned, the power switch is turned on and the sampling
begins. The elapsed time meter is activated and the start time is recorded. The pumps are checked during the
sampling process and any abnormal conditions discovered are recorded on the FTDS. Ambient temperatures and
barometric pressures are measured and recorded periodically during the sampling procedure on the FTDS.
10.3 At the end of the desired sampling period, the power is turned off, the PUF cartridge removed from the
sampler and wrapped with the original aluminum foil and placed in a sealed, labeled container for transport, under
blue ice (<4°C), back to the laboratory. At least one field blank is returned to the laboratory with each group of
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-7
-------
Method TO-10A _ Pesticides/PCBs
samples. A field blank is treated exactly like a sample except that no air is drawn through the cartridge. Samples
arc stored at <4°C or below until analyzed in the laboratory. Extraction must occur within 7 days of sampling
and analysis within 40 days of extraction. Refer to ASTM D486 1-94 (i), Appendix X3 for storage stability for
various common pesticides and other compounds on PUF or PUF/Tenax TA sandwich.
1 1. Sample Extraction Procedure
[Note: Sample extraction should be performed under a properly ventilated hood.]
11.1 Sample Extraction
11.1.1 All samples should be extracted within 1 week after collection. All samples should be stored at <4°C
until extracted,
11.1.2 All glassware should be washed with a suitable detergent; rinsed with deionized water, acetone, and
hexane; rinsed again with deionized water; and fired in an oven (500 °C).
11.13 Prepare a spiking solution for determination of extraction efficiency. The spiking solution should
contain one or more surrogate compounds that have chemical structures and properties similar to those of the
analytes of interest. Octachloronaphthalene (OCN) and dibutylchlorendate have been used as surrogates for
dejcrminationof organochlorine pesticides by GC with an BCD. Tetrachloro-m-xylene and decachlorobiphenyl
caja also be usedtogether to insure recovery of early and late elutkg compounds. For organophosphate pesticides,
tributylphosphate or triphenylphosphate may be employed as surrogates. The surrogate solution should be
prepared so that addition of 100 ^L into the PUF plug results in an extract containing the surrogate compound
at the high end of the instrument's calibration range. As an example, the spiking solution for OCN is prepared
by dissolving 10 mg of OCN in 10 mL of 10% acetone in n-hexane, followed by serial dilution n-hexanc to
achieve a final spiking solution of OCN of 1
{Note: Use the recoveries of the surrogate compounds to monitor for unusual matrix effects and gross sample
processing errors. Evaluate surrogate recovery for acceptance by determining whether the measured
concentration falls within the acceptance limits of 60-120 percent.}
,, 11.1.4 The extracting solution (5% diethyl ether/hexane) is prepared by mixing 1900 mL of freshly opened
hexane and 100 mL of freshly opened diethyl ether (preserved with ethanol) to a flask.
11.1.5 All clean glassware, forceps, and other equipment to be used should be rinsed with 5% diethyl ether/
hexane and placed on rinsed (5% diethyl ether/hexane) aluminum foil until use. The condensing towers should
also be rinsed with 5% diethyl ether/hexane. Then add 300 mL or 5% diethyl ether/hexane to the 500 mL round
bottom boiling flask and add up to three boiling granules.
" 11.1.6 Using precleaned (i.e., 5% diethyl ether/hexane Soxhlet extracted) cotton gloves, the glass PUF
cartridges are removed from the sealed container, the PUF removed from the glass container and is placed into
the 300 mL Soxhlet extractor using prerinsed forceps.
fffgte: If "sandwich" trap is used, carefully clean outside walls of cartridge with hexane-soaked cotton swabs
of laboratory tissues (discard) and place cartridge into extractor with intake (large end) downward,]
11.1.7 Before extraction begins, add 100 uL of the OCN solution directly to the top of the PUF plug.
Page 10A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/FCBs Method TO-10A
[Note: Incorporating a known concentration of the solution onto the sample provides a quality assurance
check to determine recovery efficiency of the extraction and analytical processes.]
11.1.8 Connect the Soxhlet extractor to the 500 mL boiling flask and condenser. Wet the glass joints with
5% diethyl ether/hexane to ensure a tight seal between the fittings. If necessary, the PUF plug can be adjusted
using forceps to wedge it midway along the length of the siphon. The above procedure should be followed for
all samples, with the inclusion of a blank control sample.
11.L9 The water flow to the condenser towers of the Soxhlet extraction assembly should be checked and the
heating unit turned on. As the samples boil, the Soxhlet extractors should be inspected to ensure that they are
filling and siphoning properly (4 to 6 cycles/hour). Samples should cycle for a minimum of 16 hours.
11.1.10 At the end of the extracting process (minimum of 16 hours), the heating unit is turned off and the
sample cooled to room temperature.
11.1.11 The extracts are then concentrated to 5 mL using a Kuderaa-Danish (K-D) apparatus. The K-D is
set up, assembled with concentrator tubes, and rinsed. The lower end of the filter tube is packed with glass wool
and filled with sodium sulfate to a depth of 40 mm. The filter tube is then placed in the neck of the K-D. The
Soxhlet extractors and boiling flasks are carefully removed from the condenser towers and the remaining solvent
is drained into each boiling flask. Sample extract is carefully poured through the filter tube into the K-D. Each
boiling flask is rinsed three times by swirling hexane along the sides. Once the sample has drained, the filter tube
is rinsed down with hexane. Each Synder column is attached to the K-D and rinsed to wet the joint for a tight
seal. The complete K-D apparatus is placed on a steam bath and the sample is evaporated to approximately 5
mL.
[Note: Do not allow samples to evaporate to drynessj
Remove sample from the steam bath, rinse Synder column with minimum of hexane, and allow to cool. Adjust
sample volume to 10 mL in a concentrator tube, close with glass stopper and seal with TFE fluorocarbon tape.
Alternatively, the sample may be quantitatively transferred (with concentrator tube rinsing) to prescored vials
and brought up to final volume. Concentrated extracts are stored at <4°C until analyzed. Analysis should occur
no later than 40 days after sample extraction.
11.2 Sample Cleanup
11.2.1 If polar compounds (from example, organophosphoius and carbamate classes) that interfere with
GC/ECD analysis are present, use column chromatographic cleanup or alumina. The sample cleanup will permit
the analysis of most organochlorine pesticides or PCBs.
11,2.2 Before cleanup, the sample extract is carefully reduced to 1 mL using a gentle stream of clean
nitrogen.
11.2.3 A glass chromatographic column (2-mm I.D. x 15-crn long) is packed with alumina, activity grade
IV, and rinsed with approximately 20 mL of n-hexane. The concentrated sample extract is placed on the column
and eluted with 10 mL of n-hexane at a rate of 0.5 mL/minute. The eluate volume is adjusted to exactly 10 mL
and analyzed as per Section 12.
11.2.4 If both PCBs and organochlorine pesticides are sought, alternate cleanup procedures (5,6) may be
required (i.e., silicic acid).
11.2.5 Finally, class separation and improved specificity can be achieved by column clean-up and separation
on Florisil (6).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-9
-------
Method TO-lOA Pesticides/PCBs
12. Analytical Procedure
12.1 Analysis of Organochlorine Pesticides by Capillary Gas Chromatography with Electron Capture
Detector (GC/ECD)
fflote: Organochlorine pesticides, PCBs and many nonchlorinated pesticides are responsive to electron
capture detection (see Table 1), Most of these compounds can be analyzed at concentration of I to 50 ng/mL
by GC/ECD, The fallowing procedure is appropriate. Analytical methods that have been used to determine
pesticides and PCBs collected from air by this procedure have been published (12).]
12.1.1 Select GC column (e.g., 0.3-mm by 30-m DB-5 column) and appropriate GC conditions to separate
the target analytes. Typical operating parameters for this column with spfltless injection are; Carrier gas-
chromatography grade helium at a flow rate of 1 to 2 mL/min and a column head pressure of 7 to 9 psi (48 to
60 kPa); injector temperature of 250°C; detector temperature of 350°C; initial oven temperature of 50°C held
for 2.0 raia, ramped at 15°C/min to 150°C for 8 min, ramped at 10°C/min to 295°C then held for 5 min; purge
time of 1,0 min. A typical injection volume is 2 to 3 /zL.
12,1,2 Remove sample extract from the refrigerator and allow to warm to room temperature,
12.1.3 Prepare standard solution from reference materials of known purity. Analytically pure standards of
Organochlorine pesticides and PCBs are available from several commercial sources.
; 12.1.4 Use the standard solutions of the various compounds of interest to determine relative retention times
(RRTs) to an internal standard such as p,p'-DDE, aldrin or octachloronaphthalene. Use 1 to 3-//L injections or
other appropriate volumes.
12.13 Determine detector linearity by injecting standard solutions of three different concentrations (amounts)
that bracket the range of analyses. The calibration is considered linear if the relative standard deviation (RSD)
of the response factors for the three standards is 20 percent or less.
12.1.6 Calibrate the system with a miolmum of three levels of calibration standards in the linear range. The
low standard should be near the analytical method detection limit. The calibration is considered linear if the
relative standard deviation (RSD) of the response factors for the three standards is 20 percent or less. The initial
calibration shoulcfbe verified by the analysis of a standard from an independent source. Recovery of 85 to 115
percent is acceptable. The initial calibration curve should be verified at the begining of each day and after every
tensamples by tie analysis of the mid point standard; an RPD of 15% or less is acceptable for continuing use
of the initial calibration curve.
12.1.7 Inject 1 to 3 juL of the sample extract Record volume injected to the nearest 0.05 ttL.
i 12.1.8 A typical BCD response for a mixture of single component pesticides using a capillary column is
illustrated in Figure 6. If the response (peak height or area) exceeds the calibration range, dilute the extract and
reanalyze.
: 12.1.9 Quantify PCB mixtures by comparison of the total heights or areas of GC peaks (minimum of 5) with
the corresponding peaks in the best-matching standard. Use Aroclor 1242 for earry-eluting PCBs and either
Aroclor 1254 or Aroclor 1260 as appropriate for late-eluting PCBs.
12.1.10 If both PCBs and organocMorine pesticides are present in the same sample, use column
chromatographic separation on silicic acid (5,6) prior to GC analysis.
12.1.11 If polar compounds are present that interfere with GC/ECD analysis, use column chromatographic
cleanup or alumina, activity grade IV, in accordance with Section 11.2.
12.1.12 For confirmation use a second GC column such as DB-608. All GC procedures except GC/MS
require second column confirmation.
Page 10A-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PesticMes/PCBs __ Method TO40A
12.1.13 For improved resolution use a capillary column such as an 0.25-mm I.D. x 30-m DB-5 with 0.25 /j.m
film thickness. The following conditions are appropriate.
« Helium carrier gas at 1 mL/min.
• Column temperature program, 90°C (4 min)/16°C/min to 154°C/4°C/min to 270°C.
• Detector, fflNi BCD at 350 ° C.
• Make up gas, nitrogen, or 5% methane/95% argon at 60 mL/min.
* Splitless injection, 2 /zL maximum.
• Injector temperature, 220 °C.
12.1.14 Class separation and improved specificity can be achieved by column chromatographic separation
on Florisil (6).
12.2 Analysis of Organophosphorus Pesticides by Capillary Gas Chromatography with Flame
Photometric or Nitrogen-Phosphorus Detectors (GC/FPD/NPD)
[Note: Organophosphorus pesticides are responsive to flame photometric and nitrogen-phosphorus (alkali
flame ionization) detection. Most of these compounds can be analyzed at concentrations of 50 to 500 ng/mL
using either of these detectors./
12.2.1 Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12.1.14 apply, except
for the selection of surrogates.
12.2.2 Use tributylphosphate, triphenylphosphate, or other suitable compound(s) as surrogates to verify
extraction efficiency and to determine RRTs.
12.3 Analysis of Carbamate and Urea Pesticides by Capilliary Gas Chromatography with Nitrogen-
Phosphorus Detector
12.3.1 Trazine, carbamate, and urea pesticides may be determined by capillary GC (DB-5, DB-17, or
DB-1701 stationary phase) using nitrogen-phosphorus detection or MS-SIM with detection limits in the 0.05 to
0.2 fAJwL range. Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12.1.14 apply,
except for the selection of surrogates, detector, and make up gas.
12,3.2 Thennal degradation may be minimized by reducing the injector temperature to 200° C. HPLCmay
also be used, but detection limits will be higher (1 to 5 ^ig/mL).
12.3.3 N-methyl carbamates may be determined using reverse-phase high performance Liquid
Chromatography (HPLC) (C-18) (Section 12.4) and post-column derivatization with o-phthaldehyde and
fluorescence detection (EPA Method 531). Detection limits of 0.01 to 0.1 ^g/mL can be achieved.
12.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by High Performance Liquid
Chromatography (HPLC)
(Note: Many carbamate pesticides, urea pesticides, pyrethrins, phenols, and other polar pesticides may be
analyzed by high HPLC with fixed or variable wavelength UV detection. Either reversed-phase or normal
phase Chromatography maybe used. Detection limits are 0.2 to 10 jUg/mL of extract.]
12.4.1 Select HPLC column (i.e., Zorhax-SIL, 46-tnm I.D. x 25-cm, or /^-Bondapak CIS, 3,9-mm x 30-em,
or equivalent).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-11
-------
Method TO-10A Pesticides/PCBs
12.43, Select solvent system (i.e., mixtures of methanol or acetonitrile with water or mixtures of heptane or
hexane with isopropanol).
12.4.3 Follow analytical procedures given in Sections 12.1.2 through 12.1.9.
12.4.4 If mterferences are present, adjust the HPLC solvent system composition or use column
chf omatographic clean-up with silica gel, alumina, or Florisil (6).
12.4.5 An electrochemical detector may be used to improve sensitivity for some ureas, carbamates, and
phenolics. Much mote care is required in using this detector, particularly in removing dissolved oxygen from the
mobile phase and sample extracts.
12.4.6 CbJorophenoI (di- through penta-) may be analyzed by GC/ECD or GC/MS after derivatization with
pentafluorobenzylbromide (EPA Method 604).
"12.4.7 Chlorinated phenoxyacetic acid herbicides and pentachlorophenol can be analyzed by GC/ECD or
GC/MS after derwatization with dJazoraethane (EPA Method 515). DB-5 and DB-1701 columns (0.25-mm I.D.
x 30-m) at 60 to3Q00C/4°C per min have been found to perform well
t t? : :. • ' t , I
12.5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass Spectrometry Detection
(GC/MS)
'»" • : '• • . atr- ••m • . y • , : |
[Note: A mass spectrometer operating in the selected ion monitoring mode is useful for confirmation and
identification ofpesticides.]
12.5.1 A mass spectrometer operating in the select ion monitoring (SIM) mode can be used as a sensitive
detector for multi-residue determination of a wide variety of pesticides. Mass spectrometers are now available
that provide detection limits comparable to nitrogen-phosphorus and electron capture detectors.
123.2 Most of the pesticides shown in Table 1 have been successfully determined by GC/MS/SIM. Typical
GC operating parameters are as described in Section 12.1.1.
12.5 J The mass spectrometer is typically operated using positive ion electron impact ionization (70 eV).
Other instrumental parameters are instrument specific.
12.5.4 p-Terphenyl-dM is commonly used as a surrogate for GC/MS analysis.
12.5.5 Quantification is typically performed using an internal standard method. 1,4-Dichlorobenzene,
naphthalene-dg, acenaphthene-dlo, phenanthrene-d10, chrysene-dl2 and perylene-d,2 are commonly used as internal
standards. Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12,1.14 apply, except
for the selection of surrogates, detector, and make up gas.
12.5.6 See ASTM Practice D 3687 for injection technique, determination of relative retention times, and
other procedures pertinent to GC and HPLC analyses.
t" ' «»» •,»' ' -I. •: :. |
ii." • ,::!M! "::!!:. • : • !
12.6 Sample Concentration
«• .,,„„• , i
|12.6.1 If concentrations are too low to detect by the analytical procedure of choice, the extract may be
concentrated to ,|(njL or 0.5 mL by carefully controlled evaporation under an inert atmosphere. The following
procedure is appropriate.
12.6.2 Place K-D concentrator tube in a water bath and analytical evaporator (nitrogen blow-down)
apparatus. The water bath temperature should be from 25°C to 50°C.
12.6.3 Adjust nitrogen flow through hypodermic needle to provide a gentle stream.
12.6.4 Carefully lower hypodermic needle into the concentrator tube to a distance of about 1 cm above the
liquid level.
12.6.5 Continue to adjust needle placement as liquid level decreases.
12.6.6 Reduce volume to slightly below desired level.
Page 10A-12 " Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
12.6.7 Adjust to final volume by carefully rinsing needle tip and concentrator tube well with solvent (usually
n-hexane).
13. Calculations
13.1 Determination of Concentration
13.1.1 The concentration of the analyte in the extract solution can be taken from a standard curve where peak
height or area is plotted linearly against concentration in nanograms per milliliter (ng/mL), If the detector
response is known to be linear, a single point is used as a calculation constant.
13.1.2 From the standard curve, determine the nanograms of anah/te standard equivalent to the peak height
or area for a particular compound.
13.13 Ascertain whether the field blank is contaminated. Blank levels should not exceed 10 ng/sample for
organochlorine pesticides or 100 ng/sample for PCBs and other pesticides. If the blank has been contaminated,
the sampling series must be held suspect.
13.1.4 Quantity of the compound in the sample (A) is calculated using the following equation:
f A, x V."\
A = 1000 — -
I Vi )
where:
A= total amount of analyte in the sample, ng.
A, = calculated amount of material injected onto the chromatograph based on calibration
curve for injected standards, ng.
Vc = final volume of extract, mL.
V; = volume of extract injected, yL.
1000 = factor for converting microliters to millUiters.
13.1.5 The extraction efficiency (EE) is determined from the recovery of surrogate spike as follows:
EE(%) = — [100]
Sa
where:
EE = extraction efficiency, %.
S = amount of spike recovered, ng.
Sa = amount of spike added to plug, ng.
The extraction efficiency (surrogate recovery) must fall between 60-120% to be acceptable.
13.1.6 The total volume of air sampled under ambient conditions is determined using the following equation:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-13
-------
Method TO-10A Pesticides/PCBs
£ (T.xFJ
i - I
* 1000 IJm3
where:
V. = total volume of air sampled, m3.
T; = length of sampling segment between flow checks, min.
Fj - average flow during sampling segment, L/min.
13,1.7 The air volume is corrected to EPA standard temperature (25 °C) and standard pressure (760 mm Hg)
as follows:
298K
' ,760 mm Hg tA
where:
V, = volume of air at standard conditions (25 °C and 760 mm Hg), std. m3.
V. = total volume of air sampled, m3.
Pb = average ambient barometric pressure, mm Hg.
Pw = vapor pressure of water at calibration temperature, mm Hg.
tA = average ambient temperature, °C + 273.
13.1.8 If the proper criteria for a sample have been met, concentration of the compound in a standard cubic
meter of air sampled is calculated as follows:
(A)
(100)
i* " : C (ng/std. m3)
?.; - i! ••]
v1 tl -II
where:
SE = sampling efficiency as determined by the procedure outlined in Section 14,
If it is desired to convert the air concentration value to parts per trillion (ppt) in dry air at standard
temperature and pressure (STP), the following conversion is used:
;i •:: ppt = 0.844 (CJ
' r
The air concentration can be converted to parts per trillion (v/v) in air at STP as follows:
f f (24.45)
pptv =
[ (MW)
..Jiniili " . ,i I , "! • • ' ,, . : •
where:
. . ' . •.' ':;' , : [
MW = molecular weight of the compound of interest, g/g-mole.
Page 10A-14 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs
Method TO-10A
13.1.9 If quantification is perfonned using an internal standard, a relative response factor (RRF) is calculated
by the equation:
RRF -
where:
I, = integrated area of the target analyte peak, counts.
Is, = integrated area of the internal standard peak, counts.
C;, - concentration of the internal standard, ng/j/L.
C»= concentration of the analyte, ng/uL.
13.1.10 The concentration of the analyte (C,) in the sample is then calculated as follows:
c _
where:
Ct = concentration of analyte, ng/m3
I, = integrated area of the target analyte peak, counts.
RRF = relative response factor (see Section 13.1.10).
14. Sampling and Retention Efficiencies
14.1 General
14.1.1 Before using Compendium Method TO-iOA, the user should determine the sampling efficiency for
the compound of interest The sampling efficiencies shown in Tables 2, 3, 4, and 5 were determined for
approximately 1 m3 of air at about 25 °C, sampled at 3.8 L/min. The SE values in these tables may be used for
similar sampling conditions; for other compounds or conditions, SE values must be determined.
14.1 3, Sampling efficiencies for the pesticides shown in Table 6 are for aflowrateof 3.8 L/min and at25°C.
For compounds not listed, longer sampling times, different flow rates, or other air temperatures, the following
procedure may be used to determine sampling efficiencies.
14,2 Determining SE
14.2.1 SE is determined by a modified impinger assembly attached to the sampler pump, as illustrated in
Figure 7. A clean PUF is placed in the pre-filter location and the inlet is attached to a nitrogen line.
[Note: Nitrogen should be used instead of air to prevent oxidation of the compounds under test. The
oxidation would not necessarily reflect what may be encountered during actual sampling and may give
misleading sampling efficiencies.]
Two PUF plugs (22-mra x 7.6-cm) are placed in the primary and secondary traps and are attached to the pump.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-15
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Method TO-10A _ ; __ Pesticides/PCBs
• 142 3. A standard solution of the compound of interest is prepared in a volatile solvent (i.e., hexane, pentane,
or benzene). A small, accurately measured volume (i.e., 1 mL) of the standard solution is placed into the modified
midget impinger. the sampler pump is set at the rate to be used k field application and then activated. Nitrogen
is drawn through the assembly for a period of time equal to or exceeding that intended for field application. After
the desired sampling test period, the PUF plugs are removed and analyzed separately as per Section 12,
14,2.3 The Jmpinger is rinsed with hexane or another suitable solvent and quantitatively transferred to a
volumetric flask or concentrator tube for analysis.
14,2.4 The sampling efficiency (SE) is determined using the following equation:
W,
100
. W0-Wr
where:
Wt = amount of compound extracted from the primary trap, ng.
W0 = original amount of compound added to the impinger, ng.
Wr =* residue left in the impinger at the end of the test, ng.
14.2.5 If material is found in the secondary trap, it is an indication that breakthrough has occurred The
addition of the amount found in the secondary trap, Wj, to W,, will provide an indication for the overall sampling
efficiency of a tandem-trap sampling system. The sum of W,, W2 (if any), and Wr must equal (approximately
±10%) W0 or the test is invalid.
14 .2.6 If the compound of interest is not sufficiently volatile to vaporize at room temperature, the impinger
may be heated in a water bath or other suitable heater to a maximum of 50°C to aid volatilization. If the
compound of interest cannot be vaporized at 50°C without thermal degradation, dynamic retention efficiency
(REj) may be used to estimate sampling efficiency. Dynamic retention efficiency is determined in the manner
described in Section 14.2.7. Table 7 lists those organochlorine pesticides which dynamic retention efficiencies
have been determined.
a 14.2.7 A pair of PUF plugs is spiked by slow, dropwise addition of the standard solution to one end of each
plug. No more than 0,5 to 1 mL of solution should be used. Amounts added to each plug should be as nearly
the same as possible. The plugs are allowed to dry for 2 hours in a clean, protected place (i.e., desiccator). One
spiked plug is placed in the primary trap so that the spiked end is at the intake and one clean unspiked plug is
placed in the secondary trap. The other spiked plug is wrapped in hexane-rinsed aluminum foil and stored in a
clean place for the duration of the test (this is the static control plug, Section 14.2.8). Prefiltered nitrogen or
ambient air is drawn through the assembly as per Section 14.2.2.
[Note: Impinger may be discarded.]
Each PUF plug (spiked and static control) is analyzed separately as per Section 12.
*•- < f i
" 14.2.8 This dynamic retention efficiency (% REJ is calculated as follows:
% RE . - —L x 100
W_
where:
Wj = amount of compound recovered from primary plug, ng.
Page 10A-16 Compendium, of Methods for Toxic Organic Air Pollutants
January 1999
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Pesticides/PCBs Method TO-10A
W0 = amount of compound added to primary plug, ng.
If a residue, W^ is found on the secondary plug, breakthrough has occurred. The sum of Wt + W2 must equal
WQ, within 25% or the test is invalid For most compounds tested by this procedure, % KEd values are generally
less than % SE values determined per Section 14.2. The purpose of the static KEd determination is to establish
any loss or gain of analyte unrelated to the flow of nitrogen or air through the PUF plug.
15. Performance Criteria and Quality Assurance
[Note: This section summarizes required quality assurance (QA) measures and provides guidance concerning
performance criteria that should be achieved within each laboratory.]
15.1 Standard Operating Procedures (SOPs)
15.1.1 Users should generate SOPs describing the following activities accomplished in their laboratory: (1)
assembly, calibration, and operation of the sampling system, with make and model of equipment used; (2)
preparation, purification, storage, and handling of sampling cartridges; (3) assembly, calibration, and operation
of the analytical system, with make and model of equipment used; and (4) all aspects of data recording and
processing, including lists of computer hardware and software used.
15.1.2 SOPs should provide specific stepwise instructions and should be readily available to, and understood
by, the laboratory personnel conducting the work.
15.2 Process, Field, and Solvent Blanks
15.2.1 One PUF cartridge from each batch of approximately twenty should be analyzed, without shipment
to the field, for the compounds of interest to serve as a process blank.
15.2.2 During each sampling episode, at least one PUF cartridge should be shipped to the field and returned,
without drawing air through the sampler, to serve as a field blank.
15.2.3 Before each sampling episode, one PUF plug from each batch of approximately twenty should be
spiked with a known amount of the standard solution. The spiked plug will remain in a sealed container and will
not be used during the sampling period. The spiked plug is extracted and analyzed with the other samples. This
field spike acts as a quality assurance check to determine matrix spike recoveries and to indicate sample
degradation.
15.2.4 During the analysis of each batch of samples, at least one solvent process blank (all steps conducted
but no PUF cartridge included) should be carried through the procedure and analyzed.
15.2J5 All blank levels should not exceed 10 ng/sample for single components or 100 ng/sample for multiple
component mixtures (i.e., for organochlorine pesticides and PCBs).
15.3 Sampling Efficiency and Spike Recovery
153.1 Before using the method for sample analysis, each laboratory must determine its sampling efficiency
for the component of interest as per Section 14.
15.3.2 The PUF in the sampler is replaced with a hexane-extracted PUF. The PUF is spiked with a
microgram level of compounds of interest by dropwise addition of hexane solutions of the compounds. The
solvent is allowed to evaporate.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-17
-------
Method TO-10A Pesticides/PCBs
£.; 153.3 Thejsampling system is activated and set at the desired sampling flow rate. The sample flow is
monitored for 24 hours.
15.3.4 The PUF cartridge is then removed and analyzed as per Section 12.
15.3.5 A second sampler, unspiked, is collected over the same time period to account for any background
levels of components in the ambient air matrix.
15.3.6 In general, analytical recoveries and collection efficiencies of 75% are considered to be acceptable
method performance.
15.3.7 Replicate (at least triplicate) determinations of collection efficiency should be made. Relative
standard deviations for these replicate determinations of ±15% or less are considered acceptable performance.
15.3.8 Blind spiked samples should be included with sample sets periodically as a check on analytical
performance.
15.4 Method Precision and Bias
15.4.1 Precision and bias in this type of analytical procedure are dependent upon the precision and bias of
the analytical procedure for each compound of concern, and the precision and bias of the sampling process.
15.4.2 Several different parameters involved in both the sampling and analysis steps of this method
collectively determine the precision and bias with which each compound is detected. As the volume of air
sampled is increased, the sensitivity of detection increases proportionately within limits set by: (a) the retention
efficiency for each specific component trapped on the polyurethane foam plug, and (b) the background
interference associated with the analysis of each specific component at a given site sampled. The sensitivity of
deteetioa of samples recovered by extraction depends on: (a) the inherent response of the particular GC detector
used in the determinative step, and (b) the extent to which the sample is concentrated for analysis. It is the
If " . ssm **' * -f , *.,,,.,, J
responsibility of the analyses) performing the sampling and analysis steps to adjust parameters so that the
required detection limits can be obtained.
15.4.3 The reproducibility of this method for most compounds for which it has been evaluated has been
determined to range from ±5 to ±30% (measured as the relative standard deviation) whea replicate sampling
cartridges are used (N>5). Sample recoveries for individual compounds generally fall within the range of 90 to
110%, but recoveries ranging from 65 to 125% are considered acceptable. PUF alone may give lower recoveries
for more volatile compounds (i.e., those with saturation vapor pressures >10"3 mm Hg). In those cases, another
sorbent or a combination of PUF and Tenax TA (see Figure 2) should be employed.
155 Method Safety
15.5.1 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.
15,5.2 It is the user's responsibility to consult and establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to the implementation of this procedure. This should
be part of the user's SOP manual.
16. References
1, "Standard Practice for Sampling and Analysis of Pesticides and Polyeblorinated Biphenyls in Air," Annual
Book of AS7MStandards, Method D4861-94, ASTM, Philadelphia, PA.
r. *i i . - .,, ,• i , .
Page 10A-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Pestieides/PCBs Method TO-10A
2. Lewis, R., and MacLeod, K., "Portable Sampler for Pesticides and Semi-volatile Industrial Organic Chemicals
in Air," Analytical Chemistry, Vol. 54,1982, pp. 310-315.
3. Whitmore R.W., Immerman, F.W., Camann, D.E., Bond, A,E., Lewis, R.G., and Schaum, J.L., "Non-
occupational Exposure to Pesticides for Residents of Two U.S. Cities," Arch. Environ. Contam. Toxicol., 26,
47-59 (1994).
4. Lewis, R., and Brown, A., and Jackson, M., "Evaluation of Polyurethane Foam for Sampling of Pesticides,
Polychlorinated Biphenyls and Polychlorinated Napththalenes in Ambient Air," Analytical Chemistry, Vol. 49,
1977, pp. 1668-1672.
5. Armour, J., and Burke, J., "Method for Separating Polychlorinated Biphenyls from DDT and Its Analogs,"
Journal of the Association of Official Analytical Chemists, Vol. 53, No. 4, 1970, pp. 761-768.
6. Manual of Analytical Methods for the Analysis of Pesticides in Human and Environmental Samples, U. S.
Environmental Protection Agency, Research Triangle Park, NC 27711, Report No. EPA-600/8-80-038,
June 1980 (NTIS No. PB82-208752).
7. Kogan, V., Kuhlman, ML, Coutant, R., and Lewis, R., "Aerosol Filtration in Sorbent Beds," Journal of the Air
and Waste Management Association, Vol. 43, 1993, p. 1367-1373.
8. Lewis, R_, and Lee, R., "Air Pollution from Pesticide Sources, Occurrences and Dispersion," In: Air Pollution
from Pesticides and Agricultural Processes, Lee, R., Editor, CRC Press, Boca Raton, FL, 1976, pp. 51-94.
9. Lewis, R., "Problem Associated with Sampling for Semi-volatile Organic Chemicals in Air," Proceedings of
the 1986 EPA/APCA Symposium on Measurement of Toxic Air Pollutants, Air and Waste Management
Association, Pittsburgh, PA, 1986, pp. 134-145,
10. Camann, D., Harding, J., and Lewis, R., "Trapping of Particle-Associated Pesticides in Indoor Air by
Poiyurethane Foam and Evaporation of Soil Track-In as a Pesticide Source," In: Indoor Air '90, Vol. 2,
WaUdnshaw, D., editor, Canada Mortgage and Housing Corp., Ottawa, 1990, pp. 621-626.
11. Marple, V., Rubow, K., Turner, W., and Spengler, J., "Low Flow Rate Sharp Cut Impactors for Indoor Air
Sampling Design and Calibration," Journal of the Air Pollution Control Association. Vol. 37, 1987, pp. 1303-
1307.
12. Hsu, J., Wheeler, H., Camann, D., Shatterberg, H., Lewis, R_, and Bond, A., "Analytical Methods for
Detection of Nonoccupational Exposure to Pesticides," Journal ofChromatographic Science, Vol. 26, 1988,
pp. 181-189.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-19
-------
Method TO-10A
Pestiddes/PCBs
TABLE 1. COMPOUNDS FOR WHICH PROCEDURE HAS BEEN TESTED1
Compound :¥ -•>* :':•:£.: :i'i
Alachlor
Aldrin
AJlcthrin
Aroclor 1242
Aroelor 1254
Aroclor 1260
Atrazinc
Bendioearb
BHC (a- and P-Hexachloracyelohexanes)
Captan
Carbaryl
Cirbofuran
Chlordtne, technical
Chlorathaionit
Chlorotoluron
Chlorpyritos
2,4-D esters and salts
Dacthal
P4>-T)DT
p,p-DDE
Diazinon
Diclonn
Dicldrin
Dichtorovos (DDVP)
Dieofol
Dtcrotophos
Dturon
Ethyl parathion
Fenvilcrate
Fluometufon
Folpet
"ReOTmniended'-x::?!;:*;
^Analysis* \:^K-'&
QC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/NPD
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/NPD or EPD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
HPLC/UV
HPLC/UV
GC/ECD
':&Tfyou^-JiMiiiKy^f§:XfS!$S
Heptachior
Hoptachlor epoxide
Hcxachlorobenzene
Hexachlorocyclopentadiene3'4
Lindane (y-BHC)
Linuron
Malathion
Methyl parathion
Methoxychlor
Metolachlor
Mexacarbatc
Mi rex
Monuron
Trans-nonachlor
Oxychlordane
Pentachlorobenzene
PentachJophenol
Permethrin (cis and trans)
o-Phenylphenol
Phoratc
Propazinc
Propoxur (Baygon)
Pyrethrin
Rcsmcthrin
Ronnel
Simazine
Tcrbuthluron
1 ^23,4-tetrachlotobenzene3
1 ,23-trichlorobenzene1
23f5-trichlorophenol
Trifluralin
i/Ri^pilllii
: AittlyseMssf ;fls '»&
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
GC/NPD or FPD
GC/NPD or FPD
GC/PCD
GC/ECD
GC/FCD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
GC/NPD
HPLC/UV
HPLC/UV
HPLC/UV
GC/ECD
HPLC/UV
HPLC/OV
GC/ECD
QC/ECD
GC/ECD
GC/ECD
'The following recommendations arc specific for that analytc for maximum sensitivity.
IGC ™ gas ehromatography; ECD =• electron capture detector, FPD = flame photometric detector; HPLC = high peiformance
liquid ehfomaJographyjNPD - nitrogen-phosphonis detector; UV =» ultraviolet absorption detector, (GC/MS (gas chromatography/mass
spcctrometry) may also be used).
'Using PUF/Tenax-TA "sandwfch* trap,
''Compound is very unstable in solution.
u . a
Page 10A-20
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
TABLE 2. SAMPLING EFFICIENCIES FOR SOME ORGANOCHLORINE PESTICIDES
ii£lsSA;^I^^S"J^R4^^lll^^5SM^l^^::s^-:
a-Hexachlorocyclohexane (a-BHC)
Y-Hexachlorocyclohexane (Lindane)
Chlordane, technical
E,B'-DDT
E,E'-DDE
Mirex
2,4-D Esters:
Isopropyl
Butyl
Isobutyl
Isoctyl
0.005
0.05-1.0
0.2
0.6, 1.2
0.2, 0.4
0.6, 1.2
0.5
0.5
0.5
0,5
•S?:? ^C^Vi^i'^/^V't-1*
^>y'x^*i>y, ••• •'•£+}'3?i
; vQluoigj'.irn.^1:
0.9
0.9
0.9
0.9
0.9
0.9
3.6
3.6
3.6
3.6
''ft^ytt^^Z''^-^-
115
91.5
84.0
97.5
102
85.9
92.0
82.0
79.0
>802
8
8
11
21
11
22
5
10
20
-
PsHSIli!
6
5
8
12
12
7
12
11
12
—
'Air volume = 0.9 mj.
'Not vaporized. Value base on %RE = 81.0 (RSD = 10%, n = 6).
TABLE 3. SAMPLING EFFICIENCIES FOR ORGANOPHOSPHORUS PESTICIDES
n^^^^s§l§^^^^^
:i>x;%x|;-x-wxXy:w^
K^;x;VJ>:::x-:-:':;x:i$:vL:^^^^
i§G/ta^aoMfmiiWim^M
Dichlorvos (DDVP)
Ronnel
Chlorpyrifos
Diazinon1
Methyl parathion1
Ethyl parathion1
Malathion1
||p||^2iii^ll|||
P:BiilesliKe^pj|?i:^
0.2
0.2
0.2
1.0
0.6
0.3
0.3
4S3fc^
::;riS?«:w«'5:f:Sft:«Sffl
Piiy;:BMiaili|ii
72.0
106
108
84.0
80.0
75.9
1003
13
S
9
18
19
15
_
2
12
12
18
18
18
—
'Analyzed by gas chromatography with nitrogen phosphorus detector or flame photometric detector.
2Air volume = 0.9 m3.
'Decomposed in generator; value based on %RE =101 (RDS = 1, n = 4).
January 1999
Compendium of Methods for Toxic Organic AirPoUutants
Page 10A-21
-------
Mfethod TO-lOA
Pestkides/PCBs
: TABLE 4. SAMPLING EFFICIENCIES FOR SOME SEMI-VOLATILE
ORGANOCHLORJNE COMPOUNDS AND PCBs
Compound
1 ,2,3-Trichlorobenzene
1,2,3,4-Tetrachlorobenzene
Pentachlorobenzene
Hexaehlorobenzene
Hexacblorocyclopentadiene
2,4,5-Trichlorophenol
Pentachlorophenol
Aroclor 1242
Aroelor 1254
Aroclor 1260
Quantity
Introduced, ^g'
1.0
1.0
1.0
0.5, 1.0
1.0
1.0
1.0
0.1
0.1
0.1
Sampling efficiency, %
mean
6.61
62.32
94.0
94.5
8.32
108
107
96.0
95.0
109
RSD
22
33
12
8
12
3
16
15
7
5
a
8
5
5
S
5
5
5
6
6
11
'Air volume = 0.9 m3.
*% SEs were 98, and 97% (n = 2), respectively, for these three compounds by the PUF/Tenax® TA
"sandvyich" trap.
Page 10A-22
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
TABLE S. SAMPLING EFFICIENCIES FOR CARBAMATES. UREAS. TRIAZINES. AND PYRETHRINS1
I
3
H
I
s-
Eh.
S-
i
I
Piiiiiilllliill
?Gbm^6iirtdl?ii^ii;
Carbamates:
Propoxur
Carboiuran
Bendicarb
Mexacarbatc
Caibaryl
Ureas:
Monuron
Diuron
Linuron
Terbuthiuron
Fluometuron
Chlortoluron
Triazines:
Simazine
Atrazine
Propazine
Pyrethrins:
Pyrethrin I
Pyrethrin II
Allethrin
d-trans-Allethrin
Dicroiophos
Resmelhrin
Fenvalerale
SlSjHkeif::
:-:-:-;v_-;*-.:*------:.:.i(-:.:.:.:.:--.-:
H^gYeJjfjII
Plii/piiipl
5
15
50
10
100
19
20
20
18
20
20
10
10
10
(9.7)
(6.1)
25
25
25
25
25
fifilliPlillfl
li:m&iif;:
61.4
55.3
57.3
62.8
56.6
87.0
84.1
86.7
85.0
91.4
86.2
103
104
105
90S
88.6
69.2
76.8
72.0
76.5
87.9
fillips*?-
1*RSDPP:
10
12
11
19
14
6
8
g
8
10
11
6
7
11
10
11
9
9
22
14
3
i"S:|':|i|:i:i|:-v|i|-:
'&$&&&%•$%&
6
6
6
6
6
6
6
6
6
6
6
5
5
5
6
6
5
6
6
6
6
ili^wPlBiiiJKflPlfci
77.6
64,2
69.8
62.7
63.6
91.2
90.0
92.5
88.8
101
92.0
101
98.9
99.9
95.6
69.9
58.3
74.4
71.7
66.7
57.2
lliiiill
37
46
43
41
53
6
2
4
8
3
7
9
7
14
22
29
12
9
8
14
20
':?::S:S?v:,ri"::";:¥5':-:s:
6
6
6
6
6
5
5
5
5
5
5
6
6
6
5
5
6
5
5
6
3
flSM|iflii|'Sffic«!ney|!:tel
''fs^mcaW^!-
96.7
87.2
62.1
89.8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
llfiSEll
11
14
14
14
13
:iSijSg::fc'§S$r
^KJmjMm
6
6
6
6
6
Hfl
a.
i
5
O
to
in
e
ex
H
-------
(8
i—»
O
1
TABlM! TBftfACTION
EFrtCIENCIBS FOR VARIOUS
PESTICIDES AND .RELATED COMPOUNDS
Compound
Chlropyrifos
Pcntachlorophenol
Chlordane
o-Phenylphenol
Lindane
DDVP
2,4-D Methyl Ester
Heptaehlor
Aldrin
Dieldrin
Ronnel
Diazinon
trans-Nonachlor
Oxychlorodane
a-BHC
Bendiocarb
Chlorothalonil
Heptaehlor
Epoxide
Dacthal
Aroclor 1242
Extraction Efficiency1, %
mean
83.3
84.0
95,0
47,0
96.0
88.3
_
99.0
97.7
95.0
80.3
72.0
97.7
100.0
98,0
81.3
90.3
100,0
_
91.7
RSD
il.5
22.6
7.1
46,7
6.9
20.2
_
1.7
4.0
7.0
19.5
21.8
4.0
0.0
3.5
8.4
8.4
0.0
_
14.4
Sampling Eficicnoy1, %, at
10 n
mean
83.7
66.7
96,0
46.0
91.7
51.0
75.3
97.3
90.7
82,7
74,7
63.7
96.7
95.3
86.7
59.7
76.7
95.3
87.0
95.0
E/mJ
RSD
18,0
42.2
1.4
19,1
11.6
53.7
6.8
13.6
5.5
7,6
12.1
18.9
4.2
9.5
13,7
16.9
6.1
5.5
9,5
15.5
100 ng/mj
mem
92.7
52.3
74.0
45,3
93.0
106.0
58.0
103,0
94.0
85.0
60.7
41.3
101.7
94.3
97.0
30.7
70.3
97.7
95.3
94.7
RSD
15.1
36.2
8.5
29.9
2.6
1,4
23.6
17.3
2.6
11,5
15,5
26.6
15.3
1.2
18.2
23,5
6,5
14,2
22.2
17,5
l,000nfi/mj
mean
83.7
66.7
96.0
46.0
91.7
51.0
75.3
97.3
90.7
82.7
74,7
63,7
96,7
95.3
86.7
59.7
76.7
95.3
87.0
95.0
RSD
18.0
42.2
1.4
19.1
11.6
53.7
6.8
13.6
5.5
7.6
12.2
19.9
4.2
9.5
13.7
16,9
6.1
5.5
9.5
15.5
'Mean values for one spike at 550 ng/plug and two spikes at 5,500 ng/plug.
O.
3
8?
-------
I
I
I
8-
f
s-
TABLE 7, EXTRACTION AND 24-H DYNAMIC RETENTION EFFICIENCIES FOR VARIOUS
PESTICIDES AND RELATED COMPOUNDS
®iipc«iMlillI
Propoxur
Resmethrin
Dicofol
Captan
Carbaryl
Malathion
cis-Penmethrin
trans-Permethrin
Mejhoxychlor
Atrazine
Folpet
Aroclor 1260
l»^»caoh;:E^ii:ioPWii:
tfifniawilft
77,5
95.5
57.0
73.0
74,0
76.5
88.7
88.7
65.5
75.0
86.7
92.0
11.4
71.4
8.5
12,7
82.0
44.5
10.3
11.0
4.9
50.5
11.7
14,5
iillfmeaS^Si
92.0
79.0
38.0
56.0
102.0
108.0
101.0
67.3
™
—
w
88.0
•>AV ;.jt:v:- |&t?i«* : -: .,",••,•
_
_.
25.9
—
_
_
28.5
34,8
«»
—
—
9.6
ihwn-:*:?I
91.7
100.7
65.0
45.5
61.0
54.0
85.0
80.7
—
73.0
78.0
85.3
•sis;s;s:«;'?«::^;::*s
22.8
13.1
8,7
64.3
_.
16.0
26.9
56.4
_
30.1
_
9.9
:lilillliilSiill
:illllm«i-:ftli
101.0
107.0
69.0
84,3
113.0
77.3
89.0
108.3
78.5
83.0
93.0
107.1
SSSSBWSfcSKMS
PlRSKIp
18.4
4.4
_
16.3
6.1
7.6
11.3
9,5
2.1
9.5
_
13,6
T3
I
£
a.
'Mean values for one spike at 550 ng/plug and two spikes at 5,500 ng/plug.
2Mean values for three determinations.
I
o
Q.
H
-------
Method TO-10A
Pesticides/PCBs
:; PUF or PU'F/TENAX-TA
SAMPLING CARTRIDGE
115V ADAPTER/
CHARGERPLUG
Figure 1. Low volume air sampler.
Page 10A-26
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
PUF
Adsorbent
\
L
Tenax® TA
Adsorbent
••ibSi'*'«iSfi?-ij-Si*>iJSS
L
PUF Adsorbent
Figure 2. Polyurethane foam (PUF) sampling cartridge (a) and PUF-Tenax* TA
"sandwich" sampling cartridge (b).
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-27
-------
Method TO-10A
Pesticides/PCBs
Air
Flow
Fitter Cartridge Assembly
Figure 3. Open-face filter assembly attached to a PUF cartridge:
(a) Inner Viton* o-ring, (b) filter cartridge, (c) stainless steel screen, (d) quartz filter,
' •'. (e) filter ring, and (f) cartridge screw cap.
Page 10A-28
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
FLOW RATE
METER (0-1 in. H2O)
FLOW RATE
VALVE
1,OOOmL •
BUBBLE TUBE
AIR IN
DISH WITH
BUBBLE SOLUTION
PRESSURE DROP
METER (0-50 in.
PRESSURE DROP
VALVE
PUMP
Figure 4. Calibration assembly for air sampler pump.
January 1999
Compendium of Methods for Tone Organic Air Pollutants
Page 10A-29
-------
Method TO-10A
Pesticides/PCBs
COMPENDIUM METHOD TO-10A
FIELD TEST DATA SHEET (FTDS)
I. GENERAL INFORMATION
PROJECT:.
SITE:_
DATE(S) SAMPLED:.
LOCATION:
INSTRUMENT MODEL NO.:.
PUMP SERIAL NO.:
TIME PERIOD SAMPLED:.
OPERATOR:
CALIBRATED BY:
. RAIN: YES
_NO
ADSORBENT CARTRIDGE INFORMATION:
Cartridge 1 Cartridge 2 Cartridge 3 Cartridge 4
Type:
Adsorbent:
Serial No.:
Sample No.:
H. SAMPLING DATA
Cartridge
Identifi-
cation
Sampling
Location
Ambient
Temp,. *F
Ambient
Pressure,
inHg
Flow Rate (O), mL/min
Cartridge
1
Cartridge
2
Samplin
Start
e Period
Stop
Total
Sampling
Time,
miii.
Total
Sample
Volume,
L
M. FIELD AUDIT
Cartridge 1 Cartridge 2
Cartridge 3 Cartridge 4
Audit Flow Check Within
10 % of Set Point (Y/N)? pr»-
pre-
pre-
pre-
post-
post-
post-
post-
CHECKED BY:_
DATE:
Figure 5. Compendium Method TO-10A field test data sheet.
Page 10A-30
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
OPERATING CONDITIONS
Column Type:
OB-5 0.32 capillary,
0.25 urn film thickness
Dfoutylcnlorendate
Column Temperature Program: 9CrC(4min)/16*C per min to
154'C/TC per min to 270*C.
Detector;
Carrier Gas:
Make Up Gas:
Electron Capture
Helium at 1 ml/mm.
5% Methane/95% Argon at $0 mt/min.
Heptachlar
Undone
Aldrin
Eiidrin
DbkJrlm
Metttoxychior
pjj'ODT
TIME
Figure 6. Chromatogram showing a mixture of single component pesticides determined
by GC/ECD using a capillary column.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-31
-------
Method TO-10A
Pesticides/PCBs
Page 10A-32
Compendium of Metliods for Toxic Organic Air Pollutants
January 1999
-------
EPA/62S/R-96/010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-11A
Determination of Formaldehyde in Ambient Air
Using Adsorbent Cartridge Followed by High
Performance Liquid Chromatography (HPLC)
[Active Sampling Methodology]
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 452(58
January 1999
-------
Method TO-11A
Acknowledgements
^
in AmbientAir, Second'^VfoH(EPA/625/R-96/010b), which was prepared™^
by Midwest Research Institute (MRI), as a subcontractor to Eastern Research Group, Inc. (ERG), and under the
sponsorship of the US. Environmental Protection Agency (EPA). Justice A. Manning, John 0. Burckle, and Scott Hedges,
CentoforEnvironmental Research mformation(CERfy
(NERL), all in the EPA Office of Research and Development, were responsible for overseeing the preparation of this
method. 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 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
• WilliamX 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., EnviroTech Solutions, Gary, NC
Method TO-l 1 was originally published in March of 1989 as one of a series of peer reviewed methods in the second
suppicmentto "QympenclhanofMed^jbrdKDeternmvMonofra^
018. In anefforttokeep these DK*rK>dsconsistentwi& 1 has beenrevised and updated
as Method TO-l 1A in this Compendium to incorporate new or unproved sampling and analytical technologies.
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)
William T. "Jerry11 Winberry, Jr., EnviroTech Solutions, Gary, NC
Silvestrc Tejada, U.S. EPA, NERL, RTP, NC
• Bill Lonneman, U.S. EPA, NERL, RTP, NC
Ted Kleindienst, ManTech, RTP, NC
Peer Reviewers
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
• Sucha S. Pannar, Atmospheric Analysis and Consulting, Ventura, CA
• Joette Steger, Eastern Research Group, Morrisville, NC
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bool, Cathy Whitakff, and Katty
Research Institute's Administrative Services staff whose dedication and persistence during the development of this
manuscript has enabled it's publication.
11
-------
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.
111
-------
Method TO-11A
Determination of Formaldehyde in Ambient Air Using Adsorbent Cartridge Followed by High Performance Liquid
Chromatography (HPLQ [Active Sampling Methodology!
TABLE OF CONTENTS
Page
1. Scope 11A-1
2, Applicable Documents 11A-3
2.1 ASTM Standards 11A-3
2.2 Other Documents 11A-3
2.3 Other Documents 11A-3
3. Summary of Method 11A-3
4. Significance , 11A-4
5. Definitions , 11A-6
5.1 C18 * 11A-6
5.2 HPLC 11A-6
5.3 Method Detection Limit (MDL) , 11A-6
5.4 Photochemical Reaction 11A-6
5.5 Photochemical Smog 11A-6
5.6 ppbv 11A-6
5.7 ppmv 11A-6
5.8 Silica Gel 11A-6
5.9 Denuder 11A-7
5.10 Certification Blank 11A-7
5.11 Cartridge Blank 11A-7
5.12 Scrubber 11A-7
6. Extended Methodology and Common Interferences 11A-7
7. Apparatus 11A-8
7.1 Isocratic HPLC 11A-8
7.2 Cartridge sampler. 11A-8
7.3 Sampling system 11A-9
7.4 Stopwatch. 11A-10
7.5 Polypropylene shipping container
with polyethylene-air bubble padding 11A-10
7.6 Thermometer 11A-10
7.7 Barometer (optional) 11A-10
7.8 Volumetric flasks 11A-11
7.9 Pipets 11A-11
7.10 Erlenmeyer flask, 1 L 11A-11
7.11 Graduated cylinder, 1 L 11A-11
7.12 Syringe, 100-250 pL 11A-11
7.13 Samplevials 11A-11
-------
TABLE OF CONTENTS (continued)
Page
7.14 Melting point apparatus 11A-11
7.15 Rotameters 11A-11
7.16 Calibrated syringes 11A-11
7.17 Soap bubble meter or wet test meter 11A-11
7.18 Mass flow meters and mass flow controllers 11A-11
7.19 Positive displacement 11A-11
7.20 Cartridge: drying manifold 11A-11
7.21 Liquid syringes 11A-11
7.22 Syringe rack 11A-11
7.23 Luer® fittings/plugs 11A-11
7.24 Hot plates, beakers, flasks, measuring and
disposable pipets, volumetric flasks, etc 11A-11
7.25 Culture tubes (20 mm x 125 mm) with polypropylene screw caps 11A-11
7.26 Polyethylene gloves 11A-11
7.27 Dry test meter. 11A-12
7.28 User-prepared copper tubing for ozone scrubber 11A-12
7.29 Cord heater and Variac 11A-12
7.30 Fittings. 11A-12
8. Reagents and Materials 11A-12
8.1 2,4-Dinitrophcnylhydrazine (DNPH) 11A-12
8.2 DNPH coated cartridges 11A-12
8.3 High purity acetomtrile 11A-12
8.4 Deionized-distilled water 11A-12
8.5 Perchloric acid. 11A-12
8.6 Ortho-phosphoric acid 11A-12
8.7 Formaldehyde 11A-12
8.8 Aldehydes and ketones, analytical grade, best source 11A-12
8.9 Carbonyl hydrazone 11A-12
8.10 Ethanolormethanol 11A-13
8.11 Nitrogen 11A-13
8.12 Charcoal 11A-13
8.13 Helium 11A-13
8.14 Potassium Iodide 11A-13
9. Preparation of Reagents and Cartridges 11A-13
9.1 Purity of the Acetonitrile 11A-13
9.2 Purification of 2,4-Dinitrophenylhydrazine (DNPH) 11A-14
9.3 Preparation of DNPH-Formaldehyde Derivative 11A-15
9.4 Preparation of DNPH-Formaldehyde Standards 11A-15
9.5 Preparation of DNPH-Coated Cartridges 11A-15
9.6 Equivalent Formaldehyde Cartridge Concentration 11A-18
10. Sampling Procedure 11A-18
VI
-------
TABLE OF CONTENTS (continued)
Page
11. Sample Analysis 11A-21
11.1 Sample Preparation 11A-21
11,2 Sample Extraction , 11A-21
11.3 HPLC Analysis , 11A-22
11.4 HPLC Calibration 11A-23
12. Calculations 11A-24
13. Performance Criteria and Quality Assurance 11A-27
13.1 Standard Operating Procedures (SOPs) 11A-27
13.2 HPLC System Performance 11A-27
13.3 Process Blanks 11A-28
13.4 Method Precision and Accuracy 11A-28
13.5 Method Detection Limits 11 A-28
13.6 General QA/QC Requirements 1IA-29
14. Detection of Other Aldehydes and Ketones 1 IA-29
14.1 Introduction 11A-30
14.2 Sampling Procedures 11A-30
14.3 HPLC Analysis 11A-30
15. Precision and Bias 11A-31
16. References 11A-32
vu
-------
METHOD TO-11A
Determination of Formaldehyde in Ambient Air Using Adsorbent
Cartridge Followed by High Performance Liquid
Chromatography (HPLQ
[Active Sampling Methodology]
1. Scope
1.1 This document describes a method for the determination of formaldehyde and other carbonyl compounds
(aldehydes and ketones) in ambient air utilizing a coated-solid adsorbent followed by high performance liquid
chromatographic detection. Formaldehyde has been found to be a major promoter in the formation of
photochemical ozone. In particular, short term exposure to formaldehyde and other specific aldehydes
(acetaldehyde, acrolein, crotonaldehyde) is known to cause irritation of the eyes, skin, and mucous membranes
of the upper respiratory tract.
1.2 Over die last several years, numerous methods have been developed for the sampling and analysis of
carbonyl compounds. Because of the role which formaldehyde plays in photochemistry, most of the more
recent methods were designed to quantitate formaldehyde specifically. Early methods centered around wet
chemical technology involving a bubbler or impinger containing a reactive reagent (1). In some cases the
reactive reagent produced a color in the presence of formaldehyde. Examples of the more commonly used
reagents were: 3-methyl-2-benzothiazolone hydrazone (MBTH), sodium sulfite, 4-hexylresorcinol, water,
sodium tetrachloromercurate, and chromatropic acid. These reagents demonstrated high collection efficiency
(>95%), provided fairly stable non-volatile products and minimized formation of undesirable by-products.
Indeed, as part of U. S. Environmental Protection Agency's (EPA's) effort to quantitate atmospheric
concentrations of formaldehyde, the National Air Sampling Network utilized the impinger technique for
several years containing chromatrophic acid specifically for formaldehyde. However, impinger sampling had
numerous weaknesses which eventually lead to its demise. They were:
* Labor intense.
* Used acidic/hazardous reagents.
« Lacked sensitivity.
• Prone to interferences.
• Poor reproducibility at ambient concentration levels.
AsEPA'sinterestfcois^urmformMdehydeandit^
(PSDs) developed (2). These devices were mainly used by industrial hygienists to assess the efforts of respiratory
exposure for formaldehyde on workers. However, because of the design and flow rate limitation, they require long
exposures (up to 7 days) to the atmosphere to meet traditional bubbler technique sensitivities. Consequently, the
passive PSD had limited application to ambient monitoring.
Toaddress the needforamonitoringmethodtosample carbonyl compounds in the air at sensitivities neededtoreach
health-base detection limits (10"6 risk level), a combination of wet chemistry and solid adsorbent methodology was
developed (3-6). Activating or wetting the surface of an adsorbent with a chemical specific for reacting with carbonyl
compounds allowed greater volumes of air to be sampled, thus enabling better sensitivity in the methodology. Various
chemicals and adsorbents combinations have been utilized with various levels of success. The most commonly used
technique is based onreacting airborne carbonyls with 2,4-dinitrophetiylhydrazine (2,4-DNPH) coated on an adsorbent
cartridge followed by separation and analysis of die hydrazone derivative by high performance liquid chromatography
(HPLC) with ultraviolet (UV) detection.
13 Historically, Compendium Method TO-5, "Method For the Determination of Aldehydes and Ketones in
Ambient Air Using High Performance Liquid Chromatography (HPLC)" was used to quantitate formaldehyde
in ambient air. This method involved drawing ambient air through a midget impinger sampling tram
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-1
-------
Method TO-11 A Formaldehyde
containing 10 mL of 2N HC1/0.05% 2,4-DNPH reagent. Formaldehyde (and other aldehydes and ketones)
readily formed a stable derivative with the DNPH reagent, and the DNPH derivative is analyzed for aldehydes
an it ketones utilizing HPLC. Compendium Method TO-11 modifies the sampling procedures outlined hi
Method TO-5 by introducing a coated adsorbent. Compendium Method TO-11 is based on the specific
reaction of organic carbonyl compounds (aldehydes and ketones) with DNPH-coated silica gel cartridges in
the presence of a strong acid, as a catalyst, to form a stable color hydrazone derivative according to the
following reaction:
M02
N..«Y~V.
CAnepNYL GROUP 2,4-DINITROPHB«IYLHYORAZ!NE STABLE COLOR WATER
fALDEHYDES AND KETONES) (DNHP) HYDRAZONE DERIVATIVE
•where R and R1 are organic alkyl or aromatic group (ketones) or either substituent is a hydrogen (aldehydes). The
reaction proceeds by nucleophilic addition to the carbonyl followed by 1,2-elimination of water to form the 2,4-
diphcny Ihydrazonc derivative. The determination of formaldehyde from the DNPH-formaldehyde derivative is similar
to Method TO-5 in incorporating HPLC as the analytical methodology.
1.4 Due to recent requirements in atmospheric carbonyl monitoring, EPA has determined a need to update
the present methodology found in Compendium Method TO-11. The revised Compendium Method TO-11 A,
as "published here, includes:
• Guidance on collocated sampling.
' * Addition of ozone denuder or scrubber to reduce interferences.
: * Sampler design update to allow heated-inlet and sequential sampling.
• Update HPLC procedure for column alternatives.
, • Use of commercially prepared low pressure drop DNPH-coated cartridges.
TlK target cotnpoui^fortbismethod is formaldehyde;however,atleastl4othCT
and quantified.
1.5 The sampling method gives a time-weighted average (TWA) sample. It can be used for long-term
(1-24 hr) sampling of ambient air where the concentration of formaldehyde is generally in the low ppb (v/v)
or for short-term (5-60 min) sampling of source-impacted atmospheres where the concentration of
formaldehyde could reach the ppm (v/v) levels.
1.6 The method instructs the user to purchase commercially pre-coated DNPH cartridges. The method still
includes the instructions of Compendium Method TO-11 for the preparation of DNPH-coated cartridges.
However due to the tedious preparation and clean room requirements, the method recommends the purchase
of pre-coated DNPH cartridges that are now commercially available from at least three major suppliers.
Different from previous cartridges identified in Compendium Method TO-11, the pressure drop across the
newer low-pressure drop cartridges are less than 37 inches of water at a sampling flow of up to 2.0
liters/minute, allowing compatibility with pumps used in personal sampling equipment. These pre-coated
Page 11A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde Method TO-11A
commercial cartridges have generally lower and more consistent background (7) concentration of carbonyls
than cartridges prepared under normal chemical laboratory environment, as specified in the original
Compendium Method TO-11.
1.7 The commercially-prepared pre-coated cartridges are used as received and are discarded after use. The
collected and uncollected cartridges are stored in culture tubes with polypropylene caps and placed in cold
storage when not in use.
1.8 This method may involve hazardous materials, operations, and equipments. This method does not purport
to address all the safety problems associated with its use. It is the responsibility of whoever uses this method
to consult and establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Applicable Documents
2.1 ASTM Standards
• D1193 Specification for Reagent Water
• D1356 Terminology Relating to Atmospheric Sampling and Analysis
• D3195 Practice for Rotameter Calibration
• D3631 Method for Measuring Surface Atmospheric Pressure
• D5197 Determination of Formaldehyde and Other Carbonyl Compounds in Air (Active Sampler
Methodology)
• E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• E682 Practice for Liquid Chromatography Terms and Relationships
2.2 Other Documents
• Technical Assistance Document for Sampling and Analysis Toxic Organic Compounds in Ambient Air,
U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
• Quality Assurance Handbook for Air Pollution Measurement Systems, U. S. Environmental Protection
Agency, EPA-600/R-94-D38b, May 1994.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-11, Second Supplement, U. S. Environmental Protection Agency, EPA-600/4-89-018, March 1989.
23 Other Documents
• Existing Procedures (8-10).
• Ambient Air Studies (11-15).
3. Summary of Method
3.1 A known volume of ambient air is drawn through a prepacked cartridge coated with acidified DNPH at
a sampling rate of 100-2000 mL/min for an appropriate period of time. Sampling rate and time are dependent
upon carbonyl concentration in the test atmosphere.
3.2 After sampling, the sample cartridges and field blanks are individually capped and placed in shipping
tubes with polypropylene caps. Sample identifying tags and labels are then attached to the capped tubes. The
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-3
-------
Method TO-11A [ Formaldehyde
m- <,« a j H . • .
"*" "': - Si • * - • v. ,i . •' ,' . ' . ;
capped tubes ace then placed in a polypropylene shipping container cooled to subambient temperature (~4°C),
and returned to the laboratory for analysis. Alternatively, the sample vials can be placed in a thermally-
insulated styrofoana box with appropriate padding for shipment to the laboratory. The cartridges may either
be placed in cold storage until analysis or immediately washed by gravity feed elution with 5 mL of
acetonitrile from a plastic syringe reservoir to a graduated test tube or a 5 mL volumetric flask.
33 The eluate Is then diluted to a known volume and refrigerated until analysis.
3.4 For determining formaldehyde, the DNPH-formaldehyde derivative can be determined using isocratic
reverse phase HPLC with an ultraviolet (UV) absorption detector operated at 360 nm. To determine
formaldehyde and 14 other carbonyls, the HPLC system is operated in the linear gradient program mode.
3.5 For quantitative evaluation of formaldehyde and other carbonyl compounds, a cartridge blank is likewise
desorbed and analyzed.
S» , • -fW¥ '
3.6 Formaldehyde and other carbonyl compounds in the sample are identified and quantified by comparison
of their retention times and peak heights or peak areas with those of standard solutions. Typically, Q-C?
carbonyl compounds, including benzaldehyde, are measured effectively to less than 0.5 ppbv.
4. Significance
4.1 Formaldehyde is a major compound in the formation of photochemical ozone (16). Short term exposure
to formaldehyde and other specific aldehydes (acetaldehyde, acrolein, crotonaldehyde) is known to cause
irritation of the eyes, skin, and mucous membranes of the upper respiratory tract (19), Animal studies indicate
that high concentrations can injure the lungs and other organs of the body (19). In polluted atmospheres,
formaldehyde may contribute to eye irritation and unpleasant odors that are common annoyances.
E ' iii --» - '1 , 1 ' . '
43 Over the last several years, carbonyl compounds including low molecular weight aldehydes and ketones
have received increased attention hi the regulatory community. This is due in part to their effects on humans
and animals as primary irritation of the mucous membranes of the eyes, the upper respiratory tract, and the
skin. Animal studies indicate that high concentrations of carbonyl compounds, especially formaldehyde, can
injure the lungs, may contribute to eye irritation and effect other organs of the body. Aldehydes, either
directly of indirectly, may also cause injury to plants. Sources of carbonyl compounds into the atmosphere
range from natural occurrences to secondary formation through atmospheric photochemical reactions.
Consequently, carbonyl compounds are both primary (directly emitted) and secondary (formed in the
atmosphere) air pollutants (19).
4.2.1 Natural Occurrence. Natural sources of carbonyls do not appear to be important contributors to
a|r pollution. Acetaldehyde is found in apples and as a by-product of alcoholic fermentation process. Other
lower molecular weight aliphatic aldehydes are not found in significant quantities in natural products. Olefinic
and aromatic aldehydes are present in some of the essential oils in fruits and plants. These include citronella,
in rose oil; citral, in oil of lemongrass; benzaldehyde, in oil of bitter almonds; and cinnamaldehydc, in oil of
cinnamon.
4.2.2 Production Sources. Aldehydes are commercially manufactured by various processes, depending
on the particular aldehyde. In general, they are prepared via oxidation reactions of hydrocarbons,
hydroformulation of alkenes, dehydrogenation of alcohols, and addition reactions between aldehydes and
other compounds. Formaldehyde is manufactured from the oxidation of methanol as illustrated in the
following equation:
Page I1A-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde Method TO-11A
[cat.]
CI^OH -
Formaldehyde and other aldehyde production in the United States has shown a substantial growth over the
last several years. This is due, in part, to their use in a wide variety of industries, such as the chemical, rubber,
tanning, paper, perfume, and food industries. The major use is as an intermediate in the synthesis of organic
compounds, including, alcohols, carboxylic acids, dyes, and medicinals.
4.2.3 Mobile Combustion Sources. A major source of carbonyl compounds in the atmosphere may be
attributed to motor vehicle emissions. In particular, formaldehyde is the major carbonyl hi automobile
exhaust, accounting for 50-70 percent of the total carbonyl burden to the atmosphere (19). Furthermore, motor
vehicles emit reactive hydrocarbons that undergo photochemical oxidation to produce formaldehyde and other
carbonyls in the atmosphere.
43 Secondary Pollutant As a secondary pollutant (formed in the atmosphere), carbonyls are formed by very
complex photo-oxidation mechanism involving volatile organic compounds (VOCs) with nitrogen oxide
(20,21). Both anthropogenic and biogenic (e.g., isoprene) hydrocarbons leads to in situ formation of
carbonyls, especially formaldehyde compounds. Aldehydes are both primary pollutants and secondary
products of atmospheric photochemistry.
The complete photo-oxidation mechanism is indeed complex and not well understood. However, a brief
discussion is warranted (22). When VOCs and oxides of nitrogen (NOJ are in the atmosphere and are
irradiated with sunlight, their equilibrium hi the photostationary state is changed. The photostationary state
is defined by the equilibrium between nitrogen dioxide (NOj), nitrous oxide (NO) and ozone (O3). This
equilibrium is theoretically maintained until VOCs are introduced. Various reactions occur to produce OH
radicals. The VOCs react with the OH radicals and produce RO2 radicals that oxidizes NO to NO2, destroying
the photostationary state. Carbonyls react with OH to produce RO2 radicals. Likewise carbonyls, particularly
formaldehyde in sunlight, are sources of the OH radicals.
The results of these processes lead to the following:
• Accumulation of ozone.
• Oxidation of hydrocarbons (HCs) to aldehydes and ketones which lead to the continued production of
HO2- and OH- radicals, the real driving force in photochemistry smog.
Consequently, the determination of formaldehyde and other carbonyl compounds in the atmosphere is of
interest because of their importance as precursors in the production of photochemical smog, as photochemical
reaction products and as major source of free radicals in the atmosphere.
4.4 Historically, DNPH impinger techniques have been widely used to determine atmospheric carbonyls.
However, due to the limitation of applying this technique to remote locations, the solid adsorbent
methodology has become a convenient alternative to impinger sampling. A number of solid adsorbents have
been used over the years to support the DNPH coating. They are: glass beads, glass fiber filters, silica gel,
Chromosorb® P, Florisil®, Carbopack® B, XAD-2, and CIS. Several of these adsorbents are available
commercially as pre-packed cartridges. The commercially available cartridges provide convenience of use,
reproducibility and low formaldehyde blanks. Two of the more widely used pre-packed adsorbents are silica
gel and C18.
4.4.1 Silica Gel. Silica gel is a regenerative adsorbent, consisting of amorphous silica (SiO^ with surface
OH groups, making it a polar material and enhancing surface absorption. DNPH-coated silica gel cartridges
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-5
-------
Method TO-11 A _ Formaldehyde
have been used by numerous investigators since 1980 for sampling formaldehyde in ambient air. Tejada (3,4)
evaluated several adsorbents, including CIS, Florsil, silanized glass wool, and silica gel as possible supports
for the DNPH coating. Results indicated thai silica gel provided the best support with minimum interferences.
Tjhc studies did document that olefinic aldehydes such as acrolein and crotonaldehyde degraded partially and
formed unknown species. For stable carbonyis such as formaldehyde, acetaldehyde, propionaldehyde,
benzaldehyde, and acetone, correlation with an DNPH-impinger technique was excellent. However, further
•studies by Arnts and Tejada identified a severe loss of carbonyl-DNPH derivative due to the reaction of
atmospheric ozone on DNPH-coated silica gel cartridges while sampling ambient air. This bias was eliminated
when sampling continued with the application of an ozone scrubber system (KI denuder) preceding the
cartridge.
4.4.2 C18 Cartridge. CIS is an octadecylsilane bonded silica substrate which is non-polar, hydrophobic,
and relatively inert, whose surface has been passivated with non-polar parafilnic groups. Because of these
^qualities, CIS has been used historically as an adsorbent trap for trace organics in environmental aqueous
samples through hydrophobic interactions. The adsorbed trace organic molecules are then eluted from the
adsorbent with various organic solvents, to early 1990, CIS was used in an ambient air study as the support
for DNPH. While CIS showed promising results (23), it's use today as the support for DNPH is limited.
J.5 Both adsorbents have historically performed adequately as the support for the DNPH coating. The
comparison between silica gel and CIS as the adsorbent for the DNPH is illustrated in Table 1. The user is
encouraged to review the weaknesses and strengths outlined in Table 1 for using silica gel or CIS as the
adsorbent for the DNPH coating.
5. Definitions
Definitions used in this document and any user-prepared Standard Operating Procedures (SOPs)
should be consistent with those used in ASTM DI356. All abbreviations and symbols are defined -within this
document at the point of first use.]
5.1 CIS — CIS is an octadecylsOane bonded sUica substrate, which is non-polar, hydrophobic, and relatively
inert,
5.2 HPLC — high performance liquid chromatography.
m ; - *#.r -, el* , :- s|
-S3 Method" ^Detection Limit (MDL)— the minimum concentration of an analyte that can be reported with
95% confidence that the value is above zero, based on a standard deviation of at least seven repetitive
measurements of the analyte in the matrix of concern at a concentration near the low standard.
5.4 Photochemical Reaction — any chemical reaction that is initiated as a result of absorption of light.
5.5 Photochemical Smog — air pollution resulting from photochemical reactions.
5.6 ppbv — a unit of measure of the concentration of gases in air expressed as parts of the gas per billion (109)
parts of the air-gas mixture, normally both by volume.
-J5.7 pprav — a unit of measure of the concentration of gases in air expressed as parts of the gas per million
'(10s) parts of the air-gas mixture, normally both by volume.
& 1 -If •'.*» :: •. . • , . ,. .. H,, : • . •• 1 . :. • :
'5.8 Silica Gel — silica gel is a regenerative adsorbent consisting of amorphous silica (SiOj) with OH surface
Page 11A-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde Method TO-11A
groups making it a polar material and enhancing surface reactions.
5.9 Denuder— A device designed to remove gases from an air sampling stream by the process of molecular
diffusion to a collecting surface.
5.10 Certification Blank— certification blank is defined as the mean value of the cartridge blank plus three
standard deviations. For Compendium Method TO-11 A, the Certification Blank should be less than
0.15 ug/cartridge for formaldehyde.
5.11 Cartridge Blank— cartridge blank is the measured value of the carbonyl compounds on an unsampled,
DNPH-coated cartridge. This is the value used in the calculations delineated hi section 12.
5.12 Scrubber— to remove a specific gas from the ah- stream by passing through a pack bed.
6. Extended Methodology and Common Interferences
6.1 This procedure has been written specifically for the sampling and analysis of formaldehyde. Other
carbonyl compounds found in ambient air are also observed in the HPLC analysis. Resolution of these
compounds depend upon column and mobile phase conditions during HPLC analysis. Organic compounds
that have the same retention time and significant absorbance at 360 urn. as the DNPH derivative of
formaldehyde will interfere. Such interferences (24) can often be overcome by altering the separation
conditions (e.g., using alternative HPLC columns or mobile phase compositions). In addition, other aldehydes
and ketones can be detected with a modification of the basic procedure. In particular, chromatographic
conditions can be optimized to separate acetone and propionaldehyde and 12 other higher molecular weight
aldehydes and ketones (within an analysis time of about one hour), as identified below, by utilizing one or two
Zorbax ODS columns in series under a linear gradient program:
Formaldehyde Isovaleraldehyde Propionaldehyde p-Tolualdehyde
Acetaldehyde Valeraldehyde Crotonaldehyde Hexanaldehyde
o-Tolualdehyde Butyraldehyde 2,5-Dimethylbenzaldehyde Methyl ethyl ketone
Acetone m-Tolualdehyde Benzaldehyde
The linear gradient program varies the mobile phase composition periodically to achieve maximum resolution
of the C-3, C-4, and benzaldehyde region of the chromatogram.
63 Formaldehyde may be a contamination of the DNPH reagent. If user- prepared cartridges are employed,
the DNPH must be purified by multiple recrystallizations in UV grade carbonyl-free acetonitrile.
Recrystallization is accomplished at 40-60°C by slow evaporation of the solvent to maximize crystal size. The
purified DNPH crystals are stored under UV grade carbonyl-free acetonitrile until use. Impurity levels of
carbonyl compounds in the DNPH are determined by HPLC prior to use and should be less than the
Certification Blank value of 0.15 ^g/cartridge.
63 The purity of acetonitrile is an important consideration in the determination of allowable formaldehyde
blank concentration in the reagent. Background concentrations of formaldehyde in acetonitrile will be
quantitatively converted to the hydrazone, adding a positive bias to the ambient air formaldehyde
concentration. Within the project quality control procedures, the formaldehyde in the acetonitrile reagent
should be checked on a regular basis (see Section 9.1).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-7
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Method TO-11A Formaldehyde
6A Ozone at high concentrations has been shown to interfere negatively by reacting with both the DNPH and
its carbonyl derivatives (hydrazones) on the cartridge (25,26). The extent of interference depends on the
temporal variations of both the ozone and the carbonyl compounds and the duration of sampling. Significant
negative interference from ozone was observed even at concentrations of formaldehyde and ozone typical of
clean ambient air (i.e., 2 and 40 ppb, respectively).
6.5 Exposure of the DNPH-coated sampling cartridges to direct sunlight may produce artifacts and should be
avoided.
6.6 The presence of ozone in the sample stream is readily inferred from the appearance of new compounds
with retention times different from the other carbonyl hydrazone compounds.
6.7 The most direct solution to the ozone interference is to remove the ozone before the sample stream reaches
the coated cartridge. This process entails constructing an ozone denuder (9) or scrubber and placing it in front
of the cartridge. The denuder can be constructed of 1 m of 0.64-cm outside diameter (OIX) by 0.46-cm inside
diameter (IJD.) copper tubing, that is filled with a saturated solution of KI, allowed to stand for a few minutes,
drained and dried with a stream of clean air or nitrogen for about 1 h. The capacity of the ozone denuder as
described is about 100,000 ppb-hour of ozone. Packed-bed granular potassium iodide (KI) scrubbers can also
be used in place of the denuder and are commercially available. Very little work has been done on long term
usage of a denuder or KI scrubber to remove ozone from the ambient air gas stream. The ozone removal
devices should be replaced periodically (e.g., monthly) in the sample train to maintain the integrity of the data
generated.
6.8 Test aldehydes or carbonyls (formaldehyde, acetaldehyde, acrolein, propionaldehyde, benzaldehyde, and
p-tolualdehyde) that were dynamically spiked into an ambient sample air stream passed through the KI
denuder with practically no losses (7). Similar tests were also performed for formaldehyde (26).
6.9 Ozone scrubbers (cartridge filled with granular KI) are also available from suppliers of pre-coated DNPH
cartridges. These scrubbers are optimized when the ambient air contains a minimum of 15% relative humidity.
7. Apparatus
7.1 Isocratic HPLC. System consisting of a mobile phase reservoir a high pressure pump; an injection valve
(automatic sampler with an optional 25-uL loop injector); a Zorbax ODS (DuPont Instruments, Wilmington,
DE) reverse phase (RP) column, or equivalent (25-cm x 4.6-mm ID); a variable wavelength UV detector
operating at 360 nm; and a data system, as illustrated in Figure 1.
[Note: Most commercial HPLC analytical systems will be adequate for this application.]
7.2 Cartridge sampler. Prepacked, pre-coated cartridge (see Figure 2), commercially available or coated in
situ with DNPH according to Section 9.
[Note: This method was developed using the Waters Sep-Pak cartridge, coated in situ with DNPH on silica
gel by the users, as delineated in the original Compendium Method TO-11 as a guideline. EPA has experience
in use of this cartridge during various field monitoring programs over the last several years. Other
manufacturer's cartridges should work as well However, modifications to these procedures may be necessary
if another commercially available cartridge is selected.]
Page 11A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde ; Method TO-11A
Major suppliers of pre-coated cartridges are:
• Supelco, Supelco Park, Bellefonte, PA 16823-0048, 247-6628.
« SKC Inc., 334 Valley View Road, Eighty Four, PA 15330-9614, (800) 752-8472.
• Millipore/Waters Chromatography, P.O. Box 9162, Marlborough, MA 01752-9748,
(800) 252-4752.
• Atmospheric Analysis and Consulting (AAQ toe., 4572 Telephone Rd., Suite 920, Ventura, CA 93003,
(805) 650-1642.
[Note: The SKC cartridge (see Figure 2) is an example of a dual bed tube. The glass cartridge contains a
front bed of 300 mg DNPH-coated silica gel with the back bed of 150 mg DNPH-coated silica gel. Airflow
through the tube should be from front to back bed, as indicated by the arrows enscribed on the cartridge. The
dual bed tube cartridge may be used in atmospheres containing carbonyl concentrations in excess of the
American Conference of Government Industrial Hygienists (ACGIH) 8-hour exposure limit, where
breakthrough of carbonyls on the adsorbent might occur. If used in routine ambient air monitoring
applications, the tube is recovered as one unit, as specified in Section 11.2.]
If commercially prepared DNPH-coated cartridges are purchased, ensure that a "Certification Blank for
Formaldehyde" is provided for the specific batch of which that cartridge is a member. For a commercial
cartridge to be acceptable, the following criteria must be met:
• Formaldehyde concentration: <0.15 ug/eartridge.
If the enhanced carbonyl analysis is being performed, the following Certification Blank criteria must also be
met:
• Speciated carbonyl concentration:
- Acetaldehyde:
-------
Method TO-11A Formaldehyde
» Ability to sequence two cartridges in series for breakthrough volume confirmation for a 24-hour
sampling event
• Ability to collocate with any of the 8, 3 h samples.
Traditionally, three sampling approaches have been used to monitor carbonyl compounds in the ambient air.
They are:
• Manual single-port carbonyl sampler.
• Programmable single-port carbonyl sampler.
• Automated multi-port sampler.
Components of the single-port carbonyl sampler, for both manual and semi-automatic, are illustrated in
Figure 3. Components usually include a heated manifold/sample Met, a denuder/cartridge assembly, a flow
meter, a vacuum gauge/pump, a timer and a power supply. In operation, ambient air is drawn through the
denuder/cartridge assembly with a vacuum pump at a fixed flow rate between 0.1 to 2 Lpm. The vacuum
gauge is used to measure the net vacuum hi the system for all flow-rate corrections. Controlling the system
is usually a 7-day, 14-event timer to coordinate sampling events to allow a sample to be extracted continuously
or intermittently over a period of time. Finally, an elapsed-time counter is employed to measure the actual
time the sampling took place. This is particularly suitable for unattended sampling when power fails for short
periods.
The automated multi-port sampler is especially designed to collect numerous short-term (2 to 3 hours) sample
sequentially over a 24 hour, 7 day a week, nighttime and weekend monitoring period. This arrangement
allows for the sampling of short periods where the objectives of the project are to identify progress of
atmospheric reactions involving carfaonyls. As illustrated in Figure 4, components of the fully automated
multi-port carbonyl sampler includes a heated inlet, ozone denuder (or scrubber) inlet manifold assembly, inlet
check valves, DNPH multi-port cartridge assembly, exhaust manifold, mass flow controller and sample pump.
The multi-port sampler automatically switches between sampling ports at preselected times, as programmed
by the user. Typically, a sequential ah- sampler contains a microprocessor timer/controller that provides
precise control over each sampling event The microprocessor allows the user to program individual start date
and time, sample duration, and delays between samples. The timer also allows activation of the flow system
prior (approximately 10 mm) to sequencing to allow purging of the sampler inlet with fresh sample. Finally,
the automated sequential sampler can be operated from an external signal, such as an ozone monitor, so that
sampling starts above certain preset ozone levels or via a modem. As a final option, various manufacturers
provide wind sensor instrumentation (wind speed and direction) which is connected to the automated
sequential sampler so that sampling begins when the wind is from a preset direction and speed.
Major suppliers of commercially available carbonyl samplers are:
• Supelco, Supelco Park, Bellefonte, PA 16823-0048, (800) 247-6628.
• SKC Inc., 334 Valley View Road, Eighty Four, PA 15330-9614, (800) 752-8472.
• Millipore/Waters Chromatography, P.O. Box 9162, Marlborough, MA 01752-9748, (800) 252-4752.
• XonTech, Inc. 6862 Hayvenhurst Avenue, Van Nuys, CA 91406, (818) 787-7380.
• ATEC Atmospheric Technology, P.O. Box 8062, Calabasas, CA 91372-8062, (310) 457-2671.
» Atmospheric Analysis and Consulting (AAC) Inc., 4572 Telephone Road, Suite 920, Ventura, CA
93003, (805) 650-1642.
« Scientific Instrumentation Specialists, P.O. Box 8941, Moscow, ID, (209) 882-3860.
7.4 Stopwatch.
7.5 Polypropylene shipping container (see Figure 5) with polyethylene-air bubble padding. To hold
Page 11A-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
sample cartridges.
7.6 Thermometer. To record ambient temperature.
7.7 Barometer (optional).
7.8 Volumetric flasks. Various sizes, 5-2000 mL.
7.9 Pipets. Various sizes, 1-50 mL.
7.10 Erlenmeyer flask, 1 L. For preparing HPLC mobile phase.
7.11 Graduated cylinder, 1 L. For preparing HPLC mobile phase.
7.12 Syringe, 100-250 /zL. For HPLC injection, with capacity at least four times the loop value.
7.13 Sample vials.
7.14 Melting point apparatus (optional).
7.15 Rotameters.
7.16 Calibrated syringes.
7.17 Soap bubble meter or wet test meter.
7.18 Mass flow meters and mass flow controllers. For metering/setting air flow rate through sample
cartridge of 100-2000 mL/min.
[Note: The mass flow controllers are necessary because cartridges may develop a high pressure drop and
at maximum/low rates, the cartridge behaves like a "critical orifice." Recent studies have shown that critical
flow orifices may be used for 24-hour sampling periods at a maximum rate of 2 L/minfor atmospheres not
heavily loaded with particulates without any problems.]
7.19 Positive displacement. Repetitive dispensing pipets (Lab-Industries, or equivalent), 0-10 mL range.
7.20 Cartridge drying manifold. With multiple standard male Luer® connectors.
7.21 Liquid syringes. 10 mL (polypropylene syringes are adequate) for preparing DNPH-coated cartridges.
7.22 Syringe rack. Made of an aluminum plate (0.16 cm x 36 cm x 53 cm) with adjustable legs on four
corners. A matrix (5 cm x 9 cm) of circular holes of diameter slightly larger than the diameter of the 10-mL
syringes was symmetrically drilled from the center of the plate to enable batch processing of 45 cartridges for
cleaning, coating, and/or sample elution.
733 Luer® fittings/plugs. To connect cartridges to sampling system and to cap prepared cartridges.
7.24 Hot plates, beakers, flasks, measuring and disposable pipets, volumetric flasks, etc. Used in the
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-11
-------
Method TO-11 A _ ; _ Formaldehyde
purification of DNPH.
7 JS Culture tubes (20 mm x 125 mm) with polypropylene screw caps. Used to transport coated cartridges
for field applications (see Figure 5), Fisher Scientific, Pittsburgh, PA, or equivalent.
73.6 Polyethylene gloves. Used to handle cartridges, best source.
7.27 Dry test meter.
7,28 User-prepared copper tubing for ozone scrubber (see Figure 6a). A 36 inch length of !4-ineh (XD.
copper tubing is used as the body of the ozone scrubber. The tubing should be coiled into a spiral
approximately 2 inches in OJD. EPA has considerable field experience with the use of this denuder.
lMal&' Ozone scrubbers (cartridge filled with granular KI) are also available from, suppliers ofpre-coated
DNPH cartridges, as illustrated in Figure 6(b).]
73,9 Cord heater and Variac. A 24 inch long cord heater, rated at approximately 80 watts, wrapped around
the outside of the copper coil denuder, controlled by a Variac, to provide heat (~50°C) to prevent condensation
of water or organic compounds from occurring within the coil.
730 fittings. Bulkhead unions are attached to the entrance and exit of the copper coil to allow attachment
to other components of the sampling system.
I
8. Reagents and Materials
fi." Purity of Reagents — Reagent grade chemicals shall be used in all tests. Unless otherwise indicated,
it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the
American Chemical Society where such specifications are available; Purity of Water— Unless otherwise
indicated, references to water shall be understood to mean reagent water as defined by Type II ofASTM
Specifications D1193.J
8.1 2,4-Dinitrophenylhydrazine (DNPH). Aldrich Chemical or J.T. Baker, reagent grade or equivalent
Recrystallize at least twice with UV grade aeetoniuile before use.
8.2 DNPH coated cartridges. DNPH coated cartridge systems are available from several commercial
suppliers.
83 High purity acetonitrile. UV grade, Burdick and Jackson "distilled-in-glass," or equivalent The
formaldehyde concentration in the acetonitrile should be < 1.5 ng/mL. It is imperative (mandatory) that the
user establish the purity of the acetonitrile before use (see Section 9.1).
8.4 Deionized-distilled water. Charcoal filtered.
8 J Perchloric acid. Analytical grade, best source, 60%, specific gravity 1.51.
8.6 Ortho-phosphoric acid. Analytical grade, best source, 36.5-38%, specific gravity 1.19.
8.7 Formaldehyde. Analytical grade, best source, 37% solution (w/w).
PagellA-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
8.8 Aldehydes and ketones, analytical grade, best source. Used for preparation of DNPH derivative
standards (optional).
8.9 Carbonyl hydrazones. Formaldehyde and other carbonyl hydrazones are available for use as standards
from commercial sources at various levels of purity.
8.10 Ethanol or methanol. Analytical grade, best source,
8.11 Nitrogen. High purity grade, best source.
8.12 Charcoal. Granular, best source.
8.13 Helium. High purity grade, best source.
8.14 Potassium Iodide. Analytical grade, best source. Used for coating inside of copper tubing of denuder
system to remove ozone interference. !
I
9. Preparation of Reagents and Cartridges j
I
9.1 Purity of the Acetonitrile i
i
9.1.1 The purity of acetonitrile is an important consideration in the determination of the formaldehyde
blank concentration. Formaldehyde in the reagent will be quantitatively converted to the hydrazone and
measured as part of the blank. The contribution to the blank from the reagent is dependent on the
formaldehyde concentration in the reagent and the amount of the reagent used for extraction. Some examples
will illustrate these considerations. j
!
Example A
» Silica gel DNPH cartridge has a blank level of 60 ng.
* Cartridge is eluted with 5-mL of acetonitrile reagent containing a formaldehyde of 3 ng/mL.
« Analyst measures a blank level of 75 ng of which 80% comes from the cartridge and 20% comes from
the reagent. '
|
Example B ;
« Silica gel DNPH cartridge has a blank level of 30 ng. '•
* Cartridge is eluted with 5 mL of acetonitrile reagent containing a formaldehyde of 6 ng/mL.
• Analyst measures a blank level of 60 ng of which 50% comes from the cartridge and 50% comes from
the reagent. ]
9.1.2 As a quality control procedure, the formaldehyde in the acetonitrile reagent should be checked on
a regular basis. This can be done by mixing known proportions of the acetonitrile reagent and a DNPH
solution having a measured formaldehyde blank. (The extract from a blank cartridge can serve as the DNPH
solution.) After analyzing the resultant solution, a mass balance is performed on the observed formaldehyde
level and the contribution from the DNPH reagent as shown in the following example.
» 1 mL of a DNPH solution containing 2.1 ng/mL of formaldehyde (as carbonyl) is mixed with 9 mL of
acetonitrile reagent containing as unknown formaldehyde blank. The analyst measures a resultant
January 1999 Compendium of Methods for Toxic Oi'ganic Air Pollutants PagellA-13
-------
Method TO-11 A _ Formaldehyde
solution concentration of 1.55 ng of formaldehyde. This data can be used to calculate the formaldehyde
in the reagent:
x 10 mL-Z 1 r^mLx ! ml) =
9 mL
The formaldehyde contribution to the cartridge blank should be as low as possible but certainly less than 20%
of the total measured blank. Using a cartridge blank level of 30 ng/cartridge, the formaldehyde concentration
in the reagent would have to be less than 1,5 ng/mL (i.e., 50 nAf) to give a blank level less than 20% of the
measured blank.
9.2 Purification of 2,4-Dinitrophenylhydrazine (DNPH)
[Note: This procedure should be performed under a properly ventilated hood, as inhalation of acetontirile
can result in nose and throat irritation. Various health effects are resultant from the inhalation of
acetonitrile. At 500 ppm in air, brief inhalation has produced nose and throat irritation. At 160 ppm,
inhalation for 4 hours has caused flushing of the face (2 hour delay after exposure) and bronchial tightness
(5 hour delay). Heavier exposures have produced systemic effects with symptoms ranging from headache,
nausea, and lassitude to vomiting, chest or abdominal pain, respiratory depression, extreme weakness, stupor,
convulsions and death (dependent upon concentration and time).}
fMzffi." Purified DNPH, suitable for preparing cartridges, can be purchased commercially.]
9.2.1 Prepare a supersaturated solution of DNPH by boiling excess DNPH hi 200 mL of acetonitrile for
approximately one hour.
9^2 After one hour, remove and transfer the supernatant to a covered beaker on a hot plate and allow
gradual cooling to 40-60°C.
9.2.3 Maintain the solution at this temperature (40-60 °C) until 95% of solvent has evaporated.
9.2.4 Decant solution to waste, and rinse crystals twice with three times their apparent volume of
acetonitrile.
9.2.5 Transfer crystals to another clean beaker, add 200 mL of acetonitrile, heat to boiling, and again let
crystals grow slowly at 40-60°C until 95% of the solvent has evaporated.
9.2.6 Repeat rinsing process as described in Section 9.2.4.
9.2.7 Take an aliquot of the second rinse, dilute 10 times with acetonitrile, acidify with 1 mL of 3.8 M
perchloric acid per 100 mL of DNPH solution, and analyze by HPLC.
[Note: An acid is necessary to catalyze the reaction of the carbonyls with DNPH. Most strong inorganic
acids such as hydrochloric, sulfuric, phosphoric, or perchloric acids will do the job. Perchloric or
phosphoric acids are the preferred catalyst for using acetonitrile solution of DNPH as the absorbing solution.
The DNPH derivatives do not precipitate from solution as readily as when hydrochloric or phosphoric acids
are used as the catalyst. This is an ideal situation for an HPLC analytical finish as this minimizes sample
handling. For most ambient air sampling, precipitation is not a problem because the carbonyl concentration
is generally in theppb range,]
9.2.8 An impurity level of <0.15 ^g/cartridge of formaldehyde in DNPH-coated cartridge is acceptable
(based on the Certification Blank section 5.10). An acceptable impurity level for an intended sampling
Page 11A-14 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
application may be defined as the mass of the analyte (e.g., DNPH-formaldehyde derivative) in a unit volume
of the reagent solution equivalent to less than one tenth (0.1) the mass of the corresponding analyte from a
volume of an air sample when the carbonyl (e.g., formaldehyde) is collected as DNPH derivative in an equal
unit volume of the reagent solution. An impurity level unacceptable for a typical 10 L sample volume may be
acceptable if sample volume is increased to 100 L. If the impurity level is not acceptable for intended
sampling application, repeat recrystallization.
9.2.9 If the impurity level is not satisfactory, pipet off the solution to waste, then add 25 mL of acetonitrile
to the purified crystals. Repeat rinsing with 20 mL portions of acetonitrile until a satisfactorily low impurity
level in the supernatant is confirmed by HPLC analysis.
9.2.10 If the impurity level is satisfactory, add another 25 mL of acetonitrile, stopper and shake the
reagent bottle, then set aside. The saturated solution above the purified crystals is the stock DNPH reagent
9.2.11 Maintain only a minimum volume of saturated solution adequate for day to day operation. This
will minimize wastage of purified reagent should it ever become necessary to re-rinse the crystals to decrease
the level of impurity for applications requiring more stringent purity specifications.
9.2.12 Use clean pipets when removing saturated DNPH stock solution for any analytical applications.
Do not pour the stock solution from the reagent bottle.
93 Preparation of DNPH-Formaldehyde Derivative
[Note: Purified crystals or solutions of DNPH-derivatives can be purchased commercially.]
93.1 To a portion of the recrystailized DNPH, add sufficient 2N HC1 to obtain an approximately saturated
solution. Add to this solution formaldehyde (other aldehydes or ketones may be used if their detection is
desirable), in molar excess of the DNPH. Allow it to dry in air.
9.3.2 Filter the colored precipitate, wash with 2N HC1 and water and let the precipitate air dry.
933 Check the purity of the DNPH-formaldehyde derivative by melting point determination or HPLC
analysis. The DNPH-formaldehyde derivative should melt at 167°C ± 1°C, If the impurity level is not
acceptable, recrystallize the derivative in ethanol. Repeat purity check and recrystallization as necessary until
acceptable level of purity (e.g., 99%) is achieved.
9.3.4 DNPH derivatives of formaldehyde and other carbonyls suitable for use as standards are
commercially available both hi the form of pure crystals and as individual or mixed stock solutions in
acetonitrile.
9.4 Preparation of DNPH-Formaldehyde Standards
9.4.1 Prepare a standard stock solution of the DNPH-formaldehyde derivative by dissolving accurately
weighed amounts in acetonitrile.
9A3, Prepare a working calibration standard mix from serial dilution of the standard stock solution. The
concentration of the DNPH-formaldehyde compound in the standard mix solutions should be adjusted to
reflect relative distribution in a real sample.
[Note: Individual stock solutions of approximately 100 mg/L are prepared by dissolving 10 mg of the solid
derivative in 100 mL of acetonitrile. The individual solution is used to prepare calibration standards
containing the derivative of interest at concentrations of 0.5-20 Ig/mL, which spans the concentration of
interest for most ambient air work.]
9.43 Store all standard solutions in a refrigerator. They should be stable at least one month.
9.4.4 DNPH-formaldehyde standards can also be purchased from various commercial suppliers. If
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-15
-------
Method TO-11 A _ Formaldehyde
purchased, ensure that a "Certification of Concentration" is provided.
9,5 Preparation of DNPH-Coated Cartridges
: This procedure must be performed in an atmosphere with a very low aldehyde background. All
glassware and plastic ware must be scrupulously cleaned and rinsed with deionized water and carbonylfree
acetonitrile. Contact of reagents with laboratory air must be minimized. Polyethylene gloves must be worn
when handling the cartridges. If the user wishes to purchase commercially prepared DNPH-coated
cartridges, they are available from various vendors. If commercial prepared DNPH-coated cartridges are
purchased, ensure that a "Certification Blank for Formaldehyde" is provided for the specific batch of which
that cartridge is a member. For a commercial cartridge to be acceptable, the following criteria must be met:
• Formaldehyde concentration: <0.15 ug/cartridge.
If the enhanced carbonyl analysis is being performed, the following Certification Blank criteria must also be
met:
» Speciated carbonyl concentration:
- Acetaldehyde:
-------
Formaldehyde Method TO-11A
9.5.2.3 Let liquid drain to waste by gravity.
[Note: Remove any air bubbles that may be trapped between the syringe and the silica cartridge by displacing
them with the acetonitrile in the syringe.]
9.5.2.4 Set the repetitive dispenser containing the acidified DNPH coating solution to dispense 7 mL
Into the cartridges.
9.5.2.5 Once the effluent flow at the outlet of the cartridge has stopped, dispense 7 mL of the DNPH
coating reagent into each of the syringes (see Figure 7).
9.5.2.6 Let the coating reagent drain by gravity through the cartridge until flow at the other end of the
cartridge stops.
9.5.2.7 Wipe the excess liquid at the outlet of each of the cartridges with clean tissue paper.
9.5.2.8 Assemble a drying manifold with a scrubber or "guard cartridge" connected to each of the ports
(see Rgure 7). These "guard cartridges" are DNPH-coated and serve to remove any trace of formaldehyde in
the nitrogen gas supply.
9.5.2.9 Insert cartridge connectors (flared at both ends, 0.64 by 2.5-cm outside diameter TFE-
fluorocarbon FEP tubing with inside diameter slightly smaller than the outside diameter of the cartridge port)
onto the long end of the scrubber cartridges.
9.5.2.10 Remove the cartridges from the syringes and connect the short ends to the exit end of the
scrubber cartridge.
9.5.2.11 Pass nitrogen through each of the cartridges at about 300-400 mL/min for 5-10 minutes.
9.5.2.12 Within 10 minutes of the drying process, rinse the exterior surfaces and outlet ends of the
cartridges with acetonitrile using a Pasteur pipet.
9.5.2.13 Stop the flow of nitrogen after 15 minutes, wipe the cartridge exterior free of rinsed acetonitrile
and remove the dried cartridge.
9.5.2.14 Plug both ends of the coated cartridge with standard polypropylene Luer® male plugs, place
the plugged cartridge in a shipping tube with polypropylene screw caps.
9.5.2.15 Put a serial number and a lot number label on each of the individual shipping tubes.
9.5.2.16 Store shipping tubes containing the DNPH-coated cartridges in a refrigerator at 4°C until use.
[Hole; Plugged cartridges may also be placed in screw-capped glass culture tubes and placed in a
refrigerator until use. Cartridges will maintain their integrity for up to 90 days stored in refrigerated, capped
shipping tubes. J
932.17 Take a minimum of 3 blank cartridges from the cartridge batch and analyze for formaldehyde,
as delineated in Section 11. the batch of user-prepared DNPH-coated cartridges is acceptable if the following
criteria are met:
• Formaldehyde Certification Blank: <0.15 ug/cartridge.
If the enhanced carbonyl analysis is being performed, the following certification criteria must also be met:
• Speciated carbonyl concentration:
- Acetaldehyde: <0.10 ug/cartridge
- Acetone: <0.30 ug/cartridge
- Other: <0.10 ug/cartridge
9,5.2.18 If analysis meets the above criteria, provide documentation with all cartridges associated with
January 1999 Compendium of Methods far Toxic Organic Air Pollutants Page 11 A-17
-------
Method TO-11A Formaldehyde
that batch involving "Certification Blank for Formaldehyde." This certificate must be part of the project
records.
9.5.2.19 If the cartridge results are close to, but above the Certification Blank, run a few more blank
cartridges to check background level.
9.5 JL20 If analysis indicates failure of the cartridge, then oM cartridges in that batch are unacceptable.
Prepare a new batch of cartridges according to Section 9.5 until certification is achieved.
9.5.2.21 Store all certified cartridges in a refrigerator at 4°C until use.
9.5.2.22 Before transport, remove the shipping container (or screw-capped glass culture tubes)
containing the adsorbent tubes from the refrigerator and place culture tubes in a friction-top metal can
containing 1-2 inches of charcoal for shipment to sampling location. Alternately, acidified DNPH-coated
filters can be used in place of charcoal filters to remove impurity carbonyl compounds in the air.
9.5.2.23 As an alternative to friction-top cans for transporting sample cartridges, the coated cartridges
could be shipped in their individual glass containers (see Figure 5a). A batch of coated cartridges may also
be packed in a polypropylene shipping container for shipment to the field (see Figure Sb). The container
should be padded with clean tissue paper or polyethylene-air bubble padding. Do not use polyurethane foam
or newspaper as padding material.
9.5.2.24 The cartridges should be immediately stored in a refrigerator or freezer (<4°C) upon arrival
in the field.
9.6 Equivalent Formaldehyde Cartridge Concentration
9.6.1 One can calculate the equivalent formaldehyde background concentration (ppbv) contributed from
a commercial or user-prepared DNPH-coated cartridge following exposure to formaldehyde-free air.
963. The equivalent formaldehyde background concentration includes the contribution of formaldehyde
from both the acetonitrile and the cartridge.
9.63 Knowing the equivalent background concentration, as determined by the user (see Section 9.5.2)
or supplied by the commercial supplier (see Note. Section 9.5), of formaldehyde in the cartridge (ng/cartridge),
the formaldehyde background concentration contributed by the DNPH-coated cartridge (thus the method
minimum detection limits) can be related to the total sample volume, as identified in Table 3.
9.6.4 For example, if the averaged background formaldehyde concentration supplied by the manufacturer
is 70 ng/cartridge, then that cartridge can add 0.95 ppbv of equivalent formaldehyde, to the final ambient air
concentration value, as delineated in Table 3 for a total air volume of 60 L.
9.6.5 The user should use DNPH-coated cartridges with the lowest background concentration to improve
accuracy and detection limits.
10. Sampling Procedure
10.1 The sampling system is assembled and should be similar to that shown in Figures 3 and 4.
fj^ote: Figures 3 and 4 illustrate different tube/pump configurations. The tester should ensure that the pump
Is capable of constant flow rate throughout the sampling period.]
It is recommended that the sampling system employ a heated inlet (~50°C) coupled to an ozone denuder or
scrubber to minimize water and ozone interference associated with the DNPH-coated adsorbent tube.
Historically, the coated cartridges have been used as direct probes and traps for sampling ambient air when
the ambient temperature was above freezing.
" As illustrated in Figure 8, the ozone denuder has been effective for up to 80 hours without
Page 11A-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
breakthrough at ozone levels of approximately 700 ppb. Other studies have evaluated both denuders and
scrubbers at ozone concentrations between 125 and 200ppbv and found they have effectively removed ozone
from the air stream for up to 100,000 ppb-hours; however, moisture was required (010% RH) in the gas
stream (26). The user should evaluate the length of time of the application of the denuder or scrubber to his
field -work. Caution should be utilized when using these devices for extensive periods of time at high humidity
(>65%). Regarding the 24 hour samples, special caution shoud be taken while sampling nighttime periods
when relative humidities approaching 100% are frequently encountered. It is recommended that routine
schedule of ozone removal device replacement should be implemented as part of the sampling program.]
[Note: For sampling ambient air below freezing, a short length (30-60 cm) of heated (50-60HF) stainless steel
tubing must be added to condition the air sample prior to collection on the DNPH-coated cartridges.]
10.2 Before sample collection, the system must be checked for leaks. Plug the inlet of the system so no flow
is indicated at the output end of the pump. The mass flow meter should not indicate any air flow through the
sampling apparatus.
103 Air flow through the DNPH-adsorbent cartridge may change during sampling as airborne particles
deposit on the front of the cartridge. The flow change could be significant when sampling particulate-Iaden
atmospheres. Particle concentrations greater than 50 ug/m3 are likely to represent a problem. For unattended
or extended sampling periods, a mass flow controller is highly recommended to maintain constant flow. The
mass flow controller should be set at least 20% below the maximum air flow through the cartridge.
10.4 The entire assembly (including a "test" sampling cartridge) is installed and the flow rate checked at a
value near the desired sampling rate. In general, flow rates of 1,000-2,000 mL/min should be employed. The
total sample volume should be selected to ensure that the collected formaldehyde concentration exceeds the
background formaldehyde DNPH-cartridge concentration, as illustrated in Table 3. The total moles of
carbonyl in the volume of air sampled should not exceed that of the DNPH concentration (Le., 2 mg cartridge).
In general, a safe estimate of the sample size should be 75% of the DNPH loading of the cartridge.
[Note: If the user suspects that there will be breakthrough of a DNPH-coated cartridge during the sampling
event, a backup cartridge should be used during the first sampling event. One would analyze the back-up
cartridge for formaldehyde. If the back-up cartridge concentration exceeds 10% of the formaldehyde
concentration on the front cartridge, then continue to use back-up cartridges in the monitoring program.
However, If formaldehyde is not detected above the average blank level in the back-up cartridge after the first
sampling event, then one can continue to use only one cartridge under normal representative conditions.]
[Note: The SKC tube is a dual bed configuration, allowing one to analyze the back bed (see Figure 2) for
quantifying breakthrough.]
Generally, calibration is accomplished using a soap bubble flow meter or calibrated wet test meter connected
to the flow exit, assuming the system is sealed.
[Note: ASTM Method D3686 describes an appropriate calibration scheme that does not require a sealed flow
system downstream of the pump.]
10.5 The operator must measure and record the sampling flow rate at the beginning and end of the sampling
period to determine sample volume. A dry gas meter may be included in the system to measure total sample
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-19
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Method TO-11A Formaldehyde
volume and to compare against the in-line mass flow controller. Some commerical systems use flow monitors
with data loggers to make these measurements.
10.6 Before sampling, flush the inlet (denuder/manifold, etc.) for approximately 15 min at the established
flow rate to condition the system. Remove the glass culture tube from the friction-top metal can or styrofoam
box. Let the cartridge warm to ambient temperature in the glass tube before connecting it to the sample train.
10.7 Using polyethylene gloves, remove the DNPH-coated cartridge from the shipping container and connect
it to the sampling system with a Luer® adapter fitting. Most commercially available cartridges are
bidirectional. However, review manufacturer suggestions for orientation of the cartridge to the inlet of the
sampler.
[Note: If using the SKC dual bed tube, ensure the ambient air is pulled through the tube in the direction
enscribed on the tube by an arrow.]
Record the following parameters on Compendium Method TO-11A field test data sheet (FIDS), as illustrated
in Figure 9: date, sampling location, time, ambient temperature, barometric pressure (if available), relative
humidity (if available), dry gas meter reading (if appropriate), flow rate, rotameter setting, cartridge batch
number, and dry gas meter pump identification numbers.
10.8 The sampler is turned on and the flow is adjusted to the desired rate. A typical flow rate through one
cartridge is 1.0 L/min and 0.8 L/min for two tandem cartridges.
10.9 The sampler is operated for the desired period, with periodic recording of the variables listed hi Rgure 9.
10.10 If the ambient air temperature during sampling is below 15 °C, a heated inlet probe is recommended.
However, no pronounced effect of relative humidity (between 25% - 90%) has been observed for sampling
under various weather conditions—cold, wet, and dry winter months and hot and humid summer months.
However, a negative bias has been observed when the relative humidity is <25%. At high humidity, the
possibility of condensation must be guarded against, especially when sampling is an air conditioned trailer.
10.11 At the end of the sampling period, the parameters discussed hi Section 10.7 are recorded and the sample
flow is stopped. If a dry gas meter is not used, the flow rate must be checked at the end of the sampling
interval. If the flow rates at the beginning and end of the sampling period differ by more than 10%, the sample
should be marked as suspect.
10.12 Immediately after sampling, remove the cartridge (using polyethylene gloves) from the sampling
system, cap with Luer® end plugs, and place it back in the original labeled glass shipping container or culture
tube. Cap, seal with TFE-fluorocarbon tape, and place it hi appropriate padding. Refrigerate at 4°C until
analysis. Refrigeration period prior to analysis should not exceed 2 weeks. If a longer storage period is
expected, the cartridge should be extracted with 5 mL of acetonitrile (see Section 11.2.4 and 11.2 J) and the
eluant placed in a vial for long term storage.
[Note: If samples are to be shipped to a central laboratory for analysis, the duration of the non-refrigerated
period should be kept to a minimum, preferably less than two days.]
10.13 If a dry gas meter or equivalent total flow indicator is not used, the average sample flow rate must be
calculated according to the following equation:
Page 11A-20 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
"• N
where:
QA — average flow rate, L/min.
Qt, Qj.... Qjj = flow rates determined at beginning, end, and intermediate points during sampling,
L/min.
N = number of points averaged.
10.14 The total flow rate is then calculated using the following equation:
Va = (T2-T1)xQA
where:
Vm = total volume sampled at measured temperature and pressure, L.
T2 = stop time, minutes.
Tt = start time, minutes.
T2 - T! = total sampling time, minutes.
QA = average flow rate, L/min.
10.15 The total volume (VJ at EPA standard conditions, 25°C and 760 mm Hg, is calculated from the
following equation:
V - V — ^
s "760 2B + fA
where:
Vs = total sample volume at 25°C and 760 mm Hg pressure, L.
Vm = total sample volume at measured temperature and pressure, L.
P = average ambient pressure, mm Hg.
T = average ambient temperature, °C.
11. Sample Analysis
11.1 Sample Preparation
11.1.1 The samples (trip blank, field blank and field samples) are returned to the laboratory in a shipping
container and stored in a refrigerator at (<4°C) until analysis. Alternatively, the samples may also be stored
alone in their individual containers.
11.1.2 The time between sampling and extraction should not exceed 2 weeks. Since background levels
in the cartridges may change due to adsorption during storage, always compare field samples to their
associated field and trip blank samples, stored under the same conditions.
11.2 Sample Extraction
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Method TO-11A Formaldehyde
Beware of unintentional exposure of samplers and eluted samples to aldehyde and ketone sources.
Laboratory air often holds high concentrations of acetone. Labeling inks, adhesives, and packaging
containers (including vials with plastic caps) are all possible sources on contamination.]
[Note: Contamination is most likely to occur during sample extraction. Before eluting derivatives, clean all
glassware by rinsing with acetonitrile, then heating in a 60HC vacuum oven for at least 30 minutes. Eluting
the samples in a nitrogen-purged glove bag further reduces the risk of contamination,
Tlte acetonitrile used to elute the DNPH derivatives is a typical source of contamination. Formaldehyde-free
acetonitrile used to elute samples should be used only for this purpose, and stored in a carbonyl free
environment. A concentration of 10 fig/L of any aldehyde or ketone in the acetonitrile adds 0.05 fig of that
carbonyl to sample blank values if using 5 mL extraction volumes.]
11.2.1 Remove the sample cartridge from the labeled shipping tube or container. Connect the sample
cartridge to a clean syringe.(Some commerical cartridges do not require the addition of a syringe for elution.)
[Hals.: The liquid flow during desorption should be in the reverse direction of air flow during sample
collection.]
11,2.2 Place the sample cartridge syringe in the syringe rack (see Figure 7).
[Note: If the two beds in the SKC tube are being recovered separately for breakthrough studies, break the
tube and place the beds in separate vials. Add exactly 5 mL of acetonitrile to each vial. Proceed with
recovery, as specified in Section 11.2.4 through Section 11.2.5. Paniculate in the relatively small number of
samples used in the breakthrough studies should not adversely impact the sample valve or backpressure.]
11.23 Backflush the cartridge (gravity feed) by passing 5 mL of acetonitrile from the syringe through the
cartridge to a 5-mL volumetric flask. The backflush elution approach may add paniculate particles also
collected on the cartridge to the acetonitrile solution which can cause sample valve failure and increase column
back pressure. To minimize this, frontflush the cartridge contents with the acetonitrile reagent rather than
blackflush. The use of 5mL of acetonitrile is sufficient for quantitative cartridge sample elution in either
mode.
[Note: A dry cartridge has an acetonitrile holdup volume of about 0.3 mL. The eluantflaw may stop before
the acetonitrile in the syringe is completely drained into the cartridge because of air trapped between the
cartridge filter and the syringe Luer® tip. If this happens, displace the trapped air with the acetonitrile in the
syringe using a long-tip disposable Pasteurpipet.]
11.2.4 Dilute to the 5-mL mark with acetonitrile. Label the flask with sample identification. Store in
refrigerated conditions until the sample is analyzed by HPLC. Pipet two aliquots into sample vials with TFE-
fluorocarbon-Hned septa. Analyze the first aliquot for the derivative carbonyls by HPLC. Store the second
aliquot in the refrigerator until the results of the analysis of the first aliquot are complete and validated. The
second aliquot can be used for confirmatory analysis, if necessary.
11.2.5 Sample eluates are stable at 4°C for up to one month.
113 HPLC Analysis
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Formaldehyde _ Method TO-11 A
113.1 The HPLC system is assembled and calibrated as described in Section 11.4. The operating
parameters are as follows when formaldehyde is the only carbonyl of interest:
Column: Zorbax ODS (4.6-mm ID x 25-cm), or equivalent
Mobile Phasg: 60% acetonitrile/40% water, isocratic.
Detector: ultraviolet, operating at 360 nm.
Flow Rate: l,OmL/min.
Retention Time: 7 minutes for formaldehyde with one Zorbax ODS column. Thirteen
minutes for formaldehyde with two Zorbax ODS columns.
Sample Injection Volume: 25 uL.
Before each analysis, the detector baseline is checked to ensure stable conditions.
1132 The HPLC mobile phase is prepared by mixing 600 mL of acetonitrile and 400 mL of water. This
mixture is filtered through a 0.22-pon polyester membrane filter in an all-glass and Teflon® suction filtration
apparatus. The filtered mobile phase is degassed by purging with helium for 10-15 minutes (100 mL/min) or
by heating to 60°C for 5-10 minutes in an Erlenmeyer flask covered with a watch glass. A constant back
pressure restrictor (350 kPa) or short length (15-30 cm) of 0.25-mm (0.01 inch) ID Teflon® tubing should be
placed after the detector to eliminate further mobile phase outgassing.
1133 The mobile phase is placed in the HPLC solvent reservoir and the pump is set at a flow rate of 1.0
mL/min and allowed to pump for 20-30 minutes before the first analysis. The detector is switched on at least
30 minutes before the first analysis, and the detector output is displayed on a strip chart recorder or similar
output device. The isoeratic flow of 60% acetoniuile/40% water is adequate for the analysis of formaldehyde;
however, sufficient time between air sample analyses is required to assure that all other carbonyl compounds
are eluted from the HPLC column prior to the next sample. The gradient flow approach .mentioned later (see
Section 14.3) is properly programmed to elute other carbonyl compounds.
113.4 A 100-uL aliquot of the sample is drawn into a clean HPLC injection syringe. The sample injection
loop (25-uL) is loaded and an injection is made. The data system, if available, is activated simultaneously with
the injection. If a strip chart recorder is used, mark the point of injection on the chart paper.
113.5 After approximately one minute, the injection valve is returned to the "load" position and the
syringe and valve are rinsed or flushed with acetonitrile/water mixture in preparation for the next sample
analysis.
[Note: The flush/rinse solvent should not pass through the sample loop during flushing.]
The loop is cleaned while the valve is in the "load" mode.
1 13.6 After elution of the DNPH-formaldehyde derivative (see Figure 10), data acquisition is terminated
and the component concentrations are calculated as described in Section 12.
113.7 After a stable baseline is achieved, the system can be used for further sample analyses as described
above. Be sure to examine the chromatogram closely to ensure that background DNPH-formaldehyde
derivative peaks are not on the solvent slope of the DNPH peak.
: After several cartridge analyses, background buildup on the column may be removed by flushing "with
several column volumes of 100% acetonitrile,]
113.8 If the concentration of analyte exceeds the linear range of the instrument, the sample should be
diluted with mobile phase, or a smaller volume can be injected into the HPLC.
1 13.9 If the retention time is not duplicated (±10%), the acetonitrile/water ratio may be increased or
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-23
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Method TO-11 A _ Formaldehyde
decreased to obtain the correct elution time. If the elution time is too long, increase the ratio; if it is too short,
decrease the ratio. If retention time is not reproducing, the problem may be associated with the HPLC flow
system. A control chart is recommended to evaluate retention time changes.
: The chromatographic conditions described here have been optimized for the detection of formaldehyde.
Analysts are advised to experiment -with their HPLC system to optimize chromato graphic conditions for their
particular analytical needs. If a solvent change is necessary, always recalibrate before running samples.]
11.4 HPLC Calibration
11.4.1 Calibration standards can be prepared by the user in acetonitrile from the solid
DNPH-fonnaldehyde derivative or liquid standards can be purchased from various manufacturers. From the
solid compound, individual stock solutions of 100 ug/mL are prepared by dissolving 10 mg of solid derivative
in 100 mL of acetronitrile. Since the MW of HCHO-hydrazone is 210 g/mol, and the MW of HCHO is 30
g/mol, the stock solution concentration converts to 14.3 ug/mL as formaldehyde (30/210 x lOOmg/mL). The
solid compound is weighed using a 5-place analytical balance and liquid dilutions are made with volumetric
glassware. Stock solutions obtained from commercial suppliers generally range from 1 to 50 ug/mL as the
carbonyl compound. These stock solutions are typically provided in 1 mL ampules.
11.4.2 Using the stock solution, working calibration standards are produced. To generate the highest
concentration working standard, use a pipette to quantitatively transfer 1.00 ml of the stock solution to a 25
mL volumetric flask. For example, using a 14.3 ug/mL stock solution produces a working standard solution
of 570 ng/mL ( 14300 ng/mL x 1/25 ). The high concentration working standard diluted serially, using 1 to
5 mL pipettes and volumetric flasks, can produce working standards ranging between 28.5 and 570 ng/mL.
11.43 Each calibration standard (at least five levels) is analyzed three times and area response is
tabulated against mass concentration injected (see Figure 11). All calibration runs are performed as described
for sample analyses in Section 1 1.3. The results are used to prepare a calibration curve, as illustrated in
Figure 12. The slope of the calibration curve gives the response factor, RF. Linear response is indicated where
a correlation coefficient of at least 0.999 for a linear least-squares fit of the data ( mass concentration versus
area response) is obtained. The intercept of the calibration curve should pass through the origin. If it does not,
check your reagents and standard solutions preparation procedure for possible contamination. If the calibration
curve does not pass through the origin, the equation for the calibration curve should include the intercept.
11.4.4 Each new calibration curve should be verified by analyzing a standard prepared from material
obtained from a second source. This standard should show a recovery of 85 to 1 15%. If not, corrective action
is required to eliminate the discrepancy between the two sources of the standard material.
11.4.5 Once linear response has been documented, a concentration standard near the anticipated levels
of each carbonyl component, but at least 10 times the detection limit, should be chosen for daily calibration.
The day to day response for the various components should be within 10% of the calibration value. If greater
variability is observed, prepare a fresh calibration check standard. If the variability using a freshly prepared
calibration check standard is greater than 15% , a new calibration curve must be developed from fresh
standards. A plot of the daily values on a Quality Control Chart ( day versus concentration ) is helpful to
check for long term drift of the concentration value.
11.4.6 The response for each component in the daily calibration standard is used to calculate a response
factor according to the following equation shown for formaldehyde:
RF
^^
Page 11A-24 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
where:
RFHCHO = response factor for formaldehyde given as area counts per ng/mL.
CHCHO = concentration of analyte in the calibration standard in units of ng/mL.
P = peak area counts for the formaldehyde standard.
P0 = calibration curve intercept; in most cases this is zero.
11,4.7 The RF for each carbonyl compound is determined in the same way as that given for formaldehyde.
The concentration of HCHO and other carbonyl compounds is determined with the calibration curves for each
component in the analyzed sample. Example calculation for HCHO is given in section 12.
12. Calculations
Determination of the carbonyl compound air concentration requires three steps: (1) determination of the
average blank and the standard deviation of the blank; (2) determination of the collected carbonyl compound
mass of the cartridge; (3) calculation of the carbonyl compound air concentration. The following discusion
provides these steps for formaldehyde.
12.1 Blank Determination
Since the blank level for any arbitary cartridge is unknown, an average value for the blank is used ia the
calculation. As noted earlier, the average blank value is determined for each lot of cartridges. For a given lot
size, N, a minimum of /N cartridge blanks (rounded to the next whole number) should be analyzed; i.e., for
a lot size of 200, a minimum of /200 or 14 cartridge blanks should be analyzed. A minimum of 3 of these
blanks are used for the Certification Blank, and the remaining 11 are used for field blanks. The mass of HCHO
on each cartridge is determined by multiplying the observed peak area for blank cartridge solution by the
acetonitrile extract volume (typically 5 mL) and dividing by the response factor as provided in the following
equation:
*BL-HCHOj X ^1
1¥fcL-HCHO; 51=
^•^HCHO
where:
MBL-HCHCI = me blank HCHO mass for cartridge, i.
HCHO response factor calculated in Section 1 L4.5.
area counts for HCHO in blank sample extract
VB = extract volume in mL (usually 5 mL).
Once all blank cartridges have been measured, the average blank value is determined by the following
equation:
M = — x > M
1"BL-HCHO -KT £-> x BL-HCHOJ
where:
MBL-HCHO = the average HCHO mass for all cartridges.
MBI^HCHC, = blank HCHO mass for cartridge, i.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-25
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Method TO-11 A _ : _ Formaldehyde
N = the number of blank cartridges.
[Note: Measurement of cartridge blanks should be distributed over the period that this particular cartridge
lot is used for ambient air sampling. It is recommended that a trend plot of blank results be constructed to
evaluate background carbonyl results over the period of cartridge lot utilization in the sampling program,
If significant drifting is observed, blank average values should be segmented to be more representative of
carbonyl background.]
12,2 Carbonyl Analyte Mass
The calculation equation for the mass of the collected earbonyl compounds on an individual cartridge
is the same as that for the cartridge blanks. The gross measured carbonyl mass is determined with an equation
analogous to that given in section 12.1. The equation for formaldehyde is given as:
PSA xVE
RF
*vi
where:
MSA1 = gross HCHO mass for cartridge, i.
PSAi = HCHO peak area counts for cartridge, I.
RFHCHO = the response factor for HCHO.
VE = acetonitrile extract volume in mL (typically 5 mL).
The net HCHO mass for an individual cartridge is determined by substracting the average blank value from
the gross HCHO mass obtained for sample i, and is given as:
123 Carbonyl Compound Concentration
The sample air concentration for carbonyl compounds cannot be determined directly from the mass
measurement and requires conversion to units of volume. The conversion calculation for HCHO is determined
using the ideal gas law and is given by the following equation:
_ i 760
VHCHO = MOT X ^ AM B * X
* MW " «*»«»' p
1¥A¥Y rAM B
where:
Page 11A-26 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
VHCHOi = gas volume of HCHO on cartridge, L
MHCHOi = mass of HCHO on cartridge, i.
MW = molecular weight of HCHO, 30.03 g/mole.
R = gas constant, 0.082 L-atm/mol-deg.
TAMB = ambient air temperature in degrees Kelvin, 273 + T (C°).
PAMJJ = ambient air pressure in torr.
For an ambient air temperature of 25°C and a pressure of 760 torr, the ideal law equation reduces to:
VHCHO, ' L22KxMHCHOj
In this equation, the HCHO mass in ng is converted to a volume in nL. The volume of air that was passed
through the cartridge was measured by either a mass flow controller or dry test meter calibrated at a known
temperature and pressure. To determine HCHO concentration in the units of ppbv, apply the following
equation:
v
HCHOi
VAI R
where:
VHCHOl = volume of formaldehyde in nL
\OoR = volume of sample air through the cartridge
13, Performance Criterial and Quality Assurance
This section summarizes required quality assurance measures and provides guidance concerning performance
criteria that should be achieved within each laboratory.
13.1 Standard Operating Procedures (SOPs).
13.1.1 Users should generate SOPs describing the following activities in their laboratory: (1) assembly,
calibration, and operation of the sampling system, with make and model of equipment used; (2) preparation,
purification, storage, and handling of sampling reagent and samples; (3) assembly, calibration, and operation
of the HPLC system, with make and model of equipment used; and (4) all aspects of data recording and
processing including lists of computer hardware and software used.
13.1.2 SOPs should provide specific stepwise instructions and should be readily available to and
understood by the laboratory personnel conducting the work.
13.2 HPLC System Performance
13.2.1 The general appearance of the HPLC system should be similar to that illustrated in Figure 1.
13.2.2 HPLC system efficiency is calculated according to the following equation:
January 1999 Compendium of Methods far Toxic Organic Air Pollutants Page 11A-27
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Method TO-U A , Formaldehyde
N= 5.54
t
r
where:
N = column efficiency, theoretical plates.
tj = retention time of analyte, seconds.
W1/2 = width of component peak at half height, seconds.
A column efficiency of >5,QOO theoretical plates should be utilized.
13.23 Precision of response for replicate HPLC injections should be ±10% or less, day to day, for analyte
calibration standards at 150 ng/mL or greater levels (as the carbonyl compound). At 75 ng/mL levels and
below, precision of replicate analyses could vary up to 25%. Precision of retention times should be ±7% on
a given day.
133 Process Blanks
133.1 At least one field blank should be used for each day of field sampling, shipped and analyzed with
each group of samples. The number of samples within a group and/or time frame should be recorded so that
a specified minimum number of blanks is obtained for a given cartridge lot used for field samples. The field
blank is treated identically to the samples except that no air is drawn through the cartridge. The performance
criteria described in Section 9.2 should be met for field blanks. It is also desirable to analyze trip and
laboratory blank cartridges as well, to distinguish between possible field and lab contamination.
e: Remember to use the field blank value for each cartridge lot when calculating concentration. Do not
mix cartridge lots In the blank value determinations ]
13.4 Method Precision and Accuracy
At least 50% of the sampling events should include a collocated sample. A collocated sample is
defined as a second sampling port off the common sampling manifold. If more than five samples are collected
per sampling event, a collocated sample should be collected for each sampling event. Precision for the
collocated samples should be ±20% or better. EPA historical data has demonstrated effectiveness in reaching
±20%, as illustrated in Figure 13.
13.4.2 Precision for replicate HPLC injections should be ±10% or better, day to day, for calibration
standards.
13.43 Cartridges spiked with analytes of interest can be used hi round-robin studies to intereompare
several laboratories performing carbonyl analyses. The spiked samples are prepared m the laboratory by
spiking a blank cartridge with a solution of derivatized earbonyls in acetonitrile. The laboratory preparing the
spike samples should analyze at a minimum 3 of the prepared spiked samples to evaluate the consistency of
prepared samples.
13.4.4 Before initial use of the method, each laboratory should generate triplicate spiked samples at a
minimum of three concentration levels, bracketing the range of interest for each compound. Triplicate
nonspiked samples must also be processed. Spike recoveries of >80 ±10% and blank levels should be
achieved.
13.4,5 For ambient air sampling, an ozone denuder must be used as part of the sampling system. As
discussed hi Section 6.4, ozone effects the ultimate method precision and accuracy by reacting with its
Page 11A-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Formaldehyde Method TO-11A
carbonyl derivative (hydrazones) on the cartridge. To illustrate this point, Figure 14 documents the
concentration of formaldehyde captured on collocated DNPH-cartridges, one with a denuder (see Figure 14a)
and the other without a denuder (see Figure 14b). The formaldehyde peak is considerably higher with use of
an ozone denuder.
13.5 Method Detection Limits
13.5.1 Determine method detection limits using the procedures in 40 CFR Part 136B. Prepare a low level
standard of the carbonyl derivatives at a concentration within two to five times the estimated method detection
limit. Inject the standard into the analytical system seven times.
13.5.2 Calculate the measured concentration using the calibration curve.
13.53 Determine the standard deviation for the seven analyses and use the standard deviation to calculate
the detection limit as described in 40 CFR Part 136B.
13.6 General QA/QC Requirements
13.6.1 General QA/QC requirements associated with the performance of Compendium, Method TO-11A
include;
Sampling
• Each sampling event, flow calibration with bubble meter, both pre- and post-checks.
• Mass flow meter calibration factor determined every quarter.
« Each sampling event, leak check, both pre- and post-checks.
» 10 percent of field samples collocated to help calculate method precision and evaluate biases.
* 10 percent of field samples operated with back-up cartridge to evaluate analyte breakthrough.
• Field and trip (optional) blank cartridges are included with each field sample collection program.
• Sample volumes calculated and reviewed project QA officer.
Reagents
* Coating solution prepared from concentrated stock solution immediately before each coating.
• Solution analyzed before each coating to determine acceptability (less than 0.15 pg/cartridge for each
aldehyde), control chart of contaminant concentration maintained.
* Three blank cartridges per lot for immediate elution/analysis to determine Certification Blank for the
carbonyl compounds.
Analysis
• Multi point calibration curve performed each six months.
• Each initial calibration verified with a standard from a second source.
* Continuing calibration standard (mid-level) analyses every analytical run to evaluate precision, peak
resolution and retention time drift
• Method detection limits (MDLs) verified annually or after each instrument change.
• Replicate analysis of approximately 10 percent of sample eluents to evaluate precision.
* Samples quantitated against least squares calibration line.
* Performance evaluation (PE) sample acquired from independent sources analyzed prior to and after
field samples.
• Random collocated samples shipped to independent laboratory for analysis and compared to in-house
collocated sample.
• Testing of aeetonitrile used for sample extraction for background carbonyl evaluation.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-29
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Method TO-11A : Formaldehyde
Data Acquisition
* Sample chromatograms and standards checked daily for peak shape and integration quality,
resolution of carbonyls, overall sensitivity and retention time drift.
* Separate tape backups made of raw data immediately after completion of each analysis.
* Peaks in each sample checked for correct ID and integration using system software before export to
ASCII file.
* Final results checked and edited by project QA officer before producing final report.
» Tape backups of final data files produced.
13.6.2 All results should be reviewed by the project QA officer, independent of the field and laboratory
operations, to evaluate the overall adherence to the methodology in meeting the program data quality
objectives (DQOs).
14. I>etection of Other Aldehydes and Ketones
14.1 Introduction
14.1.1 The procedure outlined above has been written specifically for the sampling and analysis of
formaldehyde in ambient air using an adsorbent cartridge and HPLC. Ambient air contains other aldehydes
and ketones. Optimizing chromatographic conditions by using two Zorbax ODS columns in series and varying
Ihe mobile phase composition through a gradient program will enable the analysis of other aldehydes and
ketones. Alternatively, other aldehydes and ketones may also be analyzed using a single C-18, reverse phase
column and a ternary gradient as described by Waters or Smith, et al. (7. Chromatography, 483,1989,431-
436). Thus, other aldehydes and ketones can be detected with a modification of the basic procedure.
14.1.2 In particular, chromatographic conditions can be optimized to separate acetaldehyde, acetone,
propionaldehyde, and some higher molecular weight carbonyls within an analysis time of about 1 h by
utilizing two Zorbax ODS columns in series, and a linear mobile phase program. Operating the HPLC in a
gradient mode with one Zorbax ODS column may also provide adequate resolution and separation. Carbonyl
compounds covered within the scope of this modification include:
Formaldehyde Crotonaldehyde
o-Toluaidehyde
Aeeteldehyde Butyraldehyde
m-Tolualdehyde
Acetone Benzaldehyde
p-Tolualdehyde
Propionaldehdye Isovaleraldehyde
Hexanaldehyde
Valeraldehyde 2,5-Dimethylbeozaldehyde Methyl ethyl ketone
14.13 The linear gradient program varies the mobile phase composition periodically to achieve maximum
resolution of the C-3, C-4 and benzaldehyde region of the chromatogram. The following gradient program
was found to be adequate to achieve this goal: Upon sample injection, linear gradient from 65% acetonitrile
(ACN)/35% water to 55% ACN/45% water in 36 min; to 100% ACN in 20 min; 100% ACN for 5 min; reverse
linear gradient from 100% ACM to 60% ACN/40% water in I min; maintain at 60% ACN/40% water for 15
min.
Page 11A-30 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde Method TO-11A
14.2 Sampling Procedures
Same as Section 10.
143 HPLC Analysis
143.1 The HPLC system is assembled and calibrated as described in Section 11, The operating parameters
are as follows:
Column: Zorbax ODS» two columns in series
Mobile Phase: Acetonitrile/water, linear gradient
Step 1. 60-75% acetonitrile/40-25% water in 30 minutes.
Step 2. 75-100% acetonitrile/25-0% water in 20 minutes.
Step 3. 100% acetonitrile for 5 minutes.
Step 4. 60% acetonitrile/40% water reverse gradient hi 1 minute.
Step 5. 60% acetonitrile/40% water, isocratic, for 15 minutes.
Detector: Ultraviolet, operating at 360 nm
How Rate: l.OinL/min
Sample Injection Volume: 25 uL
143.2 The gradient program allows for optimization of chromatographic conditions to separate
acetaldehyde, acetone, propionaldehyde, and other higher molecular weight aldehydes and ketones hi an
analysis time of about one hour.
143.3 The chromatographic conditions described here have been optimized for a gradient HPLC
system equipped with a UV detector (variable wavelength), an automatic sampler with a 25-uL loop injector
and two DuPont Zorbax ODS columns (4.6 x 250-mm), a recorder, and an electronic integrator. Analysts are
advised to experiment with their HPLC systems to optimize chromatographic conditions for their particular
analytical needs. Highest chromatographic resolution and sensitivity are desirable but may not be achieved.
The separation of acetaldehyde, acetone, and propionaldehyde should be a minimum goal of the optimization.
14.3.4 The carbonyl compounds hi the sample are identified and quantified by comparing their
retention times and area counts with those of standard DNPH derivatives. Formaldehyde, acetaldehyde,
acetone, propionaldehyde, crotonaldehyde, benzaldehyde, and o-, m-, p-tolualdehydes can be identified with
a high degree of confidence. The identification of butyraldehyde is less certain because it coelutes with
isobutyraldehyde and is only partially resolved from methyl ethyl ketone under the stated chromatographic
conditions. A typical chromatogram obtained with the gradient HPLC system for detection of other aldehydes
and ketones is illustrated hi Figure 15.
143.5 The concentrations of individual carbonyl compounds are determined as outlined hi Section 12.
143.6 Performance criteria and quality assurance activities should meet those requirements outlined
hi Section 13.
15. Precision and Bias
15.1 This test method has been evaluated by round robin testing. It has also been used by two different
laboratories for analysis of over 1,500 measurements of formaldehyde and other aldehydes hi ambient air for
EPA's Urban Air Toxics Program (UATP), conducted In 14 cities throughout the United States.
ISJJ The precision of 45 replicate HPLC injections of a stock solution of formaldehyde-DNPH derivative
over a 2-month period has been shown to be 0.85% relative standard deviation (RSD).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-31
-------
Method TO-11A : Formaldehyde
153 Triplicate analyses of each of twelve identical samples of exposed DNPH cartridges provided
formaldehyde measurements that agreed within 10.9% RSD.
15,4 A total of 16 laboratories in the U.S., Canada, and Europe participated in a round robin test that included
250 blank DNPH-cartridges, three sets of 30 cartridges spiked at three levels with. DNPH derivatives, and 13
sets of cartridges exposed to diluted automobile exhaust gas. All round robin samples were randomly
distributed to the participating laboratories. A summary of the round robin results is shown hi Table 4.
15.5 The absolute percent differences between collocated duplicate sample sets from the 1988 UATP
program were 11.8% for formaldehyde (n=405), 14.5% for acetaldehyde (n=386), and 16.7% for acetone
(n=346).
15.6 Collocated duplicate samples collected in the 1989 UATP program and analyzed by a different
laboratory showed a mean RSD of 0.07, correlation coefficient of 0.98, and bias of -0.05 for formaldehyde.
Corresponding values for acetaldehyde were 0.12,0.95 and -0.54, respectively. In the 1988 UATP program,
single laboratory analyses of spiked DNPH cartridges provided over the year showed an average bias of -f6.2%
for formaldehyde (n=14) and +13.8% for acetaldehyde («=13).
15,7 Single laboratory analyses of 30 spiked DNPH cartridges during the 1989 UATP program showed an
average bias of +1.0% (range -49 to +28%) for formaldehyde and 5.1% (range -38% to +39%) for
acetaldehyde.
16. References
1. Riggin, R. M., TJetermination of Aldehydes and Ketones hi Ambient Air: Method TO-5," in
Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, U. S.
Environmental Protection Agency, EPA-600/4-84-041, Research Triangle Park, NC, April 1984.
2. Winberry, W. T. Jr., et aL, "Determination of Formaldehyde and Other Aldehydes hi Indoor Ah* Using
Passive Sampling Device, Method BP-6C," in Compendium of Methods for the Determination of Air
Pollutants in Indoor Air, U. S. Environmental Protection Agency, EPA-600/4-90-010, May 1990.
3. Tejada, S.B., "Standard Operating Procedure For DNPH-coated Silica Cartridges For Sampling
Carbonyl Compounds In Air And Analysis by High-performance Liquid Chromatography,"
Unpublished, U. S. Environmental Protection Agency, Research Triangle Park, NC, March 1986.
4. Tejada, SJ3., "Evaluation of Silica Gel Cartridges Coated in situ with Acidified
2,4-Dinitrophenylhydrazhie for Sampling Aldehydes and Ketones hi Ah*," Intern. J. Environ. Anal.
Chem,, Vol. 26:167-185,1986.
S. Winberry, W. T. Jr., et al., "Determination of Formaldehyde in Ambient Air Using Adsorbent Cartridge
Followed by HPLC: Method TO-11," hi Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Supplement, U. S. Environmental Protection Agency,
EPA-600/4-89-018, Research Triangle Park, NC, March 1989.
6. Wmberry, W. T. Jr., et al., "Determination of Formaldehyde and Other Aldehydes hi Indoor Air 'Using
a Solid Adsorbent Cartridge: Method IP-6A," hi Compendium of Methods for the Determination of Air
Pollutants in Indoor Air, U. S. Environmental Protection Agency, EPA-600/4-90-010, May 1990.
Page 11A-32 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde Method TO-11A
7. Nolan, L., et al., "Monitoring Carbonyls in Ambient Air Using the New Supelclean™ LPD (Low
Pressure Drop) DNPH Cartridge," in Proceedings of the 1995 EPA/AWMA International Symposium
on Measurement of Toxic and Related Air Pollutants, VIP-50, pp. 279, May 1995.
8. Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II - Ambient Air Specific
Methods, EPA-600/R-94-038b, U. S. Environmental Protection Agency, Research Triangle Park, NC,
May 1994.
9. Technical Assistance Document for Sampling and Analysis of OjPrecursors, U. S. Environmental
Protection Agency, EPA-600/8-9-215, Research Triangle Park, NC, October 1991.
10. Ahonen, I., Priha, E., and Aijala, M-L, "Specificity of Analytical Methods Used to Determine the
Concentration of Formaldehyde in Workroom Air," Chemosphere, Vol. 13:521-525,1984.
11. Levin, J. O., et al., "Determination of Sub-part-per-Million Levels of Formaldehyde in Air Using Active
or Passive Sampling on 2,4-Dinitrophenylhydrazine-Coated Glass Fiber Filters and High-Performance
Liquid Chromatography," Anal. Chem., Vol. 57:1032-1035, 1985.
12. Perez, J. M., Lipari, F., and Seizinger, D. E., "Cooperative Development of Analytical Methods for
Diesel Emissions and Particulates - Solvent Extractions, Aldehydes and Sulfate Methods", presented
at the Society of Automotive Engineers International Congress and Exposition, Detroit, MI,
February-March 1984.
13. Kring, E. V., et al., "Sampling for Formaldehyde in Workplace and Ambient Air Environments-
Additional Laboratory Validation and Field Verification of a Passive Air Monitoring Device Compared
with Conventional Sampling Methods," J. Am. Ind, Hyg. Assoc., Vol. 45:318-324,1984.
14. Sirju, A., and Shepson, P. B., "Laboratory and Field Evaluation of the DNPH-Cartridge Technique for
the Measurement of Atmospheric Carbonyl Compounds," Environ. ScL Technol. Vol. 29:384-392,
1995.
15. Chasz, E. et al., "Philadelphia Air Management Lab, Summary of Procedures and Analytical Data for
Enhanced Ambient Monitoring of PAMS Carbonyls," in Proceedings of the 1995 EPA/AWMA
International Symposium on Measurement of Toxic and Related Air Pollutants, VIP-50, pp. 293, May
1995.
16. Grosjean, D., "Ambient Levels of Formaldehyde, Acetaldehyde, and Formic Acid in Southern
California: Results of a One-Year Base-Line Study," Environ. Sci. Technol., Vol. 25,710-715, 1991.
17. Bufalini, J.J., and Brubaker, K.L., "The Photooxidation of Formaldehyde at Low Pressures." In:
Chemical Reaction in Urban Atmospheres, (C.S. Tuesday), American Elsevier Publishing Co., New
York, pp. 225-240. 1971.
18. Altshuller, A.P., and Cohen, I.R., "Photooxidation of Formaldehyde in the Pressence of Aliphatic
Aldehydes", Science, Vol. 7:1043-1049, 1963.
19. "Formaldehyde and Other Aldehydes" Committee on Aldehydes, Board of Toxicology and
Environmental Hazards, National Research Council, National Academy Press, Washington, DC, 1981.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 11A-33
-------
Method TO-11A Formaldehyde
20. Altshuller, A. P., "Production of Aldehydes as Primary Emissions and Secondary Atmospheric
Reactions of Alkenes and Alkanes During the Night and Early Morning Hours," Almas. Environ., Vol.
27A.-21-31, 1993.
21. Tanner, R. L., et al., "Atmospheric Chemistry of Aldehydes; Enhanced PAN Formation From Ethanol
Fuel Vehicles," Environ. Sci. Technol, Vol. 22:1026-1034,1988.
22. Ciccioli, P., and Cecinato, A., "Advanced methods for the Evaluation of Atmospheric Pollutants
Relevant to Photochemical Smog and Dry Acid Deposition: Chapter 11" in Gaseous Pollutants:
Characterization and Cycling, edited by Jerome O. Nriagu, ISBN 0-471-54898-7, John Wiley and
Sons, Inc., 1992.
23. Parmar, S. S., et al., "A Study of Ozone Interferences in Carbonyl Monitoring Using DNPH Coated C18
and Silica Cartridges," in Proceedings of the 1995 EPA/AWMA International Symposium on
Measurement of Toxic and Related Air Pollutants, VIP-50, pp. 306, May 1995.
24. Parmar, S. S., et al., "Effect of Acidity on the Sampling and analysis of Carbonyls Using DNPH
Derivatization Method," in Proceedings of the 1996 EPA/AWMA International Symposium on
Measurement of Toxic and Related Air Pollutants, VIP-64, pp. 311, May 1996.
25. Amis, R. R., and Tejada, S. B., "2,4-Dinitrophenylhydrazine-Coated Silica Gel Cartridge Method for
Determination of Formaldehyde hi Air Identification of an Ozone Interference," Environ. Sci. Technol.
Vol. 23:1428-1430, 1989.
26. Kleindienst, T. E., et al., "Measurement of Q-Q Carbonyls on DNPH-Coated Silica Gel and C18
Cartridges in the Presence of Ozone," in Proceedings of the 1995 EPA/AWMA International Symposium
on Measurement of Toxic and Related Air Pollutants, VIP-50, pp 29T, May 1995.
Page 11A-34 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde
Method TO-11A
TABLE 1. COMPARISON OF DNPH COATED CARTRIDGES: SILICA GEL VS. CIS
lillillibpiiillll
Background
Breakthrough
Ozone interference
Extraneous chromato-
jyaghic peaks
jKftGOTapanisdiiJIij:
Silica gel< CIS
SiHcagel95% for formaldehyde for sampling rates up to 2,0 L/min
-1.0 mL
From -2 inches to ~5 inches in length
-I inch O.D. at widest ooint
'Loading is variable among commercial suppliers.
^The SKC tube is a dual bed cartridge with 300 mg of DNPH-coated silica gel in the front bed and 150 mg of
DNPH-coated silica gel in the back bed.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
PagellA-35
-------
Method TO-11A
Formaldehyde
TABLE 3. EQUIVALENT FORMALDEHYDE CONCENTRATION (ppbv) RELATED TO
BACKGROUND FORMALDEHYDE CONCENTRATION (ng/cartridge)
Equivalent fbiTOaldehydfe:'::S*5-2&^&*:?'8i^
::T:UWw:::&«^^
lliWill
0.950
L358
2.037
wfiMSi
0.475
0.679
1.018
0.317
0.453
0.679
0.040
0.057
0.085
TABLE 4. ROUND ROBIN TEST RESULTS*
Sample Type
Blank cartridges:
pg aldehyde
(% RSD)
n
Spiked6 cartridges:
% recovery (%
RSD)
low
medium
high
n
Exhaust samples:
Hg aldehyde
%RSD
n
Formaldehyde
0.13
46
33
89.0 (6.02)
972 (3.56)
97.5 (2.15)
12
5.926
12.6
31
Acetaldchyde
0.18
70
33
92.6 (13.8)
97.8 (7.98)
102.2 (6.93)
13
7.990
16.54
32
Propionaldehyde
0.12
47
23
108.7 (32.6)
100.9 (13.2)
100.1 (6.77)
12
0.522
26.4
32
Benzaldehyde
0.06
44
8
114.7 (36.1)
123.5 (10.4)
120.0 (821)
14
0288
19.4
17
'Sixteen participating laboratories. Statistics shown after removal of outliers.
""Normal spiking levels were approximately 0-5,5 and 10 fig of aldehyde, designated as low, medium, and high in this table.
Page 11A-36
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Formaldehyde
Method TO-11A
INJECTION VALVE
WATER
ACN
GUARD COLUMN
WASTE
SAMPLE LOOP
AUTOSAMPLER
ANALYTICAL
COLUMN
DETECTOR
360 nm
RECORDER
INTEGRATOR
WASTE
Figure 1. Basic high-performance liquid ehromatograpMc (HPLC) system used for carbonyl analysis.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
PagellA-37
-------
Method TO-11A
Formaldehyde
SKC
Prariston-
SeatedTips
Glass
Tube
High-Purity
Glass Wool
DNPH-Coated Adsorbent
(Back Bed)
DNPH-Coated Msaitsent
(Front Bed)
Precision
Lockspring
NiOSB^ppraved
Sealing Caps
SUPELCO Luet®
Fitting
AAC
DNPH-C-18 Cartridge
Luei®
Fitting
Luet®
Rtting
Luef®
FrtBng
DNPH- Cartridge
DNPH - Coated Adsorbent
WATERS
DNPH-SIIIca Gel Cartridge
Luen®
Fitting
DNPH-
LuettS)
Rtb'ng
Cartridge
Figure 2. Example of commercially available DNPH-cartridges.
PagellA-38
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Formaldehyde
Method TO-11A
£3
M
m-M
Mass Flow DNPH-Coated """1
Controller Sampling
•••
I "^ gg
1 )
v^/ ^
ampling Pump
Cartridge
fVj — tig!™ illPP
Shut-off
Valve
_ AAAAAA .ar-
1
1
1
1
•-S2
m—^MMt^-^m
f T * f f i
Ozone
Denuder or
Scrubber ^
I
1
1
1
Q
«H
"c
C3
HH
2
1
ra
0)
45
f
Q_
"5.
CT3
CO
T3
'«
03
X
Needle Valve
Flushing Pump
Ambient Air
Figure 3. Example of configuration of a single-port carbonyl sampler using DNPH-coated cartridges.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 11A-39
-------
Method TO-11A
Formaldehyde
Sample Inlet
I
Heated Sample Inlet
Heated Zone 0.5-1.0LPM
Ozone l_f
Denuder
Timer-controlled
Solenoid Valves
DNPH Cartridge
1 LPM
Figure 4. Example of components of an automated multi-port sampler for
carbonyls monitoring using DNPH-coated cartridges.
Page 11A-40
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Formaldehyde
Method TO-11A
Culture Tube
and Cap
DNPH
Arisofbant
Tube
(a) DNPH-cartridge in culture shipping tube
Packing
Foam
Polypropylene
Adsorbent Shipping Cap
Tubas
Polypropylene
Shipping
Container
(b) DNPH-cartridge in polypropylene shipping container
Figure 5, Example of commercially available shipping containers for DNPH cartridges.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 11A-41
-------
Method TO-11A
Formaldehyde
Top View (cutaway)
i" -»|
3' Potassium
Iodide Coated
1/4" O.D. Copper
Tubing
(a) Cross-sectional view of EPA's ozone denuder assembly
Potassium Iodide
Cartridge Ozone
Scrubber
Female Luer
— Polyethylene Frit
Male Luer
(b) Commercially available packed granular potassium iodide (K!) ozone scrubber
Figure 6. Example of (a) cross-sectional view of EPA's ozone denuder assembly, and
(b) commercially available packed granular potassium iodide (KI) ozone scrubber.
Page 11A-42 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
Formaldehyde
Method TO-11A
10mL Glass.
Syringe
Uncoated
Sample Cartridges
{
I
'/,
1
!
T£
22J
w
-»-
V/////&
Test Tube
Rack
Waste
Beaker
(a) Rack for Coating Cartridges
Syringe Fitting'
Guard Cartridge—
Sample Cartridge-
'N2Gas Stream
DNPH-Coated
Cartridges
Waste Vial
-^-
J U
(b) Rack for Drying DNPH-Coated Cartridges
Figure 7. Example of a typical syringe rack for coating (a) and drying (b) sample cartridges.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
PagellA-43
-------
Method TO-11A
Formaldehyde
JD
O.
°I
C
.2
"cS
-------
Formaldehyde
Method TO-11A
COMPENDIUM METHOD TO-1 i A
CARBONYL SAMPLING FIELD TEST DATA SHEET
(One Sample per Data Sheet1)
I. GENERAL INFORMATION
PROJECT:
SITE:
LOCATION:
INSTRUMENT MODEL NO.:
PUMP SERIAL NO.:
ADSORBENT CARTRIDGE INFORMATION:
Type:
Adsorbent:
Serial Number: .
Sample Number:
H. SAMPLING DATA INFORMATION
Start Time:
Avg,
DATES(S) SAMPLED:
TIME PERIOD SAMPLED:.
OPERATOR:
CALIBRATED BY:
OZONE DENUDER USE TIME (Hr):
HEATED INLET: YES NO
Stop Time:.
* Flow rate from rotameter or soap bubble calibrator (specify which).
Total Volume Data (Vm) (use data from dry gras meter, if available)
Vm = (Final - Initial) Dry Gas Meter Reading, or
or
fl, * fl, * Q3 -. QH
N
1
1000 x (Sampling Time in Minutes)
. COMMENTS
Figure 9. Example of Compendium Method TO-11A field test data sheet (FTDS).
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
PageIlA-45
-------
Method TO-11A
Formaldehyde
OPERATING PARAMETERS
HPLC
Column: Zorfaax ODS or C-18 RP
Mobile Phase: 60% Acetonitrile/40% Water
Detector Ultraviolet, operating at 360 nm
Flow Rate: 1 mL/min
Retention Time: ~ 7 minutes for formaldehyde
Sample Injection Volume: 25 L
o
-------
Formaldehyde
Method TO-11A
OPERATING PARAMETERS HPLC
Column: Zorbax ODS or C-18 RP
Mobile Phase: 60% Acetontri!e/4Q% Water
Detecton Ultraviolet, operating at 360 nm
Flow Rate: 1 mL/min
Retention Time: - 7 minutes for formaldehyde
Sample Injection Volume: 25 pL
Peak
a
b
c
d
e
Cone.
jig/mL
0.61
1.23
6.16
12.32
18.48
Area Counts
226541
452186
2257271
4711408
6053812
r
o
-------
Method TO-11A
formaldehyde
O
o
8-
o
g
o
8'
o«
o
rr
8-
i
3
CORRELATION COEFFICIENT:
0.9999
OPERATING PARAMETERS
HPLC
Column: Zorbax ODS or C-18 RP
Mobile Phase: 60% AcetonJtriIe/40% \Afeter
Detector Ultraviolet, operating at 360 nm
Flow Rate: 1 mL/min
Retention Time: - 7 minutes for formaldehyde
Sample Injection Volume: 25 uL
I I T I
9 12 15 18
DNPH - Formaldehyde Derivative
Figure 12. Example of calibration curve for formaldehyde.
Page 11A-48
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Formaldehyde
Method TO-11A
10
8 —
8
tf
OJ
O
±20% precision
limits
I I I I I I
4 6 8
Cart. #1
10
Figure 13. Historical data associated with collocated samples for
formaldehyde (ppbv) in establishing 20% precision.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 11A-49
-------
Method TO-11A
Formaldehyde
1
CO
.a
o
CO
JD
CD
31
-------
§
to
DNPH
PEAK IDENTIFICATION
Number
1
2
3
4
S
6
?
S
g
10
11
12
13
14
15
Compound
Formaldehyde
Acelaldehyde
Acroleln
Acetone
ProplonaWehyde
Crotonaldehyde
Birtyialdehyde
Benzaldahyde
iBovateraldahyde
ValetaWehyde
o-ToluaWenytte
tn-Tolualdehytfa
p-Tolualdshyda
Hexaldehyde
Z.-f-Dljnemylbon-
uldehyde
Concentration
Itglml
1,140
1.000
1.000
1,000
1.000
1.000
O.SOS
1.000
0.450
0.485
O.S15
O.SOS
O.S10
1.000
0.510
»
a
10
20
30
40
50
TIME, min
2s
•8
o
a.
Figure 15. Typical chromatogram of a linear gradient program for analyzing other aldehydss/ketones from a DNPH-coated cartridge.
-------
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-12
Method for the Determination of Non-Methane Organic Compounds
(NMOC) in Ambient Air Using Cryogenic Preconcentration and
Direct Flame lonization Detection (PDFID)
Summary of Method
Compendium Method TO-12 combines a cryogenic concentration technique for trapping
organics in the ambient air (similar to Compendium Method TO-3) coupled to a highly sensitive and
simple flame ionization detector (FID) to determine non-speciated total NMOC concentrations in the
ambient air.
In Compendium Method TO-12, a whole air sample is either extracted directly from the
ambient air and analyzed on-site by the GC system or collected into a precleaned specially-treated
canister and analyzed off-site.
The analysis requires drawing a fixed-volume portion of the extracted sample air, at a low
flow rate, through a glass-bead filled trap that is cooled to approximately -186°C with liquid argon.
The cryogenic trap simultaneously collects and concentrates the NMOC (either via condensation or
adsorption) while allowing the methane, nitrogen, oxygen, etc. to pass through the trap without
retention. The system is dynamically calibrated so that the volume of sample passing through the trap
does not have to be quantitatively measured, but must be precisely repeatable between the calibration
and the analytical phases.
After the fixed-volume air sample has been drawn through the trap, a helium carrier gas flow
is diverted to pass through the trap, in the opposite direction to the sample flow, and into an FID.
When the residual air and methane have been flushed from the trap and the FID baseline restabilizes,
the cryogen is removed and the temperature of the trap is raised to approximately 90°C.
The NMOC previously collected in the trap revolatilize due to the increase in temperature and
are carried into the FID, resulting in a response peak or peaks from the FID. The area of the peak
or peaks is integrated, and the integrated value is translated to concentration units via a previously
obtained calibration curve relating integrated peak areas with known concentrations of propane.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 12-1
-------
By convention, concentrations of NMOC are reported in units of parts per million carbon
(ppmC), which, for a specific compound, is the concentration by volume (ppmv) multiplied by the
number of carbon atoms in the compound.
i
Sources of Methodology
Method TO-12 has not been revised. Therefore, the original method is not repeated in the
Second Edition of the Compendium, Method TO-12 is contained in the original supplement of
Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, EPA-
600/4-89-017, which may be purchased in hard copy from: National Technical Information Service,
5285 Port Royal Road, Springfield, VA 22161; Telephone: 703-487-4650; Fax: 703-321-8547; E--
Mail: info@ntis.fedworld.gov; Internet: www.ntis.gov. Order number: PB90-116989. The TO-
methods may also be available from various commercial sources.
Electronic versions of the individual unrevised Compendium (TO-) Methods are available for
downloading from the "AMTIC, Air Toxics" section of EPA's OAQPS Technology Transfer Network
via the Internet at the "AMTIC, Air Toxics" section of the TTNWeb:
http://www.epa.gov/ttn/amtic/airtos.htnil
Methods TO-1 to TO-13 are now posted in the portable document format (PDF).
The downloaded files can be read using an Acrobat Reader. Acrobat readers are
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Page 12-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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EPA/625/R-96/010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-13A
Determination of Polycyclic Aromatic
Hydrocarbons (PAHs) in Ambient Air Using Gas
Chromatography/Mass Spectrometry (GC/MS)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-13A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/010b), under Contract No. 68-C3-0315,
WA No. 3-10, 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,
John O. Burckle, and Scott R, Hedges, Center for Environmental Research Information (CERI), and Frank F.
McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of Research and
Development (ORD), were responsible for overseeing the preparation of this method. 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 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
Heidi Schultz, ERG, Lexington, MA
William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Cary, NC
Metlwd TO-13 was originally published in March of 1989 as one of a series of peer-reviewed methods in the
second supplement to Compendium of Methods for the Determination of Toxic Organic Compounds in
Ambient Air, EPA 600/4-89-018. In an effort to keep these methods consistent with current technology,
Method TO-13 has been revised and updated as Method TO-13A in this Compendium to incorporate new or
improved sampling and analytical technologies.
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., EnviroTech Solutions, Cary, NC
• Greg Jungclaus, Midwest Research Institute, Kansas City, MO
j
Peer Reviewers
• Nancy Wilson, U.S. EPA, NERL, RTP, NC
Joan Bursey, ERG, Morrisville, NC
Irene D. DeGraff, Supelco, Bellefonte, PA
• Jane Chuang, Battelle Laboratories, Cincinnati, OH
* Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
-------
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Whitaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence during
the development of this manuscript has enabled its production.
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.
ui
-------
-------
METHOD TO-13A
Determination of Polycyclic Aromatic Hydrocarbons (PAHs)
in Ambient Air Using Gas Chromatography/Mass Spectrometry (GC/MS)
TABLE OF CONTENTS
1. Scope , ; 13A-1
2. Summary of Method 13A-2
3. Significance . 13A-3
4, Applicable Documents I3A-3
4.1 ASTM Standards : 13A-3
4.2 EPA Documents 13A-3
4.3 Other Documents 13A-4
5. Definitions 13A-4
6. Limitations and Interferences 13A-5
6.1 Limitations 13A-5
6.2 Interferences 13A-6
7. Safety ...,' , 13A-6
8. Apparatus , 13A-7
8.1 Sampling 13A-7
8.2 Sample Clean-Up and Concentration 13A-8
8.3 Sample Analysis . . , 13A-9
9. Equipment and Materials 13A-10
9.1 Materials for Sample Collection 13A-10
9.2 Sample Clean-up and Concentration 13A-11
9.3 GC/MS Sample Analysis 13A-11
10. Preparation of PUF Sampling Cartridge 13A-12
10.1 Summary of Method 13A-12
10.2 Preparation of Sampling Cartridge 13A-12
10.3 Procedure for Certification of PUF Cartridge Assembly 13A-13
10.4 Deployment of Cartridges for Field Sampling 13A-14
11. Assembly, Calibration, and Collection Using Sampling System 13A-15
11.1 Sampling Apparatus 13A-15
11.2 Calibration of Sampling System 13A-15
11.3 Sample Collection 13A-22
-------
TABLE OF CONTENTS, CONTINUED
Page
12. Sample Extraction, Concentration, and Cleanup 13A-23
12.1 Sample Identification . 13A-23
12,2 Soxhlet Extraction and Concentration I3A-24
12,3 Sample Cleanup 13A-25
13. Gas Chromatography with Mass Spectrometiy Detection -,, .. 13A-26
13.1 General 13A-26
13.2 Calibration of GC/MS/DS 13A-26
13.3 GC/MS Instrument Operating Conditions 13A-29
13.4 Sample Analysis by GC/MS ,..,. ,. ." 13A-37
14. Quality Assurance/Quality Control (QA/QC) ,.,.. 13A-41
14.1 General System QA/QC , , , 13A-41
14.2 Process, Field, and Solvent Blanks 13A-42
15. References 13A-42
¥1
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METHOD TO-13A
Determination of Polycyclic Aromatic Hydrocarbons (PAHs)
in Ambient Air Using Gas Chromatography/Mass Spectrometry (GC/MS)
1. Scope
1.1 Polycyclic aromatic hydrocarbons (PAHs) have received increased attention in recent years in air pollution
studies because some of these compounds are highly carcinogenic or mutagenic. In particular, benzo[a]pyrene
(B[a]P) has been identified as being highly carcinogenic. To understand the extent of human exposure to B[a]P
and other PAHs, reliable sampling and analytical methods are necessary. This document describes a sampling
and analysis procedure for common PAHs involving the use of a combination of quartz filter and sorbent
cartridge with subsequent analysis by gas chromatography with mass spectrometry (GC/MS) detection. The
analytical methods are modifications of EPA Test Method 610 and 625, Methods for Organic Chemical
Analysis of Municipal and Industrial Wastewater, and Methods 8000, 8270, and 8310, Test Methods for
Evaluation of Solid Waste,
1.2 Fluorescence methods were among the very first methods used for detection of B[a]P and other PAHs as
carcinogenic constituents of coal tar (1-7). Fluorescence methods are capable of measuring subnanogram
quantities of PAHs, but tend to be fairly non-selective. The normal spectra obtained are often intense and lack
resolution. Efforts to overcome this difficulty led to the use of ultraviolet (UV) absorption spectroscopy (8)
as the detection method coupled with pre-speciated techniques involving liquid chromatography (LC) and thin
layer chromatography (TLC) to isolate specific PAHs, particularly B[a]P. As with fluorescence spectroscopy,
the individual spectra for various PAHs are unique, although portions of spectra for different compounds may
be the same. As with fluorescence techniques, the possibility of spectral overlap requires complete separation
of sample components to ensure accurate measurement of component levels. Hence, the use of UV absorption
coupled with pre-speciation involving LC and TLC and fluorescence spectroscopy declined and was replaced
with the more sensitive high performance liquid chromatography (HPLC) with UV/fluorescence detection (9)
or highly sensitive and specific gas chromatography/mass spectrometry (GC/MS) for detection (10-11).
1.3 The choice of GC/MS as the recommended procedure for analysis of B[a]P and other PAHs was
influenced by its sensitivity and selectivity, along with its ability to analyze complex samples.
1.4 The analytical methodology has consequently been defined, but the sampling procedures can reduce the
validity of the analytical results. Recent studies (12-17) have indicated that non-volatile PAHs (vapor pressure
<10"8 mm Hg) may be trapped on the filter, but post-collection volatilization problems may distribute the PAHs
downstream of the filter to the back-up sorbent. A wide variety of sorbents such as Tenax®, XAD-2® and
polyurethane foam (PUF) have been used to sample common PAHs. All sorbents have demonstrated high
collection efficiency for B[a]P in particular. In general, XAD-2® resin has a higher collection efficiency (18-
21) for volatile PAHs than PUF, as well as a higher retention efficiency. PUF cartridges, however, are easier
to handle in the field and maintain better flow characteristics during sampling. Likewise, PUF has
demonstrated (22) its capability in sampling organoehlorine pesticides, polychlorinated biphenyls (22), and
polychlorinated dibenzo-p-dioxins (23). PUF also has demonstrated a lower recovery efficiency and storage
capability for naphthalene than XAD-2®. There have been no significant losses of PAHs up to 30 days of
storage at room temperature (23 °C) using XAD-2®. It also appears that XAD-2® resin has a higher
collection efficiency for volatile PAHs than PUF, as well as a higher retention efficiency for both volatile and
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-1
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Method TO-13A ; PAHs
reactive PAHs. Consequently, while the literature cites weaknesses and strengths of using either XAD-2® or
PUF, this method includes the utilization of PUF as the primary sorbent.
1.5 This method includes the qualitative and quantitative analysis of the following PAHs (see Figure 1)
specifically by utilizing PUF as the sorbent followed by GC/MS analysis:
Acenaphthene (low collection efficiency; Coronene
see Section 6.1.3) Dibenz(a,h)anthracene
Acenaphthylene (law collection efficiency; Fluoranthene
see Section 6.1.3) Fluorene
Anthracene Benzo(b)fluoranthene
Benz(a)anthracene Indeno(l,2,3-cd)pyrene
Benzo(a)pyrene Naphthalene (low collection efficiency;
Benzo(e)pyrene see Section 6.1.3)
Benzo(g,h,i)perylene Phenanthrene
Benzo(k)fluoranthene Pyrene
Chrysene Perylene
The GC/MS method is applicable to the determination of PAHs compounds involving three
member rings or higher. Naphthalene, acenaphthylene, and acenaphthene have only ~35 percent recovery when
using PUF as the sorbent. Nitro-PAHs have not been fully evaluated using this procedure; therefore, they are
not included in this method.
i
1.6 With optimization to reagent purity and analytical conditions, the detection limits for the GC/MS method
range from 1 ng to 10 pg based on field experience.
2. Summary of Method
2.1 Filters and sorbent cartridges (containing PUF or XAD-2®) are cleaned in solvents and vacuum dried.
The filters and sorbent cartridges are stored in screw-capped jars wrapped in aluminum foil (or otherwise
protected from light) before careful installation on the sampler.
2.2 Approximately 300 m3 of air is drawn through the filter and sorbent cartridge using a high-volume flow
rate air sampler or equivalent.
2,3 The amount of air sampled through the filter and sorbent cartridge is recorded, and the filter and cartridge
are placed in an appropriately labeled container and shipped along with blank filter and sorbent cartridges to
the analytical laboratory for analysis.
2.4 The filters and sorbent cartridge are extracted by Soxhlet extraction with appropriate solvent. The extract
is concentrated by Kuderna-Danish (K-D) evaporator, followed by silica gel cleanup using column
chromatography to remove potential interferences prior to analysis by GC/MS.
2.5 The duent is further concentrated by K-D evaporation, then analyzed by GC/MS. The analytical system
is verified to be operating properly and calibrated with five concentration calibration solutions.
Pagel3A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
PAHs Method TO-13A
2.6 A preliminary analysis of the sample extract is performed to check the system performance and to ensure
that the samples are within the calibration range of the instrument. If the preliminary analysis indicates non-
performance, then recalibrate the instrument, adjust the amount of the sample injected, adjust the calibration
solution concentration, and adjust the data processing system to reflect observed retention times, etc.
2.7 The samples and the blanks are analyzed and used (along with the amount of air sampled) to calculate the
concentration of PAHs in the air sample.
3. Significance
3.1 As discussed in Section 1, several documents have been published that describe sampling and analytical
approaches for common PAHs. The attractive features of these methods have been combined in this procedure.
Although this method has been validated in the laboratory, one must use caution when employing it for specific
applications.
3.2 Because of the relatively low levels of common PAHs in the environment, the methodology suggest the use
of high volume (0.22 m3/min) sampling technique to acquire sufficient sample for analysis. However, the
volatility of certain PAHs prevents efficient collection on filter media alone. Consequently, this method utilizes
both a filter and a backup sorbent cartridge, which provides for efficient collection of most PAHs involving
three member rings or higher.
4. Applicable Documents
4.1 ASTM Standards
• Method D1356 Definitions of Terms Relating to Atmospheric Sampling and Analysis.
• Method 4861-94 Standard Practice for Sampling and Analysis of Pesticides and Polychlorinated
Biphenyl in Air
• Method E260 Recommended Practice for General Gas Chromatography Procedures.
* Method E3SS Practice for Gas Chromatography Terms and Relationships.
• Method E682 Practice for Liquid Chromatography Terms and Relationships.
4.2 EPA Documents
• Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds in Ambient
Air, U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
• Quality Assurance Handbook for Air Pollution Measurement Systems, U, S. Environmental
Protection Agency, EPA-600/R-94-038b, May 1994.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air:
Method TO-J3, Second Supplement, U. S. Environmental Protection Agency, EPA-600/-4-89-018,
March 1989.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-3
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Method TO-13A ; PAHs
4.3 Other Documents
• Existing Procedures (24-32).
• Ambient Air Studies (33-50).
• General Metal Works, Inc., "Operating Procedures for Model PS-1 Sampler," Village of Cleves, OH
45002 (800-543-7412).
• Illinois Environmental Protection Agency, Division of Air Quality, "Chicago Air Quality: PCB Air
Monitoring Plan (Phase 2)," Chicago, IL, IEAP/APC/86/011, April 1986.
* Thermo Environmental, Inc. (formerly Wedding and Associates), "Operating Procedures for the
Thermo Environmental Semi-Volatile Sampler," 8 West Forge Parkway, Franklin, MA 02038
(508-520-0430).
* American Chemical Society (ACS), "Sampling for Organic Chemicals in Air," ACS Professional
Book, ACS, Washington, D.C., 1996.
« International Organization for Standardization (ISO), "Determination of Gas and Particle-Phase
Polynuclear Aromatic Hydrocarbons in Ambient Air - Collected on Sorbent-Backed Filters with Gas
Chromatographic/Mass Speetrometric Analysis," ISO/TC 146/SC 3/WG 17N, Case Postale 56,
CH-1211, Geneve 20, Switzerland.
5. Definitions
[fJote: Definitions used in this document and in any user-prepared standard operating procedures (SOPs)
should be consistent with ASTM Methods D1356, E260, and £255. All abbreviations and symbols are
defined within ihis document at point of use.J
S.I Retention time (RT)-time to elute a specific chemical from a chromatographic column. For a specific
carrier gas flow rate, RT is measured from the time the chemical is injected into the gas stream until it appears
at the detector.
5.2 Sampling efficiency (SE)-ability of the sampler to trap and retain PAHs. The %SE is the percentage of
the analyte of interest collected and retained by the sampling medium when it is introduced into the air sampler
and the sampler is operated under normal conditions for a period of time equal to or greater than that required
for the intended use.
5.3 Dynamic retention efficiency-ability of the sampling medium to retain a given PAH that has been added
to the sorbcnt trap in a spiking solution when air is drawn through the sampler under normal conditions for a
period of time equal to or greater than that required for the intended use.
5.4 Polycyclic aromatic hydrocarbons (PAHs)-two or more fused aromatic rings.
5.5 Method detection limit (MDL)-the minimum concentration of a substance that can be measured and
reported with confidence and that the value is above zero.
5.6 Kuderna-Danish apparatus-thc Kuderna-Danish (K-D) apparatus is a system for concentrating materials
dissolved in volatile solvents.
Page 13A-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs ; Method TO-13A
5.7 MS-SCAN-the GC is coupled to a mass spectrometer where the instrument is programmed to acquire all
ion data.
5.8 SubUmation-tlie direct passage of a substance from the solid state to the gaseous state and back into the
solid form without at any time appearing in the liquid state. Also applied to the conversion of solid to vapor
without the later return to solid state, and to a conversion directly from the vapor phase to the solid state.
5,9 Surrogate standard-a chemically inert compound (not expected to occur in the environmental sample)
that is added to each sample, blank, and matrix-spiked sample before extraction and analysis. The recovery
of the surrogate standard is used to monitor unusual matrix effects, gross sample processing errors, etc.
Surrogate recovery is evaluated for acceptance by determining whether the measured concentration falls within
acceptable limits.
5.10 CAL-calibration standards are defined as five levels of calibration: CAL 1, CAL 2, CAL 3, CAL 4, and
CAL 5. CAL 1 is the lowest concentration and CAL 5 is the highest concentration. CAL 3, which is the mid-
level standard, is designated as the solution to be used for continuing calibrations.
5.11 Continuing calibration check-a solution of method analytes used to evaluate the mass spectrometer
response over a period of time. A continuing calibration check (CCC) is performed once each 12-hour period.
The CCC solution (CAL 3) is the standard of the calibration curve.
5.12 GC Response (AJ-the peak area or height of analyte, x.
5.13 Internal standard (IS)-a compound added to a sample extract in known amounts and used to calibrate
concentration measurements of other compounds that are sample components. The internal standard must be
a compound that is not a sample component.
6. Limitations and Interferences
6.1 Limitations
6.1.1 PAHs span a broad spectrum of vapor pressures (e.g., from 1.1 x 10"2 kPa for naphthalene to 2
x 10"13 kPa for coronene at 25 °C). PAHs that are frequently found in ambient air are listed in Table 1. Those
with vapor pressures above approximately 10"8 kPa will be present in the ambient air substantially distributed
between the gas and particulate phases. This method will permit the collection of both phases.
6.1.2 Particulate-phase PAHs will tend to be lost from the particle filter during sampling due to
volatilization. Therefore, separate analysis of the filter will not reflect the concentrations of the PAHs
originally associated with particles, nor will analysis of the sorbent provide an accurate measure of the gas
phase. Consequently, this method calls for extraction of the filter and sorbent together to permit accurate
measurement of total PAH air concentrations.
6.1.3 Naphthalene, acenaphthylene, and acenaphthene possess relatively high vapor pressures and may
not be efficiently trapped by this method when using PUF as the sorbent. The sampling efficiency for
naphthalene has been determined to be about 35 percent for PUF. The user is encouraged to use XAD-2® as
the sorbent if these analytes are part of the target compound list (TCL).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-5
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Method TO-13A PAHs
6.2 Interferences
6.2.1 Method interferences may be caused by contaminants in solvents, reagents, glassware, and other
sample processing hardware that result in discrete artifacts and/or elevated baselines in the detector profiles.
All of these materials must be routinely demonstrated to be free from interferences under the conditions of the
analysis by running laboratory reagent blanks.
6.2.2 Glassware must be scrupulously cleaned (51). All glassware should be cleaned as soon as possible
after use by rinsing with the last solvent used in it and then high-purity acetone and hexane. These rinses
should be followed by detergent washing with hot water and rinsing with copious amounts of tap water and
several portions of reagent water. The glassware should then be drained dry and heated in a muffle furnace
at 400°C for four hours. Volumetric glassware must not be heated in a muffle furnace; rather it should be
solvent rinsed with acetone and spectrographic grade hexane. After drying and rinsing, glassware should be
scaled and stored in a clean environment to prevent any accumulation of dust or other contaminants. Glassware
should be stored inverted or capped with aluminum foil.
i
[Mote: The glassware may be farther cleaned by placing in a muffle farnace at 450 °Cfor 8 hours to remove
trace organics.J
6,2.3 The use of high purity water, reagents, and solvents helps to minimize interference problems.
Purification of solvents by distillation in all-glass systems may be required.
6.2.4 Matrix interferences may be caused by contaminants that are coextracted from the sample.
Additional clean-up by column chromatography may be required (see Section 12.3).
6.2.5 During sample transport and analysis, heat, ozone, NO2, and ultraviolet (UV) light may cause
sample degradation. Incandescent or UV-shielded fluorescent lighting in the laboratory should be used during
analysis.
6.2.6 The extent of interferences that may be encountered using GC/MS techniques has. not been fully
assessed. Although GC conditions described allow for unique resolution of the specific PAH compounds
covered by this method, other PAH compounds may interfere. The use of column chromatography for sample
clcan-up prior to GC analysis will eliminate most of these interferences. The analytical system must, however,
be routinely demonstrated to be free of internal contaminants such as contaminated solvents, glassware, or other
reagents which may lead to method interferences. A laboratory reagent blank should be analyzed for each
reagent used to determine if reagents are contaminant-free.
6.2.7 Concern about sample degradation during sample transport and analysis was mentioned above.
Heat, ozone, NOj, and ultraviolet (UV) light also may cause sample degradation. These problems should be
addressed as part of the user-prepared standard operating procedure (SOP) manual. Where possible,
incandescent or UV-shielded fluorescent lighting should be used during analysis. During transport, field
samples should be shipped back to the laboratory chilled (~4°C) using blue ice/dry ice.
i
7. Safety
7.1 The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined;
however, each chemical compound should be treated as a potential health hazard. From this viewpoint,
exposure to these chemicals must be reduced to the lowest possible level by whatever means available. The
laboratory is responsible for maintaining a current awareness file of Occupational Safety and Health
Administration (OSHA) regulations regarding the safe handling of the chemicals specified in this method. A
Page 13A-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs : Method TO-13A
reference file of material safety data sheets (MSDSs) should also be made available to all personnel involved
in the chemical analysis. Additional references to laboratory safety are available and are included in the
reference list (52-54).
7.2 B[a]P has been tentatively classified as a known or suspected, human or mammalian carcinogen. Many
of the other PAHs have been classified as carcinogens. Care must be exercised when working with these
substances. This method does not purport to address all of the safety problems associated with its use. It is
the responsibility of whomever uses this method to consult and establish appropriate safety and health practices
and determine the applicability of regulatory limitations prior to use. The user should be thoroughly familiar
with the chemical and physical properties of targeted substances (see Table 1 and Figure 1).
7.3 All PAHs should be treated as carcinogens. Neat compounds should be weighed in a glove box. Spent
samples and unused standards are toxic waste and should be disposed according to regulations. Counter tops
and equipment should be regularly checked with "black light" for fluorescence as an indicator of contamination.
7.4 The sampling configuration (filter and backup sorbent) and collection efficiency for target PAHs has been
demonstrated to be greater than 95 percent (except for naphthalene, acenaphthylene and acenaphthene).
Therefore, no field recovery evaluation will be required as part of this procedure.
[Note: Naphthalene, acenaphthylene and acenaphthene have demonstrated significant breakthrough using
PUF cartridges, especially at summer ambient temperatures. If naphthalene, acenaphthylene and
acenaphthene are target PAHs, the user may want to consider replacing the PUF with XAD-2® in order to
minimize breakthrough during sampling,}
8. Apparatus
[Note: This method was developed using the PS-1 semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has experience in the 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.}
8.1 Sampling
8.1.1 High-volume sampler (see Figure 2). Capable of pulling ambient air through the filter/sorbent
cartridge at a flow rate of approximately 8 standard cubic feet per minute (scfin) (0.225 std nrVmin) to obtain
a total sample volume of greater than 300 m3 over a 24-hour period. Major manufacturers are:
• Tisch Environmental, Village ofCleves, OH
• Andersen Instruments Inc., 500 Technology Ct, Smyrna, GA
* Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
Recent EPA studies have concluded that sample volumes less than 300 m3 still collect enough PAHs on
the filter/PUF for quantitation. The user is encouraged to investigate appropriate sample volume needed to
meet project specific data quality objectives.
January 1999 Compendium of Methods far Toxic Organic Air Pollutants Page 13A-7
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Method TO-13A i | PAHs
8.1.2 Sampling module (see Figure 3). Metal filter holder (Part 2) capable of holding a 102-mm circular
particle filter supported by a 16-mesh stainless-steel screen and attaching to a metal cylinder (Part 1) capable
of holding a 65-mm O.D. (60-mm I.D.) x 125-mm borosilicate glass sorbent cartridge containing PUF or
XAD-2®, The filter holder is equipped with inert sealing gaskets (e.g., polytetrafluorethylene) placed on either
side of the filter. Likewise, inert, pliable gaskets (e.g., silicone rubber) are used to provide an air-tight seal at
each end of the glass sorbent cartridge. The glass sorbent cartridge is indented 20 mm from the lower end to
provide a support for a 16-mesh stainless-steel screen that holds the sorbent. The glass sorbent cartridge fits
into Part 1, which is screwed onto Part 2 until the sorbent cartridge is sealed between the silicone gaskets.
Major manufacturers are:
• Tisch Environmental, Village of Cleves, OH
• Andersen Instruments Inc., 500 Technology Ct, Smyrna, GA
• Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8.1.3 High-volume sampler calibrator. Capable of providing multipoint resistance for the high-volume
sampler. Major manufacturers are:
• Tisch Environmental, Village of Cleves, OH
• Andersen Instruments Inc., 500 Technology Ct., Smyrna, GA
• Thermo Environmental Instruments, Inc., 8 West Forge Parkway, Franklin, MA
8.1.4 Ice chest. To hold samples at 4°C or below during shipment to the laboratory after collection.
8.1.5 Data sheets. Used for each sample to record the location and sample time, duration of sample,
starting time, and volume of air sampled.
8.2 Sample Clean-Up and Concentration (see Figure 4),
8.2.1 Soxhlet apparatus extractor (see Figure 4a). Capable of extracting filter and sorbent cartridges
(5.75-cm x 12.5-cm length), 1,000 mL flask, and condenser, best source.
8.2.2 Pyrex glass tube furnace system. For activating silica gel at 180 °C under purified nitrogen gas
purge for an hour, with capability of raising temperature gradually, best source.
8.2.3 Glass vial. 40 mL, best source.
8.2.4 Erlenmeyer flask. 50 mL, best source.
[Note: Reuse of glassware should be minimized to avoid the risk of cross contamination. All glassware that
Is used must be scrupulously cleaned as soon as possible after use. Rinse glassware with the last solvent
used in it and then with high-purity acetone and hexane. Wash with hot water containing detergent. Rinse
with copious amounts of tap -water and several portions of distilled water. Drain, dry, and heat in a muffle
furnace at 400 "Cfor 4 hours. Volumetric glassware must not be heated in a muffle furnace; rather, it should
be rinsed with high-purity acetone and hexane. After the glassware is dry and cool, rinse it with hexane, and
store it inverted or capped with solvent-rinsed aluminum foil in a clean environment.}
8.2.5 White cotton gloves. For handling cartridges and filters, best source.
8.2.6 Minivials. 2 mL, borosilicate glass, with conical reservoir and screw caps lined with Teflon®-
faced silicone disks, and a vial holder, best source.
8.2.7 Teflon®-coated stainless steel spatulas and spoons. Best source.
Page 13A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs _ ; _ Method TO-13A
8.2.8 Kuderna-Danish (K-D) apparatus (see Figure 4b). 500 mL evaporation flask (Kontes
K-S70001-500 or equivalent), 10 mL graduated concentrator tubes (Kontes K570050-1025 or equivalent) with
ground-glass stoppers, 1 mL calibrated K-D concentration tubes, and 3-baIl macro Snyder Column (Kontes
K-570010500, K-50300-0121, and K-569001-219, or equivalent), best source.
8.2.9 Adsorption column for column chromatography (see Figure 4c). 1-cm x 10-cm with stands,
8,2.10 Glove box. For working with extremely toxic standards and reagents with explosion-proof hood
for venting fumes from solvents, reagents, etc.
8.2.11 Vacuum oven. Vacuum drying oven system capable of maintaining a vacuum at 240 torr
(flushed with nitrogen) overnight.
8.2.12 Concentrator tubes and a nitrogen evaporation apparatus with variable flow rate. Best
source.
8.2.13 Laboratory refrigerator. Best source.
8.2.14 Boiling chips. Solvent extracted, 10/40 mesh silicon carbide or equivalent, best source.
8.2.15 Water bath. Heated, with concentric ring cover, capable of ±5°C temperature control, best
source.
8.2.16 Nitrogen evaporation apparatus. Best source.
8.2.17 Glass wool. High grade, best source.
8.3 Sample Analysis
8.3.1 Gas Chromatography with Mass Spectrometry Detection Coupled with Data Processing
System (GC/MS/DS). The gas chromatograph must be equipped for temperature programming, and all
required accessories must be available, including syringes, gases, and a capillary column. The gas
chromatograph injection port must be designed for capillary columns. The use of splitless injection techniques
is recommended. On-column injection techniques can be used, but they may severely reduce column lifetime
for nonchemically bonded columns. In this protocol, a 2 ^iL injection volume is used consistently to maximize
auto sampler reproducibility. With some gas chromatograph injection ports, however, 1 jiL injections may
produce some improvement in precision and chromatographic separation. A 1 fiL injection volume may be
used if adequate sensitivity and precision can be achieved.
[Note: If 1 pL is used as the injection volume, the injection volumes for all extracts, blanks, calibration
solutions and performance check samples must be 1
All GC carrier gas lines must be constructed from stainless steel or copper tubing. Poly-tetrafluoroethylene
(PTFE) thread sealants or flow controllers should only be used.
8.3.2 Gas ehromatograph-mass spectrometer interface The GC is usually coupled directly to the MS
source. The interface may include a diverter valve for shunting the column effluent and isolating the mass
spectrometer source. All components of the interface should be glass or glass-lined stainless steel. Glass can
be deactivated by silanizing with dichorodimethylsilane. The interface components should be compatible with
320°C temperatures. Cold spots and/or active surfaces (adsorption sites) in the GC/MS interface can cause
peak tailing and peak broadening. It is recommended that the GC column be fitted directly into the MS source.
Graphite ferrules should be avoided in the gas chromatograph injection area since they may adsorb PAHs.
Vespel® or equivalent ferrules are recommended.
8.3.3 Mass spectrometer. The MS should be operated in the full range data acquisition (SCAN) mode
with atotal cycle time (including voltage reset time) of one second or less (see Section 13.3,2). Operation of
the MS in the SCAN mode allows monitoring of all ions, thus assisting with the identification of other PAHs
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-9
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Method TO-13A ; PAHs
beyond Compendium Method TO-13A target analyte list. In addition, operating in the SCAN mode assists the
analyst with identification of possible interferences from non-target analytes due to accessibility of the complete
mass spectrum in the investigative process. The MS must be capable of scanning from 35 to 500 amu every
1 sec or less, using 70 volts (nominal) electron energy in the electron impact (El) ionization mode. The mass
spectrometer must be capable of producing a mass spectrum for a 50 ng injection of decafluorotriphyenyl
phosphine (DFTPP) which meets all of the response criteria (see Section 13.3.3). To ensure sufficient
precision of mass spectral data, the MS scan rate must allow acquisition of at least five scans while a sample
compound elutes from the GC. The GC/MS system must be in a room with atmosphere demonstrated to be
free of all potential contaminants which will interfere with the analysis. The instrument must be vented outside
the facility or to a trapping system which prevents the release of contaminants into the instrument room.
8.3,4 Data system. A dedicated computer data system is employed to control the rapid multiple ion
monitoring process and to acquire the data. Quantification data (peak areas or peak heights) and multi-ion
detector (MID) traces (displays of intensities of each m/z being monitored as a function of time) must be
acquired during the analyses. Quantifications may be reported based upon computer generated peak areas or
upon measured peak heights (chart recording). The detector zero setting must allow peak-to-peak measurement
of the noise on the baseline. The computer should have software that allows searching the GC/MS data file
for ions of a specific mass and plotting such ion abundances versus time or scan number. This type of plot is
defined as Selected Ion Current Profile (SICP). The software used must allow integrating the abundance in
any SICP between specified time or scan number limits. The data system should be capable of flagging all data
files that have been edited manually by laboratory personnel.
8.3.5 Gas chromatograph column. A fused silica DB-5 column (30 m x 0.32 mm I.D.) crosslinked
5 percent phenyl methylsilicone, 1.0 um film thickness is utilized to separate individual PAHs. Other columns
may be used for determination of PAHs. Minimum acceptance criteria must be determined as per Section 13.3.
At the beginning of each 12-hour period (after mass resolution has been demonstrated) during which sample
extracts or concentration calibration solutions will be analyzed, column operating conditions must be attained
for the required separation on the column to be used for samples.
8.3.6 Balance. Mettler balance or equivalent.
8.3.7 All required syringes, gases, and other pertinent supplies. To operate the GC/MS system.
8.3.8 Pipettes, micropipettes, syringes, burets, etc. Used to make calibration and spiking solutions,
dilute samples if necessary, etc., including syringes for accurately measuring volumes such as 25 uL and
100 uL.
9. Equipment and Materials
9.1 Materials for Sample Collection (see Figure 3)
9.1.1 Quartz fiber filter. 102 millimeter binderless quartz microfiber filter, Whatman Inc., 6 Just Road,
Fairfield, NJ 07004, Filter Type QMA-4.
9.1.2 Polyurethane foam (PUF) plugs (see Figure 5a), 3-inch thick sheet stock polyurethane type
(density .022 g/cm3). The PUF should be of the polyether type used for furniture upholstery, pillows, and
mattresses. The PUF cylinders (plugs) should be slightly larger in diameter than the internal diameter of the
cartridge. Sources of equipment are Tisch Environmental, Village of Cleves, OH; University Research
Glassware, 116 S. Merritt Mffl Road, Chapel Hill, NC; Thermo Environmental Instruments, Inc., 8 West Forge
Parkway, Franklin, MA; Supelco, Supelco Park, Bellefonte, PA; and SKC Inc., 334 Valley View Road, Eighty
Four, PA.
Page 13A-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
9.1.3 XAD-2® resin (optional). Supelco, Supelco Park, Bellefonte, PA.
9.1.4 Teflon® end caps (see Figure Sa). For sample cartridge; sources of equipment are Tisch
Environmental, Village of Cleves, OH; and University Research Glassware, 116 S. Merritt Mill Road, Chapel
Hill, NC.
9.1.5 Sample cartridge aluminum shipping containers (see Figure 5b). For sample cartridge
shipping; sources of equipment are Tisch Environmental, Village of Cleves, OH; and University Research
Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC.
9.1.6 Glass sample cartridge (see Figure Sa). For sample collection; sources of equipment are Tisch
Environmental, Village of Cleves, OH; Thermo Environmental Instruments, Inc., 8 West Forge Parkway,
Franklin, MA; and University Research Glassware, 116 S. Merritt Mill Road, Chapel Hill, NC.
9.1.7 Aluminum foil. Best source.
9.1.8 Hexane, reagent grade. Best source.
9.2 Sample Clean-up and Concentration
9.2.1 Methylene chloride (extraction solvent for XAD-2®; optional). Chromatographic grade, glass-
distilled, best source.
9.2.2 Sodium sulfate-anhydrous (ACS), Granular (purified by washing with methylene chloride
followed by heating at 400 °C for 4 hours in a shallow tray).
9.2.3 Boiling chips. Solvent extracted or heated in a muffle furnace at 450 °C for 2 hours,
approximately 10/40 mesh (silicon carbide or equivalent).
9.2.4 Nitrogen. High purity grade, best source.
9,2.5 Hexane. Chromatographic grade, glass-distilled, best source (extraction solvent for PUF).
9.2.6 Glass wool. Silanized, extracted with methylene chloride and hexane, and dried.
9.2.7 Diethyl ether. High purity, glass distilled (extraction solvent for PUF).
9.2.8 Pentane. High purity, glass distilled.
9.2.9 Silica gel. High purity, type 60, 70-230 mesh.
9.3 GC/MS Sample Analysis
9.3.1 Gas cylinder of helium. Ultra high purity, best source.
9.3.2 Chromatographic-grade stainless steel tubing and stainless steel fitting. For interconnections,
Alltech Applied Science, 2051 Waukegan Road, Deerfield, IL 60015, 312-948-8600, or equivalent.
[Note: All such materials in contact with the sample, analyte, or support gases prior to analysis should be
stainless steel or other inert metal. Do not use plastic or Teflon® tubing or fittings.]
9.3.3 Native and isotopically labeled PAH isomers for calibration and spiking standards.
Cambridge Isotopes, 20 Commerce Way, Wobum, MA 01801 (617-547-1818). Suggested isotopically labeled
PAH isomers are; D,0-fluoranthene, D,2-benzo(a)pyrene, D10-fluorene, D,0-pyrene, D12-perylene,
D10-acenaphthene, D12-chrysene, Dg-naphthalene and D!0-phenanthrene.
9.3.4 Decafluorotriphenylphosphine (DFTPP). Used for tuning GC/MS, best source.
9.3.5 Native stock pure standard PAH analytes. For developing calibration curve for GC/MS
analysis, best source.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-11
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Method TO-13A PAHs
10. Preparation of PUF Sampling Cartridge
[Note: This method was developed using the PS-1 sample cartridge provider by General Metal Works,
Village ofCleves, OH 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,]
10.1 Summary of Method
10.1.1 This part of the procedure discusses pertinent information regarding the preparation and cleaning
of the filter, sorbent, and filter/sorbent cartridge assembly. The separate batches of filters and sorbents are
extracted with the appropriate solvent.
10.1,2 At least one PUF cartridge assembly and one filter from each batch, or 10 percent of the batch,
whichever is greater, should be tested and certified before the batch is considered for field use.
10.1.3 Prior to sampling, the cartridges are spiked with field surrogate compounds.
10.2 Preparation of Sampling Cartridge
10.2.1 Bake the Whatman QMA-4 quartz filters at 400°C for 5 hours before use,
10.2.2 Set aside the filters in a clean container for shipment to the field or prior to combining with the
PUF glass cartridge assembly for certification prior to field deployment.
10.2.3 The PUF plugs are 6.0-cm diameter cylindrical plugs cut from 3-inch sheet stock and should fit,
with slight compression, in the glass cartridge, supported by the wire screen (see Figure 5a). During cutting,
rotate tlw die at high speed (e.g., in a drill press) and continuously lubricate with deiorazed or distilled water,
Pre-cleaned PUF plugs can be obtained from commercial sources (see Section 9.1.2).
10.2.4 For initial cleanup, place the PUF plugs in a Soxhlet apparatus and extract with acetone for
16 hours at approximately 4 cycles per hour. When cartridges are reused, use diethyl ether/hexane (5 to
10 percent volume/volume [v/v]) as the cleanup solvent.
[Note: A modified PUF cleanup procedure can be used to remove unknown interference components of the
PUF blank This method consists of rinsing 50 times with toluene, acetone, and diethyl ether/hexane (5 to
10 percent v/v), followed by Soxhlet extraction. The extracted PUF is placed in a vacuum oven connected
to a water aspirator and dried at room temperature for approximately 2 to 4 hours (until no solvent odor
is detected). The extract from the Soxhlet extraction procedure from each batch may be analyzed to
determine Initial cleanliness prior to certification.]
10.2.5 If using XAD-2® in the cartridge, initial cleanup of the resin is performed by placing
approximately 50-60 grams in a Soxhlet apparatus and extracting with methylene chloride for 16 hours at
approximately 4 cycles per hour. At the end of the initial Soxhlet extraction, the spent methylene chloride is
discarded and replaced with a fresh reagent. The XAD-2® resin is once again extracted for 16 hours at
approximately 4 cycles per hour. The XAD-2® resin is removed from the Soxhlet apparatus, placed in a
vacuum oven connected to an ultra-pure nitrogen gas stream, and dried at room temperature for approximately
2-4 hours (until no solvent odor is detected).
Page 13A-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
10.2,6 Fit a nickel or stainless steel screen (mesh size 200/200) to the bottom of a hexane-rinsed glass
sampling cartridge to retain the PUF or XAD-2® sorbents, as illustrated in Figure 5a. If using XAD-2® alone,
then place a small diameter (—1/4") PUF plug on top of the nickel or stainless steel screen to retain the
XAD-2® in the glass cartridge. Place the Soxhlet-extracted, vacuum-dried PUF (2,5-cm thick by 6.5-cm
diameter) on top of the screen in the glass sampling cartridge using polyester gloves. Place ~200 g of the clean
XAD-2® inside the glass sampling cartridge on top of the small diameter PUF plug.
10,2.7 Wrap the sampling cartridge with hexane-rinsed aluminum foil, cap with the Teflon® end caps
(optional), place in a cleaned labeled aluminum shipping container, and seal with Teflon® tape. Analyze at
least 1 cartridge from each batch of cartridges prepared using the procedure described in Section 10.3, before
the batch is considered acceptable for field use.
The acceptance level of the cartridge is for each target PAH analyte to be less than or equal to the
detection limit requirements to meet the project data quality objectives. It is generally not possible to eliminate
the presence of naphthalene, but the amount detected on the cleaned PUF cartridge should be less than five
times the concentration of the lowest calibration standard (~500 ng). This amount is insignificant compared
to the amount collected from a typical air sample.
In general, the following guidelines are provided in determining whether a cartridge is clean for field use:
• Naphthalene <500 ng/cartridge
• Other PAHs <200 ng total/cartridge
10.3 Procedure for Certification of PUF Cartridge Assembly
[Note: The following procedure outlines the certification of a filter and PUF cartridge assembly. If using
XAD-2® as the sorbent, the procedure remains the same, except the solvent is methylene chloride rather than
10 percent diethyl ether/hexane.]
10.3.1 Extract one filter and PUF sorbent cartridge by Soxhlet extraction and concentrate using a K-D
evaporator for each lot of filters and cartridges sent to the field.
10.3.2 Assemble the Soxhlet apparatus. Charge the Soxhlet apparatus (see Figure 4a) with 700 mL of
the extraction solvent (10 percent v/v diethyl ether/hexane) and reflux for 2 hours. Let the apparatus cool,
disassemble it, and discard the used extraction solvent. Transfer the filter and PUF glass cartridge to the
Soxhlet apparatus (the use of an extraction thimble is optional).
[Note: The filter and sorbent assembly are tested together in order to reach detection limits, to minimize
cost and to prevent misinterpretation of the data. Separate analyses of the filter and PUF would not yield
usejul information about the physical state of most of the PAHs at the time of sampling due to evaporative
losses from the filter during sampling.]
10.3,3 Add between 300 and 350 mL of diethyl ether/hexane (10 percent v/v) to the Soxhlet apparatus.
Reflux the sample for 18 hours at a rate of at least 3 cycles per hour. Allow to cool, then disassemble the
apparatus.
10.3.4 Assemble a K-D concentrator (see Figure 4b) by attaching a 10-mL concentrator tube to a
500-mL evaporative flask.
10.3.5 Transfer the extract by pouring it through a drying column containing about 10 cm of anhydrous
granular sodium sulfate (see Figure 4c) and collect the extract in the K-D concentrator. Rinse the Erlenmeyer
flask and column with 20 to 30 mL of 10 percent diethyl ether/hexane to complete the quantitative transfer.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-13
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Method TO-13A ; PAHs
l
10.3.6 Add one or two clean boiling chips and attach a 3-ball Snyder column to the evaporative flask.
Pro-wet the Snyder column by adding about 1 mL of the extraction solvent to the top of the column. Place the
K-D apparatus on a hot water bath (~50°C) so that the concentrator tube is partially immersed in the hot water,
and the entire lower rounded surface of the flask is bathed with hot vapor. Adjust the vertical position of the
apparatus and the water temperature as required to complete the concentration in 1 hour. At the proper rate
of distillation, the balls of the column will actively chatter, but the chambers will not flood with condensed
solvent. When the apparent volume of liquid reaches approximately 5 mL, remove the K-D apparatus from
the water bath and allow it to drain and cool for at least 5 minutes. Remove the Snyder column and rinse the
flask and its lower joint into the concentrator tube with 5 mL of cyclohexane. A 1-mL syringe is recommended
for this operation.
10.3.7 Concentrate the extract to 5 mL and analyze using GC/MS.
10.3.8 The acceptance level of the cartridge is for each target PAH analyte to be less than or equal to
the detection limit requirements to meet the project data qulity objectives. It is generally not possible to
eliminate the presence of naphthalene, but the amount detected on the cleaned PUF cartridge should be less than
five times the concentration of the lowest calibration standard (—500 ng). This amount is insignificant
compared to the amount collected from a typical air sample.
In general, the following guidelines are provided in determining whether a cartridge is clean for field use:
« Naphthalene <500 ng/cartridge
• Other PAHs <200 ng total/cartridge
Cartridges are considered clean for up to 30 days from date of certification when sealed in their containers.
i •[
10.4 Deployment of Cartridges for Field Sampling
10.4.1 Immediately prior to field deployment, add surrogate compounds (i.e., chemically inert
compounds not expected to occur in an environmental sample) to the center of the PUF cartridge, using a
microsyringe. Spike 20 /^L of a 50 ^g/mL solution of the surrogates onto the center bed of the PUF trap to
yield a final concentration of 1 //g. The surrogate compounds must be added to each cartridge assembly. The
following field surrogate compounds should be added to each PUF cartridge prior to field deployment to
monitor matrix effects, breakthrough, etc.
Field Surrogate Compound Total Spiked Amount (^.g)
1 |
D10-Fluoranthene 1
D|2-Benzo(a)pyrene 1
Fill out a "chain-of-custody" indicating cartridge number, surrogate concentration, date of cartridge
certification, etc. The chain-of-custody must accompany the cartridge to the field and return to the laboratory.
10.4.2 Use the recoveries of the surrogate compounds to monitor for unusual matrix effects and gross
sample processing errors. Evaluate surrogate recovery for acceptance by determining whether the measured
concentration falls within the acceptance limits of 60-120 percent.
10.4.3 Cartridges are placed in their shipping containers and shipped to the field. Blank cartridges do not
need to be chilled when shipping to the field until after exposure to ambient air.
Page 13A-14 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
11. Assembly, Calibration, and Collection Using Sampling System
[Note: This method was developed using the PS-1 semi-volatile sampler provided by General Metal Works,
Village ofCleves, OH as a guideline. EPA has experience in the 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.]
11.1 Sampling Apparatus
The entire sampling system is diagrammed in Figure 2. This apparatus was developed to operate at a rate of
4 to 10 scfrn (0.114 to 0.285 std m3/min) and is used by EPA for high-volume sampling of ambient air. The
method write-up presents the use of this device.
The sampling module (see Figure 3) consists of a filter and a glass sampling cartridge containing the PDF
utilized to concentrate PAHs from the air. A field portable unit has been developed by EPA (see Figure 6).
11.2 Calibration of Sampling System
Each sampler should be calibrated (1) when new, (2) after major repairs or maintenance, (3) whenever any
audit point deviates from the calibration curve by more than 7 percent, (4) before/after each sampling event,
and (5) when a different sample collection medium, other than that which the sampler was originally calibrated
to, will be used for sampling.
11.2.1 Calibration of Orifice Transfer Standard. Calibrate the modified high volume air sampler in the
field using a calibrated orifice flow rate transfer standard. Certify the orifice transfer standard in the laboratory
against a positive displacement rootsmeter (see Figure 7). Once certified, the recertification is performed rather
infrequently if the orifice is protected from damage. Recertify the orifice transfer standard performed once per
year utilizing a set of five multi-hole resistance plates.
[Note: The set of five multihole resistance plates is used to change the flow through the orifice so that
several points can be obtained for the orifice calibration curve. The following procedure outlines the steps
to calibrate the orifice transfer standard in the laboratory.]
11.2.1.1 Record the room temperature (Tj in °C) and barometric pressure (Pb in mm Hg) on the Orifice
Calibration Data Sheet (see Figure 8). Calculate the room temperature in K (absolute temperature) and record
on Orifice Calibration Data Sheet.
T,inK = 273°+T, in °C
11.2.1.2 Set up laboratory orifice calibration equipment as illustrated in Figure 7. Check the oil level
of the rootsmeter prior to starting. There are three oil level indicators, one at the clear plastic end, and two
sight glasses, one at each end of the measuring chamber.
11.2.1.3 Check for leaks by clamping both manometer lines, blocking the orifice with cellophane tape,
turning on the high-volume motor, and noting any change in the rootsmeter's reading. If the rootsmeter's
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-15
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Method TO-13A _ PAHs
reading changes, there is a leak in the system. Eliminate the leak before proceeding. If the rootsmeter's reading
remains constant, turn off the hi-vol motor, remove the cellophane tape, and unclamp both manometer lines,
1 1.2.1.4 Install the 5-hole resistance plate between the orifice and the filter adapter.
11.2.1.5 Turn manometer tubing connectors one turn counter-clockwise. Make sure all connectors are
open. ''
11.2.1.6 Adjust both manometer midpoints by sliding their movable scales until the zero point
corresponds with the meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on
tubing connectors. (If additional liquid is required for the water manometer, remove tubing connector and add
clean water.)
1 1.2.1.7 Turn on the high-volume motor and let it run for 5 minutes to set the motor brushes. Turn the
motor off. Ensure manometers are set to zero. Turn the high-volume motor on.
11.2.1.8 Record the time in minutes required to pass a known volume of air (approximately 5.6 to 8.4 m3
of air for each resistance plate) through the rootsmeter by using the rootsmeter's digital volume dial and a
stopwatch.
11.2.1.9 Record both manometer readings [orifice water manometer (AH) and rootsmeter mercury
manometer (aP)] on Orifice Calibration Data Sheet (see Figure 8).
[Note: &H is (he sum of (he difference from zero (0) of the two column heights J
11.2.1.10 Turn off the high-volume motor.
1 1.2.1.1 1 Replace the 5-hole resistance plate with the 7-hole resistance plate.
11.2.1.12 Repeat Sections 11.2.1.3 through 11.2.1.11.
11.2.1.13 Repeat for each resistance plate. Note results on Orifice Calibration Data Sheet (see
Figure 8). Only a minute is needed for warm-up of the motor. Be sure to tighten the orifice enough to
eliminate any leaks. Also check the gaskets for cracks.
(Note; The placement of the orifice prior to the rootsmeter causes the pressure at the inlet of the rootsmeter
to be reduced below atmospheric conditions, thus causing (he measured volume to be incorrect. The volume
measured by the rootsmeter must be corrected, J
1 1.2.1.14 Correct the measured volumes on the Orifice Calibration Data Sheet:
V = V ( * _ ¥ _ — 1
vsld vm V A /
P - iP T
std
where:
V^, = standard volume, std m3
Vm = actual volume measured by the rootsmeter, m3
P. = barometric pressure during calibration, mm Hg
&P = differential pressure at inlet to volume meter, nun Hg
P*d ~ 760 mm Hg
T«d= 298 K
T, = ambient temperature during calibration, K.
11.2.1.15 Record standard volume on Orifice Calibration Data Sheet.
Page 13A-16 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
11.2,1.16 The standard flow rate as measured by the rootsmeter can now be calculated using the
following formula:
St Q
where:
Qsld = standard volumetric flow rate, std rrvVmin
6 - elapsed time, min
11.2.1.17 Record the standard flow rates to the nearest 0.01 std m3/min.
11.2.1.18 Calculate and record ./AH (P1/Pstd)(298/T1) value for each standard flow rate.
11.2.1.19 Plot each JAM. (P1/Pstd)(298/T1) value (y-axis) versus its associated standard flow rate
(x-axis) on arithmetic graph paper and draw a line of best fit between the individual plotted points.
[Note: This graph will be used in the fie Id to determine standard flow rate.]
11.2.2 Calibration of the High-Volume Sampling System Utilizing Calibrated Orifice Transfer
Standard
For this calibration procedure, the following conditions are assumed in the field:
• The sampler is equipped with an valve to control sample flow rate.
• The sample flow rate is determined by measuring the orifice pressure differential using a Magnehelic
gauge.
• The sampler is designed to operate at a standardized volumetric flow rate of 8 fP/min (0.225 mVmin),
with an acceptable flow rate range within 10 percent of this value.
• The transfer standard for the flow rate calibration is an orifice device. The flow rate through the orifice
is determined by the pressure drop caused by the orifice and is measured using a "U" tube water
manometer or equivalent.
• The sampler and the orifice transfer standard are calibrated to standard volumetric flow rate units (scfiti
or scmm).
* An orifice transfer standard with calibration traceable to NIST is used.
• A "U" tube water manometer or equivalent, with a 0- to 16-inch range and a maximum scale division
of 0.1 inch, will be used to measure the pressure in the orifice transfer standard.
» A Magnehelic gauge or equivalent with a 9- to 100-inch range and a minimum scale division of 2 inches
for measurements of the differential pressure across the sampler's orifice is used.
• A thermometer capable of measuring temperature over the range of 32 ° to 122 °F (0 ° to 50 °C) to ±2 °F
(±1 °C) and referenced annually to a calibrated mercury thermometer is used.
* A portable aneroid barometer (or equivalent) capable of measuring ambient barometric pressure between
500 and 800 mm Hg (19.5 and 31.5 in. Hg) to the nearest mm Hg and referenced annually to a
barometer of known accuracy is used.
• Miscellaneous handtools, calibration data sheets or station log book, and wide duct tape are available.
11.2.2.1 Set up the calibration system as illustrated in Figure 9. Monitor the airflow through the
sampling system with a venturi/Magnehelic assembly, as illustrated in Figure 9. Audit the field sampling
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-17
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Method TO-13A PAHs
system once per quarter using a flow rate transfer standard, as described in the EPA High-Volume Sampling
Method, 40 CVR SO, Appendix B, Perform a single-point calibration before and after each sample collection,
using the procedures described in Section 11.2.3.
11.2.2.2 Prior to initial multi-point calibration, place an empty glass cartridge in the sampling head and
activate the sampling motor. Fully open the flow control valve and adjust the voltage variator so that a sample
flow rate corresponding to 110 percent of the desired flow rate (typically 0.20 to 0.28 m3/min) is indicated on
the Magnehelic gauge (based on the previously obtained multipoint calibration curve). Allow the motor to
warm up for 10 min and then adjust the flow control valve to achieve the desire flow rate. Turn off the
sampler. Record the ambient temperature and barometric pressure on the Field Calibration Data Sheet (see
Figure 10).
11.2.2.3 Place the orifice transfer standard on the sampling head and attach a manometer to the tap on
the transfer standard, as illustrated in Figure 9. Properly align the retaining rings with the filter holder and
secure by tightening the three screw clamps. Connect the orifice transfer standard by way of the pressure tap
to a manometer using a length of tubing. Set the zero level of the manometer or Magnehelic. Attach the
Magnehelic gauge to the sampler venturi quick release connections. Adjust the zero (if needed) using the zero
adjust screw on face of the gauge.
11.2,2.4 To leak test, block the orifice with a rubber stopper, wide duct tape, or other suitable means.
Seal the pressure port with a rubber cap or similar device. Turn on the sampler.
Caution: Avoid running the sampler for too long 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 life of the motor,
11.2.2.5 Gently rock the orifice transfer standard and listen for a whistling sound that would indicate
a Iqak in the system. A leak-free system will not produce an upscale response on the sampler's magnehelic.
Leaks are usually caused either by damaged or missing gaskets, by cross-threading, and/or not screwing sample
cartridge together tightly. All leaks must be eliminated before proceeding with the calibration. When the
sample is determined to be leak-free, turn off the sampler and unblock the orifice. Now remove the rubber
stopper or plug from the calibrator orifice.
11.2.2.6 Turn the flow control valve to the fully open position and turn the sampler on. Adjust the flow
control valve until a Magnehelic reading of approximately 70 in. is obtained. Allow the Magnehelic and
manometer readings to stabilize and record these values on the orifice transfer Field Calibration Data Sheet
(sec Figure 10).
11.2.2.7 Record the manometer reading under Yl and the Magnehelic reading under Y2 on the Field
Calibration Data Sheet. For the first reading, the Magnehelic should still be at 70 inches as set above.
11.2.2.8 Set the Magnehelic to 60 inches by using the sampler's flow control valve. Record the
manometer (Yl) and Magnehelic (Y2) readings on the Field Calibration Data Sheet (see Figure 10).
11.2.2.9 Repeat the above steps using Magnehelie settings of 50, 40, 30, 20, and 10 inches.
11.2.2.10 Turn the voltage variator to maximum power, open the flow control valve, and confirm that
the Magnehelic reads at least 100 inches. Turn off the sampler and confirm that the Magnehelic reads zero.
11.2.2.11 Read and record the following parameters on the Field Calibration Data Sheet. Record the
following on the calibration data sheet:
* Data, job number, and operator's signature.
• Sampler serial number.
« Ambient barometric pressure.
* Ambient temperature.
Page 13A-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs : Method TO-13A
11.2.2.12 Remove the "dummy" cartridge and replace with a sample cartridge.
11.2.2.13 Obtain the manufacturer high volume orifice calibration certificate.
11.2.2.14 If not performed by the manufacturer, calculate values for each calibrator orifice static
pressure (Column 6, inches of water) on the manufacturei's calibration certificate using the following equation:
^/AH(P/760)[298/(Ta + 273)]
where:
Pa = the barometric pressure (mm Hg) at time of manufacturer calibration, mm Hg
Ta = temperature at time of calibration, °C
11.2.2.15 Perform a linear regression analysis using the values in Column 7 of the manufacturer's High
Volume Orifice Calibration Certificate for flow rate (Qstd) as the "X" values and the calculated values as the
Y values. From this relationship, determine the correlation (CC1), intercept (Bl), and slope (Ml) for the
Orifice Transfer Standard.
11.2.2.16 Record these values on the Field Calibration Data Sheet (see Figure 10).
11.2.2.17 Using the Field Calibration Data Sheet values (see Figure 10), calculate the Orifice
Manometer Calculated Values (Y3) for each orifice manometer reading using the following equation:
Y3 Calculation
Y3 = (Yl(P/760)[298/(Ta + 273)]}1-4
11.2.2,18 Record the values obtained in Column Y3 on the Field Calibration Data Sheet (see Figure 10).
11.2.2.19 Calculate the Sampler Magnehelic Calculated Value (Y4) using the following equation:
Y4 Calculation
Y4 = {Y2(P/760)[298/
-------
Method TO-13A PAHs
11.2.2.24 Using the following equation, calculate a set point (SP) for the manometer to represent a
desired flow rate:
Set Point
Set point (SP) = [(Expected PJ/fBxpected Ta)(Tstd/P!itd)][M2 (Desired flow rate) + B2]2
where:
P, = Expected atmospheric pressure (PJ, mm Hg
T, = Expected atmospheric temperature (TJ, 273 + °C
M2 = Slope of developed relationship
B2 = Intercept of developed relationship
T.KJ = Temperature standard, 273 + 25 °C
P*d = Pressure standard, 760 mm Hg
11.2.2.25 During monitoring, calculate a flow rate from the observed Magnehelic reading using the
following equations:
I
FlowRate
Y5 = [Average Magnehelic Reading (AH) (P/TJ(Tst/PsUj)]V4
Y5 - B2
X2 =
M2
where:
. Y5 = Corrected average magnehelic reading
X2 = Instant calculated flow rate, scm
11.2.2.26 The relationship in calibration of a sampling system between Orifice Transfer Standard and
flow rate through the sampler is illustrated in Figure 11.
11.2.3 Single-Point Audit of the High Volume Sampling System Utilizing Calibrated Orifice Transfer
Standard
Single point calibration cheeks are required as follows:
• Prior to the start of each 24-hour test period.
* After each 24-hour test period. The post-test calibration check may serve as the pre-test calibration
check for the next sampling period if the sampler is not moved.
• Prior to sampling after a sample is moved.
Page 13A-20 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
For samplers, perform a calibration check for the operational flow rate before each 24-hour sampling event
and when required as outlined in the user quality assurance program. The purpose of this check is to track the
sampler's calibration stability. Maintain a control chart presenting the percentage difference between a
sampler's indicated and measured flow rates. This chart provides a quick reference of sampler flow-rate drift
problems and is useful for tracking the performance of the sampler. Either the sampler log book or a data sheet
will be used to document flow-check information. This information includes, but is not limited to, sampler and
orifice transfer standard serial number, ambient temperature, pressure conditions, and collected flow-check
data.
In this subsection, the following is assumed:
• The flow rate through a sampler is indicated by the orifice differential pressure;
» Samplers are designed to operate at an actual flow rate of 8 scfin, with a maximum acceptable flow-rate
fluctuation range of ±10 percent of this value;
• The transfer standard will be an orifice device equipped with a pressure tap. The pressure is measured
using a manometer; and
« The orifice transfer standard's calibration relationship is in terms of standard volumetric flow rate (Qstd).
11.2.3.1 Perform a single point flow audit check before and after each sampling period utilizing the
Calibrated Orifice Transfer Standard (see Section 11.2.1).
11.2.3.2 Prior to single point audit, place a "dummy" glass cartridge in the sampling head and activate
the sampling motor. Fully open the flow control valve and adjust the voltage variator so that a sample flow
rate corresponding to 110 percent of the desired flow rate (typically 0.19 to 0.28 nrYmin) is indicated on the
Magnehelic gauge (based on the previously.obtained multipoint calibration curve). Allow the motor to warm
up for 10 minutes and then adjust the flow control valve to achieve the desired flow rate. Turn off the sampler.
Record the ambient temperature and barometric pressure on the Field Test Data Sheet (see Figure 12).
11.2.3.3 Place the flow rate transfer standard on the sampling head.
11.2.3.4 Properly align the retaining rings with the filter holder and secure by tightening the three screw
clamps. Connect the flow rate transfer standard to the manometer using a length of tubing.
11.2.3.5 Using tubing, attach one manometer connector to the pressure tap of the transfer standard.
Leave the other connector open to the atmosphere.
11.2.3.6 Adjust the manometer midpoint by sliding the movable scale until the zero point corresponds
with the water meniscus. Gently shake or tap to remove any air bubbles and/or liquid remaining on tubing
connectors. (If additional liquid is required, remove tubing connector and add clean water.)
11.2.3.7 Turn on the high-volume motor and let run for 5 minutes.
11.2.3.8 Record the pressure differential indicated, AH, in inches of water, on the Field Test Data Sheet.
Be sure a stable AH has been established.
11.2.3.9 Record the observed Magnehelic gauge reading in inches of water on the Field Test Data Sheet.
Be sure stable AM has been established.
11.2.3.10 Using previous established Orifice Transfer Standard curve, calculate Q^ (see
Section 11.2.2.23).
11.2.3.11 This flow should be within ±10 percent of the sampler set point, normally, 0.224 m3. If not,
perform a new multipoint calibration of the sampler.
11.2.3.12 Remove flow rate transfer standard and dummy sorbent cartridge.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-21
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Method TO-13A | PAHs
11.3 Sample Collection
11.3,1 General Requirements
11.3.1.1 The sampler should be located in an unobstructed area, at least 2 meters from any obstacle to
air flow. The exhaust hose should be stretched out in the downwind direction to prevent recycling of air into
the sample head.
11,3.1.2 All cleaning and sample module loading and unloading should be conducted in a controlled
environment, to minimize any chance of potential contamination.
11.3.1.3 When new or when using the sampler at a different location, all sample contact areas need to
be cleaned. Use triple rinses of reagent grade hexane or methylene chloride contained in Teflon® rinse bottles.
Allow the solvents to evaporate before loading the PUF modules.
11.3.2 Preparing Cartridge for Sampling
11.3.2.1 Detach the lower chamber of the cleaned sample head. While wearing disposable, clean, lint-
free nylon, or cotton gloves, remove a clean glass sorbent module from its shipping container. Remove the
TcflonD end caps (if applicable). Replace the end caps in the sample container to be reused after the sample
has been collected.
11.3.2.2 Insert the glass module into the lower chamber and tightly reattach the lower chambers to the
module.
11.3.2.3 Using clean rinsed (with hexane) Teflon®-tipped forceps, carefully place a clean conditioned
fiber filter atop the filter holder and secure in place by clamping the filter holder ring over the filter. Place the
aluminum protective cover on top of the cartridge head. Tighten the 3 screw clamps. Ensure that all module
connections are tightly assembled. Place a small piece of aluminum foil on the ball-joint of the sample
cartridge to protect from back-diffusion of semi-volatiles into the cartridge during transporting to the site.
[Note; Failure to do so could expose the cartridge to contamination during transport.]
11.3.2.4 Place the cartridge in a carrying bag to take to the sampler.
11.3.3 Collection
11.3.3.1 After the sampling system has been assembled, perform a single point flow check as described
in Sections 11.2.3.
11.3.3.2 With the empty sample module removed from the sampler, rinse all sample contact areas using
reagent grade hexane in a Teflon® squeeze bottle. Allow the hexane to evaporate from the module before
loading the samples.
11.3.3.3 With the sample cartridge removed from the sampler and the flow control valve fully open, turn
the pump on and allow it to warm-up for approximately 5 minutes.
11.33.4 Attach a "dummy" sampling cartridge loaded with the exact same type of filter and PUF media
to be used for sample collection.
11.3.3.S Turn the sampler on and adjust the flow control valve to the desired flow as indicated by the
Magnehelic gauge reading determined in Section 11.2.2.24. Once the flow is properly adjusted, take extreme
care not to inadvertently alter its setting.
11.3.3.6 Turn the sampler off and remove the "dummy" module. The sampler is now ready for field use.
11.3.3.7 Check the zero reading of the sampler Magnehelic. Record the ambient temperature,
barometric pressure, elapsed time meter setting, sampler serial number, filter number, and PUF cartridge
number on the Field Test Data Sheet (see Figure 12). Attach the loaded sampler cartridge assembly to the
sampler.
Page 13A-22 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
11,3,3.8 Place the voltage variator and flow control valve at the settings used in Section 11.3.2, and the
power switch. Activate the elapsed time meter and record the start time. Adjust the flow (Magnehelic setting),
if necessary, using the flow control valve.
11.3.3.9 Record the Magnehelic reading every 6 hours during the sampling period. Use the calibration
factors (see Section 11.2.2.24) to calculate the desired flow rate. Record the ambient temperature, barometric
pressure, and Magnehelic reading at the beginning and during sampling period.
11.3.4 Sample Eeeovery
11,3,4.1 At the end of the desired sampling period, turn the power off. Carefully remove the sampling
head containing the filter and sorbent cartridge. Place the protective "plate" over the filter to protect the
cartridge during transport to a clean recovery area. Also, place a piece of aluminum foil around the bottom
of the sampler cartridge assembly.
11.3.4.2 Perform a final calculated sampler flow check using the calibration orifice, assembly, as
described in Section 11.3.2. If calibration deviates by more than 10 percent from initial reading, mark the flow
data for that sample as suspect and inspect and/or remove from service, record results on Field Test Data
Sheet, Figure 12.
11.3.4.3 Transport the sampler cartridge assembly to a clean recovery area.
11.3.4.4 While wearing white cotton gloves, remove the PTJF glass cartridge from the lower module
chamber and lay it on the retained aluminum foil in which the sample was originally wrapped.
11.3.4.5 Carefully remove the quartz fiber filter from the upper chamber using clean Teflon-tipped
forceps.
11.3.4.6 Fold the filter in half twice (sample side inward) and place it in the glass cartridge atop the
PUF.
11.3.4.7 Wrap the combined samples in the original hexane-rinsed aluminum foil, attach Teflon® end
caps (if applicable) and place them in their original aluminum shipping container. Complete a sample label
and affix it to the aluminum shipping container.
11.3.4.8 Chain-of-custody should be maintained for all samples. Store the containers under blue ice or
dry ice and protect from UV light to prevent possibly photo-decomposition of collected analytes. If the time
span between sample collection and laboratory analysis is to exceed 24 hours, refrigerate sample at 4°C.
11.3.4.9 Return at least one field blank filter/PUF cartridge to the laboratory with each group of
samples. Treat a field blank exactly as the sample except that air is not drawn through the filter/sorbent
cartridge assembly.
11.3.4.10 Ship and store field samples chilled (<4°C) using blue ice until receipt at the analytical
laboratory, after which samples should be refrigerated at less than or equal to 4°C for up to 7 days prior to
extraction; extracts should be analyzed within 40 days of extraction.
12. Sample Extraction, Concentration, and Cleanup
[Note: The following sample extraction, concentration, solvent exchange and analysis procedures are
outlined for user convenience in Figure 13.J
12,1 Sample Identification
12.1.1 The chilled (<4°C) samples are returned in the aluminum shipping container (containing the filter
and sorbents) to the laboratory for analysis. The "chain-of-eustody" should be completed.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-23
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Method TO-13A _ ; __ i _ PAHs
12.1.2 The samples are logged in the laboratory logbook according to sample location, filter and sorbent
cartridge number identification, and total air volume sampled (uncorrected).
12.1.3 If the time span between sample registration and analysis is greater than 24-hours, then the sample
must be kept refrigerated at <4°C. Minimize exposure of samples to fluorescent light. All samples should be
extracted within one week (7 days) after sampling.
12.2 Soxhlet Extraction and Concentration
' . i
{Note: IfPUFis the sorbent, the extraction solvent is 10 percent diethyl ether in hexane. IfXAD-2® resin
is the sorbent, the extraction solvent is methylene chloride.]
12,2.1 Assemble the Soxhlet apparatus (see Figure 4a). Immediately before use, charge the Soxhlet
apparatus with 700 to 750 mL of 10 percent diethyl ether in hexane and reflux for 2 hours. Let the apparatus
cool, disassemble it, transfer the diethyl ether in hexane to a clean glass container, and retain it as a blank for
later analysis, if required. Place the sorbent and filter together in the Soxhlet apparatus (the use of an
extraction thimble is optional).
[Note: The filter and sorbent are analyzed together in order to reach detection limits, avoid questionable
interpretation of the data, and minimize cost.]
12.2.1.1 Prior to extraction, add appropriate laboratory surrogate standards to the Soxhlet solvent. A
surrogate standard (i.e., a chemically compound not expected to occur in an environmental sample) should be
added to each sample, blank, and matrix spike sample just prior to extraction or processing. The recovery of
the laboratory surrogate standard is used to monitor for unusual matrix effects, gross sample processing errors,
etc. Surrogate recovery is evaluated for acceptance by determining whether the measure concentration falls
within the acceptance limits. Spike 20 ^L of a 50 //g/mL solution of the surrogates onto the PUF cartridge,
prior to Soxhlet extraction, to yield a final concentration of 1 ^g. The following laboratory surrogate standards
have been successfully utilized in determining Soxhlet extraction effects, sample process errors, etc., for
GC/MS/DS analysis.
Laboratory Total
Surrogate Spiked
Standard Amount (ug)
D10-Fluorene 1
1
Section 13.2 outlines preparation of the laboratory surrogates. Add the laboratory surrogate compounds to
the PUF cartridge. Add 700 mL of 10 percent diethyl ether in hexane to the apparatus and reflux for 18 hours
at a rate of at least 3 cycles per hour. Allow to cool, then disassemble the apparatus.
12.2.1,2 Dry the extract from the Soxhlet extraction by passing it though a drying column containing
about 10 grams of anhydrous sodium sulfate. Collect the dried extract in a K-D concentrator assembly. Wash
the extractor flask and sodium sulfate column with 100-125 mL of 10 percent diethyl ether/hexane to complete
the quantitative transfer.
12.2.2 Assemble a K-D concentrator (see Figure 4b) by attaching a 1 0 mL concentrator tube to a 500 mL
evaporative flask.
Page 13A-24 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs : Method TO-13A
[Note: Other concentration devices (vortex evaporator) or techniques may be used in place of the K-D as
long as qualitative and quantitative recovery can be demonstrated.]
12.2.2.1 Add two boiling chips, attach a three-ball macro-Snyder column to the K-D flask, and
concentrate the extract using a water bath at 60 to 65 °C. Place the K-D apparatus in the water bath so that
the concentrator tube is about half immersed in the water and the entire rounded surface of the flask is bathed
with water vapor. Adjust the vertical position of the apparatus and the water temperature as required to
complete the concentration in one hour. At the proper rate of distillation, the balls of the column actively
chatter but the chambers do not flood. When the liquid has reached an approximate volume of 5 mL, remove
the K-D apparatus from the water bath and allow the solvent to drain for at least 5 minutes while cooling.
12.2.2.2 Remove the Snyder column and rinse the flask and its lower joint into the concentrator tube
with 5 mL of eyclohexane. A 5 mL syringe is recommended for this operation. The extract is now ready for
further concentration to 1.0 mL by nitrogen blowdown.
12.2.2.3 Place the 1 mL calibrated K-D concentrator tube with an open micro-Snyder attachment in a
warm water bath (30 to 3 5°C) and evaporate the solvent volume to just below 1 mL by blowing a gentle
stream of clean, dry nitrogen (filtered through a column of activated carbon) above the extract.
12.2.2.4 The internal wall of the concentrator tube must be rinsed down several times with hexane
during the operation.
12.2.2.5 During evaporation, the tube solvent level must be kept below the water level of the bath, the
extract must never be allowed to become dry.
12.2.2.6 Bring the final volume back to 1.0 mL with hexane. Transfer the extract to a Teflon®-sealed
screw-cap amber vial, label the vial, and store at 4°C (±2°C).
[Note: It is not necessary to bring the volume to exactly 1.0 mL if the extract will be cleaned up by solid
phase extraction cleanup methods. Final volume is brought to LO mL after cleanup.]
12.3 Sample Cleanup
12.3.1 If the extract is cloudy, impurities may be removed from the extract by solid phase extraction using
activated silica gel. Clean-up procedures may not be needed for relatively clean matrix samples.
12.3.2 Approximately 10 grams of silica gel, type 60 (70-230 mesh), are extracted in a Soxhlet extractor
with 10 percent diethyl ether for 6 hours (minimum rate, 3 cycles/hr) and then activated by heating in a foil-
covered glass container for 16 hours at 150°C.
12.3.3 Using a disposable Pasteur pipette (7.5-rmn x 14.6-cm), place a small piece of glass wool in the
neck of the pipette. Prepare a slurry of activated silica gel in 10 percent diethyl ether. Place 10 grams of the
activated silica gel slurry into the column using additional 10 percent diethyl ether. Finally, 1 gram of
anhydrous sodium sulfate is added to the top of the silica gel. Prior to use, the column is rinsed with 10 percent
diethyl ether at 1 mL/min for 1 hour to remove any trace of contaminants. It is then pre-eluted with 40 mL of
pentane and the eluate discarded.
12.3.4 While the pentane pre-elutant covers the top of the column, 1 mL of the sample extract is
transferred to the column, and washed on with 2 mL of M-hexane to complete the transfer. Allow to elute
through the column. Immediately prior to exposure of the sodium sulfate layer the air, add 25 mL of pentane
and continue the elution process. The pentane eluate is discarded.
12.3.5 The column is finally eluted at 2 mL/min with 25 mL of 10 percent diethyl ether in pentane (4:6 v/v)
and collected in a 50 mL K-D flask equipped with a 5 mL concentrator tube for concentration to less than
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-25
-------
Method TO-13A PAHs
5 mL, The concentrate is further concentrated to 1.0 mL under a gentle stream of nitrogen as previously
described.
12.3.6 The extract is now ready for GC/MS analysis. Spike the extract with internal standards (ISs)
before analysis. The following internal standards (ISs) have been successfully used in PAH analysis by
GC/MS.
Internal Total Spiked
Standard (IS) Amount
D8-Naphthalene 0.5
D]0-Acenaphthene 0.5
D10-Phenanthrene 0,5
D]2-Chrysene 0,5
Di2-Peiylene 0.5
Section 13.2 outlines preparation of the ISs.
13. Gas Chromatography with Mass Spectrometry Detection
13.1 General
• ' !
..! i • i !
13.1.1 The analysis of the extracted sample for benzo[a]pyrene and other PAHs is accomplished by an
electron ionization gas chromatograph/mass spectrometer (El GC/MS) in the mode with a total cycle time
(including voltage reset time) of 1 second or less. The GC is equipped with an DB-5 fused silica capillary
column (30-m x 0.32-mm I.D.) with the helium carrier gas for analyte separation. The GC column is
temperature controlled and interfaced directly to the MS ion source.
13.1.2 The laboratory must document that the El GC/MS system is properly maintained through periodic
calibration checks. The GC/MS system should be operated in accordance with specifications outlined in Table
2.
13.1.3 The GC/MS is tuned using a 50 ng/uL solution of decafluorotriphenylphosphine (DFTPP). The
DFTPP permits the user to tune the mass spectrometer on a daily basis. If properly tuned, the DFTPP key ions
and ion abundance criteria should be met as outlined in Table 3.
13.1.4 The GC/MS operating conditions are outlined in Table 2. The GC/MS system should be calibrated
using the internal standard technique. Figure 14 outlines the following sequence involving the GC/MS
calibration.
13.2 Calibration of GC/MS/DS
13.2.1 Standard Preparation
Stock PAH Standards Including Surrogate Compounds
13.2.1.1 Prepare stock standards of B[a]P and other PAHs. The stock standard solution of B[a]P (2.0
jig/uL) and other PAHs can be user prepared from pure standard materials or can be purchased commercially.
13.2.1.2 Place 0.2000 grams of native B[a]P and other PAHs on a tared aluminum weighing disk and
weigh on a Mettler balance.
13.2.1.3 Quantitatively transfer the material to a 100 mL volumetric flask. Rinse the weighing disk with
several small portions of 10 percent diethyl ether/hexane. Ensure all material has been transferred.
Page 13A-26 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
13.2,1.4 Dilute to mark with 10 percent diethyl ether/hexane.
13.2.1.5 The concentration of the stock standard solution of B[a]P or other PAHs in the flask is
2.0 ug/uL.
[Note: Commercially prepared stock PAH standards may be used at any concentration if they are certified
by the manufacturer or by an independent source,]
13.2.1.6 Transfer the stock standard solutions into Teflon®-sealed screw-cap bottles. Store at 4°C and
protect from light. Stock standard solutions should be checked frequently for signs of degradation or
evaporation, especially just prior to preparing calibration standards from them.
13.2.1.7 Stock PAH standard solutions must be replaced after 1 year or sooner if comparison with
quality control check samples indicates a problem.
Mix Internal Standard (IS) Solution
13.2.1.8 For PAH analysis, deuterated internal standards are selected that are similar in analytical
behavior to the compound of interest. The following internal standards are suggested for PAH analysis:
Pn-Perylene Pn-Chrvsene
Benzo(e)pyrene Benz(a)anthracene
Benzo(a)pyrene Chrysene
Benzo(k)fluoranthene Pyrene
Dm-Acenaphthene Da-Naphthalene
Acenaphthene (if using XAD-2® as the sorbent) Naphthalene (if using XAD-2® as the
Acenaphthylene (if using XAD-2® as the sorbent) sorbent)
Fluorene
Benzo(g,h,i)perylene P,n-Phenanthrene
Dibenz(a,h)anthracene Anthracene
Indeno(l,2,3-cd)pyrene Fluoranthene
Perylene Phenanthrene
Benzo(b)fluoranthene
Coronene
13.2.1.9 Purchase a mix IS solution containing specific IS needed for quantitation at a concentration
of 2,000 n
Mixed Stock PAH Standard Including Surrogate Compounds
13.2.1.10 Prepare a mixed stock PAH standard by taking 125 uL of the stock PAH standard(s) and
diluting to mark with hexane in a 10-mL volumetric flask. The concentration of the mixed stock PAH
standard(s) is 25 ng/uL.
Calibration PAH Standards Including Surrogate Compounds
13.2.1.11 Calibration PAH standards can be generated from the stock PAH standard using serial dilution
utilizing the following equation:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-27
-------
Method TO-13APAHs
where; !
Ci = Concentration of stock PAH standards, ng/uL
Vj = Volume of stock PAH standard solution taken to make calibration PAH standards, uL
V2 = Final volume diluted to generate calibration PAH standards, jkL
C2 = Final concentration of calibration PAH standards, ng/uL
• 13.2.1.12 Using the above equation, prepare a series of calibration PAH standards which include the
surrogate compounds (i.e., 2.50 ng/nL, 1.25 ng/pL, 0.50 ng/uL, 0.25 ng/uL, and 0.10 ng/uL) according to
the scheme illustrated in Table 4 and described below.
• For CAL 5, transfer 1.00 mL of the mixed PAH stock standard in a 10-mL volumetric flask and dilute
to 10.0 mL with hexane. The resulting concentration is 2.5 ng/uL for the PAH analytes.
• To prepare CAL 4, transfer 500 uL of the mixed PAH stock standard solution to a 10-mL volumetric
flask and dilute to 10.0 mL with hexane. The resulting concentration is 1.25 ng/pL for PAH analytes.
* To prepare CAL 3, transfer 200 uL of the mixed PAH stock solution to a 10-mL volumetric flask and
dilute to 10-mL with hexane. The resulting concentration is 0.50 ng/uL for PAH analytes.
* To prepare CAL 2, transfer 100 ^L of the mixed PAH stock solution to a 10-mL volumetric flask and
dilute to 10-mL with hexane. The resulting concentration is 0.25 ng///L for PAH analytes.
* To prepare CAL 1, transfer 40 uL of the mixed PAH stock solution to a 10-mL volumetric flask and
dilute to 10-mL with hexane. The resulting concentration is 0.10 ng/uL for PAH analytes.
13.2,2 Internal Standard Spiking
13.2.2.1 Prior to GC/MS analysis, each 1 mL aliquot of the five calibration standards is spiked with
internal standard to a final concentration of 0.5 ng/uL. To do this, first prepare a 1:40 dilution of the
2,000 ng/uL mixed internal standard solution by diluting 250 \iL to a volume of 10 mL to yield a concentration
of 50 ng/uL.
13.2.2.2 Each 1.0-mL portion of calibration standard and sample extract is then spiked with 10 uL of
the internal standard solution prior to analysis by GC/MS/DS operated in the SCAN mode.
13.2.3 Storage, Handling, and Retention of Standards
13.2.3.1 Store the stock and mixed standard solutions at 4°C (±2°C) in Teflon®-lined screw-cap amber
bottles. Store the working standard solutions at 4°C (±2°C) in Teflon®-Iined screw-cap amber bottles.
13.2.3.2 Protect all standards from light. Samples, sample extracts, and standards must be stored
separately.
13.2.3.3 Stock standard solutions must be replaced every 12 months, or sooner, if comparison with
quality control check samples indicates a problem. Diluted working standards are usable for 6 months.
Analysis difficulties, which warrant investigation, may require preparation of new standards. All standards
are securely stored at ~4°C (±2°C) but above freezing. The concentration, preparation and expiration date,
and solvent are identified on standard vial labels. Each standard is uniquely identified with its laboratory
notebook number and a prefix. This procedure helps provide traceability to standard preparation.
13.2.3.4 Take care to maintain the integrity of each standard. The solvent, hexane, is volatile and can
easily evaporate. Make sure each vial is sealed after use, and mark the solvent level on the side of the vial.
When retrieving a vial for use, if the solvent level does not match the mark, dispose of the standard and obtain
a new one.
Page 13A-2S Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs ; Method TO-13A
13,3 GC/MS Instrument Operating Conditions
13.3.1 Gas Chromatograph (GQ. The following are the recommended GC analytical conditions, as also
outlined in Table 3, to optimize conditions for compound separation and sensitivity.
Carrier Gas: Helium
Linear Velocity: 28-29 cm3/sec
Injector Temperature: 250-300°C
Injector: Grob-type, splitless, 2 uL
Temperature Program: Initial Temperature: 70°C
Initial Hold Time: 4.0 ± 0.1 nun.
Ramp Rate: 10°C/min to 300°C, hold for 10 min
Final Temperature: 300°C
Final Hold Time: 10 min (or until all compounds of interest have eluted).
Analytical Time: Approximately 50 min,
13.3.2 Mass Spectrometer. Following are the required mass spectrometer conditions for scan data
acquisition:
Transfer Line Temperature: 290 °C
Source Temperature: According to manufacturer's specifications
Electron Energy: 70 volts (nominal)
lonization Mode: El
Mass Range: 35 to 500 amu, SCAN data acquisition
Scan Time: At least 5 scans per peak, not to exceed 1 second per scan
13.3.3 Instrument Performance Check for GC/MS.
13.3.3.1 Summary. It is necessary to establish that the GC/MS meet tuning and standard mass spectral
abundance criteria prior to initiating any on-going data collection, as illustrated in Figure 14. This is
accomplished through the analysis of decafluorotriphenylphosphine (DFTPP).
13.3.3.2 Frequency. The instrument performance check solution of DFTPP will be analyzed initially
and once per 12-hour time period of operation. Also, whenever the laboratory takes corrective action which
may change or affect the mass spectral criteria (e.g., ion source cleaning or repair, column replacement, etc.),
the instrument performance check must be verified irrespective of the 12-hour laboratory requirement. The
12-hour time period for GC/MS analysis begins at the injection of the DFTPP, which the laboratory submits
as documentation of a compliance tune. The time period ends after 12 hours have elapsed. To meet instrument
performance check requirements, samples, blanks, and standards must be injected within 12 hours of the
DFTPP injection.
13.3.3.3 Procedure. Inject 50 ng of DFTPP into the GC/MS system. DFTPP may be analyzed
separately or as part of the calibration standard.
13.3.3.4 Technical Acceptance Criteria. The following criteria have been established in order to
generate accurate data:
» Prior to the analysis of any samples, blanks, or calibration standards, the laboratory must establish that
the GC/MS system meets the mass spectral ion abundance criteria for the instrument performance check
solution containing DFTPP,
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-29
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Method TO-13A PAHs
« The GC/MS system must be tuned to meet the manufacturer's specifications, using a suitable calibrant.
The mass calibration and resolution of the GC/MS system are verified by the analysis of the instrument
performance check solution.
» The abundance criteria listed in Table 3 must be met for a 50 ng injection of DFTPP. The mass
spectrum of DFTPP must be acquired by averaging three scans (the peak apex scan and the scans
immediately preceding and following the apex). Background subtraction is required, and must be
accomplished using a single scan prior to the elution of DFTPP.
'. ' ?- . ; • ' : I
[Note: All ion abundance MUST be normalized to m/z 198, the nominal base peak, even though the ion
abundances of m/z 442 may be up to 110 percent of m/z 198,]
• The above criteria are based on adherence to the acquisition specifications identified in Table 4 and were
developed for the specific target compound list associated with this document. The criteria are based on
performance characteristics of instruments currently utilized in routine support of ambient air program
activities. These specifications, in conjunction with relative response factor criteria for target analytes,
are designed to control and monitor instrument performance associated with the requirements if this
document. As they are performance-based criteria for these specific analytical requirements, they may
not be optimal for additional target compounds.
• If the mass spectrometer has the ability for autotuning, then the user may utilize this function following
manufacturer's specifications. Autotune automatically adjusts ion source parameters within the detector
using FC-43 (Heptacos). Mass peaks at m/z 69, 219, and 502 are used for tuning. After the tuning is
completed, the FC-43 abundances at m/z 50, 69, 131, 219, 414, 502, and 614 are further adjusted such
that their relative intensities match the selected masses of DFTPP.
13.3.3.5 Corrective Action. If the DFTPP acceptance criteria are not met, the MS must be retimed.
It may be necessary to clean the ion source, or quadrupoles, or take other actions to achieve the acceptance
criteria. DFTPP acceptance criteria MUST be met before any standards, or required blanks, are analyzed.
Any standards, field samples, or required blanks analyzed when tuning criteria have not been met will require
reanalysis.
13,3.4 Initial Calibration for GC/MS.
13.3.4.1 Summary. Prior to the analysis of samples and required blanks, and after tuning criteria
(instrument performance check) have been met, each GC/MS system will be initially calibrated at a minimum
of five concentrations to determine instrument sensitivity and the linearity of GC/MS response for the analyte
compounds and the surrogates.
13.3.4.2 Frequency. Each GC/MS system must be initially calibrated wheneverthe laboratory takes
corrective action, vAichmay change or affect the initial calibration criteria (e.g., ion source cleaning or repair,
column replacement, etc.), or if the continuing calibration acceptance criteria have not been met. If time still
remains in the 12-hour time period after meeting the technical acceptance criteria for the initial calibration,
samples may be analyzed. It is not necessary to analyze a continuing calibration standard within the 12-hour
time period if the initial calibration standard (CAL 3) is the same concentration as the continuing calibration
standard and both meet the continuing calibration technical acceptance criteria. Quantify all sample results
using the mean of the relative response factors (RRFs) from the initial calibration.
13.3.4.3 Procedure. Perform the following activities to generate quantitative data:
- Set up the GC/MS system.
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PAHs _ ; _ Method TO-13A
• Warm all standard/spiking solutions, sample extracts, and blanks to ambient temperature (—1 hour)
before analysis,
« Tune the GC/MS system to meet the technical acceptance criteria (see Section 13.3.3).
* Prepare five calibration standards containing the target compounds, internal standards, and surrogate
compounds at the concentrations outlined in Table 4.
* Calibrate the GC/MS by injecting 2.0 uL of each standard. If a compound saturates when the CAL 5
standard is injected, and the system is calibrated to achieve a detection sensitivity of no less than the
MDL for each compound, the laboratory must document it and attach a quantitation report and
chromatogram. In this instance, the laboratory must calculate the results based on a four-point initial
calibration for the specific compound that saturates. Secondary ion quantitation is only allowed when
there are sample interferences with the primary quantitation ion. If secondary ion quantitation is used,
calculate a relative response factor using the area response from the most intense secondary ion which
is free of interferences and document the reasons for the use of the secondary ion.
• Record a mass spectrum of each target compound. Figure 15(a) through 15(q) documents the mass
spectrum for each of the 16 target PAHs discussed in Compendium Method TO-13A. Judge the
acceptability of recorded spectra by comparing them to spectra in libraries. If an acceptable spectrum
of a calibration standard component is not acquired, take necessary actions to correct GC/MS
performance. If performance cannot be corrected, report sample extract data for the particular
compound(s), but document the affected compound(s) and the nature of the problem.
13.3.4.4 Calculations. Perform the following calculations to generate quantitative data:
[Note: In the following calculations, the area response is that of the primary quantitation ion unless
otherwise stated.]
* Relative Response Factors (RRFs). Calculate RRFs for each analyte target compound and surrogate
using the following equation with the appropriate internal standard. Table 5 outlines characteristic ions
for the surrogate compounds and internal standards. Table 6 outlines primary quantitation ions for each
PAH. Use the following equation for RRF calculation.
RRF =
where:
AJJ = area of the primary quantitation ion for the compound to be measured, counts
Ajs = area of the primary quantitation ion for the internal standard, counts
Cis = concentration or amount of the internal standard, ng/uL
Cx = concentration or amount of the compound to be measured, ng/uL
• Percent Relative Standard Deviation (%RSD). Using the RRFs from the initial calibration, calculate
the %RSD for all target compounds and surrogates using the following equations:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-31
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Method T0-13A PAHs
SDRRF
%RSD = —5££ x 100
and
•sew
f (*/ ~ *?
h N -I
where:
SDRUF = standard deviation of initial response factors (per compound)
x = mean of initial relative response factors (per compound)
X,= ithRRF
N= number of determinations
• Relative Retention Times (RRT), Calculate the RRTs for each target compound and surrogate over
the initial calibration range using the following equation:
RT_
RRT =
RT:.
where:
RTC = retention time of the target compound, minutes
RTa = retention time of the internal standard, minutes
Mean of the Relative Retention Times (RRT). Calculate the mean of the relative retention times
(RRT) for each analyte target compound and surrogate over the initial calibration range using the
following equation:
» RRT.
RRT =
where:
RRT = mean relative retention time for the target compound or surrogate for each initial calibration
standard, minutes
RRT = relative retention time for the target compound or surrogate for each initial calibration standard,
minutes
j
• Mean Area Response (Y) for Internal Standard. Calculate the area response (Y) mean for primary
quantitation ion each internal standard compound over the initial calibration range using the following
equation:
Page 13A-32 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
Y = J^ —
i-i n
where:
Y = mean area response, counts
YJ = area response for the primary quantitation ion for the internal standard for each calibration
standard, counts
Mean of the Retention Time (RT) For Internal Standard, Calculate the mean of the retention times
(RT) for each internal standard over the initial calibration range using the following equation:
where:
RT = mean retention time, minutes
RT = retention time for the internal standard for each initial calibration standard, minutes
13.3,4.5 Technical Acceptance Criteria. All initial calibration standards must be analyzed at the
concentration levels at the frequency described in Section 13.3.3 on a GC/MS system meeting the DFTPP
instrument performance check criteria.
• The relative response factor (RRF) at each calibration concentration for each target compound and
surrogate that has a required minimum response factor value must be greater than or equal to the
minimum acceptable relative response factor (see Table 7) of the compound.
• The percent relative standard deviation (%RSD) over the initial calibration range for each target
compound and surrogate that has a required maximum %RSD must be less than or equal to the required
maximum value (see Table 7). For all the other target compounds, the value for %RSD must be less
than or equal to 30 percent. When the value for %RSD exceeds 30 percent, analyze additional aliquots
of appropriate CALs to obtain an acceptable %RSD of RRFs over the entire concentration range, or take
action to improve GC/MS performance.
* The relative retention time for each of the target compounds and surrogates at each calibration level must
be within ±0.06 relative retention time units of the mean relative retention time for the compound.
• The retention time shift for each of the internal standards at each calibration level must be within ±20.0
seconds compared to the mean retention time (RT) over the initial calibration range for each internal
standard.
• The compounds must meet the minimum RRF and maximum %RSD criteria for the initial calibration.
13.3.4.6 Corrective Action. If the technical acceptance criteria for initial calibration are not met, the
system should be inspected for problems. It may be necessary to clean the ion source, change the column, or
take other corrective actions to achieve the acceptance criteria. Initial calibration technical acceptance criteria
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-33
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Method TO-13A ; , ; ; PAHs
MUST be met before any samples or required blanks are analyzed in a 12-hour time period for an initial
calibration analytical sequence.
13.3.5 Continuing Calibration.
13,3.5.1 Summary. Prior to the analysis of samples and required blanks and after tuning criteria have
been met, the initial calibration of each OC/MS system must be routinely checked by analyzing a continuing
calibration standard (see Table 4, CAL 3) to ensure that the instrument continues to meet the instrument
sensitivity and linearity requirements of the method. The continuing calibration standard (CAL 3) shall contain
the appropriate target compounds, surrogates, and internal standards.
13.3.5.2 Frequency. Each GC/MS used for analysis must be calibrated once every time period of
operation. The 12-hour time period begins with injection of DFTPP. If time still remains in the 12-hour time
period after meeting the technical acceptance criteria for the initial calibration, samples may be analyzed. It
is not necessary to analyze a continuing calibration standard within this 12-hour time period, if the initial
calibration standard that is the same concentration as the continuing calibration standard meets the continuing
calibration technical acceptance criteria.
13.3.5.3 Procedure. The following activities should be performed for continuing calibration:
• Set up the GC/MS system as specified by the manufacturer.
• Tune the GC/MS system to meet the technical acceptance criteria (see Section 13.3.3).
• Analyze the CAL 3 standard solution containing all the target analytes, surrogate compounds, and
internal standards using the procedure listed for the initial calibration.
• Allow all standard/spiking solutions and blanks to warm to ambient temperature (approximately 1
hour) before preparation or analysis.
i • Start the analysis of the continuing calibration by injecting 2.0 uL of the CAL 3 standard solution.
13.3.5.4 Calculations. The following calculations should be performed:
Relative Response Factor (RRF). Calculate a relative response factor (RRF) for each target compound
and surrogate.
Percent Difference (%D). Calculate the percent difference between the mean relative response factor
(RRF) from the most recent initial calibration and the continuing calibration RRF for each analyte target
compound and surrogate using the following equation:
RRF - RRF-
%D = ^ ! x 100
RRF:
where:
%DRW = percent difference between relative response factors
j = average relative response factor from the most recent initial calibration
RRFC = relative response factor from the continuing calibration standard
l
13.3.5.5 Technical Acceptance Criteria. The continuing calibration standard must be analyzed for the
compounds listed in concentration levels at the frequency described and on a GC/MS system meeting the
DFTPP instrument performance check and the initial calibration technical acceptance criteria. The relative
response factor for each target analyte and surrogate that has a required minimum relative response factor value
Page 13A-34 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
must be greater than or equal to the compound's minimum acceptable relative response factor. For an
acceptable continuing calibration, the %D between the measured RRF for each target/surrogate compound of
the CAL 3 standard and the mean value calculated during initial calibration must be within ±30 percent. If the
criteria for %D are not met for the target or surrogate compounds, remedial action must be taken and
recalibration may be necessary.
13.3.5.6 Corrective Action. If the continuing calibration technical acceptance criteria are not met,
recalibrate the GC/MS instrument. It may be necessary to clean the ion source, change the column, or take
other corrective actions to achieve the acceptance criteria. Continuing calibration technical acceptance criteria
MUST be met before any samples or required blanks are analyzed in a 12-hour continuing calibration analytical
sequence. Any samples or required blanks analyzed when continuing calibration criteria were not met will
require reanalysis. Remedial actions, which include but are not limited to the following, must be taken if
criteria are not met:
* Check and adjust GC and/or MS operating conditions.
• Clean or replace injector liner.
• Flush column with solvent according to manufacturers instructions.
« Break off a short portion (approximately 0.33 cm) of the column.
» Replace the GC column (performance of all initial calibration procedures are then required).
• Adjust MS for greater or lesser resolution.
• Calibrate MS mass scale.
» Prepare and analyze new continuing calibration.
• Prepare a new initial calibration curve.
13.3.6 Laboratory Method Blank (LMB).
13.3.6.1 Summary. The purpose of the LMB is to monitor for possible laboratory contamination.
Perform all steps in the analytical procedure using all reagents, standards, surrogate compounds, equipment,
apparatus, glassware, and solvents that would be used for a sample analysis. An LMB is an unused, certified
filter/cartridge assembly which is carried though the same extraction procedure as a field sample. The LMB
extract must contain the same amount of surrogate compounds and internal standards that is added to each
sample. All field samples must be extracted and analyzed with an associated LMB.
13.3.6.2 Frequency. Analyze an LMB along with each batch of s20 samples through the entire
extraction, concentration, and analysis process. The laboratory may also analyze a laboratory reagent blanks
which is the same as an LMB except that no surrogate compounds or internal standards are added. This
demonstrates that reagents contain no impurities producing an ion current above the level of background noise
for quantitation ions for those compounds.
13.3.6.3 Procedure. Extract and analyze a clean, unused filter and glass cartridge assembly.
13.3.6.4 Technical Acceptance Criteria. Following are the technical criteria for the LMB:
• All blanks must be analyzed on a GC/MS system meeting the DFTPP instrument performance check
and initial calibration or continuing calibration technical acceptance criteria.
• The percent recovery for each of the surrogates in the blank must be within the acceptance windows.
» The area response change for each of the internal standards for the blank must be within -50 percent
and +100 percent compared to the internal standards in the most recent continuing calibration
analysis.
* The retention time for each of the internal standards must be within ±20.0 seconds between the blank
and the most recent CAL 3 analysis.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-35
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Method TO-I3A PAHs
* The LMB must not contain any target analyte at a concentration greater than the MDL and must not
contain additional compounds with elution characteristics and mass spectral features that would
interfere with identification and measurement of a method analyte at its MDL. If the LMB that was
extracted along with a batch of samples is contaminated, the entire batch of samples must be flagged.
13.3.6,5 Corrective Action. Perform the following if the LCBs exceed criteria:
; • If die blanks do not meet the technical acceptance criteria, the analyst must consider the analytical
system to be out of control. It is the analyst's responsibility to ensure that method interferences caused
by contaminants in solvents, reagents, glassware, and other sample storage and processing hardware
that lead to discrete artifacts and/or elevated baselines in gas chromatograms be eliminated. If
contamination is a problem, the source of the contamination must be investigated and appropriate
corrective measure MUST be taken and documented before further sample analysis proceeds.
• All samples processed with a method blank that is out of control (i.e., contaminated) will require data
qualifiers to be attached to the analytical results.
13.3.7 Laboratory Control Spike (LCS).
13.3.7.1 Summary. The purpose of the LCS is to monitor the extraction efficiency of Compendium
Method TO-ISA target analytes from a clean, uncontaminated PUF cartridge. An LCS is an unused, certified
PUF that is spiked with the target analytes (1 fj.g) and carried through the same extraction procedures as the
field samples. The LCS must contain the same amount of surrogate compounds and internal standards that
is added to each sample. All field samples must be extracted and analyzed with an associated LCS. All steps
in tlie analytical procedure must use the same reagents, standards, surrogate compounds, equipment, apparatus,
glassware, and solvents that would be used for a sample analysis.
13.3.7.2 Frequency. Analyze an LCS along with each of <20 samples through the entire extraction,
concentration, and analysis. (The laboratory may also analyze a laboratory reagent blank which is the same
as an LMB except that no surrogate compounds or internal standards are added. This demonstrates that
reagents contain no impurities producing an ion current above the level of background noise for quantitation
ions of those compounds.)
13.3.7.3 Procedure. Extract and analyze a clean, unused certified PUF cartridge assembly.
13.3.7.4 Technical Acceptance Criteria. Technical criteria for the LCS are:
« All LCSs must be analyzed on a GC/MS system meeting the DFTPP instrument performance check
and initial calibration or continuing calibration technical acceptance criteria.
• The percent recovery for each of the surrogates in the LCS must be within the acceptance windows.
• The area response change for each of the internal standards for the LCS must b~e within -50 percent
and -HOO percent compared to the internal standards in the most recent continuing calibration
analysis.
** • The retention time for each of the internal standards must be witliin ±20.0 seconds between the LCS
and the most recent CAL 3 analysis.
• All target analytes spiked on the certified PUF cartridge must meet a percent recovery between 60-120
to be acceptable.
13.3.7.5 Corrective Action. Perform the following if the LCS exceed criteria:
• If the LCS do not meet the technical acceptance criteria, the analyst must consider the analytical
system to be out of control. It is the analyst's responsibility to ensure that method interferences caused
by contaminants in solvents, reagents, glassware, and other sample storage and processing hardware
Page 13A-36 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs ; Method TO-13A
that lead to discrete artifacts and/or elevated baselines in gas chromatograms be eliminated. If
contamination is a problem, the source of the contamination must be investigated and appropriate
corrective measure MUST be taken and documented before further sample analysis proceeds.
» All samples processed with a LCS that is out of control (i.e., contaminated) will require re-analysis
or data qualifiers to be attached to the analytical results.
13.4 Sample Analysis by GC/MS
13.4.1 Summary. The sample extract is analyzed by GC/MS and quantitated by the internal standard
method.
13.4.2 Frequency. Before samples can be analyzed, the instrument must meet the GC/MS tuning and
initial calibration or continuing calibration technical acceptance criteria. If there is time remaining in the 12-
hour time period with a valid initial calibration or continuing calibration, samples may be analyzed in the
GC/MS system that meet the instrument performance check criteria.
13.4.3 Procedure. For sample analysis, perform the following:
• Set up the GC/MS system.
• All sample extracts must be allowed to warm to ambient temperature (~l hour) before analysis. All
sample extracts must be analyzed under the same instrumental conditions as the calibration standards.
* Add the internal standard spiking solution to the 1.0 mL extract. For sample dilutions, add an
appropriate amount of the internal standard spiking solution to maintain the concentration of the internal
standards at 2 ng/uX in the diluted extract.
• Inject 2.0 uJL of sample extract into the GC/MS, and start data acquisition.
• When all semi-volatile target compounds have eluted from the GC, terminate the MS data acquisition
and store data files on the data system storage device. Use appropriate data output software to display
full range mass spectra and SICPs. The sample analysis using the GC/MS is based on a combination
of retention times and relative abundances of selected ions (see Table 6). These qualifiers should be
stored on the hard disk of the GC/MS data computer and are applied for identification of each
chromatographic peak. The retention time qualifier is determined to be +0.10 minute of the library
retention time of the compound. The acceptance level for relative abundance is determined to be ±15%
of the expected abundance. Three ions are measured for most of the PAH compounds. When compound
identification is made by the computer, any peak that fails any of the qualifying tests is flagged (e.g., with
an *). The data should be manually examined by the analyst to determine the reason for the flag and
whether the compound should be reported as found. Although this step adds some subjective judgment
to the analysis, computer^jenerated identification problems can be clarified by an experienced operator.
Manual inspection of the quantitative results should also be performed to verify concentrations outside
the expected range.
13.4.4 Dilutions. The following section provides guidance when an analyte exceeds the calibration curve.
• When a sample extract is analyzed that has an analyte target compound concentration greater than the
upper limit of the initial calibration range or saturated ions from a compound excluding the compound
peaks in the solvent front), the extract must be diluted and reanalyzed. Secondary ion quantitation is only.
allowed when there are sample interferences with the primary quantitation ion. If secondary ion
quantitation is used, calculate a relative response factor using the area response for the most intense
secondary ion which is free of sample interferences, and document the reasons for the use of the
secondary ion.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-37
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Method TO-13A _ PAHs
• Calculate the sample dilution necessary to keep the semi-volatile target compounds that required dilution
within the upper half of the initial calibration range so that no compound has saturated ions (excluding
j, the compound peaks in the solvent front). Dilute the sample in hexane in a volumetric flask. Analyze
the sample dilution.
« The dilution factor chosen should keep the response of the largest peak for a target compound in the
upper half of the initial calibration range of the instrument.
• If the on-column concentration of any target compound in any sample exceeds the initial calibration
range, that sample must be diluted, the internal standard concentration readjusted, and the sample extract
reanalyzed.
• Use the results of the original analysis to determine the approximate dilution factor required to get the
largest analyte peak within the initial calibration range.
13.4.5 Quantitation. This section provides guidance for quantitating PAH analytes.
• Target components identified shall be quantified by the internal standard method. The internal standards
'. used for the^Jarget compounds are the ones nearest the retention time of a given analyte.
• The relative response factor (RRF) from the daily continuing calibration standard analysis (or RRF of
CAL 3) if the sample is analyzed in the same 12-hour sequence as the initial calibration) is used to
calculate the concentration in the sample. Secondary ion quantitation is allowed only when there are
sample interferences with the primary ion. If secondary ion quantitation is performed, document the
reasons. The area of a secondary ion cannot be substituted for the area of a primary ion unless a relative
, response factor is calculated using the secondary ion.
* A retention time window is calculated for each single component analyte and surrogate. Windows are
established as ±0.0 1 RRT units of the retention time for the analyte in CAL 3 of the initial calibration
or the continuing calibration.
13.4.6 Calculations. Perform the following calculations:
^ 13.4.6.1 Calculation of Concentration. Calculate target compound concentrations using the following
equation:
Concentration, (ng/std m3) = — *s-i f
where:
AX = area response for the compound to be measured, counts
A,, = area response for the internal standard, counts
I, = amount of internal standard, ng/uL
RRF = the mean RRF from the most recent initial calibration, dimensionless
V, — volume of air sampled, std m3
V, = volume of final extract, uL
Dt = dilution factor for the extract. If there was no dilution, Df equals 1 . If the sample was diluted, the
Df is greater than 1 .
i
The concentrations calculated can be converted to ppb¥ for general reference. The analyte concentration can
be converted to ppbv using the following equation:
Page 13A-38 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
CA(ppbv) = CA(ng/m3) x 24.4/MWA
where:
CA = concentration of analyte calculated, ng/std. m3
MWA = molecular weight of analyte, g/g-mole
24.4 = molar volume occupied by ideal gas at standard temperature and pressure (25 °C and 760 mm Hg),
L/mole.
13.4.6.2 Estimated Concentration. The equation in Section 13.4.6.1 is also used for calculating the
concentrations of the non-target compounds. Total area counts (or peak heights) from the total ion
chromatogram generated by the mass spectrometer for Compendium Method TO-13A PAHs (see Figure 16)
are to be used for both the non-target compound to be measured (A*) and the internal standard (Ais). Associate
the nearest internal standard free of interferences with the non-target compound to be measured. A relative
response factor (RRF) of one (1) is to be assumed. The value from this quantitation shall be qualified as
estimated ("J") (estimated, due to lack of a compound-specific response factor) and "N" (presumptive evidence
of presence), indicating the quantitative and qualitative uncertainties associated with this non-target component.
An estimated concentration should be calculated for all tentatively identified compounds (TICs) as well as those
identified as unknowns.
13.4.6.3 Surrogate Percent Recovery (%R). Calculate the surrogate percent recovery using the
following equation:
Q,
%R = _ii x 100
where:
Qd = Quantity determined by analysis, ng
Q«= Quantity added to sample/blank, ng
The surrogate percent recovery must fall between 60-120% to be acceptable.
13.4.6.4 Percent Area Response Change (%ARC). Calculate the percent area response change
(%ARC) for the sample/blank analysis compared to the most recent CAL 3 analysis for each of the internal
standard compounds using the following equation:
A, - Ax
%ARC = — x 100
where:
%ARC = percent area response change, %
A,. = area response of the internal standard in the sample/blank analysis, counts
Ax = area response of the internal standard in the most recent CAL 3 analysis, counts
The area change for the internal standard must not exceed -50 to +100 percent.
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Method TO-13A i PAHs
13.4.6.5 Internal Standard Retention Time Shift (RTS). Calculate the retention time shift (RTS)
between the sample/blank analysis and the most recent CAL 3 analysis for each of the internal standards using
the following equation:
RTS = RTs - RTX
i • •...• j
where:
RT, = retention time of the IS in the sample
RTX = retention time of the IS in the most recent CAL 3 analysis.
;: ? . i
13.4.7 Technical Acceptance Criteria. The following guideline is provided as technical acceptance
criteria.
13,4.7.1 All target compound concentrations must riot exceed the upper limit of the initial calibration
range and no compound ion (excluding the compound peaks in the solvent front) may saturate the detector.
13.4.7.2 Internal standard responses and retention times in all samples must be evaluated during or
immediately after data acquisition. If the retention time for any internal standard changes by more than 20
seconds from the latest continuing calibration standard or CAL 3 if samples are analyzed in the same 12-hour
sequence as the initial calibration, the chromatographic system must be inspected for malfunctions, and
corrections made as required. The SICP of the internal standards must be monitored and evaluated for each
field and QC sample. If the SICP area for any internal standard changes by more than a factor of-50 to
•*• 100 percent, the mass spectrometric system must be inspected for malfunction and corrections made as
appropriate. If the analysis of a subsequent sample or standard indicates that the system is functioning
properly, then corrections may not be required.
13.4.7.3 When target compounds are below the low standard, but the spectrum meets the identification
criteria, report the concentration/amount with a "J." For example, if the low standard corresponds to 0.1/^g
and an amount of 0.05 /^g is calculated, report as "0.05J."
13.4.8 Corrective Action. The following section provides guidance if analyte exceeds the technical
criteria.
• If the sample technical acceptance criteria for the surrogates and internal standards are not met, check
calculations, surrogate and internal standard solutions, and instrument performance. It may be necessary
„ to recalibrate the instrument or take other corrective action procedures to meet the surrogate and internal
standard technical acceptance criteria.
• • Sample analysis technical acceptance criteria must be met before data are reported. Samples
contaminated from laboratory sources, or associated with a contaminated method blank, or any samples
i, analyzed that are not meet the technical acceptance criteria will require reanalysis.
.» The samples or standards with SICP areas outside the limits must be reanalyzed. If corrections are
made, then the laboratory must demonstrate that the mass spectrometric system is functioning properly.
This must be accomplished by the analysis of a standard or sample that meets the SICP criteria. After
corrections are made, the reanalysis of samples analyzed while the system was malfunctioning is
required.
• If after reanalysis, the SICP areas for all internal standards are inside the technical acceptance limits (-50
to + 100 percent), then the problem with the first analysis is considered to have been within the control
of the laboratory. Therefore, submit only data from the analysis with SICPs within the technical
acceptance limits. This is considered the initial analysis and must be reported as such on all data
deliverables.
Page 13A-40 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
• If the reanalysis of the sample does not solve the problem (I.e., the SICP areas are outside the technical
acceptance limits for both analyses) then the laboratory must submit the SICP data and sample data from
both analyses. Distinguish between the initial analysis and the reanalysis on all data deliverables, using
the sample suffixes specified.
• Tentative identification of an analyte occurs when a peak from a sample extract falls within the daily
retention time window.
« If sample peaks are not detected, or all are less than full-scale deflection, the undiluted extract is
acceptable for GC/MS analysis. If any sample ions are greater than the 120 percent of the initial
calibration curve range, calculate the dilution necessary to reduce the major ion to between half- and full-
range response.
14. Quality Assurance/Quality Control (QA/QC)
14.1 General System QA/QC
14.1.1 Each laboratory that uses Compendium Method TO-13A must operate a formal quality control
program. The minimum requirements of this program consist of an initial demonstration of laboratory
capability and an ongoing analysis of spiked samples to evaluate and document quality data. The laboratory
must maintain records to document the quality of the data generated. Ongoing data quality checks are
compared with established performance criteria to determine if the results of analyses meet the performance
characteristics of the method. When results of sample spikes indicate a typical method performance, a quality
control check standard must be analyzed to confirm that the measurements were performed in an in-control
mode of operation.
14.1.2 Before processing any samples, the analyst should demonstrate, through the analysis of a reagent
solvent blank, that interferences from the analytical system, glassware, and reagents are under control. Each
time a set of samples is extracted or there is a change in reagents, a reagent solvent blank should be processed
as a safeguard against chronic laboratory contamination. The blank samples should be carried through all
stages of the sample preparation and measurement steps.
14.1.3 For each analytical batch (up to 20 samples), a reagent blank, matrix spike, and
deuterated/surrogate samples must be analyzed (the frequency of the spikes may be different for different
monitoring programs). The blank and spiked samples must be carried through all stages of the sample
preparation and measurement steps.
14.1.4 The experience of the analyst performing GC/MS is invaluable to the success of the methods. Each
day that analysis is performed, the daily calibration sample should be evaluated to determine if the
chromatographic system is operating properly. Questions that should be asked are: Do the peaks look normal?
Are the response windows obtained comparable to the response from previous calibrations? Careful
examination of the standard chromatogram can indicate whether the column is still good, the injector is leaking,
the injector septum needs replacing, etc. If any changes are made to the system (e.g., column changed),
recalibration of the system must take place,
14.2 Process, Field, and Solvent Blanks
14.2.1 One PUF cartridge and filter from each batch of approximately 20 should be analyzed without
shipment to the field for the compounds of interest to serve as a process blank. A blank level specified in
Section 10.2 for each cartridge/filter assembly is considered to be acceptable.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-41
-------
Method TO-13A PAHs
»,: I.. • \i "SI . '': I
14,2.2 During each sampling episode, at least one cartridge and filter should be shipped to the field and
returned, without drawing air through the sampler, to serve as a field blank.
14.2.3 During the analysis of each batch of samples at least one solvent process blank (all steps conducted
but no cartridge or filter included) should be carried through the procedure and analyzed. Blank levels should
be those specified in Section 10.2 for single components to be acceptable.
14.2.4 Because the sampling configuration (filter and backup sorbent) has been tested for targeted PAHs
in the laboratory in relationship to collection efficiency and has been demonstrated to be greater than 95 percent
for targeted PAHs (except naphthalene, acenaphthylene, and acenaphthene), no field recovery evaluation is
required as part of the QA/QC program outlined in this section.
15, References
1. Dubois, L., Zdrojgwski, A., Baker, C., and Monknao, J.L., "Some Improvement in the Determination of
Bcnzo[a]Pyrene in Air Samples," J.AirPollut. Contr, Assoc., 17:818-821, 1967,
2, Intcrsocicty Committee, "Tentative Method of Analysis for Polynuelear Aromatic Hydrocarbon of
Atmospheric Paniculate Matter," Health Laboratory Science, 7(1):31-40, 1970.
i
3, Cautrccls, W., and Van Cauwenberghe, K., "Experiments on the Distribution of Organic Pollutants Between
Airborne Particulate Matter and Corresponding Gas Phase," Atmos. Environ., 12:1133-1141, 1978.
j
4. "Tentative Method of Microanalysis for Benzo[a]Pyrene in Airborne Particles and Source Effluents,"
American Public Health Association, Health Laboratory Science, 7(l):56-59, 1970.
5. "Tentative Method of Chromatographic Analysis for BenzojaJPyrene and Benzo[k]Fluoranthene in
Atmospheric Particulate Matter," American Public Health Association, Health Laboratory Science, 7(1):60-
67, 1970.
6, 'Tentative Method of Spectrophotometric Analysis for Benzo[a]Pyrene in Atmospheric Particulate Matter,"
American Public Health Association, Health Laboratory Science, 7(1):68-71, 1970.
7. Jones, P.W., Wilkinson, I.E., and Strap, P.E., Measurement ofPolycyclic Organic Materials and Other
Hazardous Organic Compounds in Stack Gases: State-of-the-Art, U. S. Environmental Protection Agency,
Research Triangle Park, NC, U.S. EPA-600/2-77-202, 1977.
8. Walling, J.F., Standard Operating Procedure for Ultrasonic Extraction and Analysis of Residual
BcnzofaJPyrene from Hi-Vol Filters via Thin-Layer Chromatography, U.S. Environmental Protection
Agency, Environmental Monitoring Systems Laboratory, Methods Development and Analysis Division,
Research Triangle Park, NC, EMSL/RTP-SOP-MDAD-015, December, 1986.
9. Rasor, S., Standard Operating Procedure for Polynuelear Aromatic Hydrocarbon Analysis by High
Performance Liquid Chromatography Methods, Acurex Corporation, Research Triangle Park, NC, 1978.
I
10. Rapport, S. W., Wang, Y. Y., Wei, E. T., Sawyer, R., Watkins, B. E., and Rapport, H., "Isolation and
Identification of a Direct-Acting Mutagen in Diesel Exhaust Particulates," Envir. Sci, Technoi, 14:1505-1509,
1980.
Page 13A-42 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
PAHs Method TO-13A
11. Konlg, J., Balfanz, E., Funcke, W., and Romanowski, T., "Determination of Oxygenated Polycyclic
Aromatic Hydrocarbons in Airborne Particulate Matter by Capillary Gas Chromatography and Gas
Chromatography/Mass Spectrometry," Anal. Chem., 55:599-603, 1983.
12. Chuang, J. C., Bresler, W. E., and Hannan, S. W., Evaluation of Polyurethane Foam Cartridges for
Measurement of Polynuclear Aromatic Hydrocarbons in Air, U.S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Methods Development and Analysis Division, Research
Triangle Park, NC, EPA-600/4-85-055, September 1985,
13. Chuang, J. C., Hannan, S. W., and Koetz, J. R., Stability of Polynuclear Aromatic Compounds Collected
from Air on Quartz Fiber Filters andXAD-2 Resin, U.S. Environmental Protection Agency, Environmental
Monitoring Systems Laboratory, Methods Development and Analysis Division, Research Triangle Park, NC,
EPA-600/4-86-029, September 1986.
14. Feng, Y., and Bidleman, T. F., "Influence of Volatility on the Collection of Polynuclear Aromatic
Hydrocarbon Vapors with Polyurethane Foam," Envir. Sci. Technol., 18:330-333, 1984.
15. Yamasaki, H,, Kuwata, K., and Miyamoto, H,, "Effects of Ambient Temperature on Aspects of Airborne
Polycyclic Aromatic Hydrocarbons," Envir. Sci. Technol., 16:89-194, 1982,
16. Galasyn, J. F., Hornig, J. F., and Soderberg, R. H., "The Loss of PAH from Quartz Fiber High Volume
Filters," J. AirPollut. Contr. Assoc., 34:57-59, 1984.
17. You, F., and Bidleman, T. F., "Influence of Volatility on the Collection of Polynuclear Aromatic
Hydrocarbon Vapors with Polyurethane Foam," Envir. Sci. Technol., 18:330-333, 1984.
18. Chuang, J. C., Hannan, S. W., and Koetz, J. R., Comparison of Polyurethane Foam andXAD-2 Resin
as Collection Media for Polynuclear Aromatic Hydrocarbons in Air, U.S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Methods Development and Analysis Division, Research
Triangle Park, NC, EPA-600/4-86-034, December 1986.
19, Chuang, J. C., Mack, G, A., Mondron, P. I., and Peterson, B. A., Evaluation of Sampling and Analytical
Methodology for Polynuclear Aromatic Compounds in Indoor Air, U.S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Methods Development and Analysis Division, Research
Triangle Park, NC, EPA-600/4-85-065, January 1986.
20, Lewis, R. G,, Brown, A. R., and Jackson, M. D., "Evaluation of Polyurethane Foam for High-Volume Air
Sampling of Ambient Levels of Airborne Pesticides, Polychlorinated Biphenyls, and Polychlorinated
Naphthalenes," Anal. Chem., 49:1668-1672, 1977.
21. Lewis, R. G., and Jackson, M. D., "Modification and Evaluation of a High-Volume Air Sampler for
Pesticides and Other Semi-volatile Industrial Organic Chemicals," Anal. Chem., 54:592-594, 1982.
22. Winberry, W. T., and Murphy, N. T., Supplement to Compendium of Methods for the Determination of
Toxic Organic Compounds in Ambient Air, U.S. Environmental Protection Agency, Environmental Monitoring
Systems Laboratory, Quality Assurance Division, Research Triangle Park, NC, EPA-600/4-87-006, September
1986.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-43
-------
Method TO-13A ; PAHs
i
23. Winbcrry, W. T., and Murphy, N. T., Second Supplement to Compendium of Methods for the
Determination of Toxic Organic Compounds in Ambient Air, U.S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Quality Assurance Division, Research Triangle Park, NC,
EPA 600/4-89-018, June 1989.
24. Methods for Organic Chemical Analysis oj'Municipal andIndustrial Wastewater, U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, OH, EPA-600/4-82-Q57,
July 1982.
25. ASTM Annual Book of Standards, Part 31, D 3694, "Standard Practice for Preparation of Sample
Containers and for Preservation," American Society for Testing and Materials, Philadelphia, PA, p. 679, 1980.
26. Burke, J. A,, "Gas Chromatography for Pesticide Residue Analysis; Some Practical Aspects," Journal of
the Association of Official Analytical Chemists, 48:1037, 1965.
27, Cole, T,, Riggin, R,, and Glaser, J., Evaluation of Method Detection Limits: Analytical Curve for EPA
Method 610 - PNAs, 5th International Symposium on Polynuclear Aromatic Hydrocarbons, Battelle,
Columbus, OH, 1980."
28._ Handbook of Analytical Quality Control in Water and Wastewater Laboratories, U.S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory, Cincinnati, OH, EPA-600/4-79-019,
March 1979.
!
29. ASTMAnnual'Book of Standards, Part 31, D 3370, "Standard Practice for Sampling Water," American
Society for Testing and Materials, Philadelphia, PA, p. 76, 1980.
30. Protocol for the Collection and Analysis of Volatile POHC's (Principal Organic Hazardous
Constituents) Using VOST (Volatile Organic Sampling Train), U. S. Environmental Protection Agency,
Research Triangle Park, NC, EPA-600/8-84-007, March 1984.
31. Sampling and Analysis Methods for Hazardous Waste Combustion - Methods 3500, 3540, 3610, 3630,
8100, 8270, and8310; Test Methods for Evaluating Solid Waste (SW-846), U.S. Environmental Protection
Agency, Office of Solid Waste, Washington, D.C.
32. Riggin, R. M., Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air, U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory, Quality
Assurance Division, Research Triangle Park, NC, EPA-600/4-84-041, April 1984.
33. Chuang, C. C., and Peterson, B. A., Review of Sampling and Analysis Methodology for Polynuclear
Aromatic Compounds in Air from Mobile Sources, Final Report, U. S. Environmental Protection Agency,
Research Triangle Park, NC, EPA-600/S4-85-045, August 1985.
34. Measurement of Polycyclic Organic Matter for Environmental Assessment, U.S. Environmental
Protection Agency, Industrial Environmental Research Laboratory, Research Triangle Park, NC, EPA-600/7-
79-191, August 1979.
Page 13A-44 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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PAHs Method TO-13A
35. Hudson, J. L., Standard Operating Procedure No. FA H3C: Monitoring for Particulate and Vapor
Phase Pollutants Using the Portable Particulate/Vapor Air Sampler, U.S. Environmental Protection Agency,
Region VII, Environmental Monitoring and Compliance Branch, Environmental Services Division, Kansas
City, KS, March 1987.
36. Trane, K. E., and Mikalsen, A., "High-Volume Sampling of Airborne Polycyclic Aromatic Hydrocarbons
Using Glass Fibre Filters and Polyurethane Foam," Atmos. Environ., 15:909-918, 1981.
37, Keller, C. D., and Bidleman, T. F., "Collection of Airborne Polycyclic Hydrocarbons and Other Organics
with a Glass Fiber Filter - Polyurethane Foam System," Atmos. Environ., 18:837-845, 1984,
38. Hunt, G. T., and Pangaro, N., "Ambient Monitoring of Polynuclear Aromatic Hydrocarbons (PAHs)
Employing High Volume Polyurethane Foam (PUF) Samplers," In Polynuclear Aromatic Hydrocarbons,
Cooke, M., Dennis, and A. J., Eds, Battelle Press, Columbus, OH, pp. 583-608, 1985.
39. Alfeim, I., and Lindskog, A., "A Comparison Between Different High Volume Sampling Systems for
Collecting Ambient Airborne Particles for Mutagenicity Testing and for Analysis of Organic Compounds," Sci.
Total Environ., 34:203-222, 1984.
40. Umlauf, G., and Kaupp, H., "A Sampling Device for Semivolatile Organic Compounds in Ambient Air,"
Chemosphere, 27:1293-1296, 1993.
41. Hippelein, M., Kaupp, H., Dorr, G., and McLachlan, M. S., "Testing of a Sampling System and
Analytical Method for Determination of Semivolatile Organic Chemicals in Air," Chemosphere, 26:2255-2263,
1993.
42. Ligocki, M, P., and Ponkow, J. F., "Assessment of Adsorption/Solvent Extraction with Polyurethane Foam
and Adsorption/Thermal Desorption with Tenax-GC for Collection and Analysis of Ambient Organic Vapors,"
Anal Chem., 57; 1138-1144, 1985.
43. Yamasaki, H., Kuwata, K., and Miyamoto, H., "Effects of Ambient Temperature on Aspects of Airborne
Polycyclic Aromatic Hydrocarbons," Envir. Sci. Technol, 16:189-194, 1982.
44. Hart, K. M., and Pankow, J. F., "High-Volume Air Sampler for Particle and Gas Sampling: Use of
Backup Filters to Correct for the Adsorption of Gas-Phase Polycyclic Aromatic Hydrocarbons to the Front
Filter," Envir. Sci. Technol., 28:655-661, 1994.
45. Kaupp, H., and Umlauf, G., "Atmospheric Gas-Particle Partitioning of Organic Compounds: Comparison
of Sampling Methods," Atmos. Environ., 13:2259-2267, 1992.
46, Coutant, R. W., Brown, L., Chuang, J. C., Riggin, R, M., and Lewis, R. G., "Phase Distribution and
Artifact Formation in Ambient Air Sampling for Polynuclear Aromatic Hydrocarbons," Atmos. Environ.,
22:403-409, 1988.
47. Coutant, R. W., Callahan, P. J., Kuhlman, M. R., and Lewis, R. G., "Design and Performance of a High-
Volume Compound Annular Denuder," Atmos. Environ., 23:2205-2211.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-45
-------
Method TO-13A | PAHs
48, Lewis, R. G., Kelly, T. J., Chuang, J. C., Callahan, P. J., and Coutant, R. W., "Phase Distributions of
Airborne Polycyclic Aromatic Hydrocarbons in Two U.S. Cities," In Proceedings of the 9th World Clean Air
Congress & Exhibition, Montreal, Ontario, Canada, 1991, Vol., Paper IU-11E.02.
49. Kaupp, H., and Umlauf, G., "Atmospheric Gas-Particle Partitioning of Organic Compounds: Comparison
of Sampling Methods," Atmos. Environ., 26 A:225 9-2267, 1992.
50. Riggin, R. M., Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds
in Ambient Air, U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory,
Quality Assurance Division, Research Triangle Park, NC, EPA-600/4-83-027, June 1983.
•• '« t , ; . a j
51. ASTM Annual Book of Standards, Part 31, D 3694, "Standard Practice for Preparation of Sample
Containers and for Preservab'on,H American Society for Testing and Materials, Philadelphia, PA, p. 679, 1980.
52. Carcinogens - Working with Carcinogens, Department of Health, Education, and Welfare, Public Health
Service, Center for Disease Control, National Institute for Occupational Safety and Health, Publication No.
77-206, August 1977. . . ,
53. OSHA Safety and Health Standards, General Industry, (29CFR1910), Occupational Safety and Health
Administration, OSHA, 2206, Revised, January 1976.
i
54. "Safety in Academic Chemistry Laboratories," American Chemical Society Publication, Committee on
Chemical Safety, 3rd Edition, 1979.
Page 13A-46 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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S3
52
f
fe
I
I
n
f
n*
I
TABLE 1. FORMULAE AND PHYSICAL PROPERTIES OF SELECTED PAHs
Compound
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Anthracene
Phenanthrene
Fluoranthene
Pyrene
Benz(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Perylene
Benzo(a)pyrene
Benzo(e)pyrene
Benzo(g,h,i)perylene
Indeno( 1 ,2,3-cd)pyrene
Dibenz(a,h)anthracene
Coronene
Formula
C,nH«
CijHg
C,?HU
C,,H,0
CuH,n
CMHW
CisH,o
CisHm
C,,H,,
CnHi,
CjoHn
CraHi,
CMH,j
CI«HH
CMHtl
CjiHu
CMH,,
Ci5H,4
C«H1?
Molecular
. Weight
128.18
152,20
154,20
166.23
178.24
178.24
202.26
202.26
228.30
228.30
252.32
252.32
252.32
252.32
252.32
276.34
276.34
278.35
300.36
Melting Point,' .
°C
80,2
92-93
90-96
116-118
216-219
96-101
107-111
150-156
157-167
252-256
167-168
198-217
273-278
177-179
178-179
275-278
162-163
266-270
438-440
Boiling Point,
°c'
218
265-280
278-279
293-295
340
339-340
375-393
360-404
. 435
441-448
481
480-471
500-503
493-496
493
525
_,
524
525
Vapot Pressure,
. kPa
1.1x10-'
3.9x10-'
2.1xlO']
8,7x10''
36x10^
2.3xlO'!
6.5x1 0'7
3.U10-*
1.5x10-"
5.7x10-'°
6.7xW»
2.1x10-*
7.0x10-"
7.3X10'"1
7,4xlQ-ll!
1.3x10-"
ca,10'"
1.3x10""
2.0x10""
CASKN#
91-20-3
208-96-8
83-32-9
86-73-7
120-12-7
85-01-8
206-44-0
129-00-0
56-55-3
218-01-9
205-99-2
207-08-9
198-55-8
50-32-8
192-92-2
191-24-2
193-39-5
53-70-3
191-07-1
'Many of these compounds sublime.
I
O
a
H
O
-------
Method TO-13A
PAHs
TABLE 2. QC-MS OPERATING CONDITIONS
Activity
Conditions
Gas Chrotnatographv
Column
Carrier Gas
Injection Volume
Injector Temperature
J&W Scientific, DB-5 crosslinked 5% phenylmethyl silicone
(30 m x 0,32 mm, 1.0 (im film thickness) or equivalent
Helium, velocity between 28-30 crnYsec at 250 °C
2 uL, Grab-type, splitless
290°C
Temperature Program
Initial Column Temperature
Initial Hold Time
Program
Final Temperature
Final Hold Time
70 °C
4 ±0.1 rain.
10°C/min to 30Q°C and hold 10 min.
300°C
10 min. or until all compounds of interest have eluted
Mass Spectrometer
Transfer Line Temperature
Source Temperature
Electron Energy
lonization Mode
Mass Range
290 °C or According to Manufacturer's Specification
According to Manufacturer's Specifications
70 volts (nominal)
El
35 to 500 amu, fall range data acquisition (SCAN) mode
Scan Time
At least 5 scans per peak, not to exceed 1 second per scan.
TABLES. DFTPP KEY IONS & ION
ABUNDANCE CRITERIA
Mass
51
68
70
127
197
198
199
275
365
441
442
443
Ion Abundance Criteria
30 to 60% of mass 198
Less than 2% of mass 69
Less than 2% of mass 69
40 to 60% of mass 198
Less than 2% of mass 198
Base peak, 100% relative abundance
5 to 9% of mass 198
10 to 30% of mass 198
Greater than 1.0% of mass 198
Present but less than mass 443
40% of mass 198
17 to 23% of mass 442
Page 13A-48
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January 1999
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PAHs
Method TO-13A
TABLE 4. COMPOSITION AND APPROXIMATE CONCENTRATION
OF CALIBRATION SOLUTIONS
Target Compound
PAHs
Acenaphthene
Acenaphthylene
Anthracene
Benz(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(e)pyrene
Benzo(g,h,i)perylene
Benzo(k)fluoranthene
Chrysene
Perylene
Dibenz(a,h)anthracene
Fluoranthene
Fluorene
Indeno( 1 ,2,3-c,d)pyrene
Naphthalene
Coronene
Phenanthrene
Pyrene
Concentration, ng/nL
CAL1
0.10
0,10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
CAL2
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0,25
0.25
0.25
CAL3
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
CAL4
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
1.25
CAL5
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
2.50
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-49
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Method TO-13A
PAHs
TABLE 4. (Continued)
Target Compound
SUGGESTED INTERNAL
STANDARDS
Dt-Naphthalene
D ,B-Acenaphthcne
D|«-Phcnanthrene
D,2-Chrysene
Dl5-Perylene
SUGGESTED SURROGATE
COMPOUNDS
DI(,-Fluoranthene (Geld)
D,,-Benzo[a]pyrene (Geld)
Dw-Fluorene (lab)
Dw-Pyrene (lab)
Concentration, ftg/nL
CAL1
0.5
0.5
0.5
0.5
0.5
0.10
0.10
0,10
0.10
CAL2
0.5
0.5
0.5
0.5
0.5
0.25
0.25
0.25
0,25
CAL3
0.5
0.5
0.5
0.5
0.5
0.50
0.50
0.50
0.50
CAL4
0.5
0.5
0.5
0.5
0.5
1.25
1.25
1.25
1.25
GALS
0.5
0.5
0.5
0.5
0.5
2.50
2.50
2.50
2.50
Page13A-50
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
TABLE 5. CHARACTERISTIC IONS FOR SURROGATE SUGGESTED STANDARDS
: : ; : :-:?-; r:; i . •• ::-:;;ElI,Ctessi:iicatt;ion "/ • ;;;->- ; .:;'^ 2 S ..:•••.:.
Internal Standards
Dg-Naphthalene
D10-Acenaphthene
D10-Phenanthrene
D12-Chrysene
D12-Perylene
Laboratorv Surrogates
D10-Fluorene
Dto-Pyrene
Field Surrogates
D10-Fluoranthene
Dl3-Benzo(a)pyrene
l^/ES-S'-y-Prmalry''!^^!!:^
136
164
188
240
264
176
212
212
264
^^iiy^SiKSO^^'if^^^lj^
68,137
162,165
94,189
120,241
260,265
88,177
106,213
106,213
132,265
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-S1
-------
Method TO-I3A
PAHs
TABLE 6. EXAMPLE OF CHARACTERISTIC IONS FOR COMMON PAHs
Analyte
Pyrene
Benz(a)anthracene
Chryseiie
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Bcnzo(g,h,i)perylene
Dibenz(a,h)anthracene
Anthracene
Phenanthrene
Acenaphthene
Accnaphthylene
Bcnzo(e)pyrene
Fluoranthene
Fluorene
Ideno(l,2,3-ed)pyrene
Naphthalene
Perylene
Coronene
Primary Ion
202
228
228
252
252
252
276
278
178
178
154
152
252
202
166
276
128
252
300
Secondary Ion(s)
101,203
229,226
226,229
253,126
253,126
253,126
138,277
139,279
179,176
179,176
153,152
151,153
253,126
101,203
165,167
138,227
129,127
253,126
150,301
Page 13A-52
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
TABLE 7. EXAMPLE OF RELATIVE RESPONSE FACTOR CRITERIA
FOR INITIAL AND CONTINUING CALIBRATION OF
COMMON SEMI-VOLATILE COMPOUNDS
Semi-volatile
Compounds
Naphthalene
Acenaphthylene
Aeensphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benz(a)anfhracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Indeno{ 1 ,2,3 -cd)pyrene
Ditxmz(a,h)anthracene
Benzo(g,h,i)perylene
Perylene
Coronene
Minimum
RRF
0.700
1.300
0.800
0.900
0.700
0.700
0.600
0.600
0.800
0.700
0.700
0.700
0.700
0.500
0.400
0.500
0.500
0.700
Maximum
%RSD
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
Maximum
%Difference
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-53
-------
Method TO-13A
PAHs
TABLE 8. MINIMUM SAMPLING EQUIPMENT CALIBRATION AND
ACCURACY REQUIREMENTS
Equipment
Sampler
Acceptance limits
Indicated flow rate =
true flow rate, ±10%.
Frequency and method
of measurement
Calibrate with certified
transfer standard on
receipt, after
maintenance on sampler,
and any time audits or
flow checks deviate
more than ±10% from
the indicated flow rate or
±10% from the design
flow rate.
Action ifreqaire^:-"--;^:.
ments are not met
Recalibrate
Associated equipment
Sampler on/off timer
Elapscd-time meter
Flowrate transfer
standard (orifice
device)
±30 min/24 hour
±30 min/24 hour
Check at receipt for
visual damage
Check at purchase and
routinely on sample-
recovery days
Compare with a
standard time-piece of
known accuracy at
receipt and at 6-month
intervals
Recalibrate annually
against positive
displacement standard
volume meter
Adjust or replace
Adjust or replace
Adapt new
calibration curve
Page 13A-54
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
Acenaphthene
Benzo(g,h,i)perylene
Chrysene
Ruorene
Acenaphthylene
Benz(a)anthracene Benzo(b)fluoranlhene
Benzo(o)pyrene
Dibenz(a,h)onthracene
lndeno(1,2,3—c.d)pyrene
Anthracene
Benzo(k)fluoranthene
Benzo(e)pyrene
Ruoranthene
Naphthalene
Phenanthrene
Pyrene
Figure 1. Ring structure of common PAHs.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-55
-------
Method TO-13A
PAHs
Magnehfc Gauge
" 0-100 in.
Exhaust Duct
(6in.x10fQ
Sampling Head
see Figure 3)
Voltage Variator
Elapsed Time
Meter
7-Day Timer
Figure 2. Typical high volume air sampler for PAHs.
Page 13A-56 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
PAHs
Method TO-13A
MR FLOW
PARTICLE FILTER
PARTICULATC
FILTER
SUPPORT
'ASSEMBLED
SAMPLING!
MODULE
AIR FLOW
EXHAUST
FUER RETAINING RING
S3UCONE CASKET
102-mm
• QUARTZ-FIBER
FLTER
FUER SUPPORT SCREEN
FILTER HOLDER (PART 2)
5UJCONE GASKET
CLASS CARTRIDGE
PUF or XAD-2
SORBENT
ROA1KINC SCREEN
SUCONE GASKET
CARTRIDGE
HOLDER
Figure 3. Typical absorbent cartridge assembly for sampling PAHs.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-57
-------
Method TO-13A
PAHs
Wottr In
Soxhttt
Extraction
Tub* and
thimble
Water Out
Ailihn
Condenser
flask
(a) Soxhlet Extraction Apparatus
with Ailihn Condenser
3 Bol Uocro
Synd*r Column
500 mL
Evaporator
riatk
10 mL
Concentrator
Tube
(b) Kuderna-Danish (K-D) Evaporator
with Macro Synder Column
Disposable 6 inch
Pomleur Pipette
3
V
Inches
v> s
/rrrr>
>Ci>>*
^-^-^
sf£ >;. 15^
!•» 1 Gram Sodium Sulfole
^ 10
Gel
Cram Silico .
Siuriy
\EO-l.-:-iy^o— was* wool Mug
\s>->>X/^ *
'f^ i S » "7
(c) Silico Gel Clean—up Column
Figure 4. Apparatus used for sample clean-up and extraction.
Page 13A-58
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
PAHs
Method TO-13A
Glass PUF Cartridge with
Stainless Steel Screens
,64mm O.D.,
CM
CD
en
xt
Glass
Cartridge
End Cap
PUF Plug
-End Cap
5a. Glass PUF cartridge, plug, and end caps.
Accessories
Teflon Sealing Caps pUF Insert
with Q-rings for
capping PUF Sampler
Aluminum Canister for Shipping
and Storage of the PUF Sampler
5b. PUF shipping container.
Figure 5, Glass PUF cartridge (5a) and shipping container
(5b) for use with Compendium Method TO-13A.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-59
-------
Method TO-13A
PAHs
Exhaust Hose
4* Diameter Pullflex
Rlter and Support
PUF Adsorbent
Cartridge and Support
Quick Release Connections
for Module
Quick Release Connections
for Magnahelfc Gage
Row Control Valve
Elapsed Time Indicator
Figure 6. Example of a field portable high volume air sampler for
sampling PAHs developed by EPA.
Page 13A-60
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
Mercury
Manometer
Barometer
Thermometer
Filter Adapter
Raotsmeter
High Volume Motor
Resistance Plates
Figure 7. Positive displacement rootsmeter used to calibrate orifice transfer standard
used in Compendium Method TO-13 A.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-61
-------
2?
&
n
f
I
I
rs'
f
s-
1
COMPENDIUM METHOD TO-13A
ORIHCE CAUBRATION DATA SHEET
a
H
n
Orifice No.
Rootsmeter No.
mmHg
Name
Date
Resistance
Plants.
; (No. of
holes)
5
7
10
13
18
Air Volume
*
200
200
300
300
300
'aft'
5.66
5.66
8.50
8.50
8.50
Standard
Volume,
Ak Volunw
* 10 P-83$
^* ijiroiifflb
Rootsmeter,
- Rootsraeter
Dlfferenfial^
Drop
: Orifice,
• Standard
1 Flowrate, ".'
f ,,,'Y . :
Factois: (R'XO.OISSI
« xa3 aad (ia. E$ 25.4 (^ % = aim Hg
m. Hg
Calculation Equations:
Pj - AP T,,
where:
2.
Pgtd = 760.0 mm Hg
V^
Qstd= -Q-
Figure 8. Example of a high-volume orifice calibration data sheet for Compendium Method TO-13 A.
-------
PAHs
Method TO-13A
Sampling head
Cafibrated
orifice
Shutoff valv
Magnehelfc gauge
0 - 100 in.
Manometer
0-18 In.
Pipe fitting (1/2 in.)
rjjj-rur, rr_r;rZT, 1
Elapsed time
meter
Exhaust duct
Figure 9. Typical field calibration configuration for Compendium Method TO-13A sampler.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-63
-------
Method TO-13A
PAHs
FIELD CALIBRATION DATA SHEET FOR COMPENDIUM METHOD TO-13A PAH
SAMPLER CALIBRATION
Sampler ID:
Sampler Location:
Calibration Orifice ID:
Job No.:
High Volume Transfer Orifice Data:
Correlation Coefficient (CC1):.
(CC2):,
Intercept (Bl):
Slope (Ml):
(M2):.
(B2):.
Calibration Date:
Time:
Calibration Ambient Temperature: °F
Calibration Ambient Barometric Pressure:
Calibration set point (SP):
CALIBRATOR'S SIGNATURE
."Hg.
. mmHg
SAMPLER CALIBRATION
Actual values from calibration
Orifice manometer,
inches
(Yl)
Monitor magnehelic,
inches
(Y2)
70
60
50
40
30
20
10
Calibrated values
Orifice manometer
(Y3)
Monitor magnehelic
-------
PAHs
Method TO-13A
Shutott Valves
Y4
(ao adj.)
Y1
(Hfl)
Manometer
0-18 in.
„„--—•' / Mntnr
S Support
•••••••""•"•""^ "^^
1
=0fr—
7-D«y
Tinier
•
Elapsed Time
Meter
-> Linear regression of X1 (scmm) vs. Y4
\
Calculate B2 and M2
\
Y3
(HA) adj.
XI
(scmm)
Y5 = [avg. mag. A H (Patm /Talm)(298 / 760)]1
X2 = (Y5-B2)/M2
Figure 11. Example of relationship between orifice transfer standard and flow rate through
Compendium Method TO-13A sampler.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 13A-65
-------
Method TO-13A
PAHs
Sampler LD. No.:
Lab PUF Sample No.:
Sample location:
COMPENDIUM METHOD TO-13A
FIELD TEST DATA SHEET
GENERAL INFORMATION
Operator:
Other:
PUF Cartridge Certification Date:
Date/Time PUF Cartridge Installed:
Elapsed Timer:
Start
Stop
Diff.
Sampling
Ml
M2
Comments
Bl
B2
Start Stop
Barometric pressure ("Hg)
Ambient Temperature (°F)
Rain Yes Yes
No No
Sampling time
Start
Stop
Diff:
Audit flow check within ±10 of set point
Yes
No
TIME
Avg.
TEMP
BAROMETRIC
PRESSURE
MAGNBH1LIC
READING
CALCULATED
FLOW MATE
(std. m*)
READ BY
Figure 12. Example of typical Compendium Method TO-13A field test data sheet (FTDS).
Page 13A-66
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
Filter
1
PUF
Adsorbent
1
Reid Surrogate
Addition
(Section 10.4.1)
Laboratory
Surrogate Standard
Addition for
GC/MS Analysis
(Section 12.2)
Soxhlet Extraction in 10% Diethyl
Ether/Hexane
[18 hours/3 cycles/hr]
(Section 12.2)
Drying with Anhydrous Sodium
Sulfate
(Section 12.2.1.2)
Kuderna-Danish (K-D) Evaporator Attached
with Macro Snyder Column
(Section 12.2.2)
(No Extract Clean-up Required)
Concentrate
tol.OmL
(Extract Clean-up
Required)
Internal Standards (ISs)
Added to Concentrate
(Section 12.3.6)
Silica Gel Column Topped with
Sodium Sulfate
(Section 12.3)
Diethyl Ether/Pentane Fraction
Concentrated by K-D Apparatus to 1 mL
(Section 12.3.5)
Analysis by
GC/MS/DS
Gas Chromatography
Mass Spectroscopy
(Section 13.0)
Figure 13. Sample clean-up, concentration, separation and analysis sequence for common PAHs.
[Note: XAD-2 sequence is similar to PUF except methylene chloride is the solvent.]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-67
-------
Method TO-13A
PAHs
Filter Plus
PUF Adsorbent
Soxhlet
Extraction
Kudema-Danfsh (K-D)
Concentrator
GC/MS/SCAN
1
Initial GC/MS
Tuning with DFTPP
• Ion Abundance with DFTPP
• Moss Assignment
initial Calibration Using
Multi-Point Internal
Calibration Standards
- Retenfion Time
- Deuterated STD's Added
- Relative Response Factors
(RRF)
- System Performance Check
Compounds
Routine Calibration
- Continuous Calibration
Check (CCC) every
12-hours
- Laboratory Control Spike
(LCS) Evaluation -
• Laboratory Method Blank
(1MB)
• Solvent Method Blank
• Reid/Trip Blanks
Figure 14. Typical quality assurance specifications for GC/MS/DS operation.
Page 13A-68
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
Smt: S.UER.DIR, STB MIX CAL3 <0.Su9'nD 4273-88-4
CAP,3an,B.32nri,l. 81)0,70^380318, 38Cn/ M. MOLLOV HD-B0B-F 1ZX84X96 2833
L84FQ5' 514 (IB. 141) COMB IHE: (514 to BJ-CCC495 to 8>*C8 to 0»»1.08a>
IBB
SOW-
«\»
3,9 Hi
M^z 48
Haphthalene *•'<
(a)
127
4 6^ 6,8 , 182v 108 126, 1
634 76-78 82 O8 181 ] T^ ^
r56][!Nllll|,ff»*U«»«^l ,1 |]
a
i:
Idl
454636
6
r
60 ' a'a ' ie» ' lia ' i4e ' IBB ' iae ' aaa
SAMP: S,UEH,DIR, SID MIX CAL3 C8. Bug/tell 4273-BB-4
C»P,38«,8.32l«il.aUI1,7B-3881ia,38CMX H. MOLLO¥ HD-8BB-I1 12/84X96 2833
EBH
J.MI-
^5'934 (14.342) COMB ME: €934 to 8>-CCC91S to 8)+C8 <
Aceiwiphthylene 1!
(b)
151
.. .4- 4;- „ ^ /- * »•!
:2 * 798720
JL53
f
«o s'a a'a ' iaa iza i«e i£a IBB zee
Figure 15. Mass spectra of Compendium Method TO-13A compounds
for (a) naphthalene and (b) acenaphthylene.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-69
-------
Method TO-I3A
PAHs
BAHP: SjUER.DIRj STD H1X CAL3 C0.5u9'iil> 4273-8&-I
CAP»38MJB.3ZHH,l.BUH,7a-30eBiB,38CII>' N. MOLLOV HD-B0O-F 12/84/96 2833
L84I
too
yJTS-
fQS*9B3 C14.832) COMBINE :C9B3 *o BJ-CCC994 to BJ*CB ti
Ac»n«phtliem» •!•!
7
75
33 ^ 6a-||}-6* ||
4'0 60
(c)
432
e
I7' «?l
1 «7 Ml *1f jl
;3 * 577336
IS*
n
SB • ioo ' AZB " 140 i£0 ' IBB ' 206
SAHP: S.UEH^DIR, STD HIX CML3 CB.Suff^Ml) 4273-B8-4
C^P,30«,e.32MM,l.BU«,7B-3B8010,3eCHX H. HOLLO V HB-880-F 1ZXB4/96 2833
L0-4E
100-
XT*-
»,r
«}S* 1114 (16.142) COMBINE :C1114 to 8)-CCC1893 to 8>*
-------
PAHs
Method TO-13A
SAMP: S.MER.9IR.
STD HIX CAL3 (8. Bus/Ml) 4273-88-4
CAPJ38MJ0.32MMJ1.8U«J7B-300Bia,38CM/ H. MOLLOV HD-88B-F 12^4/96 2B33
UB4FQS* 1378 (18.782) COMBINE: (1378 to B)-(((1385 to B)+(B to B))*1.8BB)
lea-
XFS-
Anthracene 1'
76 888
»/* 40 ' e'o 88
±76
'
9,B 1J?6 1?914*S||| 17*T)1
8 86816B
p
iaa ' laa ' ±4a ida ' lea ' zea
SflMP: S^VEB^DIR, SID MIX CAL3 (B.Suff/'nl) 4273-98-4
CAP.aBM^B.aZMM^l.BUM^B-SBBBlB.Sacn/ H. MOLLOV HD-8BB-F 12/B4X96 2833
1.841
1BB-
XTS
'05*1359 f IB. 592) COMBINE: (1359 to 8>~(C(I348 to B)*<8 to 8»«i.(
Phetnan-thrcne ' 1'
(0
_.j.^r. .^.j.J
188)
CT
4'a ' fi'a ' ea ' i.aa ' lie ' i<4e i,£a * lie ' zaa
Figure 15 (Cont). Mass spectra of Compendium Method TO-13A
compounds for (e) anthracene and (f) phenanthrene.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page13A-71
-------
Method TO-13A
PAHs
BAMP: SjUER.DIR,
CAP*3BM»e.32HH,i
LB4f
IEW-
XFS-
a
vJ»
4
STB NIX CAL3 (B.Sug/Ml) 4273-68-4
.aoH.Ta-saeeia.aacM/ H. MOLLOV m>-ea»-F iz/B4/96 2833
'1666 (21.663) COMBINE: (1666 to 8J-CCC1683 to B»*CB to
Fluoranttiene 2<
5
i
55
7
jeFi
i ' ca
8
'A
3
It
ill 111
80 ' 16
(g)
aaa
1^
* *58a7a
[93
a,2
>s
i
SMIP: S.UER.DIR, SID MIX CAI3 IB .Sag/ml) 4273-88-4
ay.aeM.Q.aZHM,!. BUM, 78-388818, 30CM/ H. HOLLOV MD-8ae-F 1ZXB4^6 Z033
LB4I
ion-
KFS*
B
OS* 1723 (22.233) COMBINE: (1723 to 8)-(((1734 to B>*(B to
Pyrene 21
(h)
iai .990
"i
B8 39 184199 1]
33 *? 730,1 || »5jU»6 in if* j "0-jl
2 * 991232
r
[ a-
4*0 ' 6O " 80 ' le« ' 128 ' 140 i£H ' 18f» ' 280 ' 220 ' 240 '
Figure 15 (Cont). Mass spectra of Compendium Method TO-13A
compounds for (g) fluoranthene and (h) pyrene.
Page 13A-72
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
SAMP: S.UER.DIR, STD MIX CAL3 (8.5ug/Hl) 4273-88-4
CAP, 38M, 8. 32Mri,1.0UH, 78-380018, 38CM/ M. HOLLO ¥ MD-888-F 12/84/96 2833
L84I
100-
XFS
8
TJ5' 2833 C25.333) COMBINE: (2833 to 8)-(C(2869 to B) + (8
Benz (a)anthracene 2i
(i)
226
to 8))»i.eB8)
B 901120
229
V
8iB8T 1 1M * >" il T2 a
s'e lee ' lie ' 200 aAa ' sea
SAMP: S.WER.DIR, STD MIX CAL3 CB.Sug/Hl) 4273-88-4
CAP,3aM.B.32MM,l.eUM,7B-38Beia,38C«/ M. MOLLOV HD-BBB-F 12XB4/96 2B33
L841
IBO-
XFS-
e
'QS'2844 (25.443) COHB IME: (2644 to B)-(((2863 to B3+CB
0)
22^
T
S.3 75 ^T ]|^5 L^ W "^1
s'a ieo ' 190 ' 200
to B))«-1.BBB)
8 843776
229
a zfa
D, . ^241
zie ' sea
Figure 15 (Cont). Mass spectra of Compendium Method TO-13A
compounds for (i) benz(a)anthracene and (j) chrysene.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-73
-------
Method TO-13A
PAHs
SAMP: S,UKR,BIR, STD HIX CAL3 C0.5ugXnl> 4273-88-4
CAP, 38J1, 0.3ZMM,1. BUM, 78-368018, 3BCM/ M. HOLLO ¥ HD-888-F 12X84X96 2833
L84I
lea-
St**-
'QS'ZSBfi (28.863) COHBIME : (2386 to 8)-C«22B4 to 8>*C8 to 8))
BenzoCblf luorantjvene 3!
(K)
"\
i26
Hfl
112"il J 2*° 1
*S S,7 V 83 jHl I/27 2W ^* i
«1.8BB)
a 7BB416
asa
f*
n/i so ' i6a ' 150 ' aee ' asa ' 3011
-
SAMP: S,UER>DIR, SID HIX CALS ce.sug/Mi) 4273-88-4
CAP, 36O, 8. SZMMjl.BUH, 78-3808 IB .SeCMX M. HOLLOV MD-890-F 12X04/96 2833
L84I
10O
ars-
•d
QS'2312 (28.123) COMBINE: (2312 to BJ-CC123Z9 to B)*C8 to BJJ
BenzoCI()f luorairthene 3:
(1)
1.26 ««l
wsl 1
«a 1 0V •» «»| j M"J
*1.8fMJ
'8 £04033
353
r
s'o * iea lie ' aia asa ' aee
Figure 15 (Cont). Mass spectra of Compendium Method TO-13A
compounds for (k) benzo(b)fluoranthene and (1) benzo(k)fluoranthene.
Page I3A-74
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
SAMP: S,UER,BIR, STB MIX CAL3 (8.5ug/nl> 4273-88-4
CAP,38M,e.32Mri,l.BUM,78-3BB818,38CMX M. MOLLOV MB-888-F 12X84/96 2833
LB4F
100-
XFS-
1)5 2398 (28.983) COMBINE: (2398 to 8)-(((2374 to 8)+(8 to 8l)
Benzo(a)pyrene 2:
(m)
-TT -1
«1.888)
2 532480
f"
30 ' 100 150 ' 200 250 ' 300
SAMP: S,UER,DIH, STB MIX CAL3 (8.5ug/nl) 4273-88-4
CAP,3B«,8.32MM.1.8UM,7B-3B8018,3BCM/ M. MOLLOV HB-BBB-F 12^14X96 2833
L84I
100-
•XFS-
„,?
Q5'2384 (28.844) COMBINE: (2384 to 8)-(((2366 to 8)»(B to 8))
Benzo(o)pyrene 2!
(n)
250
125
<* 7,3 180^f 1 ±ff ^4 «
-------
Method TO-I3A
PAHs
SAMP: S,VER,DIR, STD MIX CAL3 CB.Sug/nl) 4273-88-4
CAP, 30M, 8. 32MM,1. BUM, 70-380810, 38CHX H. HOLLO V MD-888-r 12/B4/96 2833
L84I
•xFS-
e
"QS'2945 (34,454) COMBIME: (2945 to B)-(CC29f
BonzoCgjli, I Jpcrylano 3'
1
437
43 "S | ??•? I
3O ' J.OB
(0)
a
274
>4'7 221 272x
,f «3 195f,13^ f a*, )
08 in B)*(0 to B>)«1.088)
877
ft?««..f a,^^»
lia ' aaa ' ate see " 350 ' 460 ' 434
SAMP: SjUKR^DIRj STD MIX CAL3 ca.SugXnl) 4273-88-4
crtp.39MJB.32Hn.i.auni,7&-3Hagie,3Bcnx n. HQLLOV HD-qaa-F 12/84X96 zeaa
LB4fQ5'2826 (33.2&4J COMBIHE:C28Z6 to B)-CC(Z8B5 to MJ+tB to
(P)
ay?
160
isa
Figure 15 (Coot). Mass spectra of Compendium Method TO-13A
compounds for (o) benzo(g,h,i)perylene and (p) indeno(l,2,3-cd)pyrene.
Page 13A-76
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
PAHs
Method TO-13A
SAN?: S,UEB.DIR, SID HIX CAL3 CB.5u0./Ml> 4273-88-^1
CftP.3anJa.32HHJl.BUHJ7g-3eagiB,3BCM/ M. MQLLO¥ HD-888-F 12X84/96 2033
L84I
JLBB-
XFS
•Q5'2835 (33.354) COMBINE: C2B3S to 8)-acene 278
(q)
276
139
«P T ¥.^P 93.M3 1. fell 177 -i?a 2^ a,lB 87\l
274432
38B
6
MXz 30 ' IBB ' lia ' 28O ' ' ' 250 ' 3B8
Figure 15 (Cont). Mass spectra of Compendium Method TO-13A
compounds for (q) dibenz(a,h)anthracene.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 13A-77
-------
Method TO-13A
PAHs
SAMP: S,VER,DIR, STD MIX CAL3 CB.5ug/Pil> 4273-88-4
CflP,38HjB.32MH,l.BUH,7B-38BBia.3BCM/H. MQLLOV HP-88B-F 12X64/96 2833
L84FQ5
2138'
2726
fogjp.
3123
see
1BBO
158B
20061
258B
3 aee
Figure 16. Total ion chromatogram (TIC) of Compendium Method TO-13A target PAHs.
Page 13A-78
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
EPA/625/R-96/010b
Compendium of Methods
for the Determination of Toxic
Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-14A
Determination Of Volatile Organic
Compounds (VOCs) In Ambient Air Using
Specially Prepared Canisters With
Subsequent Analysis By Gas
Chromatography
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-14A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition, (EPA/625/R-96/010b), which was prepared under
Contract No. 68-C3-0315, WA No. 3-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern
Research Group, toe. (ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA).
Justice A. Manning, John O. Burckle, and Scott Hedges, Center for Environmental Research Information
(CERI), and Frank F. McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of
Research and Development, were responsible for overseeing the preparation of this method. 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, MB
* Michael 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
» Heidi Schuttz, ERG, Lexington, MA
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Method TO-14 was originally published in March of 1989 as one of a series of peer reviewed methods in the
second supplement to "Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air," EPA 600/4-89-018. Method TO-14 has been revised and updated as Method TO-14A in this
Compendium to eliminate time sensitivity material and correct a small number of errors.
Peer Reviewer
» Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Wbitaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence during
the development of this manuscript has enabled it's production.
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 TO-14A
Determination Of Volatile Organic Compounds (VOCs) In Ambient Air Using Specially
Prepared Canisters With Subsequent Analysis By Gas Chromatography
TABLE OF CONTENTS
Eags
1. Scope . 14A-1
2. Summary of Method 14A-1
3. Significance 14A-4
4. Applicable Documents 14A-5
4.1 ASTM Standards 14A-5
4.2 EPA Documents 14A-5
4.3 Other Documents 14A-6
5. Definitions 14A-6
6. Interferences and Limitations 14A-7
7. Apparatus 14A-7
7.1 Sample Collection 14A-7
7.2 Sample Analysis 14A-9
7.3 Canister Cleaning System 14A-11
7.4 Calibration System and Manifold 14A-11
8. Reagents and Materials 14A-11
8.1 Gas Cylinders of Helium, Hydrogen, Nitrogen, and Zero Air 14A-11
8.2 Gas Calibration Standards , 14A-11
8.3 Cryogen 14A-12
8.4 Gas Purifiers 14A-12
8.5 Deionized Water 14A-12
8.6 4-Bromofluorobenzene 14A-12
8.7 Hexane 14A-12
8.8 Metnanol 14A-12
9. Sampling System 14A-12
9.1 System Description 14A-12
9.1.1 Subatmospheric Pressure Sampling 14A-12
9.1.2 Pressurized Sampling 14A-13
9.1.3 All Samplers 14A-13
9.2 Sampling Procedure 14A-14
111
-------
TABLE OF CONTENTS (continued)
Ease
10, Analytical System 14A-15
10.1 System Description 14A-16
10.2 GC/MS/SCAN/SIM System Performance Criteria . . 14A-19
10.3 GC/FID/ECD System Performance Criteria (With Optional PED System) 14A-20
10.4 Analytical Procedures 14A-22
i
11, Cleaning and Certification Program 14A-25
11.1 Canister Cleaning and Certification 14A-25
r 11.2 Sampling System Cleaning and Certification 14A-26
12. Performance Criteria and Quality Assurance 14A-27
12.1 Standard Operating Procedures (SOPs) 14A-27
12,2 Method Relative Accuracy and Linearity 14A-27
12.3 Method Modification » 14A-28
12.4 Method Safety 14A-29
12.5 Quality Assurance 14A-29
13. Acknowledgements , 14A-30
14. References 14A-32
APPENDIX A. Availability of VOC Standards From U. S. Environmental Protection Agency (USEPA)
APPENDIX B, Operating Procedures for a Portable Gas Chromatograph Equipped with a
Photoionization Detector
APPENDIX C. Installation and Operating Procedures for Alternative Air Toxics Samplers
IV
-------
METHOD TO-14A
Determination Of Volatile Organic Compounds (VOCs) In Ambient Air Using Specially
Prepared Canisters With Subsequent Analysis By Gas Chromatography
1. Scope
1.1 This document describes a procedure for sampling and analysis of volatile organic compounds (VOCs) in
ambient air. The method was originally based on collection of whole air samples in SUMMA® passivated
stainless steel canisters, but has now been generalized to other specially prepared canisters (see Section 7.1.1.2).
The VOCs are separated by gas chromatography and measured by a mass spectrometer or by multidetector
techniques. This method presents procedures for sampling into canisters to final pressures both above and below
atmospheric pressure (respectively referred to as pressurized and subatmospheric pressure sampling),
1.2 This method is applicable to specific VOCs that have been tested and determined to be stable when stored
in pressurized and sub-atmospheric pressure canisters. Numerous compounds, many of which are chlorinated
VOCs, have been successfully tested for storage stability in pressurized canisters (1-3). However, minimal
documentation is currently available demonstrating stability of VOCs in subatmospheric pressure canisters.
13 The Compendium Method TO-14A target list is shown in Table 1. These compounds have been successfully
stored in canisters and measured at the parts per billion by volume (ppbv) level. This method applies under most
conditions encountered in sampling of ambient air into canisters. However, the composition of a gas mixture in
a canister, under unique or unusual conditions, will change so that the sample is known not to be a true
representation of the ambient air from which it was taken. For example, low humidity conditions in the sample
may lead to losses of certain VOCs on the canister walls, losses that would not happen if the humidity were
higher. If the canister is pressurized, then condensation of water from high humidity samples may cause
fractional losses of water-soluble compounds. Since the canister surface area is limited, all gases are in
competition for the available active sites. Hence an absolute storage stability cannot be assigned to a specific
gas. Fortunately, under conditions of normal usage for sampling ambient air, most VOCs can be recovered from
canisters near their original concentrations after storage times of up to thirty days.
2. Summary of Method
2.1 Both subatmospheric pressure and pressurized sampling modes typically use an initially evacuated canister
and pump-ventilated sample line during sample collection. Pressurized sampling requires an additional pump
to provide positive pressure to the sample canister. A sample of ambient air is drawn through a sampling train
comprised of components that regulate the rate and duration of sampling into a pre-evacuated specially prepared
passivated canister.
2.2 After the air sample is collected, the canister valve is closed, an identification tag is attached to the canister,
a chain-of-custody (COC) form completed, and the canister is transported to a predetermined laboratory for
analysis.
2.3 Upon receipt at the laboratory, the canister tag data is recorded, the COC completed, and the canister is
attached to the analytical system. During analysis, water vapor is reduced in the gas stream by a Nafion® dryer
(if applicable), and the VOCs are then concentrated by collection hi a cryogenically-cooled trap. The cryogen
is then removed and the temperature of the trap is raised The VOCs originally collected in the trap are
January 1999 Compendium of Methods for Toxic Organic Air PoUatants Page 14A-1
-------
Method TO-14A VOCs
revolatilized, separated on a GC column, then detected by one or more detectors for identification and
quantitation,
i
i
2.4 The analytical strategy for Compendium Method TO-14A involves using a high-resolution gas
chromatograph (GC) coupled to one or more appropriate GC detectors. Historically, detectors for a GC have
been divided into two groups: non-specific detectors and specific detectors. The non-specific detectors include,
but are not limited to, the nitrogen-phosphorus detector (NPD), the flame ionization detector (FDD), the electron
capture detector (BCD) and the photo-ionization detector (PID). The specific detectors include the linear
quadrupole mass spectrometer (MS) operating in either the select ion monitoring (SIM) mode or the SCAN mode,
or the ion trap detector (see Compendium Method TO-15). The use of these detectors or a combination of these
detectors as part of the analytical scheme is determined by the required specificity and sensitivity of the
application. While the non-specific detectors are less expensive per analysis and in some cases far more sensitive
than the specific detectors, they vary in specificity and sensitivity for a specific class of compounds. For
instance, if multiple halogenated compounds are targeted, an ECD is usually chosen; if only compounds
containing nitrogen or phosphorus are of interest, a NPD can be used; or, if a variety of hydrocarbon compounds
arc sought, the broad response of the FID or PID is appropriate, hi each of these cases, however, the specific
identification of the compound within the class is determined only by its retention time, which can be subject to
shifts or to interference from other non-targeted compounds. When misidentification occurs, the error is generally
a result of a cluttered chromatogram, making peak assignment difficult In particular, the more volatile organics
(chloroethanes, ethyltoluenes, dichlorobenzenes, and various freons) exhibit less well defined chromatographic
peaks, leading to possible misidentification when using nonspecific detectors. Quantitative comparisons indicate
that the FID is more subject to error than the ECD because the ECD is a much more selective detector and
exhibits a stronger response. Identification errors, however, can be reduced by: (a) employing simultaneous
detection by different detectors or (b) correlating retention times from different GC columns for confirmation.
In either case, interferences on the non-specific detectors can still cause error in identifying compounds of a
complex sample. The non-specific detector system (GC/NPD/FID/ECD/PID), however, has been used for
approximate quantitation of relatively clean samples. The non-specific detector system can provide a "snapshot"
of the constituents in the sample, allowing determination of:
i
— Extent of misidentification due to overlapping peaks.
— Determination of whether VOCs are within or not within concentration range, thus requiring further
analysis by specific detectors (GC/MS/SCAN/SIM) (i.e., if too concentrated, the sample is further
diluted).
— Provide data as to the existence of unexpected peaks which require identification by specific detectors.
On die other hand, the use of specific detectors (MS coupled to a GC) allows positive compound identification,
thus lending itself to more specificity than the multideteetor GC. Operating in the SIM mode, the MS can
readily approach the same sensitivity as the multideteetor system, but its flexibility is limited. For SIM
operation the MS is programmed to acquire data for a limited number of targeted compounds. In the SCAN
mode, however, the MS becomes a universal detector, often detecting compounds which are not detected by
the multideteetor approach. The GS/MS/SCAN will provide positive identification, while the GC/MS/SIM
procedure provides quantitation of a restricted list of VOCs, on a preselected target compound list (TCL).
l
If the MS is based upon a standard ion trap design, only a scanning mode is used (note however, that the Select
Ion Storage (SIS) mode of the ion trap has features of the SIM mode). See Compendium Method TO-15 for
further explanation and applicability of the ion-trap to the analysis of VOCs from specially prepared canisters.
Page 14A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
The analyst often must decide whether to use specific or non-specific detectors by considering such factors as
project objectives, desired detection limits, equipment availability, cost and personnel capability in developing
an analytic strategy. A list of some of the advantages and disadvantages associated with non-specific and
specific detectors may assist the analyst in the decision-making process.
Non-specific Multidetector Analytical System
Advantages
Somewhat lower equipment cost than GC/MS
Less sample volume required for analysis
More sensitive
- ECD may be 1000 tunes more sensitive than
GC/MS
Disadvantages
• Multiple detectors to calibrate
• Compound identification not positive
• Lengthy data interpretation (1 hour each for
analysis and data reduction)
• Interference(s) from co-eluting compound(s)
• Cannot identify unknown compounds
- outside range of calibration
- without standards
• Does not differentiate targeted compounds
from interfering compounds
Specific Detector Analytical System
GC/MS/SIM
Advantages
Disadvantages
positive compound identification
greater sensitivity than GC/MS/SCAN
less operator interpretation than
multidetector GC
can resolve co-eluting peaks
more specific than the multidetector GC
for
cannot identify nonspecified compounds (ions)
somewhat greater equipment cost than
multidetector GC
greater sample volume required than for
multidetector GC
universality of detector sacrified to achieve
enhancement in sensitivity
GC/MS/SCAN
• positive compound identification
• can identify all compounds
• less operator interpretation
• can resolve co-eluting peaks
lower sensitivity than GC/MS/SIM
greater sample volume required than for
multidetector GC
somewhat greater equipment cost than
multidetector GC
The analytical finish for the measurement chosen by the analyst should provide a definitive identification and
a precise quantitation of volatile organics. In a large part, the actual approach to these two objectives is subject
to equipment availability. Figure 1 indicates some of the favorite options that are used in Compendium
Method TO-14A. The GC/MS/SCAN option uses a capillary column GC coupled to a MS operated in a
scanning mode and supported by spectral library search routines. This option offers the nearest approximation
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-3
-------
Method TO-14A , , i VOCs
to unambiguous identification and covers a wide range of compounds as defined by the completeness of the
spectral library. GC/MS/SIM mode is limited to a set of target compounds which are user defined and is more
sensitive than GC/MS/SCAN by virtue of the longer dwell times at the restricted number of m/z values. Both
these techniques, but especially the GC/MS/SIM option, can use a supplemental general nonspecific detector
to verify/identify the presence of VOCs. Finally the option labelled GC-multidetector system uses a
combination of retention time and multiple general detector verification to identify compounds. However,
interference due to nearly identical retention times can affect system quantitation when using this option.
Due to low concentrations of toxic VOCs encountered in urban air (typically less than 25 ppbv and the majority
below 10 ppbv) along with their complicated ehromatographs, Compendium Method TO-14A strongly
recommends the specific detectors (GC/MS/SCAN/SIM) for positive identification and for primary
quantitation to ensure that high-quality ambient data is acquired.
: i
For tie experienced analyst whose analytical system is limited to the non-specific detectors, Section 10.3 does
provide guidelines and example ehromatograms showing typical retention times and calibration response
factors, and utilizing the nonspecific detectors (GC/F1D/ECD/PID) analytical system as the primary
quantitative technique.
" • i
Compendium Method TO-15 is now available as a guidance document containing additional advice on the
monitoring of VOCs. Method TO-15 contains information on alternative water management systems, has a
more complete quality control section, shows performance criteria that any monitoring technique must achieve
foe accepance, and provides guidance specifically directed at compound identification by mass spectrometry.
3. Significance
3.1 The availability of reliable, accurate and precise monitoring methods for toxic VOCs is a primary need for
state and local agencies addressing daily monitoring requirements related to odor complaints, fugitive emissions,
and trend monitoring, VOCs enter the atmosphere from a variety of sources, including petroleum refineries,
synthetic organic chemical plants, natural gas processing plants, biogenic sources, and automobile exhaust Many
of these VOCs are toxic so that their determination in ambient air is necessary to assess human health impacts.
i
32 The canister-based monitoring method for VOCs has proven to be a viable and widely used approach that
is based on research and evaluation performed since the early 1980s. This activity has involved the testing of
sample stability of VOCs in canisters and the design of time-integrative samplers, the development of procedures
for analysis of samples in canisters, including the procedure for VOC preconcentration from whole air, the
treatment of water vapor in the sample, and the selection of an appropriate analytical finish has been
accomplished. The canister-based method was initially summarized by EPA as Method TO-14 in the First
Supplement to the Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient
Air, The present document updates the original Compendium Method TO-14 with correction of time-sensitive
information and other minor changes as deemed appropriate.
i
33 The canister-based method is now a widely used alternative to the solid sorbent-based methods. The method
has sub-ppbv detection limits for samples of typically 300-500 mL of whole air and duplicate and replicate
precisions under 20 percent as determined in field tests. Audit bias values average within the range of
±10 percent These performance parameters are generally adequate for monitoring at the 10"s lifetime exposure
risk levels for many VOCs.
Page 14A-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
3.4 Collection of ambient air samples in canisters provides a number of advantages: (1) convenient integration
of ambient samples over a specific time period (e.g., 24 hours); (2) remote sampling and central analysis; (3) ease
of storing and shipping samples; (4) unattended sample collection; (5) analysis of samples from multiple sites
with one analytical system; (6) collection of sufficient sample volume to allow assessment of measurement
precision and/or analysis of samples by several analytical systems; and (7) storage stability for many VOCs over
periods of up to 30 days. To realize these advantages, care must be exercised in selection, cleaning, and handling
sample canisters and sampling apparatus to avoid losses or contamination,
3.5 Interior surfaces of canisters are treated by any of a number of passivation processes, one of which is
SUMMA polishing as identified to the original Compendium Method TO-14, Other specially prepared canisters
are also available (see Section 7.1.1.2).
3.6 The canister-based method for monitoring VOCs is the alternative to the solid sorbent-based method
described in conventional methods such as the Compendium Methods TO-1 and TO-2, and in the new
Compendium Method TO-17 that describes the use multisorbent packings including the use of new carbon-based
sorbents. It also is an alternative to on-site analysis in those cases where integrity of samples during storage and
transport has been established.
4. Applicable Documents
4.1 ASTM Standards
Method D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis
Method E260 Recommended Practice for General Gas Ckromatography
Method E355 Practice for Gas Chromatography Terms and Relationships
Method D31357 Practice for Planning and Sampling of Ambient Atmospheres
Method D5466-93 Determination of Volatile Organic Chemicals in Atmospheres (Canister Sampling
Methodology)
4.2 EPA Documents
• Technical Assistance Document for Sampling and Analysis Toxic Organic Compounds in Ambient Air,
U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
• Quality Assurance Handbook for Air Pollution Measurement Systems, U. S. Environmental Protection
Agency, EPA-€00/R-94-038b, May 1994.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-14, Second Supplement, U. S. Environmental Protection Agency, EPA 600/4-89-018, March 1989.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-15, Second Edition, U. S. Environmental Protection Agency, EPA 625/R-96-010b, January 1997.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, First
Supplement,, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA-60Q/4-87-Q06,
September 1997.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-1, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA-600/4-84-041, 1986.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-5
-------
Method TO-14A \ VOCs
4.3 Other Documents
7 • U. S, Environmental Protection Agency Technical Assistance Document (3).
• Laboratory and Ambient Air Studies (4-17).
5. Definitions
: Definitions used in this document and any user-prepared Standard Operating Procedures (SOPSs)
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 Absolute Canister Pressure (Pg-HPa) — gauge pressure in the canister (kPa, psi) and Pa = barometric
pressure (see Section 5.2).
•I
5.2 Absolute Pressure — pressure measured with reference to absolute zero pressure (as opposed to atmospheric
pressure), usually expressed as kPa, mm Hg or psia,
S3 Cryogen — a refrigerant used to obtain very low temperatures in the cryogenic trap of the analytical system.
A typical cryogen is liquid nitrogen (bp -195.8°C) or liquid argon (bp -185.7°C).
, „ ^
5.4 Dynamic Calibration — calibration of an analytical system using calibration gas standard concentrations
fa a form identical or very similar to the samples to be analyzed and by introducing such standards into the inlet
of the sampling or analytical system in a manner very similar to the normal sampling or analytical process.
Js.5 Gauge Pressure — pressure measured above ambient atmospheric pressure (as opposed to absolute
pressure). Zero gauge pressure is equal to ambient atmospheric (barometric) pressure.
i •. : • .
5.6 MS/SCAN — the GC is coupled to a MS programmed in the SCAN mode to scan all ions repeatedly during
the GC run. As used in the current context, this procedure serves as a qualitative identification and
characterization of the sample.
5.7 MS/SIM — the GC is coupled to a MS programmed to acquire data for only specified ions and to disregard
all others. This is performed using SIM coupled to retention time discriminators. The GC/SIM analysis provides
quantitative results for selected constituents of the sample gas as programmed by the user.
S& Megabore® Column — chromatographic column having an internal diameter (LD.) greater than 0.50-mm.
The Megabore® column is a trademark of the J&W Scientific Co. For purposes of this method, Megabore®
refers to chromatographic columns with 0.53-mm LD.
5.9 Pressurized Sampling — collection of an air sample in a canister with a (final) canister pressure above
atmospheric pressure, using a sample pump.
• • ' i
5.10 Qualitative Accuracy — the ability of an analytical system to correctly identity compounds.
5.1 1 Quantitative Accuracy — the ability of an analytical system to correctly measure the concentration of an
identified compound.
Page I4A-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
5.12 Static Calibration—calibration of an analytical system using standards in a form different from the
samples to be analyzed An example of a static calibration would be injecting a small volume of a high
concentration standard directly onto a GC column, bypassing the sample extraction and preconcentration portion
of the analytical system.
5.13 Sub atmospheric Sampling—collection of an air sample in an evacuated canister at a (final) canister
pressure below atmospheric pressure, without the assistance of a sampling pump. The canister is filled as the
internal canister pressure increases to ambient or near ambient pressure. An auxiliary vacuum pump may be used
as part of the sampling system to flush the inlet tubing prior to or during sample collection.
6. Interferences and Limitations
6.1 Interferences can occur in sample analysis if moisture accumulates in the dryer (see Section 10.1.1.2). An
automated cleanup procedure that periodically heats the dryer to about 100°C while purging with zero air
eliminates any moisture buildup. This procedure does not degrade sample integrity for Compendium
Method TO-14A target compound list (TCL) but can affect some organic compounds.
6.2 Contamination may occur in the sampling system if canisters are not properly cleaned before use.
Additionally, all other sampling equipment (e.g., pump and flow controllers) should be thoroughly cleaned to
ensure that the filling apparatus will not contaminate samples. Instructions for cleaning the canisters and
certifying the field sampling system are described in Sections 11.1 and 11.2, respectively.
6.3 The Compendium Method TO-I4A analytical system employs a Nafion® permeable membrane dryer to
remove water vapor from the sample stream. Polar organic compounds permeate this membrane in a manner
similar to water vapor and rearrangements can occur in some hydrocarbons due to the acid nature of the dryer.
Compendium Method TO-15 provides guidance associated with alternative water management systems
applicable to the analysis of a large group of VOCs in specially-treated canisters.
7. Apparatus
[Hois.: Equipment manufacturers identified in this section were originally published in Compendium
Method TO-14 as possible sources of equipment. They are repeated in Compendium Method TO-14A as
reference only. Other manufacturers' equipment should work as well, as long as the equipment is equivalent.
Modifications to these procedures may be necessary if using other manufacturers' equipment.]
7.1 Sample Collection
[Note: Subatmospheric pressure and pressurized canister sampling systems are commercially available and
have been used as part of U.S. Environmental Protection Agency's Toxic Air Monitoring Stations (TAMS),
Urban Air Toxic Monitoring Program (UATMP), the non-methane organic compound (NMOC) Sampling and
Analysis Program, and in the Photochemical Assessment Monitoring Stations (PAMS).J
7.1.1 Subatmospheric Pressure (see Figure 2 Without Metal Bellows Type Pump).
7.1.1.1 Sampling Inlet Line. Stainless steel tubing to connect the sampler to the sample inlet.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-7
-------
Method TO44A ; VOCs
i
7.1.13. SpecJally-Treated Sample Canister. Leak-free stainless steel pressure vessels of desired volume
(e.g,, 6 L), with valve and passivated interior surfaces. Major manufacturers and re-suppliers are:
i
! !
• BRC/Ramussen » XonTech Inc.
17010 NW Skyline Blvd. 6862 Hayenhurst Avenue
Portland, OR 97321 Van Nuys, CA 91406
• Meriter « Scientific Instrumentation Specialists
1790 Potrero Drive P.O. Box 8941
San Jose, CA 95124 Moscow, ED 83843
« Restec Corporation « Graseby
110 Benner Circle 500 Technology Ct.
Bellefonte, PA 16823-8812 Smyrna, GA 30832
I
|
7.1.1.3 Stainless Steel Vacuum/Pressure Gauge. Capable of measuring vacuum (—100 to 0 kPa or 0
to 30 in. Hg) and pressure (0-206 kPaor 0-30 psig) in the sampling system, Matheson, P.O. Box 136, Morrow,
GA 30200, Model 63-3704, or equivalent Gauges should be tested clean and leak tight
\ 7.1.1.4 Electronic Mass Flow Controller. Capable of maintaining a constant flow rate (± 10%) over
A sampling period of up to 24 hours and under conditions of changing temperature (20-40°C) and humidity,
Tylaa Corp., 19220 S. Normandie Ave., Torrance, CA 90502, Model FC-260, or equivalent
7.1.15 Particulate Matter Filter. 2-^m sintered stainless steel in-line filter, Nupro Co., 4800 E. 345th
St, Willoughby, OH 44094, Model SS-2F-K4-2, or equivalent
7.1.1.6 Electronic Timer. For unattended sample collection, Paragon Elect Co., 606 Parkway Blvd., P.O.
Box 28, Twin Rivers, WI54201, Model 7008-00, or equivalent
7.1.1.7 Solenoid Valve. Electrically-operated, bi-stable solenoid valve, Skinner Magnelatch Valve, New
Britain, CT, Model V5RAM49710, with Viton® seat and o-rings. A Skinner Magnelatch valve is used for
purposes of illustration only in Figures 2 and 3.
7.1.1.8 Chromatographic Grade Stainless Steel Tubing and Fittings. For interconnections, Alltech
Associates, 2051 Waukegan Rd,, Deerfield, IL 60015, Cat #8125, or equivalent All such materials in contact
with sample, analyte, and support gases prior to analysis should be chromatographic grade stainless steel.
7.1.1.9 Thermostatically Controlled Heater. To maintain temperature inside insulated sampler
enclosure above ambient temperature, Wallow Co., Pfafltown, NC, Part 04010080, or equivalent
7.1.1.10 Heater Thermostat Automatically regulates heater temperature, Elmwood Sensors, Inc., 500
Narragansett Park Dr., Pawtucket, RI02861, Model 3455-RC-0100-0222, or equivalent
7.1J.11 Fan. For cooling sample system, EG&G Rotron, Woodstock, NY, Model SUZAI, or equivalent
7.1.1.12 Fan Thermostat Automatically regulates fen operation, Elmwood Sensors, Inc., Pawtucket, RI,
Model 3455-RC-0100-0244, or equivalent
7.1.1.13 Maximum-Minimum Thermometer. Records highest and lowest temperatures during sampling
period, Thomas Scientific, Brooklyn Thermometer Co., Inc., P/N 9327H30, or equivalent
7.1.1.14 Stainless Steel Shut-Off Valve. Leak free, for vacuum/pressure gauge.
7.1.1.15 Auxiliary Vacuum Pump. Continuously draws ambient air through the inlet manifold at 10
L/min. or higher flow rate. Sample is extracted from the manifold at a lower rate, and excess air is exhausted.
[Hole.: The use of, higher inlet flow rates dilutes any contamination present in the inlet and reduces the
possibility of sample contamination as a result of contact with active adsorption sites on inlet wallsJ
Page 14A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs : Method TO-14A
7.1.1.16 Elapsed Time Meter. Measures duration of sampling, Conrac, Cramer Div., Old Saybrook, CT,
Type 6364, P/N 10082, or equivalent
7.1.1.17 Optional Fixed Orifice, Capillary, or Adjustable Micrometering Valve. May be used in lieu
of the electronic flow controller for grab samples or short duration time-integrated samples. Usually appropriate
only in situations where screening samples are taken to assess future sampling activity.
7.1.2 Pressurized (see Figure 2 With Metal Bellows Type Pump and Figure 3).
7.1.2.1 Sample Pump. Stainless steel, metal bellows type, Metal Bellows Corp., 1075 Providence
Highway, Sharon, MA 02067, Model MB-151, or equivalent, capable of 2 atmospheres output pressure. Pump
must be free of leaks, clean, and uncontaminated by oil or organic compounds.
[Note: An alternative sampling system has been developed by Dr. R. Rasmiissen, The Oregon Graduate
Institute of Science and Technology, 20000 N.W. Walker Rd., Beaverton, Oregon 97006, 503-690-1077,
(17,18) and is illustrated in Figure 3. This flow system uses, in order, a pump, a mechanical flow regulator,
and a mechanical compensation flow restrictive device. In this configuration the pump is purged with a large
sample flow, thereby eliminating the need for an auxiliary vacuumpump to flush the sample inlet. Interferences
using this configuration have been minimal.]
7.1.2.2 Other Supporting Materials. All other components of the pressurized sampling system (see
Figure 2 with metal bellows type pump and Figure 3) are similar to components discussed in Sections 7.1.1.1
through 7.1.1.16.
7.2 Sample Analysis
7.2.1 GC/MS/SCAN Analytical System (see Figure 4).
7.2.1.1 Gas Chromatograph. Capable of subambient temperature programming for the oven, with other
generally standard features such as gas flow regulators, automatic control of valves and integrator, etc. Flame
ionization detector optional, Hewlett Packard, Rt 41, Avondale, PA 19311, Model 5880A, with oven temperature
control and Level 4 BASIC programming, or equivalent. The GS/MS/SCAN analytical system must be capable
of acquiring and processing data in the MS/SCAN mode.
7.2.12 Chromatographic Detector. Mass-selective detector, Hewlett Packard, 3000-T Hanover St., 9B,
Palo Alto, CA 94304, Model HP-5970 MS, or equivalent, equipped with computer and appropriate software,
Hewlett Packard, 3000-T Hanover St., 9B, Palo Alto, CA 94304, HP-216 Computer, Quicksilver MS software,
Pascal 3.0, mass storage 9133 HP Winchester with 3.5 inch floppy disk, or equivalent. The GC/MS is set in the
SCAN mode, where the MS screens the sample for identification and quantitation of VOC species.
7.2.1.3 Cryogenic Trap with Temperature Control Assembly. Refer to Section 10.1.1.3 for complete
description of trap and temperature control assembly, Graseby, 500 Technology Ct, Smyrna, GA 30082) Model
320-01, or equivalent.
72.1.4 Electronic Mass Flow Controllers (3). Maintain constant flow (for carrier gas and sample gas)
and to provide analog output to monitor flow anomalies, Tylan Model 260, 0—100 mL/min, or equivalent.
7.2.1.5 Vacuum Pump. General purpose laboratory pump, capable of drawing the desired sample volume
through the cryogenic trap, Thomas Industries, Inc., Sheboygan, WI, Model I07BA20, or equivalent.
72,1,6 Chromatographic Grade Stainless Steel Tubing and Stainless Steel Plumbing Fittings. Refer
to Section 7.1.1.8 for description.
72.1.7 Chromatographic Column. To provide compound separation such as shown in Table 5. Hewlett
Packard, Rt. 41, Avondale, PA 19311. Typical GC column for this application is OV-1 capillary column,
0.32-mm x 50 m with 0.88-jwm crosslinked methyl silicone coating, or equivalent.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-9
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Method TO-14A VOCs
m 7.2.O Stainless Steel Vacuum/Pressure Gauge (Optional). Capable of measuring vacuum (-101.3
to 6 kPa) and pressure (0-206 kPa) in the sampling system, Matheson, P.O. Box 136, Morrow, GA 30200, Model
63-3704, or equivalent Gauges should be tested clean and tight.
7.2.1.9 Stainless Steel Cylinder Pressure Regulators. Standard, two-stage cylinder pressure gauges for
helium, zero air and hydrogen gas cylinders.
7.2.1.10 Gas Purifiers (3). Used to remove organic impurities and moisture from gas streams, Hewlett
Packard, Rt, 41, Avondale, PA 19311, P/N 19362 - 60500, or equivalent
i, 7.2.1.11 Low Dead-Volume Tee (optional). Used to split the exit flow from the GC column, Alltech
Associates, 2051 Waukegan Rd., Deerfleld, IL 60015, Cat #5839, or equivalent
i 7.2.1,12 Nafion® Dryer. Consisting of Nafion tubing coaxially mounted within larger tubing, Perma Pure
Products, 8 Executive Drive, Toms River, NJ 08753, Model MD-125-48, or equivalent Refer to Section
10.1.1.2 for description.
7.2.1.13 Sue-Port Gas Cromatographk Valve. Seismograph Service Corp., Tulsa, OK, Seiscor
Model VHI, or equivalent
7.2.1.14 Chart Recorder (optional). Compatible with the detector output signal to record optional FID
detector response to the sample.
7.2.1.15 Electronic Integrator (optional). Compatible with the detector output signal of the FID and
capable of integrating the area of one or more response peaks and calculating peak areas corrected for baseline
drift.
7.2.2 GC/MS/SM Analytical System (see Figure 4).
: 73.,2.1 The GC/MS/SIM analytical system must be capable of acquiring and processing data in the MS-
SIMmode.
7.2.2.2 All components of the GC/MS/SIM system are identical to Sections 7.2.1.1 through 7.2.1.15.
7J2.3 GC-MuMdeteetor Analytical System (see Figure 5 and Figure 6).
7.2.3.1 Gas Chromatograph with Flame lonization and Electron. Capture Detectors
(Photoionization Detector Optional). Capable of sub-ambient temperature programming for the oven and
simultaneous operation of all detectors, and with other generally standard features such as gas flow regulators,
automatic control of valves and integrator, etc., Hewlett Packard, Rt 41, Avondale, PA 19311, Model 5990A,
with oven temperature control and Level 4 BASIC programming, or equivalent
7.23.2 Chart Recorders, Compatible with the detector output signals to record detector response tot he
sample.
7.2.33 Electronic Integrator. Compatible with the detector output signals and capable of integrating
the area of one or more response peaks and calculating peak areas corrected for baseline drift.
7.2.3.4 Six-Port Gas Chromatographic Valve. See Section 7 2.1.13.
7.2.35 Cryogenic Trap with Temperature Control Assembly. Refer to Section 10.1.1.3 for complete
description of trap and temperature control assembly, Graseby, 500 Technology Ct, Smyrna, GA 30082, Model
320-01, or equivalent
7.23.6 Electronic Mass Flow Controllers (3). Maintain constant flow (for carrier gas, nitrogen make-up
gas and sample gas) and to provide analog output to monitor flow anomalies, Tylan Model 260, O-lOO mL/min,
or equivalent
• 7.23.7 Vacuum Pump. General purpose laboratory pump, capable of drawing the desired sample volume
through the cryogenic trap (see Section 7.2.1.6 for source and description).
'' 7.23.8 Chromatographic Grade Stainless Steel Tubing and Stainless Steel Plumbing Fittings. Refer
to Section 7.1.1.8 for description.
7.23.9 Chromatographic Column. To provide compound separation such as shown in Table 7, Hewlett
Packard, Rt 41, Avondale, PA 19311. Typical GC column for this application is OV-1 capillary column, 0.32
mm x 50 m with 0.88 um crosslinked methyl silicone coating, or equivalent
Page 14A-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
[Note: Other columns (e.g., DB-624) can be used as long as the system meets user needs. The Wider
Megabore9 column fl,e.t 0.53-mm l.D.) is less susceptible to plugging as a result of trapped water, thus
eliminating the need far Nqflon9 dryer in the analytical system. The Megabore9 column has sample capacity
approaching that of a packed column, while retaining much of the peak resolution traits of narrower columns
Ci.e.,0.32-mmLD.).]
7.2.3.10 Vacuum/Pressure Gauges (3). Refer to Section 7.2.1.9 for description.
7.2.3,11 Cylinder Pressure Stainless Steel Regulators. Standard, two-stage cylinder regulators with
pressure gauges for helium, zero air, nitrogen, and hydrogen gas cylinders.
7.23.12 Gas Purifiers (4). Used to remove organic impurities and moisture from gas streams, Hewlett
Packard, Rt, 41, Avondale, PA 19311, P/N 19362 - 60500, or equivalent
7.2.3.13 Low Dead-Volume Tee. Used to split (50/50) the exit flow from the GC column, Alltech
Associates, 2051 Waukegan Rd., Deerfield, IL 60015, Cat. #5839, or equivalent.
7.3 Canister Cleaning System (see Figure 7)
73.1 Vacuum Pump. Capable of evacuating sample eanister(s) to an absolute pressure of <0.05 mm Hg.
7.3 J. Manifold. Stainless steel manifold with connections for simultaneously cleaning several canisters.
7.33 Shut-off Valve(s). Seven (7) on-off toggle valves.
7.3.4 Stainless Steel Vacuum Gauge. Capable of measuring vacuum in the manifold to an absolute
pressure of 0.05 mm Hg or less.
73.5 Cryogenic Trap (2 required). Stainless steel U-shaped open tubular trap cooled with liquid oxygen
or argon to prevent contamination from back diffusion of oil from vacuum pump and to provide clean, zero air
to sample canister(s).
73.6 Stainless Steel Pressure Gauges (2). 0-345 kPa (0-50 psig) to monitor zero air pressure.
7.3.7 Stainless Steel Flow Control Valve. To regulate flow of zero air into canister(s).
73.8 Humidifier. Pressurizable water bubbler containing high performance liquid chromatography (HPLC)
grade deionized water or other system capable of providing moisture to the zero air supply.
73.9 Isothermal Oven (optional). For heating canisters, Fisher Scientific, Pittsburgh, PA, Model 349, or
equivalent.
7.4 Calibration System and Manifold (see Figure 8)
7.4.1 Calibration Manifold. Glass manifold, (1.25-cm I.D. x 66-cm) with sampling ports and internal
baffles for flow disturbance to ensure proper mixing.
7.4.2 Humidifier. 500-mL impinger flask containing HPLC grade deionized water.
7.43 Electronic Mass Flow Controllers. One 0 to 5 L/min and one 0 to 50 mL/min, Tylan Corporation,
23301-TS Wilmington Ave., Carson, CA 90745, Model 2160, or equivalent
7.4.4 Teflon® Filter(s). 47-mm Teflon<§ filter for particulate control, best source.
8. Reagents and Materials
8.1 Gas Cylinders of Helium, Hydrogen, Nitrogen, and Zero Air. Ultrahigh purity grade, best source.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-11
-------
Method TO-14A VOCs
8.2 Gas Calibration Standards. Cylinders) containing approximately 10 ppmv of each of the following
compounds of interest
vinyl chloride
vinylidene chloride
l,l,2-trichloro-l,2,2-trifluoroethane
chloroform
1,2-dicfaloroetfaane
benzene
toluene methyl chloroform
Freon 12 carbon tetrachloride
methyl chloride trichloroethylene
1,2-diehloro-1,1,2,2-tetrafluoroetbane cis-1,3-dichloropropene
methyl bromide trans-1,3-dichloropropene
ethyl chloride ethylbenzene
Freon 11 o-xylene
dicblorometfaane m-xylene
1,1-dicholoroethane p-xylene
cis-l,2-dicholoroethylene styrene
1,2-dichloropropane 1,1,2,2-tetrachloroethane
r. 1,1,2-tricMoroethane 1,3,5-trimethylbenzene
1,2-dibromoethane 1,2,4-trimelhylbenzene
tetrachloroethylene m-dichlorobenzene
cblorobenzene o-dichlorobenzene
benzyl chloride p-dichlorobenzene
hexachloro-l,3-butadiene 1,2,4-trichlorobenzene
The cylinder should be traceable to a National Institute of Standards and Technology (NIST) Standard
Reference Material (SRM). The components may be purchased in one cylinder or may be separated into
different cylinders. Refer to manufacturer's specification for guidance on purchasing and mixing VOCs in
gas cylinders. Those compounds purchased should match one's own TCL.
83 Cryogen. Liquid nitrogen (bp-195.8°C) or liquid argon (bp-185.7°C), best source.
8.4 Gas Purifiers. Connected in-line between hydrogen, nitrogen, and zero air gas cylinders and system inlet
line, to remove moisture and organic impurities from gas streams, Alltech Associates, 2051 Waukegan Rd,
Deerfield, IL 60015, or equivalent
8.5 Deionized Water. HPLC grade, ultrahigh purity (for humidifier), best source.
8.6 4-Brotnofluorofacnzene. Used for tuning GC/MS, best source.
8.7 Heiane. For cleaning sample system components, reagent grade, best source.
8.8 Methanol. For cleaning sampling system components, reagent garde, best source.
Page I4A-12 ComperuBum of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
9. Sampling System
9.1 System Description
9.1.1 Subatmospheric Pressure Sampling [see Figure 2 (Without Metal Bellows Type Pump)],
9.1.1.1 In preparation for subatmospheric sample collection in a canister, the canister is evacuated to 0.05
mm Hg. When opened to the atmosphere containing the VOCs to be sampled, the differential pressure causes
the sample to flow into the canister. This technique may be used to collect grab samples (duration of 10 to 30
seconds) or time-integrated samples (duration of 12-24 hours) taken through a flow-restrictive inlet (e.g., mass
flow controller, critical orifice).
9.1.1.2 With a critical orifice flow restrictor, there will be a decrease hi the flow rate as the pressure
approaches atmospheric. However, with a mass flow controller, the subatmospheric sampling system can
maintain a constant flow rate from full vacuum to within about 7 kPa (1.0 psig) or less below ambient pressure,
9.1.2 Pressurized Sampling [See Figure 2 (With Metal Bellows Type Pump)].
9.1.2.1 Pressurized sampling is used when longer-term integrated samples or higher volume samples are
required. The sample is collected in a canister using a pump and flow control arrangement to achieve a typical
103-206 kPa (15-30 psig) final canister pressure. For example, a 6-liter evacuated canister can be filled at 10
mL/min for 24 hours to achieve a final pressure of about 144 kPa (21 psig),
9.1.2.2 In pressurized canister sampling,a metal bellows type pump draws in ambient air from the
sampling manifold to fill and pressurize the sample canister.
9.1.3 All Samplers.
9.1.3.1 A flow control device is chosen to maintain a constant flow into the canister over the desired
sample period. This flow rate is determined so the canister is filled (to about 88.1 kPa for subatmospheric
pressure sampling or to about one atmosphere above ambient pressure for pressurized sampling) over the desired
sample period. The flow rate can be calculated by
F-
Tx 60
where:
F = flow rate, mL/min.
P = final canister pressure, atmospheres absolute. P is approximately equal to
kPa gauge + ^
101.2
V = volume of the canister, mL.
T = sample period, hours.
For example, if a 6-L canister is to be filled to 202 kPa (2 atmospheres) absolute pressure in 24 hours, the flow
rate can be calculated by
F - 2 * 600Q - 8.3 ml/min
24 x 60
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-13
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Method TO-14A VOCs
For automatic operation, the timer is wired to start and stop the pump at appropriate times for the
desired sample period. The timer must also control the solenoid valve, to open the valve when starting the pump
and close the valve when stopping the pump.
r 9.13 3 The use of the Skinner Magnelatch valve avoids any substantial temperature rise that would occur
with a conventional, normally closed solenoid valve that would have to be energized during the entire sample
period. The temperature rise in the valve could cause outgassing of organic compounds from the Viton valve seat
material. The Skinner Magnelatch valve requires only a brief electrical pulse to open or close at the appropriate
start and stop times and therefore experiences no temperature increase. The pulses may be obtained either with
art electronic tinier that can be programmed for short (5 to 60) seconds ON periods, or with a conventional
mechanical timer and a special pulse circuit. A simple electrical pulse circuit for operating the Skinner
Msgnelatch solenoid valve with a conventional mechanical timer is illustrated in Figure 9(a). However, with this
simple circuit, the valve may operate unreliably during brief power interruptions or if the timer is manually
switched on and off too fast A better circuit incorporating a time-delay relay to provide more reliable valve
operation is shown in Figure 9(b),
9.1.3.4 The connecting lines between the sample inlet and the canister should be as short as possible to
minimize their volume. The flow rate into the canister should remain relatively constant over the entire sampling
period. If a critical orifice is used, some drop in the flow rate may occur near the end of the sample period as the
canister pressure approaches the final calculated pressure.
9.1 .3.5 As an option, a second electronic timer (see Section 7. 1. 1.6) may be used to start the auxiliary
pump several hours prior to the sampling period to flush and condition the inlet line.
9.1.3.6 Prior to field use, each sampling system must pass a humid zero air certification (see
Section 1 1.2.2). All plumbing should be check carefully for leaks. The canisters must also pass a humid zero
air certification before use (see Section 1 1. 1).
9.2 Sampling Procedure
9.2.1 The sample canister should be cleaned and tested according to the procedure in Section 11.1.
9.2.2 A sample collection system is assembled as shown in Figure 2 (and Figure 3) and must meet
certification requirements as outlined in Section 1 1.2.3.
/MM2." The sampling system should.be contained in an appropriate enclosure.]
9.2.3 Prior to locating the sampling system, the user may want to perform "screening analyses" using a
portable GC system, as outlined in Appendix B, to determine potential volatile organics present and potential "hot
spots." The information gathered from the portable GC screening analysis would be used in developing a
monitoring protocol, which includes the sampling system location, based upon the "screening analysis" results.
9.2.4 After "screening analysis," the sampling system is located. Temperatures of ambient air and sampler
box interior are recorded on the Compendium Method TO- 14A field test data sheet (FTDS), as illustrated in
Figure 10.
[$ote: The following discussion is related to Figure 2.J
' i.: '! ' j
9.2 £ To verify correct sample flow, a "practice" (evacuated) canister is used in the sampling system.
-' For a svbatmospheric sampler, the flow meter and practice canister are needed. For the pump-driven
system, the practice canister is not needed, as the flow can be measured at the outlet of the system.]
Page 14A-14 Compendium ofMetltodsfor Toxic Organic Air Pollutants January 1999
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VOCs _ _ _ Method TO-14A
A certified mass flow meter is attached to the inlet line of the manifold, just in front of the filter. The canister
is opened. The sampler is turned on and the reading of the certified mass flow meter is compared to the
sampler mass flow controller. The valves should agree within ± 10%. If not, the sampler mass flow meter
needs to be recalibrated or there is a leak in the system. This should be investigated and corrected.
Mass flow meter readings may drift. Check the zero reading carefully and add or subtract the zero
reading when reading or adjusting the sampler flow rate, to compensate for any zero drift. ]
After two minutes, the desired canister flow rate is adjusted to toe proper value (as indicated by the certified
mass flow meter) by the sampler flow control unit controller (e.g., 3.5 mL/min for 24 hr, 7.0 mL/rain for 12
hr). Record final flow under "CANISTER FLOW RATE," as provided in Figure 10.
9.2.6 The sampler is turned off and the elapsed time meter is reset to 000.0.
[Hoje,; Any time the sampler is turned off, wait at least 30 seconds to turn the sampler back on.]
9.2.7 The "practice" canister and certified mass flow meter are disconnected and a clean certified (see
Section 11.1) canister is attached to the system.
9.2.8 The canister valve and vacuum/pressure gauge valve are opened.
9.2.9 Pressure/vacuum in the canister is recorded on the canister sampling field data sheet (see Figure 10)
as indicated by the sampler vacuum/pressure gauge.
9.2.10 The vacuum/pressure gauge valve is closed and the maximum-minimum thermometer is reset to
current temperature. Time of day and elapsed time mete1 readings are recorded on the canister sampling field data
sheet
9J2.11 The electronic timer is set to begin and stop the sampling period at the appropriate times. Sampling
commences and stops by the programmed electronic timer.
9.2.12 After the desired sampling period, the maximum, minimum, current interior temperature and current
ambient temperature are recorded on the sampling field data sheet The current reading from the flow controller
is recorded.
9.2.13 At the end of the sampling period, the vacuum/pressure gauge valve on the sampler is briefly opened
and closed and the pressure/vacuum is recorded on the sampling FTDS. Pressure should be close to desired
pressure.
For a subatmospheric sampling system, if the canister is at atmospheric pressure when the field final
pressure check is performed, the sampling period may be suspect. This information should be noted on the
sampling FTDS.]
Time of day and elapsed time meter readings are also recorded.
9,2.14 The canister valve is closed. The sampling line is disconnected from the canister and the canister is
removed from the system. For a subatmospheric system, a certified mass flow meter is once again connected to
the inlet manifold in front of the in-line filter and a "practice" canister is attached to the Magnelatch valve of the
sampling system. The final flow rate is recorded on the canister sampling field data sheet (see Figure 10).
[Nojte: For a pressurized system, the final flow may be measured directly.}
The sampler is turned off.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-1S
-------
Method TO-14A | VOCs
92.15 An identification tag is attached to the canister. Canister serial number, sample number, location, and
date arc recorded on the tag. Complete the Chain-of-Custody (COC) for the canister and ship back to the
laboratory for analysis.
10. Analytical System (see Figures 4, 5 and 6)
The following section relates to the use of the linear quadrupole MS technology as the detector. The
Ion-trap technology is as applicable to the detection ofVOCsfrom a specially-treated canister. EPA developed
this method using the linear quadrupole MS, as part of it's air toxics field and laboratory monitoring programs
over the last several years. Modifications to these procedures may be necessary if other technology is utilized.}
I
10.1 System Description
10.1.1 GC/MS/SCAN System.
10.1,1,1 The analytical system is comprised of a GC equipped with a mass-selective detector set in the
SCAN mode (see Figure 4). All ions are scanned by the MS repeatedly during the GC run. The system includes
a computer and appropriate software for data acquisition, data reduction, and data reporting. A 400 mL air
saffiple is collected from the canister into the analytical system. The sample air is first passed through a Nafion®
dryer, through the 6-port chromatographic valve, then routed into a cryogenic trap.
[Ho!£: While the GC-multidetector analytical system does not employ a Nafion* dryer for drying the sample
gas stream, it is used here because the GC/MS system utilizes a larger sample volume and is far more sensitive
to excessive moisture than the GC-multidetector analytical system. Moisture can adversely affect detector
precision. The Nafion* dryer also prevents freezing of moisture on the 0.32-mm l.D. column, which may cause
column blockage and possible breakage.]
The trap is heated (-160°C to I20°C in 60 sec) and the analyte is injected onto the OV-1 capillary column
(0.32-mm x 50-m).
Rapid heating of the trap provides efficient transfer of the sample components onto the gas
chromatographic column.]
\
Upon sample injection unto the column, the MS computer is signaled by the GC computer to begin detection
of compounds which elute from the column. The gas stream from the GC is scanned within a preselected
range of atomic mass units (amu). For detection of compounds in Table 1, the range should be 18 to 250 amu,
resulting in a 1 ,5 Hz repetition rate. Six (6) scans per eluting chromatographic peak are provided at this rate.
The 10-15 largest peaks are chosen by an automated data reduction program, the three scans nearest the peak
apex are averaged, and a background subtraction is performed. A library search is men performed and the
top ten best matches for each peak are listed. A qualitative characterization of the sample is provided by this
procedure. A typical chromatogram of VOCs determined by GC/MS/SCAN is illustrated in Figure 11 (a).
10.1.1.2 A Nafion® permeable membrane dryer is used to remove water vapor selectively from the sample
stream. The permeable membrane consists of Nafion® tubing (a copolymer of tetrafluoroethylene and
0uorosulfonyl monomer) that is coaxially mounted within larger tubing. The sample stream is passed through
the interior of the Nafion® tubing, allowing water (and other light, polar compounds) to permeate through the
walls into the dry purge stream flowing through the annular space between the Nafion® and outer tubing.
Page 14A-16 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
[Note: To prs-.-erj excessive moisture build-up and any memory effects in the dryer, a clean-up procedure
involving periodic heating of the dryer (100 °Cfor 20 minutes) while purging with dry zero air (~500 mL/min)
should be implemented as pan of the user's SOP ittanual. The clean-up procedure is repeated during each
analysis (7). Studies have indicated no substantial bss of targeted VOCs utilizing the above clean-up procedure
(7). However, use of the cleanup procedure for compounds other than those on the TCL can lead to loss of
sample integrity (19). This clean-up procedure is particularly usefiil when employing cryogenic
preconcentration of VOCs with subsequent GC analysis using a 0.32-mm I.D. column because excess
accumulated water can cause trap and column blockage and also adversely affect detector precision. In
addition, the improvement in water removal from the sampling stream will allow analyses of much larger
volumes of sample air in the event that greater system sensitivity is required for targeted compounds.]
10.1.13 The packed metal tubing used for reducing temperature trapping of VOCs is shown in Figure 12.
The cooling unit is comprised of a 0.32-cm outside diameter (O.D.) nickel tubing loop packed with 60-80 mesh
Pyrex® beads, Nutech Model 320-01, or equivalent The nickel tubing loop is wound onto a cylindrically formed
tube heater (~250 watt). A cartridge heater (~25 watt) is sandwiched between pieces of aluminum plate at the
trap inlet and outlet to provide additional heat to eliminate cold spots in the transfer tubing. During operation,
the trap is inside a two-section stainless steel shell which is well insulated. Rapid heating (-150 to +100°C in
55 s) is accomplished by direct thermal contact between the heater and the trap tubing. Cooling is achieved by
vaporization of the cryogen. In the shell, efficient cooling (+120 to -150° C in 225 s) is facilitated by confining
the vaporized cryogen to the small open volume surrounding the trap assembly. The trap assembly and
chromatographic valve are mounted on a baseplate fitted into the injection and auxiliary zones of the GC on an
insulated pad directly above the column oven for most commercially available GC systems.
(Note: Alternative trap assembly and connection to the GC may be used depending on the user's requirements.]
The carrier gas line is connected to the injection end of the analytical column with a zero-dead-volume fitting
that is usually held hi the heated zone above the GC oven. A 15-cm x 15-cm x 24-cm aluminum box is flitted
over the sample handling elements to complete the package. Vaporized cryogen is vented through the top of
the box.
10.1.1.4 As an option, the analyst may wish to split the gas stream exiting the column with a low dead-
volume tee, passing one-third of the sample gas (~1.0 mL/min) to the mass-selective detector and the remaining
two-thirds (~2.0 mL/min) through an FID, as illustrated as an option in Figure 4. The use of the specific detector
(MS/SCAN) coupled with the non-specific detector (FID) enables enhancement of data acquired from a single
analysis, hi particular, the FID provides the user:
• Semi-real time picture of the progress of the analytical scheme.
• Confirmation by the concurrent MS analysis of other labs that can provide only FID results.
• Ability to compare GC/FID with other analytical laboratories with only GC/FID capability.
10.1.2 GC/MS/SIM System.
10.1.2.1 The analytical system is comprised of a GC equipped with an OV-1 capillary column (0.32-mm
x 50-m) and a mass-selective detector set in the SIM mode (see Figure 4). The GC/MS is set up for automatic,
repetitive analysis. The system is programmed to acquire data for only the target compounds and to disregard
all others. The sensitivity is 0.1 ppbv for a 250 mL air sample with analytical precision of about 5% relative
standard deviation. Concentration of compounds based upon a previously installed calibration table is reported
January 1999 Compendium, of Methods for Toxic Organic Air Pollutants Page 14A-17
-------
Method TO44A _ VOCs
by an automated^ data reduction program. A Nafion® dryer is also employed by this analytical system prior to
cryogenic preconcentration; therefore, many polar compounds are not identified by this procedure.
10.1.2.2 SIM analysis is based on a combination of retention times and relative abundances of selected
ions (see Table 2). These qualifiers are stored on the hard disk of the GC/MS computer and are applied for
identification of each chromatographic peak The retention time qualifier is determined to be ± 0.10 minute of
the library retention time of the compound. The acceptance level for relative abundance is determined to be ±
15% of the expected abundance, except for vinyl chloride and methylene chloride, which is determined to be ±
25%. Three ions are measured for most of the forty compounds. When compound identification is made by the
computer., any peak that fails any of the qualifying tests is flagged (e.g., with an *). All the data should be
manually examined by the analyst to determine the reason for the flag and whether the compound should be
reported as found Whfle this adds some subjective judgment to the analysis, computer-generated identification
problems can be clarified by an experienced operator. Manual inspection of the quantitative results should also
be performed to verify concentrations outside the expected range. A typical chromatogram of VOCs determined
by GC/MS/SM mode is illustrated in Figure 1 l(b).
10.1.3 GC-Multidetector (GC/FTO/ECD) System with Optional PID.
10.1J3.1 The analytical system (see Figure 5) is comprised of a gas chromatograph equipped with a
capillary column and electron capture and flame ionization detectors (see Figure 5). In typical operation, sample
air from pressurized canisters is vented past the inlet to the analytical system from the canister at a flow rate of
75 mL/mut For analysis, only 35 mL/min of sample gas is used, while excess is vented to the atmosphere. Sub-
ambient pressure canisters are connected directly to the inlet and air is pulled through a trap by a downstream
vacuum. The sample gas stream is routed through a six port chromatographic valve and into the cryogenic trap
for a total sample volume of 490 mL.
[Hois," This represents a 14 minute sampling period at a rate of 35 mL/min.]
The trap (see Section 10.1.1.3) is cooled to -150°C by controlled release of a cryogen. VOCs are condensed
on the trap surface while N2, O2, and other sample components are passed to the pump. After the organic
compounds are concentrated, the valve is switched and the trap is heated. The revolatilized compounds are
transported by helium carrier gas at a rate of 4 mL/min to the head of the Megabore* OV-1 capillary column
(0.53-mm x 30-m). Since the column initial temperature is at -50°C, the VOCs are cryofocussed on the head
of the column. Then, the oven temperature is programmed to increase and the VOCs in me carrier gas are
chromatographicaEy separated. The carrier gas containing the separated VOCs is then directed to two parallel
detectors at a flow rate of 2 mL/min each. The detectors sense the presence of the speciated VOCs, and the
response is recorded by either a strip chart recorder or a data processing unit.
10.1.3.2 Typical chromatograms of VOCs determined by the GC/FID/ECD analytical system are
illustrated in Figures ll(c) and ll(d), respectively.
10.1.3.3 Helium is used as the carrier gas (~4 mL/min) to purge residual air from the trap at the end of
the sampling phase and to carry the revolatilized VOCs through the Megabore* GC column. Moisture and
organic impurities are removed from the helium gas stream by a chemical purifier installed in the GC (see Section
7.2.1.11). After exiting the OV-1 Megabore* column, the carrier gas stream is split to the two detectors at rates
of -2 mL/min each.
10.1.3.4 Gas scrubbers containing Drierite* or silica gel and 5A molecular sieve are used to remove
moisture and organic impurities from the zero air, hydrogen, and nitrogen gas streams.
Purity of gas purifiers is checked prior to use by passing humid zero-air through the gas purifier and
analyzing according to Section 11.2.2.]
Page 14A-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
10.1.3.5 All lines should be kept as short as practical. All tubing used for the system should be
chromatographic grade stainless steel connected with stainless steel fittings. After assembly, the system should
be checked for leaks according to manufacturer's specifications.
10.13.6 The FID burner air, hydrogen, nitrogen (make-up), and helium (carrier) flow rates should be set
according to the manufacturer's instructions to obtain an optimal FID response while maintaining a stable flame
throughout the analysis. Typical flow rates are: burner air, 450 mL/min; hydrogen, 30 raL/min; nitrogen, 30
ml ,/mitr helium, 2 mL/min.
10.1.3.7 The ECD nitrogen make-up gas and helium carrier flow rates should be set according to
manufacturer's instructions to obtain an optimal ECD response. Typical flow rates are: nitrogen, 76 mL/min and
helium, 2 mL/min.
10.13.8 The GC/FID/ECD could be modified to include a PID (see Figure 6) for increased sensitivity (20).
In the photoionkation process, a molecule is ionized by ultraviolet light as follows: R + hv - R* + e-, where R*
is the ionized species and a photon is represented by hv, with energy less than or equal to the ionization potential
of the molecule. Generally all species with an ionization potential less than the ionization energy of the lamp are
detected Because the ionization potential of all major components of air (O2, N^ CO, CO2, and H2O) is greater
than the ionization energy of lamps in general use, they are not detected. The sensor is comprised of an argon-
filled, ultraviolet (UV) light source where a portion of the organic vapors are ionized in the gas stream. A pair
of electrodes are contained in a chamber adjacent to the sensor. When a potential gradient is established between
the electrodes, any ions formed by the absorption of UV light are driven by the created electric field to the
cathode, and the current (proportional to the organic vapor concentration) is measured. The PID is generally used
for compounds having ionization potentials less than the ratings of the ultraviolet lamps. This detector is used
for determination of most chlorinated and oxygenated hydrocarbons, aromatic compounds, and high molecular
weight aliphatic compounds. Because the PID is insensitive to methane, ethane, carbon monoxide, carbon
dioxide, and water vapor, it is an excellent detector. The electron volt rating is applied specifically to the
wavelength of the most intense emission line of the lamp's output spectrum. Some compounds with ionization
potentials above the amp rating can still be detected due to the presence of small quantities of more intense light.
A typical system configuration associated with the GC/FID/ECD/PID is illustrated in Figure 6,
10.2 GC/MS/SCAN/SIM System Performance Criteria
10.2.1 GC/MS System Operation.
10.2.1.1 Prior to analysis, the GC/MS system is assembled and checked according to manufacturer's
instructions.
10.2.1.2 Table 3.0 outlines general operating conditions for the GC/MS/SCAN/SIM system with optional
FID.
10.2.1.3 The GC/MS system is first challenged with humid zero air (see Section 11.2.2).
10.2.1.4 The GC/MS and optional FDD system is acceptable if it contains less than 0.2 ppbv of targeted
VOCs.
10.2.2 Daily GC/MS Tuning (see Figure 13)
10.2.2.1 At the beginning of each day or prior to a calibration, the GC/MS system must be tuned to verify
that acceptable performance criteria are achieved.
10.2.2.2 For tuning the GC/MS, a cylinder containing 4-bromofluorobenzene (4-BFB) is introduced via
a sample loop valve injection system.
[Mots.: Some systems allow auto-tuning to facilitate this process.]
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-19
-------
Method TO44A 5 ; VOCs
i
The key ions and ion. abundance criteria that must be met are illustrated in Table 4. Analysis should not begin
until all those criteria are met.
10.2.2.3 The GC/MS tuning standard could also be used to assess GC column performance
(chronaatographic check) and as an internal standard. Obtain a background correction mass spectra of 4-BFB
and check that all key ions criteria are met. If the criteria are not achieved, the analyst must retune the mass
spectrometer and repeat the test until all criteria are achieved.
10.2.2.4 The performance criteria must be achieved before any samples, blanks or standards are analyzed
If any key ion abundance observed for the daily 4-BFB mass tuning check differs by more than 10% absolute
abundance from that observed during the previous daily tuning, the instrument must be retimed or the sample
and/or calibration gases reanalyzed until the above condition is met.
^10.2.3 GC/MS Calibration (see Figure 13)
lNoi$: Initial and routine calibration procedures are illustrated in Figure 13.]
' 10.2,3.1 Initial Calibration. Initially, a multipoint dynamic calibration (three levels plus humid zero air)
is performed on the GC/MS system, before sample analysis, with the assistance of a calibration system (see
Figure 8). The calibration system uses MIST traceable standards [containing a mixture of the targeted VOCs at
ixxninal concentrations of 10 ppmv in nitrogen (see Section 8.2)] as working standards to be diluted with humid
zero air. the contents of the working standard cylinders) are metered (~2 mL/min) into the heated mixing
chamber where they are mixed with a 2-L/min humidified zero air gas stream to achieve a nominal 10 ppbv per
compound calibration mixture (see Figure 8). This nominal 10 ppbv standard mixture is allowed to flow and
equilibrate for a minimum of 30 minutes. After the equilibration period, the gas standard mixture is sampled and
analyzed by the real-time GC/MS system [see Figure 8(a) and Section 7.2.1]. The results of the analyses are
averaged, flow audits are performed on the mass flow meters and the calculated concentration compared to
generated values. After the GC/MS is calibrated at three concentration levels, a second humid zero air sample
is passed through the system and analyzed. The second humid zero air test is used to verify that the GC/MS
system is certified clean (<0.2 ppbv of target compounds).
i
As an alternative, a multipoint humid static calibration (three levels plus zero humid air) can be performed on
the GC/MS system. During the humid static calibration analyses, three (3) specially-treated canisters are filled
each at a different concentration between 1-20 ppbv from the calibration manifold using a pump and mass flow
control arrangement [see Figure 8(c)]. The canisters are then delivered to the GC/MS to serve as calibration
standards. The canisters are analyzed by the MS in the SIM mode, each analyzed twice.
%
''£ ' '-* J * m • • f
The expected retention time and ion abundance (see Table 2 and Table 5) are used to verify proper operation of
the GC/MS system. A calibration response factor is determined for each analyte, as illustrated in Table 5, and
the computer calibration table is updated with this information, as illustrated in Table 6. The relative standard
deviation (RSD) of the response factors should be <30% for the curve to be acceptable. If the RSD is >30%,
rccalibration is required. The samples are calculated using the mean of the response factors.
10.232 Routine Calibration. The GC/MS system is calibrated daily (and before sample analysis) with
a one-point calibration. The GC/MS system is calibrated either with the dynamic calibration procedure [see
Figure 8(a)] or with a 6-L specialty prepared passivated canister filled with humid calibration standards from the
calibration manifold (see Section 10.2.3.2). After the single point calibration, the GC/MS analytical system is
challenged with a humidified zero gas stream to insure the analytical system returns to specification (<0.2 ppbv
of selective organics). The relative percent difference (RPD) of each response factor from the mean response
factor of the initial calibration curve should be <30% for continued use of the mean response factors. If the RPD
is >30%, recalibration is required.
Page 14A-20 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
10.3 GC/FID/ECD System Performance Criteria (With Optional PID System) [see Figure 14])
10.3.1 Humid Zero Air Certification
103.1.1 Before system calibration and sample analysis, the GC/FED/ECD analytical system is assembled
and checked according to manufacturer's instructions.
10.3.1.2 The GC/FID/ECD system is first challenged with humid zero air (see Section 11.2.2) and
monitored.
10.3.1,3 Analytical systems contaminated with <0.2 ppbv of targeted VOCs are acceptable.
10.3.2 GC Retention Time Windows Determination (see Table 7)
10.3.2.1 Before analysis can be performed, the retention time windows must be established for each
analyte.
10.3.2.2 Make sure the GC system is within optimum operating conditions.
10.3.2.3 Make three injections of the standard containing all compounds for retention time window
determination.
[Note: The retention time window must be established for each analyte every 72 hours during continuous
operation.]
10.3.2.4 Calculate the standard deviation of the three absolute retention times for each single component
standard. The retention window is defined as the mean plus or minus three times the standard deviation of the
individual retention times for each standard In those cases where the standard deviation for a particular standard
is zero, the laboratory must substitute the standard deviation of a closely-eluting, similar compound to develop
a valid retention time window.
10.3.2.5 The laboratory must calculate retention time windows for each standard (see Table 7) on each
GC column, whenever a new GC column is installed or when major components of the GC are changed. The data
must be noted and retained in a notebook by the laboratory as part of the user SOP and as a quality assurance
check of the analytical system.
10.3.3 GC Calibration
[Note: Initial and routine calibration procedures are illustrated in Figure 14.]
1033.1 Initial Calibration. Initially, a multipoint dynamic calibration (three levels plus humid zero air)
is performed on the GC/FID/ECD system, before sample analysis, with the assistance of a calibration system (see
Figure 8). The calibration system uses NIST traceable standards or [containing a mixture of the targeted VOCs
at nominal concentrations of 10 ppmv in nitrogen (see Section 8.2)] as working standards to be diluted with
humid zero air. The contents of the working standard cylinders are metered (2 mL/min) into the heated mixing
chamber where they are mixed with a 2-L/min humidified zero air stream to achieve a nominal 10 ppbv per
compound calibration mixture (see Figure 8). This nominal 10 ppbv standard mixture is allowed to flow and
equilibrate for an appropriate amount of time. After the equilibration period, the gas standard mixture is sampled
and analyzed by the GC/MS system [see Figure 8(a)|. The results of the analyses are averaged, flow audits are
performed on the mass flow controllers used to generate the standards and the appropriate response factors
(concentration/area counts) are calculated for each compound, as illustrated in Table 5. The relative standard
deviation (RSD) of the response factors should be <30% for the curve to be acceptable. If the RSD is
> 30%, recalibration is required. The samples are calculated using the mean of the response factors.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-21
-------
Method TO-14A VOCs
(Note: GC/FIDs are linear in the 1-20 ppbv range and may not require repeated multipoint calibrations;
whereas, the GC/ECD will require frequent linearity evaluation.]
i
Table 5 outlines typical calibration response factors and retention times for 40 VOCs. After the GC/FID/ECD
is calibrated at the three concentration levels, a second humid zero air sample is passed through the system and
analyzed. The second humid zero air test is used to verify that the GC/FID/ECD system is certified clean (<0.2
ppbv of target compounds).
7 10.3.3,2 Routine Calibration. A one point calibration is performed daily on the analytical system to
verily the initial multipoint calibration (see Section 10.3,3.1). The analyzers (GC/FID/ECD) are calibrated
(before sample analysis) using the static calibration procedures (see Section 10.2.3.2) involving pressurized gas
cylinders containing low concentrations of the targeted VOCs (-10 ppbv) in nitrogen. After calibration, humid
zero air is once again passed through the analytical system to verify residual VOCs are not present The relative
percent difference (RPD) of each response factor from the mean response factor of the initial calibration curve
should be <30% for continued use of the mean response factors. If the RPD is >30%, recalibration is required.
10.3.4 GQFID/ECD/PID System Performance Criteria
10.3.4.1 As an option, the user may wish to include a PID to assist in peak identification and increase
sensitivity.
10.3.4JL This analytical system has been used in U.S. Environmental Protection Agency's Urban Air Toxic
Monitoring Program (UATMP).
10,3.4.3 Preparation of the GC/FID/ECD/PID analytical system is identical to the GC/FID/ECD system
(see Section 10.3).
103.4.4 Table 8 outlines typical retention times (minutes) for selected organics using the
GC/FID/ECD/PID analytical system.
10.4 Analytical Procedures
10.4.1 Canister Receipt
10.4.1.1 The overall condition of each sample canister is observed Each canister should be received with
an attached sample identification tag and FTDS. Complete the canister COC.
10.4.1.2 Each canister is recorded in the dedicated laboratory logbook. Also noted on the identification
tag are date received and initials of recipient
10.4.1.3 The pressure of the canister is checked by attaching a pressure gauge to the canister inlet The
canister valve is opened briefly and the pressure (kPa, psig) is recorded.
(Note: If pressure is <83 kPa (<12 psig), the user may wish to pressurize the canisters, as an option, with
zero grade nitrogen up to 137 kPa (20 psig) to ensure that enough sample is available for analysis. However,
pressurizing the canister can introduce additional error, increase the minimum detection limit (MDL), and
is time consuming. The user should weigh these limitations as part of his program objectives before
pressurizing.]
Final cylinder pressure is recorded on the canister FTDS (see Figure 10),
10.4.1.4 If the canister pressure is increased, a dilution factor (DF) is calculated and recorded oa the
sampling data sheet
Page 14A-22 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
DF -L
X.
where:
5Q = canister pressure absolute before dilution, kPa, psia.
Ya = canister pressure absolute after dilution, kPa, psia.
After sample analysis, detected VOC concentrations are multiplied by the dilution factor to determine
concentration in the sampled air.
10.4.2 GC/MS/SCAN Analysis (With Optional FID System)
10.42,1 "Die analytical system should be properly assembled, humid zero air certified (see Section 11.3),
operated (see Table 3), and calibrated for accurate VOC determination.
10,4.2.2 The mass flow controllers are checked and adjusted to provide correct flow rates for the system.
10.4.23 The sample canister is connected to the inlet of the GC/MS/SCAN (with optional FED) analytical
system. For pressurized samples, a mass flow controller is placed on the canister and the canister valve is opened
and the canister flow is vented past a tee inlet to the analytical system at a flow of 75 mL/min so that 35 mL/min
is pulled through the Nafion* dryer to the six-port chromatographic valve.
[Note: Flow rate is not as important as acquiring sufficient sample volume.}
Sub-ambient pressure samples are connected directly to the inlet
10.4.2,4 The GC oven and cryogenic trap (inject position) are cooled to their set points of -50°C and
-150°C, respectively.
10.4.2J As soon as the cryogenic trap reaches its lower set point of-150°C, the six-port chromatographic
valve is turned to its fill position to initiate sample collection.
10.4,2.6 A 10 minute collection period of canister sample is utilized.
[Note: 40 mL/min x 10 min = 400 mL sampled canister contents.]
10.42.1 After the sample is preconcentrated in the cryogenic trap, the GC sampling valve is cycled to the
inject position and the cryogenic trap is heated The trapped analytes are thermally desorbed onto the head of the
OV-1 capillary column (0.31-mm ID. x 50-m length). The GC oven is programmed to start at -50°C and after
2 min to heat to 150°C at a rate of 8°C per minute.
10.4.2.8 Upon sample injection onto the column, the MS is signaled by the computer to scan the eluting
carrier gas from 18 to 250 amu, resulting in a 1.5 Hz repetition rate. This corresponds to about 6 scans per
eluting chromatographic peak.
10,4.2.9 Primary identification is based upon retention time and relative abundance of eluting ions as
compared to the spectral library stored on the hard disk of the GC/MS data computer.
10.4.2.10 The concentration (ppbv) is calculated using the previously established response factors (see
Section 10.2.3.2), as illustrated in Table 5.
[Note: If the canister is diluted before analysis, an appropriate multiplier is applied to correct for the volume
dilution of the canister (see Section 10.4.1.4),]
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-23
-------
Method TO-14A ' VOCs
10.4.2.11 The optional FID trace allows the analyst to record the progress of the analysis.
10.4.3 GC/MS/SIM Analysis (With Optional FID System).
• 10.4.3.1 When the MS is placed in the SIM mode of operation, the MS monitors only preselected ions,
rather than scanning all masses continuously between two mass limits,
10.4.3.2 As a result, increased sensitivity and improved quantitative analysis can be achieved.
10.43.3 Similar to the GC/MS/SCAN configuration, the GC/MC/SIM analysis is based on a combination
of retention times and relative abundances of selected ions (see Table 2 and Table 5). These qualifiers are stored
on the hard disk of the GC/MS computer and are applied for identification of each chromatographic peak. Once
the GC/MS/SIM has identified the peak, a calibration response factor is used to determine the analyte's
concentration.
10.43.4 The individual analyses are handled in three phases: data acquisition, data reduction, and data
reporting. The data acquisition software is set in the SIM mode, where specific compound fragments are
monitored by the MS at specific times in the analytical run. Data reduction is coordinated by the postprocessing
macro program that is automatically accessed after data acquisition is completed at the end of the GC run.
Resulting ion profiles are extracted, peaks are identified and integrated, and an internal integration report is
generated by the program. A reconstructed ion chromatogram for hardcopy reference is prepared by the program
and various parameters of interest such as time, date, and integration constants are printed. At the completion
of the macro program, the data reporting software is accessed. The appropriate calibration table (see Table 9)
is retrieved by the data reporting program from the computer's hard disk storage and the proper retention time
and response factor parameters are applied to the macro program's integration file. With reference to certain pre-
set acceptance criteria, peaks are automatically identified and quantified and a final summary report is prepared,
as illustrated in Table 10.
10.4.4 GOTTD/ECD Analysis (With Optional PID System)
10.4.4.1 The analytical system should be properly assembled, humid zero air certified (see Section 12.2)
and calibrated through a dynamic standard calibration procedure (see Section 10.3.2). The FID detector is lit and
allowed to stabilize.
10.4.43, Sixty-four minutes are required for each sample analysis: 15 min for system initialization, 14 min
for sample collection, 30 min for analysis, and 5 min for post-time, during which a report is printed.
(Note: This may vary depending upon system configuration and programming.]
10.4.43 The helium and sample mass flow controllers are checked and adjusted to provide correct flow
rates for the system. Helium is used to purge residual air from the trap at the end of the sampling phase and to
carry the revolatilized VOCs from the trap onto the GC column and into the FDD/ECD. The hydrogen, burner
air, and nitrogen flow rates should also be checked. The cryogenic trap is connected and verified to be operating
properly while flowing cryogen through the system.
10,4.4.4 The sample canister is connected to the inlet of the GC/FID/ECD analytical system. The canister
valve is opened and the canister flow is vented past a tee inlet to the analytical system at 75 mL/min using a mass
flow controller. During analysis, 35 mL/min of sample gas is pulled through the six-port chromatographic valve
and routed through the trap at the appropriate time while the extra sample is vented. The VOCs are condensed
m the trap while the excess flow is exhausted through an exhaust vent, which assures that the sample air flowing
"through the trap is at atmospheric pressure.
10.4.4.5 The six-port valve is switched to the inject position and the canister valve is closed.
10.4.4.6 The electronic integrator is started.
10.4.4.7 After the sample is preeoneentrated on the trap, the trap is heated and the VOCs are thermally
desorbed onto the head of the capillary column. Since the column is at -50°C, the VOCs are cryofocussed on the
Page 14A-24 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs : Method TO-14A
column. Then, the oven temperature (programmed) increases and the VOCs elute from the column to the parallel
FED/ECD assembly.
10,4,4.8 The peaks elutiag from the detectors are identified by retention time (see Table 7 and Table 8),
while peak areas are recorded in area counts. Typical response of the FID and BCD, respectively, for the forty
(40) targeted VOCs identified in Compendium Method TQ-14A are illustrated in Figures 15 and 16, respectively.
[Note: Refer to Table 7 for peak number and identification,]
10.4.4.9 The response factors (see Section 10.3.3.1) are multiplied by the area counts for each peak to
calculate ppbv estimates for the unknown sample. If the canister is diluted before analysis, an appropriate
dilution multiplier (DF) is applied to correct for the volume dilution of the canister (see Section 10.4.1.4).
10,4.4.10 Each canister is analyzed twice and the final concentrations for each analyte are the averages
of the two analyses.
10.4.4.11 However, if the GC/FED/ECD analysis shows unexpected peaks which need further identification
and attention or overlapping peaks are discovered, eliminating possible quantitation, the sample should then be
subjected to a GC/MS/SCAN for positive identification and quantitation.
11. Cleaning and Certification Program
11.1 Canister Cleaning and Certification
11.1.1 All canisters must be clean and free of any contaminants before sample collection.
11.1.2 All canisters are leak tested by pressurizing them to approximately 206 kPa (~30 psig) with zero air.
[Note: The canister cleaning system in Figure 7 can be used for this task. The initial pressure is measured,
the canister value is closed, and the final pressure is checked after 24 hours. If leak tight, the pressure should
not vary more than ± 13.8 kPa (± 2 psig) over the 24 hour period.]
11.1.3 A canister cleaning system, may be assembled as illustrated in Figure 7. Cryogen is added to both the
vacuum pump and zero air supply traps. The canister(s) are connected to the manifold. The vent shut-off valve
and the canister valve(s) are opened to release any remaining pressure in the canister(s). The vacuum pump is
started and the vent shut-off valve is then closed and the vacuum shut-off valve is opened. The canister(s) are
evacuated to <0.05 mm Hg (for at least one hour).
[Note: On a daily basis or more often if necessary, the cryogenic traps should be purged with zero air to
remove any trapped water from previous canister cleaning cycles.]
11.1.4 The vacuum and vacuum/pressure gauge shut-off valves are closed and the zero air shut-off valve is
opened to pressurize the canister(s) with humid zero air to approximately 206 kPa (~30 psig). If a zero gas
generator system is used, the flow rate may need to be limited to maintain the zero air quality.
11.1.5 The zero shut-off valve is closed and the canister(s) is allowed to vent down to atmospheric pressure
through the vent shut-off valve. The vent shut-off valve is closed. Repeat Sections 11.1.3 through 11.1.5 two
additional times for a total of three (3) evacuation/pressurization cycles for each set of canisters.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-25
-------
Method TO-14A | VOCs
* 11.1.6 At the end of the evacuation/pressurization cycle, the canister is pressurized to 206 kPa (30 psig) with
humid zero air. The canister is then analyzed by a GC/MS or GC/FID/ECD analytical system. Any canister that
has not tested clean (compared to direct analysis of humidified zero air of <0.2 ppbv of targeted VOCs) should
not be used. As a "blank" check of the canister(s) and cleanup procedure, the final humid zero air fill of 100%
of the canisters is analyzed until the cleanup system and canisters are proven reliable (<0.2 ppbv of targeted
VOCs). The check can then be reduced to a lower percentage of canisters.
f 11.1.7 The canister is reattached to the cleaning manifold and is then reevacuated to <0.05 mm Hg and
remains in this condition until used The canister valve is closed. The canister is removed from the cleaning
system and the canister connection is capped with a stainless steel fitting. The canister is now ready for collection
of an air sample. An identification tag is attached to the neck of each canister for field notes and chain-of-custody
purposes. « \
. 11,1.8 As an option to the humid zero air cleaning procedures, the canisters could be heated in an isothermal
oven to 100°C during the procedure described in Section 11.1.3 to assist in removing less volatile VOCs from
thp walls of the canister.
i
i
flfote: Do not heat the values of the canister during Ms sequence.]
Once heated, the canisters are evacuated to 0.05 mm Hg. At the end of the heated/evacuated cycle, the canisters
are pressurized with humid zero air and analyzed by the GC/FID/ECD system. Any canister that has not tested
clean (<0.2 ppbv of targeted compounds) should not be used. Once tested clean, the canisters are reevacuated
to 0.05 mm Hg and remain in the evacuated state until used
11.2 Sampling System Cleaning and Certification
: ••'. •-- . . .
11.2.1 Cleaning Sampling System Components
112.1.1 Sample components are disassembled and cleaned before die sampler is assembled Nonmetallic
parts are rinsed with HPLC grade deionized water and dried in a vacuum oven at 50*C. Typically, stainless steel
parts and fittings are cleaned by placing them in a beaker of methanol in an ultrasonic bath for 15 minutes. This
procedure is repeated with hexane as the solvent
11.2,1.2 The parts are then rinsed with HPLC grade deionized water and dried in a vacuum oven at 100°C
for 12 to 24 hours.
" 11.2.1.3 Once the sampler is assembled, the entire system is purged with humid zero air for 24 hours.
11.2.2 Humid Zero Air Certification
[Note: In the following sections, "certification" is defined as evaluating the sampling system with humid zero
air and humid calibration gases that pass through all active components of the sampling system. The system
is "certified" if no significant additions or deletions (<0.2 ppbv of targeted compounds) have occurred when
challenged -with the test gas stream.]
'- 11.2 2,1 The cleanliness of the sampling system is determined by testing the sampler with humid zero air
without an evacuated gas cylinder, as foEows.
11.2.2.2 Thejjalibration system and manifold are assembled as Elustrated in Figure 8. The sampler
(without an evacuated gas cylinder) is connected to the manifold and the zero air cylinder activated to generate
a humid gas stream (~2 L/min) to the calibration manifold [see Figure 8(b)].
11223 The humid zero gas stream passes through the calibration manifold through the sampling system
(without an evacuated canister) to a GC/FID/ECD analytical system at 75 mL/min so that 35 mL/min is pulled
Pagel4A-26 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs _ ; _ Method TO-14A
through the six-port valve and routed through the cryogenic trap (see Section 10.2.2. 1) at the appropriate time
while the extra sample is vented.
{Note: The exit of the sampling system (without the canister) replaces the canister in Figure 4.]
After the sample (~400 mL) is preconcentrated on the trap, the trap is heated and the VOCs are thermally
desorbed onto the head of the capillary column. Since the column is at -50°C, the VOCs are cryofocussed on the
column. Then, the oven temperature (programmed) increases and the VOCs begin to elute and are detected by
a GC/MS (see Section 10.2) or the GC/FID/ECD (see Section 10.3). The analytical system should not detect
greater than 0.2 ppbv of targeted VOCs in order for the sampling system to pass the humid zero air certification
test Chromatograms of a certified sampler and contaminated sampler are illustrated in Figures 17(a) and (b),
respectively. If the sampler passes the humid zero air test, it is then tested with humid calibration gas standards
containing selected VOCs at concentration levels expected in field sampling (e.g., -0.5 to 2 ppbv) as outlined
in Section 1 1.2.3.
11.2.3 Sampler System Certification with Humid Calibration Gas Standards.
11.2.3.1 Assemble the dynamic calibration system and manifold as illustrated in Figure 8.
11.2.3.2 Verify that the calibration system is clean (less than 0.2 ppbv of targeted compounds) by
sampling a humidified gas stream, -without gas calibration standards, with a previously certified clean canister
(see Section 12.1).
1 1233 The assembled dynamic calibration system is certified clean if <0.2 ppbv of targeted compounds
are found.
11.23.4 For generating the humidified calibration standards, the calibration gas cylinder(s) (see Section
8.2) containing nominal concentrations of 10 ppmv in nitrogen of selected VOCs, are attached to the calibration
system, as outlined in Section 10.2.3. 1. The gas cylinders are opened and the gas mixtures are passed through
0 to 10 mL/min certified mass flow controllers and blended with humidified zero air to generate ppbv levels of
calibration standards.
11.2.3.5 After the appropriate equilibrium period, attach the sampling system (containing a certified
evacuated canister) to the manifold, as illustrated in Figure 8(a).
11,23.6 Sample the dynamic calibration gas stream with the sampling system according to Section 9.2. 1.
[Note: To conserve generated calibration gas, bypass the canister sampling system manifold and attach the
sampling system to the calibration gas stream at the inlet of the in-line filter of the sampling system so the flow
less than 500 mL/min.]
11.23.7 Concurrent with the sampling system operation, realtime monitoring of the calibration gas stream
is accomplished by the on-line GC/MS or GC-multideteetor analytical system [Figure 8(b)] to provide reference
concentrations of generated VOCs.
11.23.8 At the end of the sampling period (normally same time period used for anticipated sampling), the
sampling system canister is analyzed and compared to the reference GC/MS or GC-muIti-detector analytical
system to determine if the concentration of the targeted VOCs was increased or decreased by the sampling
system.
11.2.3.9 A recovery of between 90% and 1 10% is expected for all targeted VOCs.
12. Performance Criteria and Quality Assurance
January 1999 Compendium of Methods for Toxic Organic Air PoOutants Page 14A-27
-------
Method TO-14A ; VOCs
12.1 Standard Operating Procedures (SOPs)
12.1,1 SOPs should be generated in each laboratory describing and documenting the following activities:
(1) assembly, calibration, leak check, and operation of specific sampling systems and equipment used; (2)
preparation, storage, shipment, and handling of samples; (3) assembly, leak-check, calibration, and operation of
tfie analytical system, addressing the specific equipment used; (4) canister storage and cleaning; and (5) all
aspects of data recording and processing, including lists of computer hardware and software used.
12.1.2 Specific stepwise instructions should be provided in the SOPs and should be readily available to and
understood by the laboratory personnel conducting the work.
L" : - - p ; •« .
12.2 Method Relative Accuracy and Linearity
1U.1 Accuracy can be determined by injecting VOC standards (see Section 8.2) from an audit cylinder into
a sampler. The contents are then analyzed for the components contained in the audit canister. Percent relative
accuracy is calculated:
X - Y
% Relative Accuracy = x 100
J\,
where:
'! 1^™ concentration of the targeted compound recovered from sampler, ppbv.
X = concentration of VOC targeted compounds in the NIST-SRM audit cylinders, ppbv.
122.2 If the relative accuracy does not fall between 90 and 110 percent, the field sampler should be removed
from use, cleaned, and recertified according to initial certification procedures outlined in Sections 11.2.2 and
11.2.3. Historically, concentrations of carbon tetrochloride, tetrachloroethylene, and hexaehlorobutadiene have
sometimes been detected at lower concentrations when using parallel ECD and FED detectors. When these three
compounds are present at concentrations close to calibration levels, both detectors usually agree on the reported
concentrations. At concentrations below 4 ppbv, there is a problem with nonlinearity of the ECD. Plots of
concentration versus peak area for calibration compounds detected by the ECD have shown that the curves are
nonlinear for carbon tetrachloride, tetrachloroethylene, and hexachlorobutadiene, as illustrated in Figures 18(a)
through 18(c). Other targeted ECD and FID compounds scaled linearly for the range 0 to 8 ppbv, as shown for
chloroform in Figure 18(d). For compounds that are not linear over the calibration range, area counts generally
roll off between 3 and 4 ppbv. To correct for the nonlinearity of these compounds, an additional calibration step
is performed. An evacuated stainless steel canister is pressurized with calibration gas a nominal concentration
of 8 ppbv. The sample is then diluted to approximately 3.5 ppbv with zero air and analyzed. The instrument
response factor (ppbv/area) of the ECD for each of the three compounds is calculated for the 3.5 ppbv sample.
Then, both the 3.5 ppbv and the 8 ppbv response factors are entered into the ECD calibration table. Most
commercial analytical systems have software designed to accommodate multilevel calibration entries, so the
correct response factors are automatically calculated for concentrations in this range.
123 Method Modification
12.3.1 Sampling
123.1.1 The sampling system for pressurized canister sampling could be modified to use a lighter, more
compact pump. The pump currently being used weights about 16 kilograms (~35 Ibs). Commercially available
pumps that could be used as alternatives to the prescribed sampler pump arc described below. Metal Bellow MB-
Page 14A-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs ; Method TO-14A
41 pomp: These pumps are cleaned at the factory; however, some precaution should be taken with the circular
(~4.8 cm diameter) Teflon® and stainless steel part directly under the flange. It is often dirty when received and
should be cleaned before use. This part is cleaned by removing it from the pump, manually cleaning with
deionized water, and placing in a vacuum oven at 100 °C for at least 12 hours. Exposed parts of the pump head
arc also cleaned with swabs and allowed to air dry. These pumps have proven to be very reliable; however, they
are only useful up to an outlet pressure of about 137 kPa (~20 psig). Neuberger Pump: Viton gaskets or seals
must be specified with this pump. The "factory direct" pump is received contaminated and leaky. The pump is
cleaned by disassembling the pump head (which consists of three stainless steel parts and two gaskets), cleaning
the gaskets with deionized water and drying in a vacuum oven, and remachining (or manually lapping) the sealing
surfaces of the stainless steel parts. The stainless steel parts are then cleaned with methanol, hexane, deionized
water and heated in a vacuum oven. The cause for most of the problems with this pump has been scratches on
the metal parts of the pump head. Once this rework procedure is performed, the pump is considered clean and
can be used up to about 240 kPa (~35 psig) output pressure. This pump is utilized in the sampling system
illustrated in Figure 3.
12.3.1.2 Alternative Sampler Configuration. The sampling system described in Compendium
Method TO-14A can be modified as described in Appendix C (see Figure C-l). Originally, this configuration
was used in EPA's FY-88 Urban Air Toxics Pollutant Program.
12.3.2 Analysis.
12.3.2.1 Wet tubing from the calibration manifold could be heated to 50 °C (same temperature as the
calibration manifold) to prevent condensation on the internal walls of the system.
12-53,3, The analytical strategy for Method TO-14A involves positive identification and quantitation by
GC/MS/SCAN/SIM mode of operation with optional FID. This is a highly specific and sensitive detection
technique. Because a specific detector system (GC/MS/SCAN/SIM) is more complicated and expensive than
the use of non-specific detectors (GC/FID/ECD/PDD), the analyst may want to perform a screening analysis and
preliminary quantitation of VOC species in the sample, including any polar compounds, by utilizing the GC-
multidetector (GC/FID/ECD/PID) analytical system prior to GC/MS analysis. This system can be used for
approximate quaatitation. The GC/FID/ECD/PID provides a "snap-shot" of the constituents in the sample,
allowing the analyst to determine:
- Extent of misidentification due to overlapping peaks.
- Whether the constituents are within the calibration range of the anticipated GC/MS/SCAN/SIM
analysis or does the sample require further dilution.
- Are there unexpected peaks which need further identification through GC/MS/SCAN or are there peaks
of interest needing attention?
If unusual peaks are observed from the GC/FID/ECD/PID system, the analyst then performs a GC/MS/SCAN
analysis. The GC/MS/SCAN will provide positive identification of suspect peaks from the GC/FID/ECD/PID
system. If no unusual peaks are identified and only a select number of VOCs are of concern, the analyst can then
proceed to GC/MS/SIM. The GC/MS/SIM is used for final quantitation of selected VOCs. Polar compounds,
however, cannot be identified by the GC/MS/SIM due to the use of a Nafion® dryer to remove water from the
sample prior to analysis. The dryer removes polar compounds along with the water. The analyst often has to
make this decision incorporating project objectives, detection limits, equipment availability, cost and personnel
capability in developing an analytical strategy. The use of the GC/FID/ECD/PID as a "screening" approach, with
the GC/MS/SCAN/SIM for final identification and quantitation, is outlined in Figure 20,
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-29
-------
Method TO-14A ' VOCs
12.4 Method Safety
This procedure may involve hazardous materials, operations, and equipment. This method does not purport to
acidress all of the safety problems associated with its use. It is the user% responsibility to establish appropriate
safety and health practices and determine the applicability of regulatory limitation prior to the implementation
of this procedure. This should be part of the user's SOP manual.
12*3 Quality Assurance (see Figure 21)
12.5.1 Sampling System
12.5.1.1 Section 9,2 suggests that a portable GC system be used as a "screening analysis" prior to
locating fixed-site samplers (pressurized or subatmospheric).
12.5.1.2 Section 9.2 requires pre and post-sampling measurements with a certified mass flow
controller for flow verification of sampling system.
12.5.13 Section 11.1 requires all canisters to be pressure tested to 207 kPa ± 14 fcPa (30 psig ± 2
psig) over a period of 24 hours.
12.5.1.4 Section 11.1 requires that all canisters be certified clean (<0.2 ppbv of targeted VOCs)
through a humid zero air certification program.
12.5.1.5 Section 11.2.2 requires all field sampling systems to be certified initially clean (<0.2 ppbv
of targeted VOCs) through a humid zero air certification program.
123.1.6 Section 11.2.3 requires all field sampling systems to pass an initial humidified calibration
gas certificaa'on|at VOC concentration levels expected in the field (e.g., 0.5 to 2 ppbv)J with a percent recovery
of greater than 90.
123.2 GOMS/SCAN/SIM System Performance Criteria
12.5.2.1 Section 10.2.1 requires the GC/MS analytical system to be certified clean (<0.2 ppbv of
targeted VOCs) prior to sample analysis, through a humid zero air certification.
12.5.2.2 Section 10.2.2 requires the daily tuning of the GC/MS with 4-BFB and that it meet the key
ions and ion abundance criteria (10%) outlined in Table 5.
I23JL3 Section 10.2.3 requires both an initial multipoint humid static calibration (three levels plus
humid zero air) and a daily calibration (one point) of the GC/MS analytical system.
1233 GC-Multidetector System Performance Criteria
1233.1 Section 10.3.1 requires the GC/FID/ECD analytical system, prior to analysis, to be certified
clean (<0.2 ppbv of targeted VOCs) through a humid zero air certificatioa
12.53.2 Section 10.3.2 requires that the GC/FID/ECD analytical system establish retention time
windows for each anaryte prior to sample analysis, when a new GC column is installed, or major components of
the GC system altered since the previous determination.
12.533 Section 8.2 requires that all calibration gases be traceable to NIST-SRMs.
12.53.4 Section 10.3.2 requires that the retention time window be established throughout the course
of a 72-hr analytical period
12.533 Section 10.3.3 requires both an initial multipoint calibration (three levels plus humid zero
air) and a daily calibration (one point) of the GC/FID/ECD analytical system with zero gas dilution of NIST
traceable gases.
Pogel4A-30 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
13, Acknowledgements
The determination of VOCs m ambient air is a complex task, primarily because of the wide variety of compounds
of interest and the lack of standardized sampling and analytical procedures. While there are numerous procedures
for sampling and analyzing VOCs in ambient air, this method draws upon the best aspects of each one and
combines them into a standardized methodology. In many cases, the individuals listed in the acknowledgement
table contributed to the research, documentation and peer review of the original Compendium Method TO-14 and
now revised as Compendium Method TO-14A. In some cases, new names appear as likely sources of new
information.
14. References
1. Oliver, K. D., Pleil, I D., and McClenny, W. A. "Sample Integrity of Trace Level Volatile Organic
Compounds in Ambient Air Stored in Specially Prepared Polished Canisters," Atmos. Environ. 20; 1403, 1986.
2. Holdren, M. W. and Smith, D. L. "Stability of Volatile Organic Compounds While Stored in Specially
Prepared Polished Stainless Steel Canisters," U. S. Environmental Protection Agency, Research Triangle Park,
NC, Final Report, EPA Contract No. 68-02-4127, BatteUe, January 1986.
3. Kelly, T. J. and Holdren, M. W., "Applicability of Canisters for Sample Storage in the Determination of
Hazardous Air Pollutants," Atmos, Environ., 29(19):2595, 1995.
4. McClenny, W. A., Pleil, J. D., Evans, G. F., Oliver, K. D., Holdren, M. W., and Winberry, W. T., "Canister-
Based Method for Monitoring Toxic VOCs in Ambient Air," JAWMA, 41(10):1038, 1991.
5. McClenny, W. A., Pleil, J. D., Holdren, J. W., and Smith, R. N. "Automated Cryogenic Preeoncentration and
Gas Chromatographic Determination of Volatile Organic Compounds," Anal. Chem. 56:2947,1984.
6. PleiJ, J. D,, Oliver, K. D., and McClenny, W. A., "Enhanced Performance of Nafion® Dryers in Removing
Water from Samples Prior to Gas Chromatographic Analysis," JAPCA, 37:244, 1987.
7. Oliver, K. D. and Pleil, J. D., "Automated Cryogenic Sampling and Gas Chromatographic Analysis of
Ambient Vapor-Phase Organic Compounds: Procedures and Comparison Tests," ManTech, Inc. - Environmental
Services, EPA Contract No. 68-02-4035, U. S. Environmental Protection Agency, Research Triangle Park, NC,
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-31
-------
Method TO-14A
VOCs
COMPENDIUM METHOD TO-14A ACKNOWLEDGEMENT
Topic
Sampling System
Analytical System
GC/FID,
GC/FID/ECD
Contact
Mr. Frank McElroy
Dr. Bill McCIenny
Mr. Joachim PleU
Mr. BiM Taylor
Mr. Joseph P. Krasneo
Dr. Bill McCIenny
Mr. Joachim Pleil
Ms. Karen D. Oliver
Mr. Dave-Paul Dayton
Ms. Jo Ann Rice
Dr. Bill McCIenny
Mr. Joachim PleU
Dr. BUI McCIenny
Mr. Joachim Pleil
Mr. Dave-Paul Dayton
Ms. JoAnn Rice
Dr. R.K.M. Jayanty
Cryogenic Dr. Bill McCIenny
Sampling Unit Mr. Joachim PleU
U.S. EPA Mr. Howard Christ
Audit Gas Standards
GC/FID,
GC/FID/EGD/PID
GC/MS/SCAN/SIM
Canister Cleaning
Certification and
yOC Canister Storage
Stahiita
Address
U.S. Environmental Protection Agency
National Exposure Research Laboratory
MD-77
Research Triangle Park, NC 27711
U.S. Environmental Protection Agency
National Exposure Research Laboratory
Research Triangle Park, NC 27711
Graseby '
500 Technology Ct.
Smyrna, GA 30082
Scientific Instrumentation Specialists, Inc.
P.O. Box 8941
Moscow, Idaho 83843
U.S. Environmental Protection Agency
National Exposure Research Laboratory
Research Triangle Park, NC 27711
ManTech, Inc.
Environmental Sciences
P.O. Box 12313
Research Triangle Park, NC 27709
ERG '
P.O. Box 13000
Progress Center
Research Triangle Park, NC 27709
i
U.S. Environmental Protection Agency
National Exposure Research Laboratory
MD-44
Research Triangle Park, NC 27711
U.S. Environmental Protection Agency
National Exposure Research Laboratory
MD-44
Research Triangle Park, NC 2771 1
ERG
P.O. Box 13000
Progress Center
Research Triangle Park, NC 27709
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, NC 27709
U.S. Environmental Protection Agency
National Exposure Research Laboratory
MD-44
Research Triangle Park, NC 2771 1
U.S. Environmental Protection Agency
National Exposure Research Laboratory
MD-77B
Research Triangle Park, NC 27711
Telephone No.
919-541-2622
919-541-3158
919-541-4680
1-800-241-6898
208-882-3860
919-541-3158
919-541-4680
919-549-0611
919-481-0212
919-541-3158
919-541-4680
919-541-3158
919-541-4680
919-481-0212
919-541-6000
919-541-3158
919-541-4680
919-541-4531
Page 14A-32
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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VOCs : Method TO-14A
1985.
8. McClenny, W, A. and Pleil, J. D., "Automated Calibration and Analysis of VOCs with a Capillary Column
Gas Chromatograph Equipped for Reduced Temperature Trapping," in Proceedings of the 1984 Air Pollution
Control Association Annual Meeting, San Francisco, CA, June 24-29,1984.
9. McClenny, W. A., Pleil, J. D., Lumpkin, T. A., and Oliver, K. D., "Update on Canister-Based Samplers for
VOCs," in Proceedings of the 1987 EPA/APCA Symposium on Measurement of Toxic and Related Air
Pollutants, May 1987.
10. Pleil, J. D., "Automated Cryogenic Sampling and Gas Chromatographic Analysis of Ambient Vapor-Phase
Organic Compounds: System Design," ManTech, fee. -Environmental Services, U. S. Environmental Protection
Agency, Research Triangle Park, NC, 1982, EPA Contract No. 68-02-2566.
11. Oliver, K. D. and Pleil, J. D., "Analysis of Canister Samples Collected During the CARB Study in August
1986," U. S. Environmental Protection Agency, Research Triangle Park, NC, ManTech, Inc. - Environmental
Services, 1987.
12. Pleil, J. D., and Oliver, K. D., "Measurement of Concentration Variability of Volatile Organic Compounds
in Indoor Air: Automated Operation of a Sequential Syringe Sampler and Subsequent GC/MS Analysis," U. S.
Environmental Protection Agency, Research Triangle Park, NC, ManTech, Inc. - Environmental Services, 1987.
13. Walling, J. F., "The Utility of Distributed Air Volume Sets When Sampling Ambient Air Using Solid
Adsorbents," Atmos. Environ., 18:855-859,1984.
14. Walling, J. F,, Bumgamer, J. E., Driscoll, J. D., Morris, C. M., Riley, A. E. and Wright, L. H., "Apparent
Reaction Products Desorbed From Tenax Used to Sample Ambient Air," Atmos. Environ., 20:51-57, 1986.
15. Berkley, R. E., "Overview of Field Deployable Gas Chromatographic Analyzers of Airborne Toxic Organic
Vapors," Proceedings of the 1994 On-Site Analysis Conference., Houston, TX, January 24-26, 1994.
16. McElroy, F, F., Thompson, V. L., Holland, D. M., Lonneman, W. A., and Seila, R. L., "Cryogenic
Preconcentration-Direct FED Method for Measurement of Ambient NMOC: Refinement and Comparison with
GC Speciation," JAPCA,35(6):710,1986.
17. Rasmussen, R. A. and Lovelock, J. E., "Atmospheric Measurements Using Canister Technology," J.
Geophys. Res., 83:8369-8378,1983.
18. Rasmussen, R, A. and Khalil, M. A. K., "Atmospheric Halocarbons: Measurements and Analysis of Selected
Trace Gases," i&Proc. NATOASIon Atmospheric Ozone, BO: 209-231.
19. Dayton, D. D. and Rice, J., Development and Evaluation of a Prototype Analytical System for Measuring
Air Toxics, U. S. Environmental Protection Agency, Research Triangle Park, NC 27711, EPA Contract No. 68-
02-3889, WA No. 120, November 1987.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-33
-------
Method TO-14A
VOCs
TABLE 1. COMPENDIUM METHOD TO-14AVOCTCL DATA SHEET
COMPOUND (SYNONYM)
Fitoo 12 (WcMonxUfluMooMthane)
Methyl chloride (Chloromethine)
Prcon 1 14 (l,2-Dich!oro-l,l,2,2-
trtrxfluocoeihine)
Vinyl chloride (CUoroethytene)
Methyl bromide (Bromomethane)
Ethyl chloride (Chloroethsne)
Fitoo 1 1 (Trichlofofluoromethane)
Vinylidene chloride (1,1-Dichloroethene)
DichJorocMthanc (Methyiene chloride)
Frcon 113 (l,l,2-Tirichloro-l,2,2-
trifluorocthane)
1,1-Dichloroethane (Ethylidcnc chloride)
cit-l^-DichlorcxMhylcoe
Chloroform (Trichloromethine)
1,2-Dichloroelhinc (Ethylcne dichloride)
Methyl eUonfixm (1, 1, l-Trichloroclhmc)
Benzeoe (Cyclobcxairiene)
Cirboa tctnchloride (Tctnchlorometliane)
1,2-DiehIoropropine (Propylene dichloride)
Trichloroethylcne (Trichloroethene)
cu-lJ-DiehloroprQpene (ca~l ,3-
dichloropropytene)
tnni-13-DictJoropropctic (tnas-13-
Dichlocopropylene)
1,1,2-Trichloroelhaac {Vinyl ttichloride)
Toluene (Mdhyl benzene)
1,2-DibronxxHhinc (Ethylcne dtbromide)
Tedachlorocthylcne (Perchloroethyleoe)
Chlorobcnzov: (Phcnyf chloride)
Eihylbcozcno
m-Xylcnc (l^-Dirocthylbenzene)
p-Xy!en« (,14-Dimcthyb^kne)
StjTcnc (Vinyl benzene)
1 , 1 ,2,2-Teirachloroethane
o-Xylene (1,2-Dunefhyibcnzene)
13.5-TrirncthylbcQzeoe (Mesitylene)
1 A^-TrimelhylDeiizene (Pseudocumene)
m-Dichlorobciizcne (I^-Dichlorobenzeue)
Benzyl chloride (cc-Chlorotolueae)
o-Dtchlorobenzene (1,2-dicUorobenzene)
p-DicWorobenzcnc (1,4-dichlorobenzene)
1 ,2,4-Trichlorobenzene
Hexachlorobutadicnc (1,1 33,4,4-Hcxitidaro-
1.3 -butadiene)
FORMULA,
C1.CF,
CH3CI
ClCFjCClFj
CH2-CHC1
CHjBr
CH,CH,Cl
CCI,F
C,H,C1,
CH.C1,
CF,CICC1,F
CHjCHCl,
CHC1=CHC1
CHCI3
CICH.CHjCl
CHjCCIj
C.H.
CCI,
CHsCHCICH,a
cicH<<:ci2
CH3CC1=CHC1
CICH,CH=CHC1
CHjClCHC!,
C,H,CHj
BrCHjCHjBr
CIjC^CCI,
C,HjC[
CACjH,
UKCH,),C,H,
1,
-------
VOCs
Method TO-14A
TABLE 2. ION/ABUNDANCE AND EXPECTED RETENTION TIME FOR SELECTED
COMPENDIUM METHOD TO-I4A VOCs ANALYZED BY GC/MS/STM
COMPOUND (SYNONYM)
Freoa 120Dichlorodifluoromethane)
Methyl chloride (Chloromethane)
Freon 1 14 (l^-Dichloro-l,l,2,2-tetrafluoroethane)
Vinyl chloride (Chloroethene)
Methyl bromide (Bromomethane)
Ethyl chloride (Chloroethane)
Freon 1 1 (Trichlorofluoromethane)
Vinylidene chloride (1.1 -Diehloroethene)
Dichloromethane (Methylene chloride)
Freon 1 13 (l,l,2-Trichloro-l^,2-trifluoroethane)
1,1-Dichloroethane (Ethylidene chloride)
cis- 1 ,2-Dichloroethylene
Chloroform (Trichloromethane)
1,2-Dichloroethane (Ethylene dichloride)
Methyl chloroform (1,1,1-Triehloroethane)
Ion/Abundance
(amu/% base peak)
85/100
87/31
50/100
52/34
85/100
135/56
87/33
62/100
. 27/125
64/32
94/100
96/85
64/100
29/140
27/140
101/100
103/67
61/100
96/55
63/31
49/100
84/65
86/45
151/100
101/140
103/90
63/100
27/64
65/33
' 61/100
96/60
98/44
83/100
85/65
47/35
62/100
27/70
64/31
97/100
99/64
61/61
Expected Retentioa
Time (min)
5.01
5,69
6.55
6.71
7.83
8.43
9.97
10.93
11.21
11.60
12.50
13.40
13.75
14.39
14.62
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-3S
-------
Method TO-14A
VOCs
TABLE 2. (continued)
COMPOUND (SYNONYM):.' ;P ;^v- " :^SsmS^fK
Benzene (Cyclohexatriene)
Carbon tetrachloride (Tetrachlorometfaane)
1 ,2-DichIoropropane (Propylene dichloride)
Trichloraethylene CTricMoroethene)
cis- 1 ,3-Dichloropropenc
trans- 1,3-Dichlorapropeoe (cis- 1, 3 DicMoropropylene)
1 , 1 ^-Trichloroethane (Vinyl trichloride)
Toluene (Methyl benzene)
1,2-Dibromoethane (Ethylene dibromide)
Tctrachloroethylene (PercbJoroethylene)
Chlorobenzenc (Phenyl chloride)
Ethylbenzene
m,p-Xylenc (l,3/l,4-Dimethylbenze0e)
Styrene (Vinyl benzene)
1 , 1 ^,2-TetracMoroethane (Tetrachlorethane)
o-Xylene (1^-Dunethylbenzene)
4-Ethyitoluenc
^flbny^aldibiSslil-
•- %:;.x ^>>^-.-^_ V^'-J
:«:;(amu^;ftaW|5ealy;;ss
78/100
77/25
50/35
117/100
119/97
63/100
41/90
62/70
130/100
132/92
95/87
75/100
39/70
77/30
75/100
39/70
77/30
97/100
83/90
61/82
91/100
92/57
107/100
109/96
27/1 15
166/100
164/74
131/60
112/100
77/62
114/32
91/100
106/28
91/100
106/40
104/100
78/60
103/49
83/100
85/64
91/100
106/40
105/100
120/29
i;:;jEg?e||^:Repnj|^y;:;
MflMJ^mMf^myy^K
15.04
15.18
15.83
16.10
16.96
17.49
17.61
17.86
18.48
19.01
19.73
20.20
20.41
20.81
20.92
20.92
22.53
Page 14A-36
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-14A
TABLE 2. (continued)
'•i5*i?:S?sf:S:^
1,3,5-Trimethylbenzene (Mesitylene)
1,2,4-Trimethylbenzene (Pseudocumene)
m-Diehlorobenzene (1,3-Dichlorobeozene)
Benzyl chloride (a-Chlorotoluene)
p-Dichlorobenzene (l,4-dichloroben2ene)
o-Dichlorobenzene (1,2-diehlorobenzeae)
1 ,2,4-Trichlorobenzene
Hexachlorobutadiene (1,1,2,3,4,4 Hexachloro-l,3-butadiene)
'•f-ti\ • •-• :-*:«:JWS:*»»» #* '»"Ki'.; fy.::'-K.
v i||p]TO^pK|iMOB|g||
IjtsfaiHti^^Ba^t^alySf
105/100
120/42
105/100
120/42
146/100
148/65
111/40
91/100
126/26
146/100
148/65
1 1 1/40
146/100
148/65
111/40
180/100
182/98
184/30
225/100
227/66
223/60
i|ix^t^]^pii||i
IftsS Tin^^ffiiifllilllf?;
22.65
23.18
23.31
23.32
23.41
23.88
26.71
27.68
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-37
-------
Method TO-14A
VOCs
TABLE 3. GENERAL GC AND MS OPERATING CONDITIONS FOR
: :: ' COMPENDIUM METHOD TO-14A
Chromatography
Column
Carrier Gas
Injection Volume
Injection Mode
Temperature Program
Initial Column Temperature
Initial Hold Time
Program
Final Hold Time
Mass Spectrometer
Mass Range
Scan Time
El Condition
Mass Scan
Detector Mode
FID System (Optional)
Hydrogen How
Carrier Flow
Burner Air
General OV-1 crosslinked methyl silicone (50-m x 0.31-mm I.D., 17 um
film thickness), or equivalent
Helium (-2.0 mL/min at 250°C)
Constant (1-3 uL)
Splitless
-50°C
2min
8°C/mintol50°C
15min
18 to 250 arau
1 sec/scan
70 eV
Follow manufacturer's instruction for selecting mass selective detector
(MS) and selected ion monitoring (SIM) mode
Multiple ion detection
~30 mL/minute
~30 mL/minute
~400 mL/minute
Page 14A-38
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-14A
TABLE 4. 4-BFB KEY IONS AND ION ABUNDANCE CRITERIA
50
75
95
96
173
174
175
176
177
:Abundance Criteria ' '• :;;ipll::-™ftW::™-K";'
15 to 40% of mass 95
30 to 60% of mass 95
Base Peak, 100% Relative Abundance
5 to 9% of mass 95
<2% of mass 174
>50%ofmass95
5 to 9% of mass 174
>95% but< 101% of mass 174
5 to 9% of mass 176
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-39
-------
Method TO-14A
VOCs
TABLE 5. COMPENDIUM METHOD TO-14A RESPONSE FACTORS
(ppbv/area count) AND EXPECTED RETENTION TIME FOR
; GC/MS/SM ANALYTICAL CONFIGURATION
Compounds
Freonll
Methyl chloride
FreonlM
Vinyl chloride
Methyl bromide
Ethyl chloride
Freon 11
Vinylidene chloride
Dichloromethane
Trichlorotrifluoroethane
1 ,1-Dichloroethane
cis-1 ,2-DicMoroethylene
Chlorofona
1 ,2-Dichloroethane
Methyl chloroform
Benzene
Carbon tetrachloride
1 ,2-Dichloropropane
Trichloroethylene
cis-1 ,3-DicMoropropene
trans-1 ,3-Dichloropropene
1 . 1 ^-Trichtoroethane
Toluene
1^-Dibromoethane (EDB)
Tetrachloroethylene
Chloro benzene
Ethylbenzene
m,p-Xylene
Styrene
1,1 ,2,2-Tetrachloroethane
o-Xylene
4-Ethyltoluene
1 ,3 , 5-Trimethylbenzene
1 ^,4-Trimethylbenzene
m-Dichlorobenzene
Benzyl chloride
p-Diehlorobenzene
o-Dichlorobenzene
1 ,2,4-Trichlorobenzene
Hexachlorobutadiene
Response Factor
(ppbv/area count)
0.6705
4.093
0.4928
2.343
2.647
2.954
0.5145
1.037
2.255
0.9031
1.273
1.363
0.7911
1.017
0.7078
1.236
0.5880
2.400
1.383
1.877
1.338
1.891
0.9406
0.8662
0.7357
0.8558
0.6243
0.7367
1.888
1.035
0.7498
0.6181
0.7088
0.7536
0.9643
1.420
0.8912
1.004
2.150
0.4117
Expected "Retention
Time (minutes)
5.01
5.64
6.55
6.71
7.83
8.43
9,87
10.93
11.21
11.60
12.50
13.40
13.75
14.39
14.62
15.04
15.18
15,83
16.10
16.96
17.49
17.61
17.86
18.48
19.01
19.73
20.20
20.41
20.80
20.92
20.92
22,53
22.65
23.18
23.31
23.32
23.41
23.88
26.71
27.68
Page 14A-40
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
TABLE 6. COMPENDIUM METHOD TO-14A
GC/MS/SM CALIBRATION TABLE
*** External Standard ***
Operator: JDP
Sample Info: SYR 1
Misc Info:
Integration File Name: DATA:SYR2AO2A.I
Sequence Index: I
Last Update:
Reference Peak Window:
Non-Reference Peak Window:
Sample Amount:
8 Jan 97 10:02 am
Bottle Number: 2
8 Jan 87 8:13 am
5.00 Absolute Minutes
0.40 Absolute Minutes
0.000 Uncalibrated Peak RF: 0.000 Multiplier: 1.667
tosi
i
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
?:,;::•: ; :' , :: :;f;- ' :'•#%& • ' ' •>:.:•.:.. C:.i:. .&;.< -V.fc
K :• :'; ; ;': Signal Efescripfibii?: :.:: ;: >?.
Mass 85.00 amu
Mass 50.00 amu
Mass 85.00 amu
Mass 62.00 amu
Mass 94.00 amu
Mass 64.00 amu
Mass 101.00 amu
Mass 61.00 amu
Mass 49.00 amu
Mass 41.00 amu
Mass 151.00 amu
Mass 63.00 amu
Mass 61.00 amu
Mass 83.00 amu
Mass 62.00 amu
Mass 97.00 amu
Mass 78.00 amu
Mass 117.00 amu
Mass 63.00 amu
Mass 130.00 amu
Mass 75.00 amu
Mass 75.00 amu
Mass 97.00 amu
Mass 91.00 amu
Mass 107.00 amu
Mass 166.00 amu
Mass 112.00 amu
Mass 91.00 amu
M^*
-------
Method TO-14A
VOCs
TABLE 6. (continued)
Peak
No,
30
31
32
33
34
35
36
37
38
39
40
41
type
1
1
I
1
I
I
1
1
1
1
1
I
IntType
BV
BH
BP
W
VB
BB
BV
W
VB
BP
BB
BB
Ret Time
20.778
20.887
20.892
22.488
22.609
23.144
23.273
23.279
23378
23.850
26.673
27.637
Signal Description
Mass 104.00 amu
Mass 83.00 amu
Mass 91.00 amu
Mass 105.00 amu
Mass 105.00 amu
Mass 105.00 amu
Mass 146.00 amu
Mass 91.00 amu
Mass 146.00 amu
Mass 146.00 amu
Mass 180.00 amu
Mass 225.00 amu
CompouncTName
STYREME
TETRACHLETHA
o-XYLENE
4-ETHYLTOLUE
U,5METHBEN
U.4METHBEN
m-DICHLBENZE
BENZYLCHLORI
p-DICHLBENZE
o-DICHLBENZE
U4CHLBENZ
HEXACHLBUTAD
Area
3145
4531
9798
7694
6781
7892
3046
3880
6090
2896
562
6309
^-/-••fpiiillli:
"-:-*:: -• • - ' Amount ?'•£,£:•
1695 pptv
1376 pptv
2010 pptv
1481 pptv
1705 pptv
2095 pptv
1119 pptv
1006 pptv
2164 pptv
1249 pptv
767.1 pptv
1789 pptv
Pagel4A-42
Compendwm of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCS
Method TO-14A
TABLE 7. COMPENDIUM METHOD TO-14A TYPICAL RETENTION TIME (MIN) AND
CALIBRATION RESPONSE FACTORS (ppbv/area count) FOR TARGETED
VOCs ASSOCIATED WITH FID AND BCD ANALYTICAL SYSTEM
'Peatilll
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Ml|||||«^|^«||i;;l||
^^siS^ifvSSMi^fS^/^^^^^-
:<3bWjtound^;?%4^il:;;S^l^S§P-''
Freon 12
Methyl chloride
Freon 114
Vinyl chloride
Methyl bromide
Ethyl chloride
Freon 1 1
Vinylidene chloride
Dichloromethane
Trichlorotrifluoroethane
1 , 1 -Dtehloroethane
cis- 1 ,2-DichloroethyIene
Chloroform
I ,2-Dichloroethane
Methyl chloroform
Benzene
Carbon tetrachloride
1 ,2-DiehIoropropane
Trichloroethylene
cis-13-Dichloropropene
trans- 1 3-Diehloropropene
1 , 1 ,2-Trichloroethane
Toluene
1 2-Dibromoethane (EDB)
Tetraehloroethylene
Chlorobenzene
Ethylbenzene
m,p-XyIene
Styrene
1,122-Terrachloroethanc
o-Xylene
4-Ethyltoluene
1 3,5-TrimethyIbenzene
1 2,4-Trimethylbenzene
m-Diehlorobenzene
Benzyl chloride
p-Dichloro benzene
o-Diehlorobcnzene
1 2,4-TrichIorobenzene
Hexachlorobutadiene
H?^«^i66i^tttBe^
pr(RT);rn!inute;S
3.65
430
5.13
528
6.44
7.06
8.60
9.51
9.84
1022
11.10
11.99
1230
12.92
13.12
13.51
13.64
1426
14.50
1531
15.83
15.93
16.17
16.78
1731
18.03
18.51
18.72
19.12
1920
1923
20.82
20.94
21.46
21.50
21.56
21.67
22.12
24.88
25.82
,;,-" :-:-;:•'-•;•:•:-.•: • ••__• ••-•:•.•-•:•:•:•:•:-:•:•:•:•:-.•: : .-'-v*. -.*.•:
™?:S: ';8v!:?:v •" V, tuj^y^fi&KMi'KAi
•^¥y^maefv^rj^^M?\
;:B^a%pbvfetea:coiii^piil;;
3.465
0.693
0.578
0.406
0.413
6.367
0.347
0.903
0.374
0359
0.368
1.059
0.409 "
0.325
0.117
1.451
0214
0.327
0.336
0.092
0.366
OJ24
0.120
0.092
0.095
0.143
0.100
0.109
O.IH
0.188
0.188
0.667
0.305
:f(ppWffaic&:cssintxlQ?y-
13.89
2232
26.34
1.367
3.955
11.14
3258
1.077
8.910
5.137
1.449
9.856
1.055
'Refer to Figures 15 and 16 for peak location.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-43
-------
Method TO-14A
VOCs
TABLE 8. TYPICAL RETENTION TIME (minutes) FOR SELECTED ORGANICS USING
GC/FID/ECD/PID ANALYTICAL SYSTEM FOR COMPENDIUM METHOD TO-14A1
"
Compound
Acetylene
1,3-Butadiene
Vinyl chloride
Chloromethane
Chloroethane
Bromoethane
Methylene Chloride
trans- 1 ,2-Dichloroethane
1 , 1 -Dichloroethane
Chloroprene
Perfluorobenzene
Bromochloromethane
Chloroform
1, 1 ,1-Trichloroethane
Carbon Tetrachloride
Benzene/l,2-DichIoroethane
Perfluorotoluene
Trichloroethylene
1,2-DichIoropropene
Bromodichloromethane
trans- 1 ,3-Dichloropropylene
Toluene
cis- 1,3-Dichloropropylene
1 , 1,2-Trichloroethane
Tetrachloroethylene
Dibromochloromethane
Chlorobenzene
m/p-Xylene
Styrene/o-Xylene
Bromofluorobenzene
1 , 1 ,2,2-Tetrachloroethane
m-Dichlorobenzene
p-Dichlorobenzene
o-Dichlorobenzene
* R
FID
2.984
3.599
3.790
5.137
5.738
8.154
9.232
10.077
11.190
11.502
13.077
13.397
13.768
14.151
14.642
15.128
15.420
17.022
17.491
18.369
19.694
20.658
21.461
21.823
22.340
22.955
24.866
25.763
27.036
28.665
29.225
32.347
32.671
33.885
etention Time (minute
—
—
..
13.078
13.396
13.767
14.153
14.667
15.425
17.024
17.805
19.693
21.357
22.346
22.959
—
28.663
29.227
32.345
32.669
33.883
il^lJS^IH^^^iH:
3.594
3.781
~
„
9.218
10.065
11.491
13.069
13.403
13.771
14.158
14.686
15.114
15.412
17.014
17.522
19.688
20.653
21.357
22.335
22.952
24.861
25.757
27.030
28.660
29.228
32.342
32.666
33.880
'Varian* 3700 GC equipped with J&W Megabore* DB 624 Capillary Column
(30 m x 0.53 ID. mm) using helium carrier gas.
Page 14A-44
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
TABLE 9. GC/MS/SIM CALIBRATION TABLE FOR COMPENDIUM METHOD TO-14A
Last Update:
Reference Peak Window:
Non-Reference Peak Window:
Sample Amount:
18 Dec 96 7:54 am
5,00 Absolute Minutes
0.40 Absolute Minutes
0.000 Uncalibrated Peak RF: 0.000 Multiplier: 1.000
tllilllfl
5.008
5.690
6.552
6.709
7.831
8.431
9.970
10.927
11.209
11.331
11.595
12.502
13.403
13.747
14.387
14.623
15.038
15.183
15.829
16.096
16.956
17.492
17.610
17.862
18.485
19.012
19.729
20.195
20.407
20.806
20.916
20.921
22.528
22.648
23.179
23.307
23.317
23.413
23.885
26.714
27.680
Hit:
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
:l-|i§}pa|I^dnpioii;*S
Mass 85.00 amu
Mass 50.00 amu
Mass 85.00 amu
Mass 62.00 amu
Mass 94.00 amu
Mass 64.00 amu
Mass 101.00 amu
Mass 61.00 amu
Mass 49.00 amu
Mass 41.00 amu
Mass 151.00 amu
Mass 63.00 amu
Mass 61.00 amu
Mass 83.00 amu
Mass 62.00 amu
Mass 97.00 amu
Mass 78.00 amu
Mass 117.00 amu
Mass 63.00 amu
Mass 130.00 amu
Mass 75.00 amu
Mass 75.00 amu
Mass 97.00 amu
Mass 91.00 amu
Mass 107.00 amu
Mass 166.00 amu
Mass 112.00 amu
Mass 91.00 amu
Mass 91.00 amu
Mass 104.00 amu
Mass 83.00 amu
Mass 91.00 amu
Mass 105.00 amu
Mass 105.00 amu
Mass 105,00 amu
Mass 146.00 amu
Mass 91.00 amu
Mass 146.00 amu
Mass 146.00 amu
Mass 180.00 amu
Mass 225.00 amu
tAtttpptTp-
13620
12720
8380
8050
12210
12574
12380
7890
12760
12650
7420
12710
12630
7670
9040
8100
10760
8340
12780
8750
4540
3380
12690
10010
6710
7830
7160
12740
25400
12390
11690
11085
12560
12620
12710
12650
7900
12390
13510
15520
7470
j;liv£
I
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
1
1
1
1
1
1
1
1
s;:[ftnaiff;;
72974
36447
81251
20118
28265
16149
80088
38954
43507
1945
40530
61595
50900
40585
33356
38503
69119
42737
38875
30331
17078
13294
32480
88036
33350
43454
44224
127767
200973
38332
64162
90096
108747
83666
79833
57409
50774
58127
52233
18967
43920
I'Ei-Type;;:-
1
1
1
1
1
1
1
1
1
1
1
1
1
1
I
1
1
1
1
I
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
vJ - -; Wj vV::;- ::;::.-:-::::;- *XX;***!W;W-^-:f-:-^--« - - :•
%mtsaM8me^mmmmvm*.»m.
FREON12
METHYLCHLORID
FREON114
VINYLCHLORIDE
MEIHYLBROMDE
ETHYLCHLORIDE
FREON11
VINDENECHLORI
DICHLOROMETHA
ALLYLCHLORIDE
3CHL3FLUETHAN
UDICHLOETHA
c-l,2DICHLETH
CHLOROFORM
UDICHLETHAN
METHCHLOROFOR
BENZENE
CARBONTETRACH
UDICHLPROPA
TRICHLETHENE
c-t^DICHLPRO
t-UDICHLPRO
U-2CHLETHAN
TOLUENE
EDB
TETRACHLETHEN
CHLOROBENZENE
ETHYLBENZENE
m,p-XYLENE
STYRENE
TETOACHLETHAN
o-XYLENE
4-ETHYLTOLUEN
U,5METHBENZ
1A4METHBENZ
m-DICHLBENZEN
BENZYLCHLORID
p-DICHLBENZEN
o-DICHLBENZEN
1.24CHLBENZE
HEXACHLBUTADI
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-45
-------
Method TO-14A
VOCs
TABLE 10. EXAMPLE OF HARD-COPY OF GC/MS/SIM ANALYSIS BY
COMPENDIUM METHOD TO-14A
Quantitation Report
Data f.ila : Ci\HFCHEM\l\DATA\6D2SM03.D
Acs On 5 25 Apr 96 12:50 pm
Sample : AUDIT SAMPLE #239-54 2SOML
Misa
Quant Sines Apr 25 Ifii33 1936
Vial; 3
Operator: BANI1LS
Inot : 5972 - In
Multiple: 2.00
Method
Title
Last Update
ReapoxuM." via
CCal File
: G! \ffiPCHEMM\METHODS\AODIT.M
s Initial Calibration 4/8/96 Std $4036-94
: Thu Apr 25 16 .-36 .-11 1996
: continuing Calibration
: C:\H5CHEM\1\DAXA\6D2SM01.D
TIC: 6D25MQ3.O
450000 J
1
400000 .
350000 ,
300000.
250000.
200000.
.
150000 .
10OOOO .
50000-
.
n '
S
4
3
2
t
(
Eima--> S.'OO
4
1
8 9
7
L
i
i
14 1§
i:
12
L"
ioloo
L.
' H
IS
J
[
,
2
Z
33
38
36
356
33
27
;
2
2
2!
24
J
' ISlOQ
1
32
g31
|0
w
1
1
1
!
llu
<
4J.4
-
4
41
Mkjl
£6
I
1
43
47
2o!oo 2s!o6 ioloo
Page 14A-46
Compendium of Methods for Toxic Organic Air Pottutants
January 1999
-------
VOCs
Method TO-14A
TABLE 10. (continued)
Internal Standards
R..T. Qlon Response Cone onica
1} BROMOC3JLOROMETHANE
17) 1,4-DIFI.DOROBBNZEJJE
27) CHLOROBSN2ENE-D5
System Monitoring Compounds
IS) l<2~DICHL0RQEISjyaE-04
28) TOLUENE -D8
40} BROMOFLUOROBEWZENE.
Target Ccmpounds
2} Freon 12
3} Chloronethana
4} Fraoa 114
5) Chloroethena
S } Bromo methane
7 } Chloroetliana
3} Fsreon. 11
9 ) 1,1 - Dichlora* theno
10} Metnylene Chloride
11) Fraca 113
12) l.l-Dicaloroethaae •'
13) cia-l, 2-Dirhloro«tbsne
14) Chloroform
IS) 1,2-Dichlaroethane
18) l , i , l-Trichloroechane
19) Bnnzena
20) Carbon Tecrachloride
21) 1,2-Dicaloropropane
22 ) BromodichloromethaLne
23 ) Tricklaroeeliane
24) cis-l,3-O±chlo*oprop«a«
25) crana -1,3 -Oieiilotoprapene
26) 1,1,2 -trichloroethana
29) Toluen*
3 0 ) Dibrotnochloroiufitiiane
31) 1,2-Dibromoetthane
32) Tecrachloroeth«ne
33) chlorobenzen* ....
34} EthyLbenzane
3SJ m,p-Xylene
36) Bromoform
37) scyren*
38) 1,1,2,2-Tetrachloroeehaaa
39} o-Xylena
415 1,3,3 -Trimethy lienzene
42) 1,2,4-TrinusthylJbeiizene
43) Benzyl chloride
44) 1,3-Qichlarabenzene
45) i,4-DlcaIarobe&zane
46 ) 1,2 -Dichlorobenzane
47} 1,2, 4 -Trichlorotaenzena
48 } Hexachlorobutadiene
13.40
15.79
21.73
14.39
19.07
24.01
S.17
S.6S
5.94
6,25
7.26
7.64
9.13
10.21
10.35
10.75
12.05
13. IS
13,54
'14.33
14.89
IS. SI
15.70
16.52
16.74
is, ao
17.84
3.8.49
18.81
19.22
19.85
20.23
20.81
21.80
22.29
23. S3
22 . 80
23.09
23.24
23.26
25,37
2S.1S
26,47
26. 5S
26.66
27,36
31.19
32.45
49
. 114
117
SS
98
95
85
SO
85
62
94
64
101
Si'
49
101
£3
61
83
S3
9^
78
117
-63
S3
95
75
75
97
91
129
107
1S6
112
91
91
173
104
83
31-
10S
10S
91
146
146
146
180
225
173440
383363
346903
177334
393347
310217
295965
113926
376276
113201
106443
574.S1
266209
186189
158173
22S11S
211903
170091
236380
144398
208233
329475
215628
135206
27S403
139564
97972
2733 0
120253
334950
243321
173047
145120
2S3495
454 S12
581163
210707
133812
268481
257133
198466
160459
107854
"186397
180374
164427
42255
56763
4.80 PPBV
4.80 PPBV
4.80 PPBV
«
4. 82 PPBV
4.78 PPBV
4.61 PPBV
7.67 PPBV
7.96 P?BV
7.88 ?5BV
8.60 PPBV
8.74 PPBV
7.48 PPBV
7.77 PPIV
8.03 PPBV
8.40 PPBV
7.85 PPBV
7.80 PPBV
B.55 PPBV
8.15 PBBV
7.92 PPBV
7.72 PPIV
8.45 PPBV
7.87 PPBV
7.80 PPBV
8.98 PPBV
7.76 PPBV
4.79 PPBV
1.61 PPBV
7.66 PPBV
7.69 PPBV
8.35 PPBV
7.17 PPBV
7.91 PPBV
7.80 PPBV
8.32 PPBV
12.91 PPBV
8.71 PPBV
5.06 PPBV
6.70 PPBV
5.29 PPBV
4.39 PPBV
3.49 PPBV
6.40 PPBV
6.44 PPSV
6,04 PPBV
6.03 PPSV
2.96 PPBV
3.47 PPBV
0.00
0.00
0.00
leeovery
100.33%
99.61%
95.94%
QvalUe
' 99
# 100
97
.100
96
99
SS
99
99
99
99
99
98
10Q
99
100
99
99
98
100
98
100
98
97
99
100
99
97
99
39
100
99
99
100
99
99
99
99
99
99
99
99
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-47
-------
Method TO-14A
VOCs
GC/MS/SCAN
(Section 10.4J2J
Log SamjJto In AwrfyHcat
Logbook (Sector 10.4.1.2)
Check and Record WW
Preswune (Secfioo 10.4.1J5)
Araiyza
GC/MS/SIM
(Section 10.4.3)
Non-S p^inc Dutector (FID) J
»«WWHH_VW«__»
-------
VOCs
Method TO-14A
To AC
in!«t
Figure 2. Example of sampler configuration for subatmospheric pressure or
pressurized canister sampling used in Compendium Method TO-14A.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-49
-------
Method TO-14A
VOCs
Vent
Wet
Figure 3. Example of alternative sampler configuration for pressurized canister sampling
used in Compendium Method TO-14A.
Page 14A-5Q
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
Prwmuo*
Itoguiotor
Vent
^
Procure
Regulators 5^
Purifier*
1 1 r
1 r i
Flam*
(FIO)
Carrier
Gas
C3V—1
Capillary
Column
(O,32-mm x SO-m)
, Low Dead—Volume
1 T«« (Optional)
I
rS
i i
i i
M
Flow
Reatrictor
(OpUo
Mass Spectrametef In
SCAN/SIM Mode
Figure 4, Compendium Method TO-14A canister analysis utilizing GC/MS/SCAN/SIM
analytical system with optional FID with 6-port valve.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-51
-------
C/i
w
Gas
f»uf«I«r
Ho» Bow
Control«r
Pftnvt*
RtyuMet
O
ft
3
H*
Corcfef
Gas
JAW Meaotx>f«*
C8-E24
Capillary Column
(30-m x 0.5J-mm LO.)
Go* Hot* Row
Purifltr Controller
Prtnuira
Nltrootn
Uak«-Up
Go*
I
Figure S, Compendium Method T014A GC/FID/ECD Analytical System With the 6-Port Chromtographic Valve in the Sample
Desorption Mode
-------
I
i
I
Cat Moss
Purifier Contraijtr
Pressure
Regulator
Most Flow
Controller
Vent
Pmtttr*
Regulator ^ now
0—Q Purifier Contrpljer
r5r-^>-aC^i
H (80 mt/mW
Nitrogen
Uok«-Up
Co*
Figure 6. Compendium Method TO-14A system configuration associated with the GC/FID/ECD/PID analytical
system with the 6-port chromatographic valve in the sample desorption mode.
s.
3
-------
Method TO-14A
VOCs
Pressure
Regulator
Exhaust
Vacuum Pump
Shut Off Valve
Exhaust
Exhaust
» ^ Off Vatve M
_ «—-Orwar 1—*
— - ^
Cryogenic
Trap Cooler
(Liquid Arqon)
Trap
Vacuum
Shut Off
Vatve
Prtssur*
V
Cryog«nie
Trap Cooler
(UqukJ Ar^on)
Humidifier
Vacuum
Gouge
Vacuum
Gaum
Shut Off
Va)v«
Zero
shut orr
Valve
Flow
Control
Vent
Shyt Off
Valve
MonifoM
Sample \ / Sample
Canister/ \Canisteri i
Optional
isothermal
Oven
Figure 7. Compendium Method TO-14A canister cleaning system.
Page 14A-54
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
1
I
!
I
s-
s*
s-
0
(a) Real Time
GC/FID/ECD/PID,
GC/MS or GC/lon Imp
Castration Goi
Cylinder
Mai* Row
Controller
(0-50 mL/min)
Internal
Baffles
Teflon
Filter
Zero Air
Cinder
Ma** Row
Controller
(0-SO t/rota)
Vacuum/Pressure
Heated Colfcration Manifold
Teflon
Filter
Pump
Slut Off
Yohf«
flow
Control
Vato
(b) Evacuated or Pre«uriz«d
Conlst«r Sampling System
900 ml
(c) Contour Trontfer
Standard
Round-Bottom
Floik
Humidifier
Figure 8. Compendium Method TO-14A schematic of calibration system and manifold for (a) analytical system calibration,
(b) testing canister sampling system for (c) preparing canister transfer standards.
H
O
-------
Method TO-14A
VOCs
TIMER
SWITCH
.o-
100K
RED
115 V AC
40M/d. 450 V DC
«» 100K
Oi
BUCK
+*
. «SO V DC
o»
WHITC
Ci M C* - <0 «l. *SD «OC (Soratuf Na« Mk 1711 or
i tM *t - O5 -xt Ml UMrancc
D> V Oj - MOO MM, J-S A t»C*. St JOB) w i»it ll» t)
lOUMOe
wtvc
•K *i
(o). Simple Circuit far Operating Mognelotch Valve
its v AC
Own** Ci - 200 l*. 2» «C (S»ntM «lwi IW !«• V
• C] - 30 ul. 400 VQC HO*-?**** PX»« *<•" MN 1KB w
«n< Rj - OS -o
(b). Improved Circuit Designed to Handle Power Interruptions
Figure 9. Compendium Method TO-14A electrical pulse circuits for driving skinner
magnelatch solenoid valve with a mechanical timer.
Page 14A-56
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
COMPENDIUM METHOD TO-14A
CANISTER FIELD TEST DATA SHEET
A. GENERAL INFORMATION
SITE LOCATION:
SITE ADDRESS:
SHIPPING DATE:
CANISTER SERIAL NO.:
SAMPLER ID:
OPERATOR:
SAMPLING DATE:
CANISTER LEAK
CHECK DATE:
B. SAMPLING INFORMATION
TEMPERATURE
PRESSURE
START
STOP
CAN1STERPRESSURE
i||illi||i|
SAMPLING TIMES
FLOW RATES
START
STOP
SAMPLING SYSTEM CERTIFICATION DATE:.
QUARTERLY RECERTMCATION DATE:
C. LABORATORY INFORMATION
DATA RECEIVED:
INITIAL PRESSURE:
FINAL PRESSURE:
DILUTION FACTOR: _____
RESULTS*:
ANALYSIS
GC/FID/ECD DATE: _
GC/MSD/SCAN DATE:
GC/MSD/SIM DATE:
GC/FID/ECD: _
GC/MSD/SCAN:
GC/MSD/SIM:
SIGNATURE/TITLE
*ATTACH DATA SHEETS
Figure 10. Compendium Method TO-14A field test data sheet (FTDS).
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-57
-------
Method TO-14A
VOCs
TIME —I
(a) SCAN analysis
31NI
TWC
(b) SIM analysis
§
UJ
rue
(c) FID analysis
IblL
TIUE
(d) ECO analysis
Figure 11. Compendium Method TO-14A typical chromatograms of a VOC sample
analyzed by GC/MS/SCAN/SIM mode and GC-muItidetector mode.
Page 14A-58
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-14A
Trap
Cryogen
Exhaust
t
Insulated Shell
Cylindrically Wound
Tube Heater (250 watt)
Bracket and
Cartridge
Heaters (25 watt)
Cryogen in
(Liquid Nitrogen)
Sample
in
Figure 12. Example of Compendium Method TO-14A cryogenic trapping unit.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-59
-------
Method TO-14A
VOCs
InRSai Preparation and Tuning
Humid Zero Air Test
Can «l»r (Section
9-2J)
Log Sampi* In Laboratory
Logbook (Section 10.4.12}
Check and Record
WUml Pressure
CSadfon 10.4.13)
-------
YOCs
Method TO-14A
f M«ah»3Mpl»\
CMrt*r«S«*Bi
0.2.2)
tog Sample In
(StcBon 10.4.12)
Check and Record
Initial Pressure
(Section 1CU.1.3)
(Optional)
Pressurize with N 2
to1.38kPa(20psig)
Record Final Pressure
(Section 10.4.1.3}
Analyz*
Catenate ODution Factor
(Section 10.4.1.4)
Preparation of G C/F1D/ECD/P to
Analytical System
Initial Pmparatior
Humid Zero Air Test and
Retention Time Window Test
Mai Three <3) Point Static Calibration
Addfflonal Five (5) Point Static
Calibration for Nonlinear Compounds
Routine Preparation
i
HumM Zero Air Teat and
Retortion Tine Window Test
!
Dafy One (1) Point Static Cattwatlon
i
Additional Three (3) Point Static
Calibration for Nontioear Compounds
GC/FIO/ECD/P1D
Analysis for Primary QuantHation
Figure 14. Compendium Method TO-14A flowchart of GC/FTD/ECD/PBD analytical
system preparation.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-61
-------
Method TO-14A
VOCs
. •
tl
I
I
o
o
u>
1
I
u
gp
•3
CO
1
"S
2
cu
3
10
2
J»
tu
Page 14A-62
Compendium, of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-14A
eg
s
~3
3
i
i
i
1
I
u
60
3
CD
us
£
Q
&i
S
I
~
January
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-63
-------
Method TO-144
VOCs
-Jt
(a). Certified Sampler
Contaminated Sampler
Rgure 17. Example of humid zero air test results for a clean sampler (a)
and a contaminated sampler (b) used in Compendium Method TO-14A.
Pagel4A-64
Compendium of Methods far Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-14A
1000 —
900 —
000 —
X, 600-
S 500 —
| 300-
200 —
too —
0
I
10
Concentration (ppbv)
FIGURE 18(a). NONLINEAR RESPONSE OF
TETRACHLOETHYLENE ON THE ECO
1100 —
1000 —
•00 —
aao —
I »-
x, eoo —
£ 500-
3 «o
I
200 —
100 —
0
I I I
a a 4
I
10
Concentration (ppbv)
FIGURE 18(b). NONLINEAR RESPONSE OF
CARBON TETRACHLORIOE ON THE ECO
1000 —
900 —
000 —
700 —
SOO —
500 —
400 —
300 —
200 —
100 —
0
I I
2 3 4 S § 7 0
Concentration (ppbv)
10
FIGURE 18(c). NONLINEAR RESPONSE OF
HEXACHLOROBUTADIENE ON THE ECD
ISO —
140 —
I" '»
><. 100 —
I »H
§
0 »H
o
I «J
20 —
0
JJ4587
Concentration (ppbv)
10
FIGURE 18(d). LINEAR RESPONSE OF
CHLOROFORM ON THE ECD
Figure 18. Response of ECD to various VOCs as part of Compendium Method TO-14A.
January 1599
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A.-65
-------
U
44.
I
i
^
!
t
3
s
8-
i-
s-
3-
I
Sompte Intet lii«
Wol
1/4" ss
(1 —
U
£
-*\
I PQwer/TC
^ s StaWtM ^**
^^Stotl Tubing
I
1 "p.
~*i 0.3 meter •*• I
(~1 ft) ^.L.
Outdoor S
Air In)
^Port
a
O
Tltmr It
(eoAtrals
pump)
a
O
Tim*- |3
(eontralt
sampling voh«»)
Vacuum
Pump
O
I
I
3
Figure 19, Example of sampler schematic used in EPA's UATMP.
O
Q
-------
VOCs
Method TO-14A
Canister Receipt |
Record Sample Canister In Dedicated Logbook
Check Canister Pressure
Pressure with No
to 15-20 pslg
Calculate Dilution Factor
GOF1D/ECD and GC/MS
Sample Analysis
Record Initial/Final Pressure
QC/FID/ECD/PID
Analytical Preparation
Routine Preparation
Routine Preparation
Humid Zero Air Test
_t
JL
Humid Zsro Air Test
Dally One (1) Point
Dynamic Calibration
*
Additional Three (3) Point Dynamic Calibration
for Nonlinear Compounds
-
External
Standard
Calibration
]
Daly One (1) Point
Dynamic Calibration
*
Additional Three (3) Point Dynamic Calibration
for Noninear Compounds
GC;FID/ECD/PIO
Screening Analysts
QC/MS Analytical
Preparation
SCAN Mode
SIM Mode
ZZl
Routine Preparation
Routine Preparation
Humid Zero Air Test
Humid Zero Air Test
L
Daily One (1) Point
Dynamic Calibration
*
Additional Flw (5) Point StaBc Dynamic
Calibration for Nonlinear Compounds
-
External
Standard
Calibration
__
Daily One (1} Point
Dynamic Calibration
*
Additional Tnrae (3) Point Static Dynamic
Calibration for Nonlinear Compounds
QC/MS/SCAN Identification and
SemJ-fluantftatton of VOCe
GQMS/SIM Selected VOCs for
Identification and Quantrtatton
Figure 20. Flowchart of analytical systems preparation used in Compendium Method TO-14A.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-67
-------
I
|
vfi
vo
(Section 112.2)
1
3,
-3
Cwkrter Stmpttng
Sy»t»ro
Humid Gw
Cdfcoifon Standmh
(S#c«c*i 11.Z3)
*• . RtceMnQ Station
CanMer Aramaic
OC/MS/8CAN/S1M Of
OCflon Tmp (S«c*xi 10.2)
aC-MnWd«Uctor 9y*tem
(SacOon 10.3)
Figure 21, Compendium Method TO-14A system quality assurance/quality control (QA/QC) activities associated
with various analtical systems.
O
0
-------
VOCs Method TO-14A
Appendix A
Availability Of VOC Standards From United States Environmental Protection Agency
1. Availability of Audit Cylinders
1.1 At the time of the publication of the original Compendium Method TO-14, the USEPA provided cylinder
gas standards of hazardous organic compounds at the ppb level. These standards were used to audit the
performance of monitoring systems such as those described in the original Compendium Method TO-14.
However, this service is no longer provided.
1.2 To obtain information about the availability of different audit gases, interested parties are encouraged to call
commercial gas suppliers.
2. Audit Cylinder Certification
2.1 All audit cylinders should be periodically analyzed to assure that cylinder concentrations have remained
stable.
2.2 All audit gases, including quality control analyses, of ppbv hazardous VOC standards should be traceable
toNIST.
3. Information on EPA's VOC Standards
3.1 USEPA program/regional offices, state/local agencies, and others may obtain advice and information on
VOC standards by calling:
Mr. Howard Christ
U.S. Environmental Protection Agency
National Exposure Research Laboratory (NERL)
Research Triangle Park, NC 27711
919-541-4531
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-69
-------
Method TO-14A VOCs
[This page intentionally left blank]
Page 14A.-7CI CoJtipen&an of Methods for Toxic Organic Air Pollutants January
" -' . •-
-------
VOCs Method TO-14A
Appendix B
Operating Procedures For A Portable Gas Chromatograph Equipped
With A Photoionization Detector
1. Scope
This procedure is intended to screen ambient air environments for volatile organic compounds. Screening is
accomplished by collection of VOC samples within an area and analysis on site using a portable gas
chromatograph/integrator. This procedure is not intended to yield quantitative or definite qualitative information
regarding the substances detected. Rather, it provides a chromatographic "profile" of the occurrence and intensity
of unknown volatile compounds which assists in placement of fixed-site samplers.
2. Applicable Documents
2.1 ASTM Standards
• E260 Recommended Practice for General Gas Chromatography Procedures
• E355 Practice for Gas Chromatography Terms and Relationships
2.2 Other Documents
Portable Instruments User's Manual for Monitoring VOC Sources. EPA-34011-86-015, U. S. Environmental
Protection Agency, Washington, DC, June, 1986.
3. Summary of Method
3.1 An air sample is extracted directly from ambient air and analyzed on site by a portable GC.
3.2 Analysis is accomplished by drawing an accurate volume of ambient air through a sampling port and into
a concentrator, then the sample air is transported by carrier gas onto a packed column and into a FED, resulting
in response peak(s). Retention times are compared with those in a standard chromatogram to predict the probable
identity of the sample components.
4. Significance
4.1 VOCs are emitted into the atmosphere from a variety of sources including petroleum refineries, synthetic
organic chemical plants, natural gas processing plants, and automobile exhaust. Many of these VOC emissions
are acutely toxic; therefore, their determination in ambient air is necessary to assess human health impacts.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-71
-------
Method TO-14A VOCs
4,2 Conventional methods for VOC determination use solid sorbent and canister sampling techniques,
43 Collection of ambient air samples in canisters provides (1) convenient integration of ambient samples over
a. specific time period, (e,g., 24 hours); (2) remote sampling and central analysis; (3) ease of storing and shipping
samples, if necessary; (4) unattended sample collection; (5) analysis of samples from multiple sites with one
analytical system; and (6) collection of sufficient sample volume to allow assessment of measurement precision
and/or analysis of samples by several analytical systems.
4.4 The use of portable GC equipped with multidetectors has assisted air toxics programs by using the portable
GC as a "screening tod" to determine "hot spots," potential interferences, and semi-quantitation of VOCs, prior
to locating more traditional fixed-site samplers.
5. Definitions
Definitions used in this document and in any user-prepared Standard Operating Procedures (SOPs) should be
consistent with ASTM Methods D1356 and E355. Abbreviations and symbols pertinent to this method are
defined at point of use.
6. Interferences
»#«c . ~; •'- ,^ , ,.wr , ^
6.1 The most significant interferences result from extreme differences in limits of detection (LOD) among the
target VOCs (see Table B-l). Limitations in resolution associated with ambient temperature, chromatography
andjhe relatively large number of chemicals result in coelution of many of the target components. Coelution of
compounds with significantly different PID sensitivities will mask compounds with more modest sensitivities.
This will be most dramatic in interferences from benzene and toluene.
Ill' 1i :. , ii* , ,1, . •• ,
63. A typical chromatogram and peak assignments of a standard mixture of target VOCs (under the prescribed
analytical conditions of this method) are illustrated in Figure B-l. Samples which contain a highly complex
mixture of components and/or interfering levels of benzene and toluene are analyzed on a second, longer
chromatographic column. The same liquid phase in the primary column is contained in the alternate column but
at a higher percent loading.
6.3_ Recent designs in commercially available GCs have preeoneentrator capabilities for sampling lower
concentrations of VOCs, pre-column detection with back-flush capability for shorter analytical time, constant
column temperature for method precision and accuracy and multidetector (PID, ECD, and FID) capability for
versatility. Many of these newer features address the weaknesses and interferences mentioned above. A list of
major manufacturers of portable GC systems is provided in Table B-2.
1 1 •$ • •:•!•!
7, Apparatus
7.1 Gas Chromatogram
A GC, Pbotovac Inc., 739 B Parks Avc, Huntington, NY 11743, Model 10S10 or 10S50, or equivalent used for
surveying ambient air environments (which could employ a multidetector) for sensing numerous VOCs
compounds eluting from a packed column at ambient temperatures. This particular portable GC procedure is
Page 14A-72 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
written employing the photoionization detector as its major sensing device, as part of the portable GC survey tool.
Chromatograrns are developed on a column of 3% SP-2100 on 100/120 supelcoport (0.66-m x 3.2-mm I.D.) with
a flow of 30 mL/min air.
7.2 GC Accessories
In addition to the basic gas ehromatograph, several other pieces of equipment are required to execute the survey
sampling. Those include gas-tight syringes for standard injection, alternate carrier gas supplies, high pressure
connections for filling the internal carrier gas reservoir, and if the Model 10S10 is used, a recording integrator.
8. Reagents and Materials
8.1 Carrier Gas
"Zero" air [<0.1 ppm total hydrocarbon(THC)] is used as the carrier gas. This gas is conveniently contained in
0.84 m3 (30 ft3) aluminum cylinders. Carrier gas of poorer quality may result in spurious peaks in sample
chromatograms. A Brooks, Type 1355-OOF1AAA rotameter (or equivalent) with an R.-215-AAA tube and glass
float is used to set column flow.
8.2 System Performance Mixture
A mixture of three target compounds (e.g., benzene, trichloroethylene, and styrene) in nitrogen is used for
monitoring instrument performance. The approximate concentration for each of the compounds in this mixture
is 10 parts per billion (ppb). This mixture is manufactured in small, disposable gas cylinders [at 275 kPa (40
psi)] various commercial vendors.
8.3 Reagent Grade Nitrogen Gas
A small disposable cylinder of high purity nitrogen gas is used for blank injections.
8.4 Sampling Syringes
Gas-tight syringes, without attached shut-off valves (Hamilton Model 10Q2LT, or equivalent) are used to
introduce accurate sample volumes into the high pressure injectors on the portable gas chromatograph. Gas
syringes with shut-off valves are not recommended because of memory problems associated with the valves. For
samples suspected of containing high concentrations of volatile compounds, disposable glass syringes (e.g.,
Glaspak, or equivalent) with stainless steel/Teflon® hub needles are used,
8.5 High Pressure Filter
An adapter (Photovac SA101, or equivalent) for filling the internal carrier gas reservoir on the portable GC is
used to deliver "zero" air.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-73
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Method TO-14A VOCs
9, Procedure
i m* • " • r • m »
9.1 Instrument Setup
- 9.1.1 The portable gas ehromatograph must be prepared prior to use in the ambient survey sampling. The
pre-sampling activities consist of filling the internal carrier gas cylinder, charging the internal power supply,
adjusting individual column carrier gas flows, and stabilizing the photoionization detector,
-9.1.2 The internal reservoir is filled with "zero" air. The internal I2V battery can be recharged to provide
up to eight hour of operation. A battery which is discharged will automatically cause the power to the instrument
to jjjeshut down and will require an overnight charge. During AC operation, the batteries will automatically be
trickle-charged or in a standby mode.
9.13 The portable GC should be operated (using the internal battery power supply) at least forty minutes
prior to collection of the first sample to insure that the photoionization detector has stabilized. Upon arriving at
thejurea to be sampled, the unit should be connected to AC power, if available.
9.2 Sample Collection
9.2.1 After the portable gas chromatograph is located and connected to 110V AC, the carrier gas glows must
be adjusted Flows to the 1.22 meter, 5% SE-30 and 0.66 meter, 3% SP2100 columns are adjusted with needle
valves, flows oF^'mL/mln (5°/o SE-30) and 30 mL/min (3% SP2100) are adjusted by means of a calibrated
rofameteifr Switching between the two columns is accomplished by turning the valve located beneath the
electronic module. During long periods of inactivity, the flows to both columns should be reduced to conserve
pressure in the internal carrier gas supply. The baseline on the recorder/integrator is set to 20% full scale.
~93.3. Prior to analysis of actual samples, an injection of the performance evaluation mixture must be made
to verity chromatograpMc and detector performance. This is accomplished by withdrawing 1.0 mL samples of
tMs mixture from the calibration cylinder and injecting it onto the 3% SP2100 column. The next sample
analyzed should be a blank, consisting of reagent grade nitrogen.
9.2.3 Ambient air samples are injected onto the 3% SP2100 column. The chromatogram is developed for
15^ minutes. Samples which produce particularly complex chromatograms, especially for early eluting
components, are reinjected on the 5% SE-30 column.
-«.• • ». - ",'„ **,„ ...... - ' j
[Note: In no instance should a syringe -which has been used for the injection of the calibrant/system
performance mixture be use for the acquisition and collection of samples, or vice versa.}
- • • I
9.2.4 Samples have generally been collected from the ambient air at sites which are near suspected sources
of VOCs and compared with those which are not. Typically, selection of sample locations is based on the
presence of chemical odors. Samples collected in areas without detectable odors have not shown significant PID
responses. Therefore, sampling efforts should be initially concentrated on "suspect" environments (i.e., those
which have appreciable odors). The objective of the sampling is to locate sources of the target compounds.
Ultimately, samples slbuldbe collected throughout the entire location, but with particular attention given to areas
of high or frequent occupation.
Page 14A-74 Compendium of Methods for Toxic Organic Air Pollutants January
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VOCs - ; Method TO-14A
9.3 Sample Analysis
9,3.1 Quantitative Analysis, Positive identification of sample components is not the objective of this
"screening" procedure. Visual comparison of retention rimes to those in a standard chromatogram (Figure B-l)
are used only to predict the probable sample component types.
9.3.2 Estimation of Levels, As with qualitative analysis, estimates of component concentrations are
extremely tentative and are based on instrument responses to the calibrant species (e.g., benzene,
trichloroethylene, styrene), the proposed component identification, and the difference in response between sample
component and calibrant For purposes of locating pollutant emission sources, roughly estimated concentrations
and suspected compound types are considered sufficient
10. Performance Criteria and Quality Assurance
i
Required quality assurance measures and guidance concerning performance criteria that should be achieved within
each laboratory are summarized and provided in the following section.
10.1 Standard Operating Procedures
10.1.1 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 portable GC sampling system and
equipment used; (2) preparation, storage, shipment,and handling of the portable GC sampler; (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,
10.13. Specific stepwise instructions should be provided in the SOPs and should be readily available to and
understood by the personnel conducting the survey work.
10.2 Quality Assurance Program
10.2.1 Reagent and Materials Control. The carrier gas employed with the portable GC is "zero air"
containing less than 0,1 ppm VOCs, System performance mixtures are certified standard mixtures purchased
form Scott Specialty Gases, or equivalent.
10JL2 Sampling Protocol and Chain of Custody. Sampling protocol sheets must be completed for each
sample. Specifics of the sample with regard to sampling location, sample volume, analysis conditions, and
supporting calibration and visual inspection information are detailed by these documents. An example form is
exhibited in Table B-3.
10.23 Blanks, Duplicates, and System Performance Samples.
10.2.3.1 Blanks and Duplicates. Ten percent of all injections made to the portable GC are blanks, where
the blank is reagent grade nitrogen gas. This is the second injection in each sampling location. An additional
10% of all injections made are duplicate injections. This will enhance the probability that the chromatograph of
a sample reflects only the composition of that sample and not any previous injection. Blank injections showing
a significant amount of contaminants will be cause for remedial action.
10.232, System Performance Mixture. An injection of the system performance mixture will be made
at the beginning of a visit to a particular sampling location (i.e., the first injection). The range of acceptable
chromatographic system performance criteria and detector response is shown in Table B-4. These criteria are
selected with regard to the intended application of this protocol and the limited availability of standard mixtures
in this area. Corrective action should be taken with the column or PUD before sample injections are made if the
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-75
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Method TO-14A
VOCs
performance is deemed out-of-range. Under this regimen of blanks and system performance samples,
approximately eight samples can be collected and analyzed in a three hour visit to each sampling location.
• . • _— .-.-- • i.
10.3 Method Precision and Accuracy
The purpose of the analytical approach outlined in this method is to provide presumptive information regarding
the presence of selected VOCs emissions. In this context, precision and accuracy are to be determined. However,
quality assurancecriteria are described in Section 10.2 which insure the samples collected represent the ambient
environment. ' ' " " " "" " "
10.4 Range and Limits of Detection
, . , , , ....
The range and limits of detection of this method are highly compound dependent due to large differences in
response of the portable GCs photoionization detector to die various target compounds. Aromatic compounds
and olcfinic halogenated compounds will be detected at lower levels than the halomethanes or aliphatic
hydrocarbons. The concentration range of application of this method is approximately two orders of magnitude.
TABLE B-L ESTIMATED LIMITS OF DETECTION (LOD) FOR
SELECTED VOCs BASED ON 1 uL SAMPLE VOLUME
. Cbmpou^d-'B^v'-llllll
Chloroform1
1,1,1 -Trichloroethane1
Carbon tetrachloride1
Benzene
1,2-Dicbloroethane2
Trichloroethylene2
Tetrachloroethylene2
1,2-Dibromoethane
p-Xylene3
m-Xylene3
o-Xylene4
Styrcne4
2
2
2
.006
.05
.05
.05
.02
.02
.02
.01
.01
450
450
450
2
14
14
14
2
4
4
3
3
'Chloroform, 1,1,1-trichloroethane, and carbon tetrachloride
coelute pnp.66-m3% SP210Q.
2l^S-Dichloroethane, tricholroethylene, and tetracUoroethylene
coelute on 0.66-m 3% SP2100.
3p-Xylene and m-xylene coelute on 0.66-m 3% SP2100.
4Styrene arid o-xylene coelute on 0.66-m 3% SP2100.
Page WA-76
Compen&m of Methods/or Toxic Organic Air Pollutants
January 1999
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VOCs
Method TO-14A
TABLE B-2. LIST OF COMMERCIALLY AVAILABLE PORTABLE
VOC INSTRUMENT MANUFACTURERS
Viking Instruments Corporation
3800 Concorde Parkway
Chantffly,VA 22021
Phone (703) 968-0101
FAX (703)968-0166
Photo-vac International Inc.
25-B Jefiyn Boulevard
Deer Park, NY 11729
Phone (516)254-4199
FAX (516)254-4284
MSA Baseline
North Star Route PO Box 649
Lyons, CO 80540
Phone (303)823-6661
FAX (303)823-5151
SRI Instruments Inc.
3882 Dei Amo Boulevard
Suite 601
Torrance,CA 90503
Phone (310)214-5092
FAX (310)214-5097
MTI Analytical Instruments
41762 Christy Street
Fremont, CA 94538
Phone (510)490-0900
FAX (510)651-2498
Sentex Sensing Technology
552 Broad Avenue
RidgefiekLNJ 07657
Phone (201)945-3694
FAX (201)941-6064
CMS Research Corporation
200 Chase Park South, Suite 100
Birmingham, AL 35244
Phone (205)733-6910
FAX (205)733-6919
HNU Systems Inc.
160 Charlemont Street
Newton Highlands, MA 021161-9987
Phone (617)964-6690
FAX (617)965-5812
Microsensor Systems Inc.
62 Corporate Court
Bowling Green, KY 42104
Phone (502)745-0099
FAX (502) -
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-77
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Method TO-14A
VOCs
TABLE B-3. PORTABLE GAS CHROMATOGRAPH SAMPLING DATA SHEET
DATE; LOCATION: TIME;
CHROMATOGRAPfflC CONDITIONS:
COLUMN 1: COLUMN TYPE:
f D. (mm): LENGTH (mm):,
COLUMN 2: COLUMN TYPE:
I.D. (mm): LENGTH (mm):.
FLOW(mL/min):.
FLOW(mL/min):.
INI NO. 1NJ. VOL. COLUMN NO. SETTING LOCATION
SITE PLAN (indicate sampling locations):
DATE
SIGNATURE
Page 14A-78
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-14A
TABLE B-4. SYSTEM PERFORMANCE CRITERIA FOR PORTABLE GC1
'^&&&&®%$$£®8'.
.^tenas;««g;;:p|
PID Response
Elution Time
Resolution2
^wzmm*s;ymmmm»im*
|i^Cooipouwtef;i»M^i:
Trichloroethylene
Styrene
Benzene/Trichloro-ethylene
• Ae^table Range! •
a 108uV-sec/ng
2.65±0.15min
i 1.4
S>u:f^esfe^:Cdrro^£^^
Re-tune or replace lamp
Inspect for leaks, adjust carrier flow
Replace column
'Based on analysis of a vapor mixture of benzene, styrene, and trichloroethylene.
2Define by: R 4- = 2d/(W1+W2); where d = distance between the peaks and W = peak width at
base.
TABLE B-5. ESTIMATED LIMITS OF
DETECTION (LOP) FOR SELECTED VQCs
Compound
Chloroform'
1,1,1 -Trichloroethane1
Carbon tetrachloride1
Benzene
1 ,2-Dichloroethane2
Trichloroethylene2
Tetrachloroethylene2
1,2-Dibromoethane
p-Xylene3
m-Xylene3
o-Xylene4
Styrene4
LOD(ng)
2
2
2
.006
.05
.05
.05
.02
.02
.02
.01
.01
LOD (ppb)
450
450
450
2
14
14
14
2
4
4
3
3
'Chloroform, 1,1,1-trichloroethane, and carbon tetrachloride
coelute on 0.66-m 3% SP2100.
2l,2-Dichloroethane, tricholroethylene, and
tetrachloroethylene coelute on 0.66-m 3% SP2100.
3p-XyIene and m-xylene coelute on 0.66-m 3% SP2100.
4Styrene and o-xylene coelute on 0.66-m 3% SP2100.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 14A-79
-------
Method TO-14A
VOCs
Peak Assignments for Siflrtdord Utxtures
P«ok No.
Corrtpound(«}(
2
3
4
5
6
Benzene! Chloroform;
1,1.1 -Trithtoroethone;
Carbon fetraehlorfd*
1,2-Dichloroelhooe:
Trichlmo«thon«
m.o-Xvt«n«
: Styrene
0 Toluwe (nci listed) ehites between
1 and 2.
Time-
Figure B-L Typical eMrdmatogram of VOCs (tetermined by a portable GC.
"I » - "I ill If? ' . r, ;.fr ; . ', •: ' ; • ,»', ... • ti- , .'i , .j -:,
Page 14A-80 Compendium of Methods for Toxic Organic Air i
Jaiiiiaf y
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VOCs Method TO-14A
Appendix C
Installation And Operation Procedures For U.S. Environmental
Protection Agency's Urban Air Toxic Monitoring Program Sampler
1. Scope
1.1 The subatmospheric sampling system described in this method was designed specifically for use in USEPA's
Urban Air Toxic Monitoring Program (UATMP) to provide analytical support to the states in their assessment
of potential health risks from certain toxic organic compounds that may be present in urban atmospheres.
1.2 The sampler is based on the collection of whole air samples in 6-liter, specially prepared passivated stainless
steel canisters. The sampler features electronic timer for ease, accuracy and flexibility of sample period
programming, an independently setabie presample warm-up and ambient air purge period, protection from loss
of sample due to power interruptions, and a self-contained configuration housed in an all-metal portable case, as
illustrated in Figure C-1.
13 The design of the sampler is pumpless, using an evacuated canister to draw the ambient sample air into itself
at a fixed flow rate (3-5 mL/min) controlled by an electronic mass flow controller. Because of the relatively low
sample flow rates necessary for the integration periods, auxiliary flushing of the sample inlet line is provided by
a small, general-purpose vacuum pump (not in contact with the sample air stream). Further, experience has
shown that inlet lines and surfaces sometimes build up or accumulate substantial concentrations of organic
materials under stagnant (zero flow rate) conditions. Therefore such lines and surfaces need to be purged and
equilibrated to the sample air for some time prior to the beginning of the actual sample collection period. For this
reason, the sampler includes dual timers, one of which is set to start the pump several hours prior to the specified
start of the sample period to purge the inlet lines and surfaces. As illustrated in Figure C-l, sample air drawn
into the canister passes through only four components: the heated inlet line, a 2-micron particulate filter, the
electron flow controller, and the latching solenoid valve.
2. Summary of Method
2.1 In. operation, tinier 1 is set to start the pump about 6 hours before the scheduled sample period. The pump
draws sample air in through the sample inlet and particulate filter to purge and equilibrate these components, at
a flow rate limited by the capillary to approximately 100 mL/min, Timer 1 also energizes the heated inlet line
to allow it to come up to its controlled temperature of 65 to 70 degrees C, and turns on the flow controller to allow
it to stabilize. The pump draws additional sample air through the flow controller by way of the normally open
port of the 3-way solenoid valve. This flow purges the flow controller and allows it to achieve a stable controlled
flow at the specified sample flow rate prior to the sample period.
2.2 At the scheduled start of the sample period, timer 2 is set to activate both solenoid valves. When activated,
the 3-way solenoid valve closes its normally open port to stop the flow controller purge flow and opens its
normally closed port to start flow through the aldehyde sample cartridges. Simultaneously, the latching solenoid
valve opens to start sample flow through into the canister.
January 1999 Compendium, of Methods for Toxic Organic Air Pollutants Page 14A-81
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Method TO-14A ; ; VOCs
23 At the end of the sample period, timer 2 closes the latching solenoid valve to stop the sample flow and seal
the sample in the canister and also de-energizes the pump, flow controller, 3-way solenoid, and heated inlet Une.
During operation, the pump and sampler are located external to the sampler. The 2.4 meter (~8 foot) heated inlet
line is installed through the outside wall, with most of its length outside and terminated externally with an inverted
glass funnel to exclude precipitation. The indoor end is terminated in a stainless steel cross fitting to provide
connectiqns for Jhe canister sample and the two optional formaldehyde cartridge samples.
S.JSampIer Installation
3.1 The sampler must be operated indoors with the temperature between 20-32°C (—68 to 90°F). The sampler
case should be located conveniently on a table, shelf, or other flat surface. Access to a source of 115 vac line
power (500 watts/min) is also required. The pump is removed from the sampler case and located remotely from
the sampler (connected with a 1/4 inch O.D. extension tubing and a suitable electrical extension cord).
3,2 Electrical Connections (~Ffgure C-l)
" '"' ' "::" ' ' •' : " ' ' ' I ••'..:'
3.2.1 The sampler cover is removed. The sampler is not plugged into the 115 vac power until all other
electricaT connections are completed
3.2 2 The pump is plugged into its power connector (if not already connected) and the battery connectors are
snapped onto the battery packs on the covers of both timers.
3.2.3 The sampler power plug is inserted into a 115 volts ac line grounded receptacle. The sampler must be
grounded for operator safety. The electrical wires are routed and tied so they remain out of the way.
3.3 Pneumatic Connections
— 3.3.1 The length of 1/16 inch O.D. stainless steel tubing is connected from port A of the sampler (on the right
side of the flow controller module) to the air inlet line.
333, The pump is connected to the sampler with 1/4 inch O,D. plastic tubing. This tubing may be up to 7
meters (~20 feet) long. A short length of tubing is installed to reduce pump noise. All tubing is conveniently
routed and, if necessary, tied in place.
4, Sampler Preparation
4.1 Canister
4.1.1 The sample canister is installed no more than 2 days before the scheduled sampling day.
4.1.2 With timer. #1 ON, the flow controller is allowed to warm up for at least 15 minutes, longer if possible.
_ 4.1.3 An evacuated canister is connected to one of the short lengths of 1/8 inch O.D. stainless steel tubing
from port B (solenoid valve) of the sampler. The canister valve is left closed. The Swagelock® fitting on the
canister must not be cross-threaded. The connection is tightened snugly with a wrench.
4.1.4 TJhcend of the other length of stainless steel tubing from port B (solenoid valve) is connected with a
Swagelock® plug. " "
4.1,5 If duplicate canisters are to be sampled, the plug is removed from the second 1/8 inch O.D. stainless
steel tubina from port B (solenoid valve) and the second canister is connected. The canister valve is left closed.
Page 14A-S2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-14A
4.1.6 The ON button of timer #2 is pressed. The flow through the flow controller should be stopped by this
action.
4.1.7 The flow controller switch is turned to "READ" and the zero flow reading is obtained. If this reading
is not stable, wait until the reading is stabilized
4.1.8 The flow controller switch is turned to "SET" and the flow setting is adjusted to the algebraic SUM
of the most recent entry on Table C-1 and the zero reading obtained in step 4.1.7 (If the zero reading is negative,
SUBTRACT the zero reading from the Table C-l value). Be sure to use the correct Table C-l flow value for one
or two canisters, as appropriate.
[Note: If the analytical laboratory determines that the canister sample pressure is too low or too high, a new
flow setting or settings will be issued for the sampler. The new flow setting should be recorded in Table C-l
and used until superseded by new settings.]
4.1$ Timer #2 is turned OFF to again start the flow through the flow controller. With the pump (timer #1)
ON and the sampling valve (timer #2) OFF, the flow controller is turned to "READ" and the flow is verified to
be the same as the flow setting made in Section 4.1.8. If not, the flow setting is rechecked in Section 4.1.8 and
the flow setting is readjusted if necessary.
4.1.10 The OFF button of timer #1 is pressed to stop the pump.
4.1.11 The canister valve(s) are fully opened.
4.2 Timers
4,2.1 Timer #2 is set to turn ON at the scheduled ON time for the sample period, and OFF at the scheduled
OFF time (see the subsequent section on setting the timers). Normal ON time: 12:00 AM on the scheduled
sampling day. Normal OFF time: 11:59 PM on the scheduled sampling day. The OFF time is 11:59 PM instead
of 12:00 AM so that the day number for the OFF time is the same as the day number for the ON time. Be sure
to set the correct day number.
43,3. Timer # 1 is set to turn ON six (6) hours before the beginning of the scheduled sample period and OFF
at the scheduled OFF time for the sample period (same OFF time as for timer #2). See the subsequent section
on setting the timers. Normal ON time: 06:00 PM on the day prior to the scheduled sampling day. Normal OFF
time: 11:59 PM on the scheduled sampling day.
[Note: The timers are wired so that the pump will be on whenever either timer is on. Thus the pump will run
if timer #2 is ON even if timer #1 is OFF.]
4.2.3 The elapsed time meter is set to 0.
4.3 Sampler Check
4.3.1 The following must be verified before leaving the sampling site:
(1) Canister(s) is (are) connected properly and the unused connection is capped if only one canister is
used.
(2) Canister valve(s) is (are) opened.
(3) Both timers are programmed correctly for the scheduled sample period.
(4) Both timers are set to "AUTO".
(5) Both timers are initially OFF.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-83
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Method TO-14A VQCs
mm.
• •• . - . . . , o». , . „, ,
(6) Both timers are set to the correct current time of day and day number.
(7) Elapsed time meter is set to 0.
4.4 Sampler Recovery (Post Sampling)
4.4.1 The valve on the canister is closed.
4.4 2 The canister is disconnected from the sampler, the sample data sheet is completed, and the canister is
prepared for shipment to the analytical laboratory.
"4.4.3 If two canisters were sampled, Section 2.4.2 is repeated for the other canisters.
° *° ^ : -
5._Ttmer Setting
Since the timers are 7-day timers, the days of the week are numbered from 1 to 7. The assignment of day
numbers to days of the week is indicated on the timer keypad: 1 = Sunday, 2 = Monday, 3 = Tuesday, 4 =
V^edixsday, 5 =» Thursday, 6 = Friday, and 7 = Saturday. This programming is quite simple, but some timers may
malfunction or operate erratically if not programmed exactly right To assure correct operation, the timers should
be reset and completely reprogrammed "from scratch" for each sample. The correct current time of day is re-
entered to rcprogram the timer. Any program in the timer's memory is erased by resetting the timer (pressing the
reset button). The timer is set by the following:
(1) pressing the reset button,
(2) entering the correct day number and time of day,
(3) entering the ON and OFF times for the sample period, and
(4) verifying that the ON and OFF time settings are correct
5.1 Timer Reset
The timer reset button is pressed, which is recessed in a small hole just above the LED (light emitting diode)
indicator's ght A smaE object that will fit through the hole, such as a pencil, match, or pen is used to press the
timer. After reset, the timer display should show 1 1| 1 10:00|.
[Npfe; The timers may operate erratically when the batteries are discharged, which happens when the
sampler is unplugged or without power for several hours. When the sampler is again powered up, several
hours may be required to recharge the batteries. To avoid discharging the batteries, the battery pack should
be disconnected from the timer -when the sampler is unplugged.]
53. Date and Tline^Intry
Klllili , li II I
The selector switch is turned to SET and the number button corresponding to the day number is pressed For
example, a "2" is pressed for Monday. The current time of day is entered. For example, if the time is 9:00 AM,
900 is pressed AM or PM is pressed as applicable. Display should show 1 2 1 | '9:00 1 for 9:00 AM Monday.
[Not?: 'indicates AM and, indicates PM.]
Page 14A-84 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-14A
The CLOCK button is pressed. Display should show |-| |—:—|. If an error is made, |E| |EE:EE| is shown on
the display. The CLEAR button is pressed and the above steps are repeated. The selector switch is turned to
AUTO or MAN to verify correct time setting.
5.3 ON and OFF Entry
The selector switch is turned to SET. The ON and OFF program is entered in the following order: day, number,
time, AM or PM, ON or OFF. (Example: To turn ON at 12:00 AM on day 5 (Thursday); 5, 1200, AM, ON is
entered). (Example: To turn OFF at 11:59 PM on day 5 (Thursday); 5, 11:59, PM, OFF is entered.) If the
display indicates an error (|Ej |EE:EEj), the timer is reset. The selector switch is turned to AUTO.
5.4 ON and OFF Verification
5,4.1 The selector switch is turned to REVIEW. The number of the scheduled sample day is pressed. ON
is pressed. The display should show the time of the beginning of the sample period (for example, 151 | '12:001).
[' indicates AM] ON is pressed again. The display should show j 51 j —:—|, indicating no other ON times are
programmed.
5.4.2 OFF is pressed. The display should show the time of the end of the sample period, (for example, 151
|, 11:591). PM is indicated by the"," mark before the time. OFF is pressed again. The display should show j 51
j—:—|, indicating no other OFF times are programmed. The selector is switched to AUTO. If anything is
incorrect, the timer is reset and reprogrammed.
TABLE C-l. NET FLOW CONTROLLER SETTING
DATE 1 CANISTER 2 CANISTERS
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 14A-85
-------
Method TO44A
VOCs
B : t- r Ji'
-------
EPA/625/R-96/0!Ob
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-15
Determination Of Volatile Organic
Compounds (VOCs) In Air Collected In
Specially-Prepared Canisters And
Analyzed By Gas Chromatography/
Mass Spectrometry (GC/MS)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-15
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/OlOb), which was prepared under
Contract No, 68-C3-0315, WA No. 3-10, by Midwest Research Institute (MRI), as a subcontractor to
Eastern. Res eaS Group, Sac' (ERG), and under the sponsorship of the U.S. Environmental Protection
Agency (EPA). Justice A. Manning, John O. Burckle, and Scott Hedges, Center for Environmental Research
Information (CERT), and Frank F. McElroy, National Exposure Research Laboratory (NERL), all in the EPA
Office of Research and Development, were responsible for overseeing the preparation of this method.
Additional support was provided by other members of the Compendia Workgroup, which include:
John O. Burckle, EPA, ORD, Cincinnati, OH
« James L. Cheney, Corps of Engineers, Omaha, MB
Michael Davis, U.S. EPA, Region 7, KC, KS
« Joseph BVElMns Jr., U.S. EPA, OAQPS, RTF, NC
• Robert G. Lewis, U.S. EPA, NERL, RTP, NC
> -i Justice A^Manning, U.S. EPA, ORD, Cincinnati, OH
?"; .; William A. McClenny, U.S. EPA, NERL, RTP, NC
:»*.»'"'** vmfx.'^mami-rKf.mm: i*-,,.*.™, , _,?..„ ,'„ .'
**" *l FnmkF. McElroy,U.S. EPA,NERL, RTP,NC
* Heidi Schultz, ERG, Lexington, MA
William T_. "Jerry" Winbeny, Jr., EnviroTech Solutions, Cary, NC
™ »5 .. ::f £ ;, . •; ; . ..-; ,_ : ^ , . Jf::t --".. ..-,,• .,.»,*. " ]"." '"" ., ,
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.
§.., ;r,; -.m'm "••>'• ••*.'••<. • • -i . .- *.•: - •} ••;
Author(s) _ ' ,1,1
•" WiUiam A. McClenny, U.S. EPA, NERL, RTP, NC
Michael W. Holdren, Battelle, Columbus, OH
Peer Reviewers
-- • Karen Oliver, ManTech, RTP, NC
• Jim Cheney, Corps of Engineers, Omaha, NB
* EUzabetih_Almasi, Varian Chromatography Systems, Watout Creek, CA
« :: Nom Kirshen, yarian Chromatograiphy Systems, Wabut Creek, CA
• Richard Jesser, Graseby, Smyrna, GA
Bill Taylor, Graseby, Smyrna, GA
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
K: •"' ' :'JB1 jflj - " ;ii ' '-•' - '' " >•''»"- • ' ''•' """- ••'ft •"*•'. '•'• "i: '4''•'•• ' "' ' • '
Finally, recognition is given to Frances Beyer, Lynn Kaufinan, Debbie Bon3, Cathy Wmtaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence
during the development of this manuscript has enabled it's production.
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 TO-15
Determination of Volatile Organic Compounds (VOCs) In Air Collected In
Specially-Prepared Canisters And Analyzed By Gas Chromatography/
Mass Spectrometry (GC/MS)
TABLE OF CONTENTS
1. Scope 15-1
2. Summary of Method 15-2
3. Significance , 15-3
4. Applicable Documents 15-4
4.1 ASTM Standards 15-4
4.2 EPA Documents , 15-4
5. Definitions 15-4
6. Interferences and Contamination 15-6
7. Apparatus and Reagents 15-6
7,1 Sampling Apparatus 15-6
7.2 Analytical Apparatus 15-8
7.3 Calibration System and Manifold Apparatus 15-10
7.4 Reagents 15-10
8. Collection of Samples in Canisters 15-10
8.1 Introduction 15-10
8.2 Sampling System Description 15-11
8.3 Sampling Procedure 15-12
8.4 Cleaning and Certification Program 15-14
9. GC/MS Analysis of Volatiles from Canisters 15-16
9.1 Introduction 15-16
9.2 Preparation of Standards 15-17
10. GC/MS Operating Conditions 15-21
10.1 Preconcentrator 15-21
10.2 GC/MS System 15-22
10.3 Analytical Sequence 15-22
10.4 Instrument Performance Check 15-23
10.5 Initial Calibration 15-23
10.6 Daily Calibration 15-27
10.7 Blank Analyses 15-27
10.8 Sample Analysis 15-28
ill
-------
TABLE OF CONTENTS (continued)
Eags
1 1'. Requirements for Demonstrating Method Acceptability for VOC Analysis from
Canisters ...................... . ............................................ 15-31
11.1 Introduction ____ . ............................................. '. ......... 15-31
_ 11.2 ^Mefed^tection Limit :_. .... ..... . .............. ... ..... ... ..... ... ...... . 15-31
- 1 1,3" Replicate Precision ........................... . . .............. . ......... 15-3 1
11.4 Audit Accuracy ............................................... .......... 15-32
12. References .... ............... . ................... . ........ ....... . . ........ . 15-32
IV
-------
METHOD TO-I5
Determination of Volatile Organic Compounds (VOCs) In Air Collected In
Specially-Prepared Canisters And Analyzed By Gas Chromatography/
Mass Spectrometry (GC/MS)
1. Scope
1.1 This method documents sampling and analytical procedures for the measurement of subsets of the 97 volatile
organic compounds (VOCs) that are included in the 189 hazardous air pollutants (HAPs) listed in Title III of the
Clean Air Act Amendments of 1990. VOCs are defined here as organic compounds having a vapor pressure
greater than 10-l Torr at 25 °C and 760 mm Hg. Table 1 is the list of the target VOCs along with their CAS
number, boiling point, vapor pressure and an indication of their membership in both the list of VOCs covered
by Compendium Method TO-14A (1) and the list of VOCs in EPA's Contract Laboratory Program (CLP)
document entitled: Statement-of-Work (SOW) for the Analysis of Air Toxics from Superfitnd Sites (2).
Many of these compounds have been tested for stability in concentration when stored in specially-prepared
canisters (see Section 8) under conditions typical of those encountered in routine ambient air analysis. The
stability of these compounds under all possible conditions is not known. However, a model to predict compound
losses due to physical adsorption of VOCs on canister walls and to dissolution of VOCs in water condensed in
the canisters has been developed (3). Losses due to physical adsorption require only the establishment of
equilibrium between the condensed and gas phases and are generally considered short term losses, (i.e., losses
occurring over minutes to hours). Losses due to chemical reactions of the VOCs with cocoUected ozone or other
gas phase species also account for some short term losses. Chemical reactions between VOCs and substances
inside the canister are generally assumed to cause the gradual decrease of concentration over time (i.e., long term
losses over days to weeks). Loss mechanisms such as aqueous hydrolysis and biological degradation (4) also
exist. No models are currently known to be available to estimate and characterize all these potential losses,
although a number of experimental observations are referenced in Section 8. Some of die VOCs listed in Title
in have short atmospheric lifetimes and may not be present except near sources.
1.2 This method applies to ambient concentrations of VOCs above 0.5 ppbv and typically requires VOC
enrichment by concentrating up to one liter of a sample volume. The VOC concentration range for ambient air
in many cases includes the concentration at which continuous exposure over a lifetime is estimated to constitute
a 10"6 or higher lifetime risk of developing cancer in humans. Under circumstances in which many hazardous
VOCs are present at 10"* risk concentrations, the total risk may be significantly greater.
1.3 This method applies under most conditions encountered in sampling of ambient air into canisters. However,
the composition of a gas mixture in a canister, under unique or unusual conditions, will change so diat die sample
is known not to be a true representation of the ambient air from which it was taken. For example, low humidity
conditions in the sample may lead to losses of certain VOCs on the canister walls, losses that would not happen
if the humidity were higher. If the canister is pressurized, then condensation of water from high humidity samples
may cause fractional losses of water-soluble compounds. Since the canister surface area is limited, all gases are
in competition for the available active sites. Hence an absolute storage stability cannot be assigned to a specific
gas. Fortunately, under conditions of normal usage for sampling ambient air, most VOCs can be recovered from
canisters near their original concentrations after storage times of up to thirty days (see Section 8).
1.4 Use of the Compendium Method TO-15 for many of the VOCs listed in Table 1 is likely to present two
difficulties: (1) what calibration standard to use for establishing a basis for testing and quantitation, and (2) how
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-1
-------
Method TO-15 i VOCs
15obtain an audit standard. In certain cases a chemical similarity exists between a thoroughly tested compound
and others on the Title HI list In this case, what works for one is likely to work for the other in terms of making
standards. However, this is not always the case and some compound standards will be troublesome. The reader
is referred to the Section 9.2 on standards for guidance. Calibration of compounds such as formaldehyde,
diazomcthane, and many of the others represents a challenge.
1.5 Compendium Method TO-15 should be considered for use when a subset of the 97 Title HI VOCs constitute
the target list Typical situations involve ambient air testing associated with the permitting procedures for
eniissionsources. In this case sampling and analysis of VOCs is performed to determine the impact of dispersing
source emissions injhe surrounding areas. Other important applications are prevalence and trend monitoring for
hazardous VOCs in urban areas and risk assessments downwind of industrialized or source-impacted areas.
1.6 Solid adsorbents can be used in lieu of canisters for sampling of VOCs, provided the solid adsorbent
packings, usually multisorbcnt packings in metal or glass tubes, can meet the performance criteria specified in
Compendium Method TO-17 which specifically addresses the use of multisorbent packings. The two sample
collection techniques are different but become die same upon movement of the sample from the collection
medium (canister or multisorbent tubes) onto die sample concentrator. Sample collection directly from the
atmosphere by automated gas chromatographs can be used in lieu of collection in canisters or on solid adsorbents.
2. Summary of Method
2.1 The atmosphere is sampled by introduction of air into a specially-prepared stainless steel canister. Both
subaimosphenc pressure and pressurized sampling modes use an initially evacuated canister. A pump ventilated
sampling line is used during sample collection with most commercially available samplers. Pressurized sampling
requires an additional pump to provide positive pressure to the sample canister. A sample of air is drawn through
a sampling train comprised of components that regulate die rate and duration of sampling into the pre-evacuated
and passivated canister.
2.2 After the air sample is collected, the canister valve is closed, an identification tag is attached to the canister,
Sid the canister is transported to the laboratory for analysis.
2.3 Upon receipt at the laboratory, the canister tag data is recorded and the canister is stored until analysis.
Storage times of up to tiiirty days have been demonstrated for many of the VOCs (5).
2.4 To analyze the sample, a known volume of sample is directed from the canister through a solid multisorbent
|»ocra|rator, A portion of the water vapor in the sample breaks through the concentrator during sampling, to a
degree depending on the multisorbent composition, duration of sampling, and other factors. Water content of
the sample can be further reduced by dry purging the concentrator with helium while retaining target compounds.
After the concentration and drying steps are completed, the VOCs are thermally desorbed, entrained to a carrier
gas stream, and then focused in a small volume by trapping on a reduced temperature trap or small volume
multisorbent trap. The sample is then released by thermal desorption and carried onto a gas chrotnatographic
column for separation.
As a simple alternative to the multisorbent/dry purge water management technique, the amount of water vapor
in the sample can be reduced below any threshold for affecting the proper operation of the analytical system by
Page 15-2 Compendium of Methods for Toxic Organic Air Pottutants January 1099
-------
VOCs Method TO-15
reducing the sample size. For example, a small sample can be concentrated on a cold trap and released directly
to the gas chromatographic column. The reduction in sample volume may require an enhancement of detector
sensitivity.
Other water management approaches are also acceptable as long as their use does not compromise the attainment
of the performance criteria listed in Section 11. A listing of some commercial water management systems is
provided in Appendix A. One of the alternative ways to dry the sample is to separate VOCs from condensate
on a low temperature trap by heating and purging the trap.
2.5 The analytical strategy for Compendium Method TO-15 involves using a high resolution gas chromatograph
(GC) coupled to a mass spectrometer. If the mass spectrometer is a linear quadrapole system, it is operated either
by continuously scanning a wide range of mass to charge ratios (SCAN mode) or by monitoring select ion
monitoring mode (SIM) of compounds on the target list If the mass spectrometer is based on a standard ion trap
design, only a scanning mode is used (note however, that the Selected Ion Storage (SIS) mode for the ion trap has
features of the SIM mode). Mass spectra for individual peaks in the total ion chromatogram are examined with
respect to the fragmentation pattern of ions corresponding to various VOCs including the intensity of primary
and secondary ions. The fragmentation pattern is compared with stored spectra taken under similar conditions,
in order to identify the compound. For any given compound, the intensity of the primary fragment is compared
with the system response to the primary fragment for known amounts of the compound. This establishes the
compound concentration that exists in the sample.
Mass spectrometry is considered a more definitive identification technique than single specific detectors such as
flame ionization detector (FID), electron capture detector (ECD), photoionization detector (PH5), or a
multidetector arrangement of these (see discussion in Compendium Method TO-14A). The use of both gas
chromatographic retention time and the generally unique mass fragmentation patterns reduce the chances for
misidentification. If the technique is supported fay a comprehensive mass spectral database and a knowledgeable
operator, then the correct identification and quantification of VOCs is further enhanced.
3. Significance
3.1 Compendium Method TO-15 is significant in that it extends the Compendium Method TO-14A description
for using canister-based sampling and gas chromatographic analysis in die following ways:
• Compendium Method TO-15 incorporates a multisorbent/dry purge technique or equivalent (see Appendix
A) for water management thereby addressing a more extensive set of compounds (the VOCs mentioned
in Title ffl of the CAAA of 1990) than addressed by Compendium Method TO-14A. Compendium
Method TO-14A approach to water management alters the structure or reduces the sample stream
concentration of some VOCs, especially water-soluble VOCs.
* Compendium Method TO-15 uses the GC/MS technique as the only means to identify and quantitate target
compounds. The GC/MS approach provides a more scientifically-defensible detection scheme which is
generally more desirable than the use of single or even multiple specific detectors.
* In addition, Compendium Method TO-15 establishes method performance criteria for acceptance of data,
allowing the use of alternate but equivalent sampling and analytical equipment. There are several new and
viable commercial approaches for water management as noted in Appendix A of this method on which to
base a VOC monitoring technique as well as other approaches to sampling (i.e., autoGCs and solid
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-3
-------
yj .Method TO-15 [ VOCs
w * |;™:rw '* !• .: -,» ti;;?.: t\< ^-i- ,\ •; Sji'/ JP .- ,- {• .^^nr^ *
IT adsorbents) that are often used. This method lists performance criteria that these alternatives must meet
to be acceptable alternatives for monitoring ambient VOCs.
I 3* Finally, Compendium Method TO-15 includes enhanced provisions for inherent quality control. The
method uses internal analytical standards and frequent verification of analytical system performance to
assure controlof the analytical system. This more formal and better documented approach to quality
control guarantees a higher percentage of good data.
3,2 With these features. Compendium Method TO-15 is a more general yet better defined method for VOCs than
-~ Compendium Method TO-14A. As such, the method can be appliedwith a higher confidence to reduce the
• ; .uncertainty b risk assessments in environments where the hazardous volatile gases listed in the Title IJJ of the
Clean Air Act Amendments of 1990 are being monitored. An emphasis on risk assessments for human health
and effects on the ecology is a current goal for the U.S. EPA.
. • • *•'• • *j '•»? ' Ipi ,-':
> * " * -it • ' ''• -**f 'ij ° ••*
4. Applicable Documents
• :; T: •. : ,| • , ;
4.1 ASTM Standards
-"- —e Method D13S6 Definitions of Terms Relating to Atmospheric Sampling and Analysis,
• jiff. .:;, in.? •J$g£$dEffi(!fyejcommended Practice for General Gas Chromatography Procedures.
Is* S» Method E35S Practice for Gas Chromatography Terms and Relationships.
™*i Method D5466 Standard Test Method of Determination of Volatile Organic Compounds in
" -" AttnospKefes][Camster'SamplingMethodology).
..... . i r
••''( ' 43. EPA Documents
,,, ^* Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II, U. S. Environmental
13 ii -^Protection Agency, EPA-600/Rr94-038b, May 199*4.
-» Technical Assistance Document for Sampling and Analysis of 'Toxic Or-ganic Compounds in Ambient
Air, U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
^* Comgendjum qfMethodsfor the Determination of Toxic Organic Compounds in Ambient Air: Method
W-14, 'S^onJSupplemeni,lJ^.EnvliomimM Protection Agency, EPA-600/4-89-018, March 1989.
— *. Statement-of-Work (SOW) for the Analysis of Air Toxics from Superfitnd Sites, U, S. Environmental
Protection Agency, Office of Solid Waste, Washington, D.C., Draft Report, June 1990.
- Clean Air Act Amendments of1990, U, S. Congress, Washington, D.C., November 1990.
"j. S. Definitions
[$ote: Definitions used in this document and any user-prepared standard operating procedures (SOPs)
' " should be cqnsisJentv/ith^ASjM"Methods-JD7 356, E260, and_E355. Aside from the definitions given below,
5 A 'aupertinent abbreviations and symbols are defined within this document at point oj^use.]
^ '" :i '• i*"i"? »•'''•*:'''-•*>? ••*••'?$' m ^f=' ?'Hf cv * • vii\ ' i j' ikt .','/I.".s
5.1 Gauge Pressure—pressure measured with reference to the surrounding atmospheric pressure, usually
expressed in units of kPa or psi. Zero gauge pressure is equal to atmospheric (barometric) pressure.
Page 15-4' Compendium of Methods for Toxic' Organic &ir Fbftutanis ' January 1999"
-------
VOCs , Method TO-1S
5.2 Absolute Pressure—pressure measured with reference to absolute zero pressure, usually expressed in units
of kPa, or psi.
5.3 Cryogen—a refrigerant used to obtain sub-ambient temperatures in the VOC concentrator and/or on front
of the analytical column. Typical cryogens are liquid nitrogen (bp -195,8°C), liquid argon (bp -I85.7°C), and
liquid CO2(bp-79,5°C),
5.4 Dynamic Calibration—calibration of an analytical system using calibration gas standard concentrations
in a form identical or very similar to the samples to be analyzed and by introducing such standards into the inlet
of the sampling or analytical system from a manifold through which the gas standards are flowing.
5.5 Dynamic Dilution—means of preparing calibration mixtures in which standard gas(es) from pressurized
cylinders are continuously blended with humidified zero air in a manifold so that a flowing stream of calibration
mixture is available at the inlet of the analytical system.
5.6 MS-SCAN—mass spectrometric mode of operation in which the gas chromatograph (GC) is coupled to a
mass spectrometer (MS) programmed to SCAN all ions repeatedly over a specified mass range.
5.7 MS-SIM—mass spectrometric mode of operation in which the GC is coupled to a MS that is programmed
to scan a selected number of ions repeatedly [i.e., selected ion monitoring (SIM) mode].
5.8 Qualitative Accuracy—the degree of measurement accuracy required to correctly identify compounds with
an analytical system.
5.9 Quantitative Accuracy—the degree of measurement accuracy required to correctly measure the
concentration of an identified compound with an analytical system with known uncertainty.
5.10 Replicate Precision—precision determined from two canisters filled from the same air mass over the same
time period and determined as the absolute value of the difference between the analyses of canisters divided by
their average value and expressed as a percentage (see Section 11 for performance criteria for replicate precision).
5.11 Duplicate Precision—precision determined from the analysis of two samples taken from the same canister.
The duplicate precision is determined as the absolute value of the difference between the canister analyses divided
by their average value and expressed as a percentage.
5.12 Audit Accuracy—the difference between the analysis of a sample provided in an audit canister and the
nominal value as determined by the audit authority, divided by the audit value and expressed as a percentage (see
Section 11 for performance criteria for audit accuracy).
6. Interferences and Contamination
6.1 Very volatile compounds, such as chloromethane and vinyl chloride can display peak broadening and
co-elution with other species if the compounds are not delivered to the GC column in a small volume of carrier
gas. Refocusing of the sample after collection on the primary trap, either on a separate focusing trap or at the
head of the gas chromatographic column, mitigates this problem.
January 1999 Compendium of Methods for Toide Organic Air Pollutants Page 15-5
-------
Method TO-15
6.2 Interferences in canister samples may result from improper use or from contamination of: (1) the canisters
due to poor manufacturing practices, (2) the canister cleaning apparatus, and (3) the sampling or analytical
system. Attention to the following details will help to minimize the possibility of contamination of canisters.
I . ....
6.2.1 Canisters should be manufactured using high quality welding and cleaning techniques, and new
canisters should be filled with humidified zero air and then analyzed, after "aging" for 24 hours, to determine
cleanliness, Ttecjteanjig apparatus, sampling system, and analytical system should be assembled of clean, high
quality components and each system should be shown to be free of contamination.
Z6.2,2 Canisters sjbpu]d be storedJn a contaminant-free location and should be capped tightly during shipment
to prevent leakage and minimize any compromise of the sample.
6.22 Impurities in the calibration dilution gas (if applicable) and carrier gas, organic compounds out-gassing
from the system components ahead of the trap, and solvent vapors in the laboratory account for the majority of
contamination problems. The analytical system must be demonstrated to be free from contamination under the
conditions; of .the analysis by running humidified zero air blanks. The use of non-ehroraatographic grade stainless
steel tubing, non-PTFE thread sealants, or flow controllers with Buna-N rubber components must be avoided.
6,2.4 Significant contamination of the analytical equipment can occur whenever samples containing high
VOC concentrations are analyzed. This in turn can result in carryover contamination in subsequent analyses.
Whenever a high concentration (>25 ppbv of a trace species) sample is encountered, it should be followed by
. an analysis of humid zero air to check for carry-over contamination.
!"5: :' :5?3^r,n^ ^e H56"! *°,.9onc^nfra^ ^e sample prior to analysis, the sorbents should
be tested to identify artifact formation (see Compendium Me'thod"¥6-i7 for more information on artifacts).
'•• *£ v-'-ivi -TV! /:.• ••••>.*• ' <•," s-i.^v • iffr- •< :;-;vt---\#, :-ws. i r, -t.-^m IE
7. Apparatus and Reagents
1 •'''* ' '!'!',I'1'!'? ' '•• '!', ' '., • . MWiV1. KwA'Kw ••',',,,,',,,' .••
Compendium Method To-l4A list more specific requirements for sampling and analysis apparatus
•which may be of help in identifying options. The listings below are generic.]
7.1 Sampling Apparatus
[Note: Subatmospheric pressure and pressurized canister sampling systems are commercially available and
: have been used as part ofU.S. Environmental Protection Agency's Toxic Air Monitoring Stations (TAMS),
Urban Air Toxic Monitoring Program (UAJMP), the non-methane organic compound (NMOC) sampling and
analysis program, and the Photochemical Assessment Monitoring Stations (PAMS).]
7.1.1 Subatmospheric Pressure (see Figure 1, without metal bellows type pump).
_ 7.L1.1 Sampling Inlet Line. Stainless steel tubing to connect the sampler to the sample inlet.
- 7.1.1.2 Sample Canister. Leak-free stainless steel pressure vessels of desired volume (e.g., 6 L), with
valve and specialty prepared interior surfaces (see Appendix B for a listing of known manufacturers/reseEers of
canisters).
_ .7.1.1.3 Stainless Steel Vacuum/Pressure Gauges. Two types are required, one capable of measuring
vacuum f-100 to 0 kPa or 0 to - 30 uTfig) and pressure (0-^206T3*a or (£-30 psig) in tie sampling system and
a second type (for checking the vacuum of canisters during cleaning) capable of measuring at 0.05 mm Hg (see
Appendix B) within 20%. Gauges should be tested clean and leak tight.
7.1.1.4 Electronic Mass Flow Controller. Capable of maintaining a constant flow rate (± 10%) over
a sampling period of up to 24 hours and under conditions of changing temperature (20-40 °C) and humidify.
7.1.1.5 Particulate Matter Filter. 2-^m sintered stainless steel in-line filter.
5Ei!*l!i , ,:.''• .'",, >:,1H,: !JS '.'' .st^iM"' it*". "K ,";•} V- il : ; ;.'. ™':ii2'-™;i-;l-I5i-£t.'.,l , i-i-t1 l\ -f' "K! '. '• ""i j^S'iJB
Page 15^ Compendium of Methods for Toxic Organic Air Pollutants January 1999
.1.'. jv nfc .-h^ . ">p * -.••• * , tc«<-"it \..- -L \ ' • .'2 i . ''KI" TS
* •; • <_.••" ••' -• -yy- " • • _.- y : -~™ v.-^ '„ , '. .. ' |g • f
-------
VOCs , Method TO-15
7.1.1.6 Electronic Timer. For unattended sample collection.
7.1.1.7 Solenoid Valve. Electrically-operated, bi-stable solenoid valve with Viton® seat and O-rings. A
Skinner Magnelatch valve is used for purposes of illustration in the text (see Figure 2).
7,1.1.8 Chromatographic Grade Stainless Steel Tubing and Fittings. For interconnections. All such
materials in contact with sample, analyte, and support gases prior to analysis should be chromatographic grade
stainless steel or equivalent.
7.1.1.9 Thermostatically Controlled Heater, To maintain above ambient temperature inside insulated
sampler enclosure,
7.1.1.10 Heater Thermostat Automatically regulates heater temperature.
7.1.1.11 Fan. For cooling sampling system.
7.1.1.12 Fan Thermostat Automatically regulates fan operation.
7.1.1.13 Manmum-Minimum Thermometer. Records highest and lowest temperatures during sampling
period.
7.1.1.14 Stainless Steel Shut-off Valve. Leak free, for vacuum/pressure gauge.
7.1.1.15 Auxiliary Vacuum Pump. Continuously draws air through the inlet manifold at 10 L/mia or
higher flow rate. Sample is extracted from the manifold at a lower rate, and excess air is exhausted.
[Note: The use of higher inlet flow rates dilutes any contamination present in the inlet and reduces the
possibility of sample contamination as a result of contact with active adsorption sites on inlet walls.]
7.1,1.16 Elapsed Tune Meter. Measures duration of sampling.
7.1.1.17 Optional Fixed Orifice, Capillary, or Adjustable Micrometering Valve. May be used in lieu
of the electronic flow controller for grab samples or short duration time-integrated samples. Usually appropriate
only in situations where screening samples are taken to assess future sampling activity.
7.1.2 Pressurized (see Figure 1 with metal bellows type pump and Figure 3).
7.1.2.1 Sample Pump. Stainless steel, metal bellows type, capable of 2 atmospheres output pressure.
Pump must be free of leaks, clean, and uncontaminated by oil or organic compounds,
[Note: An alternative sampling system has been developed by Dr. R. Rasmussen, The Oregon Graduate
Institute of Science and Technology, 20000 N.W. Walker Rd., Beaverton, Oregon 97006, 503-690-1077, and
is illustrated in Figure 3. This /low system uses, in order, a pump, a mechanical flow regulator, and a
mechanical compensation flow restrictive device. In this configuration the pump is purged with a large
sample flow, thereby eliminating the need for an auxiliary vacuum pump to flush the sample inlet. J
7.1.2.2 Other Supporting Materials. All other components of the pressurized sampling system are
similar to components discussed in Sections 7.1.1.1 through 7.1,1.17,
7.2 Analytical Apparatus
7.2.1 Sampling/Concentrator System (many commercial alternatives are available).
7.2.1.1 Electronic Mass Flow Controllers. Used to maintain constant flow (for purge gas, carrier gas
and sample gas) and to provide an analog output to monitor flow anomalies.
7.2.1.2 Vacuum Pump. General purpose laboratory pump, capable of reducing the downstream pressure
of the flow controller to provide the pressure differential necessary to maintain controlled flow rates of sample
air.
7.2.1.3 Stainless Steel Tubing and Stainless Steel Fittings. Coated with fused silica to minimize active
adsorption sites.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-7
-------
: : "!' " • !;
VOCs
= . 7. 2.1 A Stainless Steel Cylinder Pressure Regulators. Standard, two-stage cylinder regulators with
pressure gaugesT ""*" " ' " ** •••••••—*• - • . - ••- •<•--•. > . •— — - ........^ • : « . . .
7.2.1.5 .Gas Purifiers.., Used tojemoye organic impurities and moisture from gas streams.
73.1.6 Six-port Gas Chromatographic Valve. For routing sample and carrier gas flows.
7.2.1.7 Multisorbent Concentrator. Solid adsorbent packing with various retentive properties for
adsorbing trace gases are commercially available from several sources. The packing contains more than one type
of adsorbent packed in series.
- 7.2,L7.IX pre-packed adsorbent trap (Supelco 2-0321) containing 200 mg Carbopack B (60/80 mesh)
and 50 mg Carbosieve S-IH (60/80 mesh) has been found to retain VOCs and allow some water vapor to pass
through (6). The addition of a dry purging step allows for further water removal from the adsorbent trap. The
steps constituting the dry purge technique that are normally used with multisorbent traps are illustrated in
Figure 4 The optimum trapping ancf dry purging procedure for the Supelco trap consists of a sample volume of
32*0 mL and a dry nitrogen purge of 1300 mL. Sample trapping and drying is carried out at 25 °C. The trap is
back-flushed with helium and heated to 220°C to transfer material onto the GC column. A trap bake-out at
260 °C for 5 minutes is conducted after each run.
! jijijijijijilljii!!!1' '.!| I'm, ....... IB", „]:;! .,;!|,,r :|i|i|i|i|i|M^ ..... "H'HP IlilU'Ui '•• "Mi ..... , i»i <„ < 'mil!, P • n< „ .• .......... PI ......... ,i ............................. in - • ., ........ , .,,
7.2. 1.7.2 An example of the effectiveness of dry purging is shown in Figure 5. The multisorbent used in
this case is Tena^Ambersorb 340/Charcoal (7). Approximately 20% of the jnitial water content in the sample
remains after sampling 500 mL of air. The detector response to water vapor (hydrogen atoms detected by atomic
emission detection) is plotted versus purge gas volume. Additional water reduction by a factor of 8 is indicated
afjjnipefa&ires ! of 45 °C or higher. Still further water reduction is possible using a two-stage concentration/dryer
system.
7,2.1.8 Cryogenic Concentrator. Complete units are commercially available from several vendor
sources. The characteristics of the Jatest concentrators include a rapid, "ballistic" heating of the concentrator to
release any trapped VOCs into a small carrier gas volume. This facilitates the separation of compounds on the
gas Chromatographic column.
7 3.2 Gas Chromatographie/Mass Spectrometric (GC/MS) System.
7.2.2.1 ^G^is jGhrpmatograph. The gas chromatographie (GC) system must be capable of temperature
progfa^nming. The column oven can be cooled to subambient temperature (e.g., -50°C) at the start of the gas
cb^Dmatogr^tejTunjto effect a resolution of the very volatile organic compounds. In other designs, the rate of
release of comgxmi&fiixn the focusing trap in a two stage system obviates the need for retrapping of compounds
on the column. The system must include or be interfaced to a concentrator and have all required accessories
% iJ, ^yHRPti "I liiliiH I illllll "*.»» r.*w,i mm*. .j.js* — ••:• •,*«.*, r .i.^i,w^,™,-.«^.. ,,-... - ~ , ,„ _„..., _ _„- _ ___ „ ,.,.„. ____ t ... ~ .. _________ „ ..
including analytical columns and gases. All GC carrier gas lines must be constructed from stainless steel or
copper tubing. Non-polytetrafluoroethylene (PTFE) thread sealants or flow controllers with Buna-N rubber
components must not be used.
7.2.2.2 Chromatographic Columns. 100% methyl silicone or 5% phenyl, 95% methyl silicone fused
silica capillary columns of 0.25- to 0.53-mm LD. of varying lengths are recommended for separation of many
of the possible subsets of target compounds involving nonpolar compounds. However, considering the diversity
of the target list, the choice is left to the operator subject to the performance standards given in Section 1 1.
*"* * 7 J53 H&ss SpectrometerT Either a linear quadrupole or ion trap mass spectrometer can be used as long
as it is capable of scanning from 35 to 300 amu every 1 second or less, utilizing 70 volts (nominal) electron
energy in the electron impact ionization mode, and producing a mass spectrum which meets all the instrument
performance acceptance criteria when 50 ng or less of p-bromofluorobenzene (BFB) is analyzed.
- 7.2 .2.3.1Liniir Quadrupole Technology. A simplified diagram of the heart of the quadrupole mass
spectrometer is shown in Figure 6. The quadrupole consists of a parallel set of four rod electrodes mounted in
a square configuration. The field within the analyzer is created by coupling opposite pairs of rods together and
applying radiofrequency (RF) and direct current (DC) potentials between the pairs of rods. Ions created in the
ioji source from the reaction of column eluates with electrons from the electron source are moved through the
- • • '-'• > • .••* •• . - ". - . '• .. -
Page 15-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-15
parallel array of rods under the influence of the generated field. Ions which are successfully transmitted through
the quadrupole are said to possess stable trajectories and are subsequently recorded with the detection system.
When the DC potential is zero, a wide band of m/z values is transmitted through the quadrupole. This "RF only"
mode is referred to as the "total-ion" mode. In this mode, the quadrupole acts as a strong focusing lens analogous
to a high pass filter. The amplitude of the RF determines the low mass cutoff. A mass spectrum is generated by
scanning the DC and RF voltages using a fixed DC/RF ratio and a constant drive frequency or by scanning the
frequency and holding the DC and RF constant. With the quadrupole system only 0.1 to 0.2 percent of the ions
formed in the ion source actually reach the detector.
7.2.2.3.2Ion Trap Technology. An ion-trap mass spectrometer consists of a chamber formed between
two metal surfaces in the shape of a hyperboloid of one sheet (ring electrode) and a hyperboloid of two sheets
(the two end-cap electrodes). Ions are created within the chamber by electron impact from an electron beam
admitted through a small aperture in one of the end caps. Radio frequency (RF) (and sometimes direct current
voltage offsets) are applied between the ring electrode and the two end-cap electrodes establishing a quadrupole
electric field. This field is uncoupled in three directions so that ion motion can be considered independently in
each direction; the force acting upon an ion increases with the displacement of the ion from the center of the field
but the direction of the force depends on the instantaneous voltage applied to the ring electrode, A restoring force
along one coordinate (such as the distance, r, from the ion-trap's axis of radial symmetry) will exist concurrently
with a repelling force along another coordinate (such as the distance, z, along the ion traps axis), and if the field
were static the ions would eventually strike an electrode. However, in an RF field the force along each coordinate
alternates direction so that a stable trajectory may be possible in which the ions do not strike a surface. In
practice, ions of appropriate mass-to-charge ratios may be trapped within the device for periods of milliseconds
to hours. A diagram of a typical ion trap is illustrated in Figure 7. Analysis of stored ions is performed by
increasing the RF voltage, which makes the ions successively unstable. The effect of the RF voltage on the ring
electrode is to "squeeze" the ions in the xy plane so that they move along the z axis. Half the ions are lost to the
top cap (held at ground potential); the remaining ions exit the lower end cap to be detected by the electron
multiplier. As the energy applied to the ring electrode is increased, the ions are collected in order of increasing
mass to produce a conventional mass spectrum. With the ion trap, approximately 50 percent of the generated
ions are detected As a result, a significant increase in sensitivity can be achieved when compared to a full scan
linear quadrupole system.
7.2.2.4 GC/MS Interface. Any gas chromatograph to mass spectrometer interface that gives acceptable
calibration points for each of the analytes of interest and can be used to achieve all acceptable performance
criteria may be used. Gas chromatograph to mass spectrometer interfaces constructed of all-glass, glass-lined,
or fused silica-lined materials are recommended. Glass and fused silica should be deactivated.
7.2.2.5 Data System. The computer system that is interfaced to the mass spectrometer must allow the
continuous acquisition and storage, on machine readable media, of all mass spectra obtained throughout the
duration of the chromatographic program. The computer must have software that allows searching any GC/MS
data file for ions of a specified mass and plotting such ion abundances versus time or scan number. This type
of plot is defined as a Selected Ion Current Profile (SICP). Software must also be available that allows integrat-
ing the abundance in any SICP between specified time or scan number limits. Also, software must be available
that allows for the comparison of sample spectra with reference library spectra. The National Institute of
Standards and Technology (MIST) or Wiley Libraries or equivalent are recommended as reference libraries.
7.2JL6 Off-line Data Storage Device. Device must be capable of rapid recording and retrieval of data
and must be suitable for long-term, off-line data storage.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-9
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'.' Method TO-15 ; VOCs
^» 7 J Calibration System and Manifold Apparatus (see Figure 8)
7.3.1 Calibration Manifold, Stainless steel, glass, or high purity quartz manifold, (e,g.,1.25-cmI.D. x
66-cm) with sampling ports and internal baffles for flow disturbance to ensure proper mixing. The manifold
should be heated to ~50°C.
733, Humidifier. 500-mL impinger flask containing HPLC grade deionized water.
,._ . 733 Electronic Mass Flow Controllers. One 0 to 5 L/ntin unit and one or more 0 to 100 mL/min units
for air, depending on number of cylinders in use for calibration.
13.4 Teflon Filter(s). 47-mm Teflon® filter for paniculate collection.
7.4 Reagents
7.4.X .Neat:.Materials, or Manufact3urer-Certifiejd_SoIutions/Mixtares. Best source (see Section 9).
411 , 1 ,AA_JBfl|um and j|ir. Ujta-MgJi pjnity grade in gas cylinders. He is used as carrier gas in the GC.
7.43 Liquid Nitrogen or Liquid Carbon Dioxide. Used to c^ol secondary trap. " ..-.
7,4.4 Deionized Water. High performance liquid chromatography (HPLC) grade, ultra-high purity (for
u-r» • ! imiir-f'i HmTiu . ,r t -JT-.. *>.-«• v« ,c ;• ••<•<.* n raT. 1, ,» . -«c«> ' ,» i •» i. • -T^ > , , _
hiraidifier). ' ' — ..-•.....- -,,
'I'1!' i'l'il M'I'M'M , ' 'i m i ' ,!!>!>» '. I , . ' | I | ,' "i • • , „„ •
1 . ... ,'| ' " ' ' ' ;! „ '
...8. Collection of Samples in Canisters
8.1 Introduction
!i .' W •':, :Wr, m •• : ' .'. • •' . <- ,"f i^^t-'M't ' , . i-.il ' '• VJ. ' '. . . '.
8.1.1 Canister samplers, sampling procedures, and canister cleaning procedures have not changed very much
from the description given in the original Compendium Method TO-14. Much of the material in this section is
therefore simply a restatement of the material given in Compendium Method TO-14, repeated here in order to
- have all the relevant information in one place.
> *4 imii -siFrrjfpRjmK' ^imiiicfyiw wKT«my*;i ? ^m, ^,^ > ..* ,. ..., ^ „ * * , ^^
8,. 1.2 Recent notable additions to the canister technology has been in the application of canister-based
- systems for example, to microenvironmental monitoring (8), the capture of breath samples (9), and sector
sampling to Identlfy^enuision sources of VOCs (10).
8fl3 RFAh|||lsp sponsored the development of a mathematical model to predict the storage stability of
arbitrary mixtures oFtrace gases in humidified air (3), and the investigation of the SilcoSteel™ process of coating
the canister Interior with a film of fiised silica to reduce surface activity (11). A recent summary of storage
!" stability data for VOCs in canisters is given in the open literature (5).
-•- •• - : :, .... _ _. . j
" 8JZ Sampling System Description
8.2.1 Subatraospheric Pressure Sampling [see Figure 1 (without metal bellows type pomp)].
8.2.1.1 In preparation for subatmospheric sample collection in a canister, the canister is evacuated to
0.05 jam Hg (see Appendix C for discussion of evacuation pressure). When the canister is opened to the
** atmosphere containing the VOCs to be sampled, the differential pressure causes the sample to flow into the
capsjer. JThis. tec^Sqiwmay be used to collect grabsamples (duration of 10 to 30 seconds) or time-weighted-
average (TWA) samples (duration of 1-24 Eours) taken tirougli a flow-restrictive inlet (e.g., mass flow controller,
critical orifice!. " " '" ""' "" -•••••
8.2.1.2 With a critical orifice flow restrictor, there will be a decrease in the flow rate as the pressure
approaches atmospheric. However, with a mass flow controller, the subatmospheric sampling system can
maintain a constant flow rate from fuU vacuum to within about 7 kPa (LO psi) or less below ambient pressure.
s j>
Page 15-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
>:m 6 •
...
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VOCs Method TO-15
8.2.2 Pressurized Sampling [see Figure 1 (with metal bellows type pump)].
8.2.2.1 Pressurized sampling is used when longer-term integrated samples or higher volume samples are
required. The sample is collected in a canister using a pump and flow control arrangement to achieve a typical
101-202 kPa (15-30 psig) final canister pressure. For example, a 6-liter evacuated canister can be filled at 10
mL/min for 24 hours to achieve a final pressure of 144 kPa (21 psig).
8.2.2.2 In pressurized canister sampling, a metal bellows type pump draws in air from the sampling
manifold to fill and pressurize the sample canister.
8.23 All Samplers.
8.2.3.1 A flow control device is chosen to maintain a constant flow into the canister over the desired
sample period. This flow rate is determined so the canister is filled (to about 88.1 kPa for subatmospheric
pressure sampling or to about one atmosphere above ambient pressure for pressurized sampling) over the desired
sample period. The flow rate can be calculated by:
where:
F = flow rate, mL/min.
P = final canister pressure, atmospheres absolute. P is approximately equal to
kPa gauge + ^
101.2
V = volume of the canister, mL.
T = sample period, hours.
For example, if a 6-L canister is to be filled to 202 kPa (2 atmospheres) absolute pressure in 24 hours, the flow
rate can be calculated by:
„ 2 x 6000
24 x 60
0 _ T , .
= gj tnL/mm
8 3, 3.2 For automatic operation, the timer is designed to start and stop the pump at appropriate times for
the desired sample period. The timer must also control the solenoid valve, to open the valve when starting the
pump and to close the valve when stopping the pump.
8.2.3.3 The use of the Skinner Magnelatch valve (see Figure 2) avoids any substantial temperature rise
that would occur with a conventional, normally closed solenoid valve that would have to be energized during the
entire sample period. The temperature rise in the valve could cause outgassing of organic compounds from the
Viton® valve seat material. The Skinner Magnelatch valve requires only a brief electrical pulse to open or close
at the appropriate start and stop times and therefore experiences no temperature increase. The pulses may be
obtained either with an electronic timer that can be programmed for short (5 to 60 seconds) ON periods, or with
a conventional mechanical timer and a special pulse circuit A simple electrical pulse circuit for operating the
Skinner Magnelatch solenoid valve with a conventional mechanical timer is illustrated in Figure 2(a). However,
with this simple circuit, the valve may operate unreliably during brief power interruptions or if the timer is
manually switched on and off too fast. A better circuit incorporating a time-delay relay to provide more reliable
valve operation is shown in Figure 2(b).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-11
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Method TO-1S VOCs
; 8.2.3.4 The connecting lines between the sample inlet and the canister should be as short as possible to
minimize their volume. The flow rate into the canister should remain relatively constant over the entire sampling
period.
8.23,5 As an option, a second electronic timer may be used to start the auxiliary pump several hours prior
to the sampling period to flush and condition the inlet line.
8.2.3.6 Prior to field use, each sampling system must pass a humid zero air certification (see
Section 8.4.3). All plumbing should be checked carefully for leaks. The canisters must also pass a humid zero
air certification before use (see Section 8,4.1).
8.3 Sampling Procedure
8.3.1 The sample canister should be cleaned and tested according to the procedure in Section 8.4.1.
8.33. A sample collection system is assembled as shown in Figures 1 and 3 and must be cleaned according
to the procedure outlined in Sections 8.4.2 and 8.4.4.
fffpte; The sampling system should be contained in an appropriate enclosure.]
i
8,3.3 Prior to locating the sampling system, the user may want to perform "screening analyses" using a
portable GC system, as outlined in Appendix B of Compendium Method TO-14A, to determine potential volatile
organics present and potential "hot spots." The information gathered from the portable GC screening analysis
would be used in developing a monitoring protocol, which includes the sampling system location, based upon the
"screening analysis" results.
83.4 After "screening analysis," the sampling system is located. Temperatures of ambient air and sampler
box interior are recorded on the canister sampling field test data sheet (FTDS), as documented in Figure 9.
fffote: The following discussion is related to Figure I]
8.3.5 To verify correct sample flow, a "practice" (evacuated) canister is used in the sampling system.
[Note: For a subatmospheric sampler, a flow meter and practice canister are needed. For the pump-driven
system, the practice canister is not needed, as the flow can be measured at the outlet of the system,]
A certified mass flow meter is attached to the inlet line of the manifold, just in front of the filter. The canister
is opened The sampler is turned on and the reading of the certified mass flow meter is compared to the sampler
mass flow controller. The values should agree within ±10%. If not, the sampler mass flpw meter needs to be
recalibrated or there is a leak in the system. This should be investigated and corrected.
[Note: Mass /low meter readings may drift. Check the zero reading carefully and add or subtract the zero
reading when reading or adjusting the sampler flow rate to compensate for any zero drift.]
After 2 minutes, the desired canister flow rate is adjusted to the proper value (as indicated by the certified mass
flow meter) by the sampler flow control unit controller (e.g., 3.5 mL/min for 24 hr, 7,0 mL/min for 12 hr).
Record final flow under "CANISTER FLOW RATE" on the FTDS.
8.3.6 The sampler is turned off and the elapsed time meter is reset to 000.0.
Whenever the sampler is turned off, wait at least 30 seconds to turn the sampler back on.]
Page 15-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-15
8.3.7 The "practice" canister and certified mass flow meter are disconnected and a clean certified (see
Section 8.4.1) canister is attached to the system.
8.3.8 The canister valve and vacuum/pressure gauge valve are opened.
8.3.9 Pressure/vacuum in the canister is recorded on the canister FTDS (see Figure 9) as indicated by the
sampler vacuum/pressure gauge.
8.3.10 The vacuum/pressure gauge valve is closed and the maximum-minimum thermometer is reset to
current temperature. Time of day and elapsed time meter readings are recorded on the canister FTDS.
8.3.11 The electronic timer is set to start and stop the sampling period at the appropriate times. Sampling
starts and stops by the programmed electronic timer.
83.12 After the desired sampling period, the maximum, nuiumum, current interior temperature and current
ambient temperature are recorded on the FTDS, The current reading from the flow controller is recorded.
83.13 At the end of the sampling period, the vacuum/pressure gauge valve on the sampler is briefly opened
and closed and the pressure/vacuum is recorded on the FTDS. Pressure should be close to desired pressure.
[Note: For a subatmospheric sampling system, if the canister is at atmospheric pressure when the field final
pressure check is performed, the sampling period may be suspect. This information should be noted on the
sampling field data sheet.]
Time of day and elapsed time meter readings are also recorded.
83.14 The canister valve is closed. The sampling line is disconnected from the canister and the canister is
removed from the system. For a subatmospheric system, a certified mass flow meter is once again connected to
the inlet manifold in front of the in-line filter and a "practice" canister is attached to the Magnelatch valve of the
sampling system. The final flow rate is recorded on the canister FTDS (see Figure 9).
[Note: For a pressurized system, the final flow may be measured directly.]
The sampler is turned off.
83.15 An identification tag is attached to the canister. Canister serial number, sample number, location, and
date, as a minimum, are recorded on the tag. The canister is routinely transported back to the analytical
laboratory with other canisters in a canister shipping case.
8.4 Cleaning and Certification Program
8.4.1 Canister Cleaning and Certification.
8.4.1.1 All canisters must be clean and free of any contaminants before sample collection.
8.4.1.2 All canisters are leak tested by pressurizing them to approximately 206 kPa (30 psig) with zero
air.
[Note: The canister cleaning system in Figure 10 can be used for this task.]
The initial pressure is measured, the canister valve is closed, and the final pressure is checked after 24 hours. If
acceptable, the pressure should not vary more than ± 13.8 kPa (± 2 psig) over the 24 hour period.
8.4.13 A canister cleaning system may be assembled as illustrated in Figure 10. Cryogen is added to both
the vacuum pump and zero air supply traps. The canisters) are connected to the manifold. The vent shut-off
valve and the canister valve(s) are opened to release any remaining pressure in the canister(s). The vacuum pump
is started and the vent shut-off"valve is then closed and the vacuum shut-off valve is opened. The canister(s) are
evacuated to
-------
Method TO-15 VOCs
[Note: On a daily basis or more often if necessary, the cryogenic traps should be purged with zero air to
remove any trapped water from previous canister cleaning cycles.}
Air released/evacuated from canisters should be diverted to a fume hood.
8.4 JL.4 The vacuum and vacuum/pressure gauge shut-off valves are closed and the zero air shut-off valve
is opened to pressurize the canister(s) with humid zero air to approximately 206 kPa (30 psig). If a zero gas
generator system is used, the flow rate may need to be limited to maintain the zero air quality.
8,4.15 The zero air shut-off valve is closed and the canister(s) is allowed to vent down to atmospheric
pressure through the vent shut-off valve. The vent shut-off valve is closed. Repeat Sections 8.4.1.3 through
8.4.1.5 two additional times for a total of three (3) evacuation/pressurization cycles for each set of canisters.
8.4.1,6 At the end of the evacuation/pressurization cycle, the canister is pressurized to 206 kPa (30 psig)
with humid zero air. The canister is then analyzed by a GC/MS analytical system. Any canister that has not
tested clean (compared to direct analysis of humidified zero air of less than 0.2 ppbv of targeted VOCs) should
not be used As a "blank" check of the canister(s) and cleanup procedure, the final humid zero air fill of 100%
of the canisters is analyzed until the cleanup system and canisters are proven reliable (less than 0.2 ppbv of any
target VOCs). The check can then be reduced to a lower percentage of canisters.
8.4.1.7 The canister is reattached to the cleaning manifold and is then reevacuated to <0.05 mm Hg (see
Appendix B) and remains in this condition until used. The canister valve is closed. The canister is removed from
the cleaning system and the canister connection is capped with a stainless steel fitting. The canister is now ready
for collection of an air sample. An identification tag is attached to the inlet of each canister for field notes and
chain-of-custody purposes. An alternative to evacuating the canister at this point is to store the canisters and
reevacuate them just prior to the next use.
8.4.1J As an option to the humid zero air cleaning procedures, the canisters are heated in an isothermal
oven not to exceed 100°C during evacuation of the canister to ensure that higher molecular weight compounds
are not retained on the walls of the canister.
[Note: For sampling more complex VOC mixtures the canisters should be heated to higher temperatures
during the cleaning procedure although a special high temperature valve would be needed]'.
Once heated, the canisters are evacuated to <0.05 mm Hg (see Appendix B) and maintained there for 1 hour. At
the end of the heated/evacuated cycle, the canisters are pressurized with humid zero air and analyzed by a GC/MS
system after a minimum of 12 hrs of "aging." Any canister that has not tested clean (less than 0.2 ppbv each of
targeted compounds) should not be used. Once tested clean, the canisters are reevacuated to <0.05 mm Hg (see
Appendix B) and remain in the evacuated state until used. As noted in Section 8.4.1.7, reevacuation can occur
just prior to the next use.
8.4.2 Cleaning Sampling System Components.
8.4.2.1 Sample components are disassembled and cleaned before the sampler is assembled. NonmetaUic
parts are rinsed with HPLC grade deionized water and dried in a vacuum oven at 50 ° C. Typically, stainless steel
parts and fittings are cleaned by placing them in a beaker of methanol in an ultrasonic bath for 15 minutes. This
procedure is repeated with hexane as the solvent.
8.4.2.2 The parts are then rinsed with HPLC grade deionized water and dried in a vacuum oven at 100°C
for 12 to 24 hours.
8.4.2 J Once the sampler is assembled, the entire system is purged with humid zero air for 24 hours.
• 8.43 Zero Air Certification.
Page 15-14 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs ; Method TO-15
[Note: In the following sections, "certification" is defined as evaluating the sampling system with humid zero
air and humid calibration gases that pass through all active components of the sampling system. The system
is "certified" if no significant additions or deletions (less than 0.2 ppbv each of target compounds) have
occurred when challenged with the test gas stream,]
8.4.3,1 The cleanliness of the sampling system is determined by testing the sampler with humid zero air
without an evacuated gas sampling canister, as follows.
8,4.3.2 The calibration system and manifold are assembled, as illustrated in Figure 8. The sampler
(without an evacuated gas canister) is connected to the manifold and the zero air cylinder is activated to generate
a humid gas stream (2 L/min) to the calibration manifold [see Figure 8(b)].
8.4.3.3 The humid zero gas stream passes through the calibration manifold, through the sampling system
(without an evacuated canister) to the water management system/VOC preconcentrator of an analytical system.
[Note: The exit of the sampling system (without the canister) replaces the canister in Figure 11.]
After the sample volume (e.g., 500 mL) is preconcentrated on the trap, the trap is heated and the VOCs are
thermally desorbed and refocussed on a cold trap. This trap is heated and the VOCs are thermally desorbed onto
the head of the capillary column. The VOCs are refocussed prior to gas chromatographic separation. Then, the
oven temperature (programmed) increases and the VOCs begin to elute and are detected by a GC/MS (see
Section 10) system. The analytical system should not detect greater than 0.2 ppbv of any targeted VOCs in order
for the sampling system to pass the humid zero air certification test Chromatograms (using an FID) of a certified
sampler and contaminated sampler are illustrated in Figures 12(a) and 12(b), respectively. If the sampler passes
the humid zero air test, it is then tested with humid calibration gas standards containing selected VOCs at
concentration levels expected in field sampling (e.g., 0.5 to 2 ppbv) as outlined in Section 8.4.4,
8.4.4 Sampler System Certification with Humid Calibration Gas Standards from a Dynamic
Calibration System
8.4.4.1 Assemble the dynamic calibration system and manifold as illustrated in Figure 8.
8.4.4.2 Verify that the calibration system is clean (less than 0.2 ppbv of any target compounds) by
sampling a humidified gas stream, without gas calibration standards, with a previously certified clean canister
(see Section 8.1).
8.4.43 The assembled dynamic calibration system is certified clean if less than 0.2 ppbv of any targeted
compounds is found,
8,4.4.4 For generating the humidified calibration standards, the calibration gas cylinders) containing
nominal concentrations of 10 ppmv in nitrogen of selected VOCs is attached to the calibration system as
illustrated in Figure 8. The gas cylinders are opened and the gas mixtures are passed through 0 to 10 mL/min
certified mass flow controllers to generate ppb levels of calibration standards.
8.4.4.5 After the appropriate equilibrium period, attach the sampling system (containing a certified
evacuated canister) to the manifold, as illustrated in Figure 8(b).
8.4.4.6 Sample the dynamic calibration gas stream with the sampling system.
8.4.4.7 Concurrent with the sampling system operation, realtime monitoring of the calibration gas stream
is accomplished by the on-line GC/MS analytical system [Figure 8(a)] to provide reference concentrations of
generated VOCs.
8.4.4.8 At the end of the sampling period (normally the same time period used for experiments), the
sampling system canister is analyzed and compared to the reference GC/MS analytical system to determine if the
concentration of the targeted VOCs was increased or decreased by the sampling system.
8.4.4.9 A recovery of between 90% and 110% is expected for all targeted VOCs.
8.4.5 Sampler System Certification without Compressed Gas Cylinder Standards.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-15
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Method TO-15 VOCs
8.4.5.1 Not all the gases on the Title HI list are available/compatible with compressed gas standards. In
these cases sampler certification must be approached by different means.
8,4.5.2 Definitive guidance is not currently available in these cases; however, Section 9,2 lists several ways
to generate gas standards. In general, Compendium Method TO-14A compounds (see Table 1) are available
commercially as compressed gas standards.
9. GOMS Analysis of Volatiles from Canisters
9J Introduction
9.1.1 The analysis of canister samples is accomplished with a GC/MS system. Fused silica capillary columns
are used to achieve high temporal resolution of target compounds. Linear quadrupole or ion trap mass
spectrometers are employed for compound detection. The heart of the system is composed of the sample inlet
concentrating device that is needed to increase sample loading into a detectable range. Two examples of
concentrating systems are discussed. Other approaches are acceptable as long as they are compatible with
achieving the system performance criteria given in Section 11.
9,1.2 With the first technique, a whole air sample from the canister is passed through a multisorbent packing
(including single adsorbent packings) contained within a metal or glass tube maintained at or above the
surrounding air temperature. Depending on the water retention properties of the packing, some or most of the
water vapor passes completely through the trap during sampling. Additional drying of the sample is
accomplished after the sample concentration is completed by forward purging the trap with clean, dry helium or
another inert gas (air is not used). The sample is then thermally desorbed from the packing and backflushed from
the trap onto a gas chromatographic column. In some systems a "refocusing" trap is placed between the primary
trap and the gas chromatographic column. The specific system design downstream of the primary trap depends
on technical factors such as the rate of thermal desorption and sampled volume, but the objective in most cases
is to enhance chromatographic resolution of the individual sample components before detection on a mass
spectrometer.
9.1.3 Sample drying strategies depend on the target list of compounds. For some target compound lists, the
multisorbent packing of the concentrator can be selected from hydrophobic adsorbents which allow a high
percentage of water vapor in the sample to pass through the concentrator during sampling and without significant
loss of the target compounds. However, if very volatile organic compounds are on the target list, the adsorbents
required for their retention may also strongly retain water vapor and a more lengthy dry purge is necessary prior
to analysis.
9.1.4 With the second technique, a whole air sample is passed through a concentrator where the VOCs are
condensed on. a reduced temperature surface (cold trap). Subsequently, the condensed gases are thermally
desorbed and backflusbed from the trap with an inert gas onto a gas chromatographic column. This concentration
technique is similar to that discussed in Compendium Method TO-14, although a membrane dryer is not used
The sample size is reduced in volume to limit the amount of water vapor that is also collected (100 mL or less
may be necessary). The attendant reduction in sensitivity is offset by enhancing the sensitivity of detection, for
example by using an ion trap detector.
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VOCs Method TO-15
9.2 Preparation of Standards
9.2.1 Introduction.
9.2.1.1 When available, standard mixtures of target gases in high pressure cylinders must be certified
traceable to a NIST Standard Reference Material (SRM) or to a MIST/EPA approved Certified Reference
Material (CRM). Manufacturer's certificates of analysis must be retained to track the expiration date.
9.2.1.2 The neat standards that are used for making trace gas standards must be of high purity; generally
a purity of 98 percent or better is commercially available.
9.2.1.3 Cylinder(s) containing approximately 10 ppmv of each of the target compounds are typically used
as primary stock standards. The components may be purchased in one cylinder or in separate cylinders depending
on compatibility of the compounds and the pressure of the mixture in the cylinder. Refer to manufacturer's
specifications for guidance on purchasing and mixing VOCs in gas cylinders.
9.2.2 Preparing Working Standards.
9*2.2.1 Instrument Performance Check Standard. Prepare a standard solution of BFB in humidified
zero air at a concentration which will allow collection of 50 ng of BFB or less under the optimized concentration
parameters.
9.2.2.2 Calibration Standards. Prepare five working calibration standards in humidified zero air at a
concentration which will allow collection at the 2,5, 10, 20, and 50 ppbv level for each component under the
optimized concentration parameters.
9.2.2.3 Internal Standard Spiking Mixture. Prepare an internal spiking mixture containing bromo-
chloromethane, chlorobenzene-dj, and 1,4-difluorobenzene at 10 ppmv each in humidified zero air to be added
to the sample or calibration standard. 500 jiL of this mixture spiked into 500 mL of sample will result in a
concentration of 10 ppbv. The internal standard is introduced into the trap during the collection time for all
calibration, blank, and sample analyses using the apparatus shown in Figure 13 or by equivalent means. The
volume of internal standard spiking mixture added for each analysis must be the same from run to run.
9.2_3 Standard Preparation by Dynamic Dilution Technique.
9.23.1 Standards may be prepared by dynamic dilution of the gaseous contents of a cylinders) containing
the gas calibration stock standards with humidified zero air using mass flow controllers and a calibration
manifold. The working standard may be delivered from the manifold to a clean, evacuated canister using a pump
and mass flow controller.
9.23.2 Alternatively, the analytical system may be calibrated by sampling directly from the manifold if
the flow rates are optimized to provide the desired amount of calibration standards. However, the use of the
canister as a reservoir prior to introduction into the concentration system resembles the procedure normally used
to collect samples and is preferred. Flow rates of the dilution air and cylinder standards (all expressed in the same
units) are measured using a bubble meter or calibrated electronic flow measuring device, and the concentrations
of target compounds in the manifold are then calculated using the dilution ratio and the original concentration of
each compound.
Mamfold Come. = (Original Cone.) (Sid. Gas Flowrate)
(Air Flowrate) + (Std. Gas Flowrate)
9.233 Consider the example of 1 mL/min flow of 10 ppmv standard diluted with 1,000 mL/min of humid
air provides a nominal 10 ppbv mixture, as calculated below:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-17
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Method TO-15 VOCs
Manifold Cone. = (10 PPm)(l mMnin)(1000 ppb/1 ppm) = p fa
(1000 mL/min) * (I mUmin)
i
9.2.4 Standard Preparation by Static Dilution Bottle Technique
[Note: Standards may be prepared in canisters by spiking the canister with a mixture of components prepared
in a static dilution bottle (12). This technique is used specifically for liquid standards.]
9.2.4.1 The volume of a clean 2-liter round-bottom flask, modified with a threaded glass neck to accept
a Mininert septum cap, is determined by weighing the amount of water required to completely fill up the flask.
Assuming a density for the water of 1 g/mL, the weight of the water in grams is taken as the volume of the flask
in millilitcrs.
9.2.4.2 The flask is flushed with helium by attaching a tubing into the glass neck to deliver the helium.
After a few minutes, the tubing is removed and the glass neck is immediately closed with a Mininert septum cap.
9.2.4.3 The flask is placed in a 60°C oven and allowed to equilibrate at that temperature for about
15 minutes. Predetermined aliquots of liquid standards are injected into the flask making sure to keep the flask
temperature constant at 60 ° C.
9,2,4.4 The contents are allowed to equilibrate in the oven for at least 30 minutes. To avoid condensation,
syringes must be preheated in the oven at the same temperature prior to withdrawal of aliquots to avoid
condensation.
9.2.4.5 Sample aliquots may then be taken for introduction into the analytical system or for further
dilution. An aliquot or aliquots totaling greater than I percent of the flask volume should be avoided.
9.2.4.6 Standards prepared by this method are stable for one week. The septum must be replaced with
each freshly prepared standard.
9,2,4.7 The concentration of each component in the flask is calculated using the following equation:
Concentration, mg/L =
where: V, = Volume of liquid neat standard injected into the flask, uL.
d= Density of the liquid neat standard, mg/uL.
Vf=« Volume of the flask, L.
9.2.4.8 To obtain concentrations in ppbv, the equation given in Section 9.2.5.7 can be used,
: In the preparation of standards by this technique, the analyst should make sure that the volume of neat
standard injected into the flask does not result in an overpressure due to the higher partial pressure produced
by the standard compared to the vapor pressure in the flash Precautions should also be taken to avoid a
significant decrease in pressure inside the flask after withdrawal ofaliquot(s),]
9.2.5 Standard Preparation Procedure in High Pressure Cylinders
(Note: Standards may be prepared in high pressure cylinders (13). A modified summary of the procedure
is provided below.]
9,2.5.1 The standard compounds are obtained as gases or neat liquids (greater than 98 percent purity).
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VOCs
Method TO-15
9.2.5.2 An aluminum cylinder is flushed with high-purity nitrogen gas and then evacuated to better than
25 in. Hg.
9.2.5.3 Predetermined amounts of each neat standard compound are measured using a microliter or
gaslight syringe and injected into the cylinder. The cylinder is equipped with a heated injection port and nitrogen
flow to facilitate sample transfer.
9.2.5.4 The cylinder is pressurized to 1000 psig with zero nitrogen.
[Note: User should read all SOPs associated with generating standards in high pressure cylinders. Follow
all safety requirements to minimize danger from high pressure cylinders.]
9.2.5.5 The contents of the cylinder are allowed to equilibrate (-24 hrs) prior to withdrawal of aliquots
into the GC system.
9,2.5.6 If the neat standard is a gas, the cylinder concentration is determined using the following equation:
Concentration, ppbv =
»mnfarf x 109
[Note: Both values must be expressed in the same units.}
9.2.5.7 If the neat standard is a liquid, the gaseous concentration can be determined using the following
equations:
v.
and:
n -
MW
where: V= Gaseous volume of injected compound at EPA standard temperature (25°C) and
pressure (760 mm Hg), L.
n= Moles.
R = Gas constant, 0.08206 L-atm/mole °K.
T= 298°K (standard temperature).
P = 1 standard pressure, 760 mm Hg (1 atm).
roL— Volume of liquid injected, mL.
d= Density of the neat standard, g/mL.
MW = Molecular weight of the neat standard expressed, g/g-mole.
The gaseous volume of the injected compound is divided by the cylinder volume at STP and then multiplied by
10* to obtain the component concentration in ppb units.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-19
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Method TO-15 ; VOCs
9.2.6 Standard Preparation by Water Methods.
i
[Note: Standards may be prepared by a water purge and trap method (14) and summarized as followsJ,
: |
9.2.6,1 A previously cleaned and evacuated canister is pressurized to 760 mm Hg absolute (1 atm) with
zero grade air.
9.2.63. The air gauge is removed from the canister and the sparging vessel is connected to the canister with
the short length of 1/16 in. stainless steel tubing.
(ffotc: Extra effort should be made to minimize possible areas of dead volume to maximize transfer of
analytesfrom the water to the canister.]
9.2.0 A measured amount of the stock standard solution and the internal standard solution is spiked into
5 mL of water.
9.2.6.4 This water is transferred into the sparge vessel and purged with nitrogen for 10 mins at
IQOmL/min. The sparging vessel is maintained at 40°C.
9.2.6.5 At the end of 10 mins, the sparge vessel is removed and the air gauge is re-installed, to further
pressurize the canister with pure nitrogen to 1500 mm Hg absolute pressure (approximately 29 psia).
9.2.6.6 The canister is allowed to equilibrate overnight before use.
9.2.6.7 A schematic of this approach is shown in Figure 14.
9.2.7 Preparation of Standards by Permeation Tubes.
9,2.7.1 Permeation tubes can be used to provide standard concentration of a trace gas or gases. The
permeation of the gas can occur from inside a permeation tube containing the trace species of interest to an air
stream outside. Permeation can also occur from outside a permeable membrane tube to an air stream passing
through the tube (e.g,, a tube of permeable material immersed in a liquid).
9.2.7.2 The permeation system is usually held at a constant temperature to generate a constant
concentration of trace gas. Commercial suppliers provide systems for generation and dilution of over
250 compounds. Some commercial suppliers of permeation tube equipment are listed in Appendix D.
9.2.8 Storage of Standards.
9.2.8.1 Working standards prepared in canisters may be stored for thirty days in an atmosphere free of
potential contaminants.
9,2.8.2 It is imperative that a storage logbook be kept to document storage time.
10. GOMS Operating Conditions
10,1 Preconcentrator
I
The following ate typical cryogenic and adsorbent preconcentrator analytical conditions which, however, depend
on the specific combination of solid sorbent and must be selected carefully by the operator. The reader is referred
to Tables 1 and 2 of Compendium Method TO-17 for guidance on selection of sorbents. An example of a system
using a solid adsorbent preconcentrator with a cryofocusing trap is discussed in the literature (15). Oven
temperature programming starts above ambient
10.1.1 Sample Collection Conditions
Cryogenic Trap Adsorbent Trap
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VOCs Method TO-15
Set point -150°C Set point 27°C
Sample volume - up to 100 mL Sample volume - up to 1,000 mL
Carrier gas purge flow - none Carrier gas purge flow - selectable
[Note: The analyst should optimize the flow rate, duration of sampling, and absolute sample volume to be
used. Other preconcentration systems may be used provided performance standards (see Section 11) are
realized.]
10.1.2 Desorption Conditions
Cryogenic Trap Adsorbent Trap
Desorb Temperature 120°C Desorb Temperature Variable
Desorb Flow Rate ~ 3 mL/rain He Desorb Flow Rate ~3 mL/min He
Desorb Time <60 sec Desorb Time <60 sec
The adsorbent trap conditions depend on the specific solid adsorbents chosen (see manufacturers' specifications).
10.13 Trap Reconditioning Conditions.
Cryogenic Trap Adsorbent Trap
Initial bakeout 120°C (24 hrs) Initial bakeout
Variable (24 hrs)
After each run 120°C (5 rain) After each run Variable (5 DUE)
10.2 GC/MS System
10.2.1 Optimize GC conditions for compound separation and sensitivity. Baseline separation of benzene
and carbon tetrachloride on a 100% methyl polysiloxane stationary phase is an indication of acceptable
chromatographic performance.
10.2.2 The following are the recommended gas chromatographie analytical conditions when using a 50-meter
by 0.3-mm I.D., 1 um film thickness fused silica column with refocusing on the column.
Item Condition
Carrier Gas: Helium
Flow Rate: Generally 1-3 mL/min as recommended by manufacturer
Temperature Program: Initial Temperature: -50 °C
Initial Hold Time: 2 min
Ramp Rate: 8° C/min
Final Temperature: 200°C
Final Hold Time: Until all target compounds elute.
10.23 The following are the recommended mass spectrometer conditions:
Item Condition
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-21
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Method TO-15 ' VOGs
Electron Energy: 70 Volts (nominal)
Mass Range: 35-300 amu [the choice of 35 amu excludes the detection of some target compounds
1 such as methanol and formaldehyde, and the quantitation of others such as ethylene
oxide, ethyl carbamate, etc. (see Table 2). Lowering the mass range and using special
programming features available on modem gas chromatographs will be necessary in
' these cases, but are not considered here.
Scan Time: To give at least 10 scans per peak, not to exceed 1 second per scan].
A schematic for a typical GC/MS analytical system is illustrated in Figure 15.
103 Analytical Sequence
103.1 Introduction. The recommended GC/MS analytical sequence for samples during each 24-hour time
period is as follows:
* Perform instrument performance check using bromofluorobenzene (BFB).
* Initiate multi-point calibration or daily calibration checks.
« Perform a laboratory method blank.
"• Complete this sequence for analysis of & 20 field samples.
10.4 Instrument Performance Check
10.4.1 Summary. It is necessary to establish that a given GC/MS meets tuning and standard mass spectral
abundance criteria prior to initiating any data collection. The GC/MS system is set up according to the
manufacturer's specifications, and the mass calibration and resolution of the GC/MS system are then verified by
the analysis of the instrument performance check standard, bromofluorobenzene (BFB).
10.4.2 Frequency. Prior to the analyses of any samples, blanks, or calibration standards, the Laboratory
must establish that the GC/MS system meets the mass spectral ion abundance criteria for the instrument
performance check standard containing BFB. The instrument performance check solution must be analyzed
initially and once per 24-hour time period of operation.
The 24-hour time period for GC/MS instrument performance check and standards calibration (initial calibration
or daily calibration check criteria) begins at the injection of the BFB which the laboratory records as
documentation of a compliance tune.
10.43 Procedure. The analysis of the instrument performance check standard is performed by trapping 50
ng of BFB under the optimized preconcentration parameters. The BFB is introduced from a cylinder into the
GC/MS via a sample loop valve injection system similar to that shown in Figure 13.
The mass specaum of BFB must be acquired in the following manner. Three scans (the peak apex scan and the
scans immediately preceding and following the apex) are acquired and averaged. Background subtraction is
conducted using a single scan prior to the elution of BFB.
10.4.4 Technical Acceptance Criteria. Prior to the analysis of any samples, blanks, or calibration
standards, the analyst must establish that the GC/MS system meets the mass spectral ion abundance criteria for
the instrument performance check standard as specified in Table 3.
10.4.5 Corrective Action. If the BFB acceptance criteria are not met, the MS must be retimed. It may be
necessary to dean the ion source, or quadrupoles, or take other necessary actions to achieve the acceptance
criteria.
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YOCs : ; : Method TO-15
10.4.6 Documentation. Results of the BFB tuning are to be recorded and maintained as part of the
instrumentation log.
10.5 Initial Calibration
10.5.1 Summary. Prior to the analysis of samples and blanks but after the instrument performance check
standard criteria have been met, each GC/MS system must be calibrated at five concentrations that span the
monitoring range of interest in an initial calibration sequence to determine instrument sensitivity and the linearity
of GC/MS response for the target compounds. For example, the range of interest may be 2 to 20 ppbv, in which
case the five concentrations would be 1,2,5,10 and 25 ppbv.
One of the calibration points from the initial calibration curve must be at the same concentration as the daily
calibration standard (e.g., 10 ppbv).
10.5.2 Frequency. Each GC/MS system must be recalibrated following corrective action (e.g., ion source
cleaning or repair, column replacement, etc.) which may change or affect the initial calibration criteria or if the
daily calibration acceptance criteria have not been met.
If time remains in the 24-hour time period after meeting the acceptance criteria for the initial calibration, samples
may be analyzed.
If time does not remain in the 24-hour period after meeting the acceptance criteria for the initial calibration, a new
analytical sequence shall commence with the analysis of the instrument performance check standard followed by
analysis of a daily calibration standard.
10 JJ Procedure. Verify that the GC/MS system meets the instrument performance criteria in Section 10.4.
The GC must be operated using temperature and flow rate parameters equivalent to those in Section 10.2.2.
Calibrate the preconcentration-GC/MS system by drawing the standard into the system. Use one of the standards
preparation techniques described under Section 9.2 or equivalent
A minimum of five concentration levels are needed to determine the instrument sensitivity and linearity. One of
the calibration levels should be near the detection level for the compounds of interest. The calibration range
should be chosen so that linear results are obtained as defined in Sections 10.5.1 and 10.5.5.
Quantitation ions for the target compounds are shown in Table 2. The primary ion should be used unless
interferences are present, in which case a secondary ion is used,
10.5.4 Calculations.
[Note: In the following calculations, an internal standard approach is used to calculate response factors.
The area response used is that of the primary quantitation ion unless otherwise stated.]
10.5.4.1 Relative Response Factor (RRF). Calculate the relative response factors for each target
compound relative to the appropriate internal standard (i.e., standard with the nearest retention time) using the
following equation:
RRF =
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-23
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Method TO-1S , VOCs
where: RRF = Relative response factor,
A, = Area of the primary ion for the compound to be measured, counts.
A;, = Area of the primary ion for the internal standard, counts.
C;, = Concentration of internal standard spiking mixture, ppbv,
C* = Concentration of the compound in the calibration standard, ppbv.
[Note: The equation above Is valid under the condition that the volume of internal standard spiking mixture
added in oilfield and QC analyses is the same from run to run, and that the volume of field and QC sample
introduced into the trap is the same for each analysis. Q, and Cx must be in the same units.]
\
10,5.4.2 Mean Relative Response Factor. Calculate the mean RRF for each compound by averaging
the values obtained at the five concentrations using the following equation:
a -v
RRF =£-i
i-i n
where: RRF = Mean relative response factor.
X; — RRF of the compound at concentration L
n = Number of concentration values, in this case 5.
10.5.4.3 Percent Relative Standard Deviation (%RSD). Using the RRFs from the initial calibration,
calculate the %RSD for all target compounds using the following equations:
SDPIJP !
%RSD = RRF x 100
RRF
i
and
SD
RRF
A (RRF; - RRF)'1
If N^l
where: SD^^ Standard deviation of initial response factors (per compound).
RRFf — Relative response factor at a concentration level i.
RRF = Mean of initial relative response factors (per compound).
10.S.4.4 Relative Retention Times (RRT). Calculate the RRTs for each target compound over the initial
calibration range using the following equation:
RT.
RRT =
where: RT,,1* Retention time of the target compound, seconds
RT;,= Retention time of the internal standard, seconds.
10.5.4.5 Mean of the Relative Retention Times (RRT). Calculate the mean of the relative retention
times (RRT) for each anah/te target compound over the initial calibration range using the following equation:
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VOCs Method TO-15
i-i
where: RRT = Mean relative retention time for the target compound for each initial calibration
standard.
RRT = Relative retention time for the target compound at each calibration level.
10.5.4,6 Tabulate Primary Ion Area Response (Y) for Internal Standard. Tabulate the area response
(Y) of the primary ions (see Table 2) and the corresponding concentration for each compound and internal
standard.
10.5.4.7 Mean Area Response (Y) for Internal Standard. Calculate the mean area response (Y) for
each internal standard compound over the initial calibration range using the following equation:
i-i n
where: Y — Mean area response.
Y = Area response for the primary quantitation ion for the internal standard for each initial
calibration standard.
10.5.48 Mean Retention Times (RT). Calculate the mean of the retention times (RT) for each internal
standard over the initial calibration range using the following equation:
i-l 1
where: RT = Mean retention time, seconds
RT = Retention time for the internal standard for each initial calibration standard, seconds.
10.5.5 Technical Acceptance Criteria for the Initial Calibration.
1053.1 The calculated %RSD for the RRF for each compound in the calibration table must be less than
30% with at most two exceptions up to a limit of 40%.
[Note: This exception may not be acceptable for all projects. Many projects may have a specific target list
of compounds which -would require the lower limit for all compounds.]
10.5.5.2 The RRT for each target compound at each calibration level must be withiin 0.06 RRT units of
the mean RRT for the compound.
10.5,5 J The area response Y of at each calibration level must be within 40% of the mean area response Y
over the initial calibration range for each internal standard.
1035.4 The retention time shift for each of the internal standards at each calibration level must be within
20 s of the mean retention time over the initial calibration range for each internal standard.
10.5.6 Corrective Action.
10.5.6.1 Criteria. If the initial calibration technical acceptance criteria are not met, inspect the system
for problems. It may be necessary to clean the ion source, change the column, or take other corrective actions to
meet the initial calibration technical acceptance criteria,
10.5.6.2 Schedule. Initial calibration acceptance criteria must be met before any field samples,
performance evaluation (PE) samples, or blanks are analyzed.
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Method TO-1S VOCs
10.6 Daily Calibration
10,6.1 Summary. Prior to the analysis of samples and blanks but after tuning criteria have been met, the
initial calibration of each. GC/MS system must be routinely checked by analyzing a daily calibration standard to
ensure that the instrument continues to remain under control. The daily calibration standard, which is the nominal
10 ppbv level calibration standard, should contain all the target compounds.
10.6.2 Frequency. A check of the calibration curve must be performed once every 24 hours on a GC/MS
system that has met the tuning criteria. The daily calibration sequence starts with the injection of the BFB. If
the BFB analysis meets the ion abundance criteria for BFB, then a daily calibration standard may be analyzed.
10.63 Procedure. The mid-level calibration standard (10 ppbv) is analyzed in a GC/MS system that has
met the tuning and mass calibration criteria following the same procedure in Section 10.5.
10.6.4 Calculations. Perform the following calculations.
{Note: As indicated earlier, the area response of the primary quantitation ion is used unless otherwise
stated.]
' , • • I
10.6.4.1 Relative Response Factor (RRF). Calculate a relative response factor (RRF) for each target
compound using the equation in Section 10.5.4.1.
10.6.4.2 Percent Difference (%D). Calculate the percent difference in the RRF of the daily RRF
(24-hour) compared to the mean RRF in the most recent initial calibration. Calculate the %D for each target
compound using the following equation:
RRF - RRF.
1 x 100
where: RRF,, = RRF of the compound in the continuing calibration standard.
RRF. = Mean RRF of the compound in the most recent initial calibration.
10.6.5 Technical Acceptance Criteria. The daily calibration standard must be analyzed at the
concentration level and frequency described in mis Section 10.6 and on a GC/MS system meeting the BFB
instrument performance check criteria (see Section 10.4).
The %D for each target compound in a daily calibration sequence must be within ±30 percent in order to proceed
with the analysis of samples and blanks. A control chart showing %D values should be maintained
10.6.6 Corrective Action. If the daily calibration technical acceptance criteria are not met, inspect the
system for problems. It may be necessary to clean the ion source, change the column, or take other corrective
actions to meet the daily calibration technical acceptance criteria.
Daily calibration acceptance criteria must be met before any field samples, performance evaluation (PE) samples,
or blanks are analyzed. If the % D criteria are not met, it will be necessary to rerun the daily calibration sample.
10.7 Blank Analyses
10.7.1 Summary. To monitor for possible laboratory contamination, laboratory method blanks are analyzed
at least once in a 24-hour analytical sequence. All steps in the analytical procedure are performed on the blank
Page 15-26 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-15
using all reagents, standards, equipment, apparatus, glassware, and solvents that would be used for a sample
analysis.
A laboratory method blank (LMB) is an unused, certified canister that has not left the laboratory. The blank
canister is pressurized with humidified, ultra-pure zero air and carried through the same analytical procedure as
a field sample. The injected aliquot of the blank must contain the same amount of internal standards that are
added to each sample.
10.7.2 Frequency. The laboratory method blank must be analyzed after the calibration standard(s) and
before any samples are analyzed.
Whenever a high concentration sample is encountered (i.e., outside the calibration range), a blank analysis should
be performed immediately after the sample is completed to check for carryover effects.
10.73 Procedure. Fill a cleaned and evacuated canister with humidified zero air (RH >20 percent, at 25 ° C),
Pressurize the contents to 2 atm.
The blank sample should be analyzed using the same procedure outlined under Section 10.8.
10,7,4 Calculations. The blanks are analyzed similar to a field sample and the equations in Section 10.5.4
apply.
10.7,5 Technical Acceptance Criteria. A blank canister should be analyzed daily.
The area response for each internal standard (IS) in the blank must be within ±40 percent of the mean area
response of the IS in the most recent valid calibration.
The retention time for each of the internal standards must be within ±0.33 minutes between the blank and the
most recent valid calibration.
The blank should not contain any target analyte at a concentration greater than its quantitation level (three times
the MDL as defined in Section 11.2) and should not contain additional compounds with elution characteristics
and mass spectral features that would interfere with identification and measurement of a method analyte.
10.7.6 Corrective Action. If me blanks do not meet the technical acceptance criteria, the analyst should
consider the analytical system to be out of control. It is the responsibility of the analyst to ensure that
contaminants in solvents, reagents, glassware, and other sample storage and processing hardware that lead to
discrete artifacts and/or elevated baselines in gas chromatograms be eliminated. If contamination is a problem,
the source of the contamination must be investigated and appropriate corrective measures need to be taken and
documented before further sample analysis proceeds.
If an analyte in the blank is found to be out of control (i.e., contaminated) and the analyte is also found in
associated samples, those sample results should be "flagged" as possibly contaminated.
10.8 Sample Analysis
10.8.1 Summary. An aliquot of the air sample from a canister (e.g., 500 mL) is preconcentrated and
analyzed by GC/MS under conditions stated in Sections 10.1 and 10.2. If using the multisorbent/dry purge
approach, adjust the dry purge volume to reduce water effects in the analytical system to manageable levels.
[Note: The analyst should be aware that pressurized samples of high humidity samples mil contain
condensed water. As a result, the humidity of the sample released from the canister during analysis mil vary
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-27
-------
Method TO-1S ; VQCs
1 ' !
in humidity, being lower at the higher canister pressures and increasing in humidity as the canister pressures
decreases. Storage integrity of water soluble compounds may also be affected.}
i
10.8.2 Frequency, If time remains in the 24-hour period in which an initial calibration is performed,
samples may be analyzed without analysis of a daily calibration standard.
If time does not remain in the 24-hour period since the injection of the instrument performance check standard
in which an initial calibration is performed, both the instrument performance check standard and the daily
calibration standard should be analyzed before sample analysis may begin.
10.8.3 Procedure for Instrumental Analysts. Perform the following procedure for analysis.
10.8.3.1 All canister samples should be at temperature equilibrium with the laboratory.
10.8.3.2 Check and adjust the mass flow controllers to provide correct flow rates for the system.
10.8.3.3 Connect the sample canister to the inlet of the GC/MS analytical system, as shown in Figure 15
[Figure 16 shows an alternate two stage concentrator using multisorbent traps followed by a trap cooled by a
closed cycle cooler (15)]. The desired sample flow is established through the six-port chromatographic valve and
the prcconcentrator to the downstream flow controller. The absolute volume of sample being pulled through the
trap must be consistent from run to run.
10.83.4 Heat/cool the GC oven and cryogenic or adsorbent trap to their set points. Assuming a six-port
value is being used, as soon as the trap reaches its lower set point, the six-port chromatographic valve is cycled
to the trap position to begin sample collection. Utilize the sample collection time which has been optimized by
the analyst.
10.8.3.5 Use the arrangement shown in Figure 13, (i.e., a gaslight syringe or some alternate method)
introduce an internal standard during the sample collection period. Add sufficient internal standard equivalent
to 10 ppbv in the sample. For example, a 0.5 mL volume of a mixture of internal standard compounds, each at
10 ppmv concentration, added to a sample volume of 500 mL, will result in 10 ppbv of each internal standard
in the sample.
10.8-3.6 After the sample and internal standards are preconcentrated on the trap, the GC sampling valve
is cycled to the inject position and the trap is swept with helium and heated. Assuming a focusing trap is being
used, the trapped analytes are thermally desorbed onto a focusing trap and then onto the head of the capillary
column and are separated on the column using the GC oven temperature program. The canister valve is closed
and the canister is disconnected from the mass flow controller and capped. The trap is maintained at elevated
temperature until the beginning of the next analysis.
10.8.3.7 Upon sample injection onto the column, the GC/MS system is operated so that the MS scans the
atomic mass range from 35 to 300 amu. At least ten scans per eluting chroraatographic peak should be acquired.
Scanning also allows identification of unknown compounds in the sample through searching of library spectra.
10.8.3.8 Each analytical run must be checked for saturation. The level at which an individual compound
will saturate the detection system is a function of the overall system sensitivity and the mass spectral
characteristics of that compound.
10.8.3.9 Secondary ion quantisation is allowed only when there are sample matrix interferences with the
primary ion. If secondary ion quantitation is performed, document the reasons in the laboratory record book.
10.8.4 Calculations. The equation below is used for calculating concentrations.
AxCbDF
C
* AJ.RRF
where: C, = Compound concentration, ppbv.
Page 15-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TQ-15
A* = Area of the characteristic ion for the compound to be measured, counts.
Aj, = Area of the characteristic ion for the specific internal standard, counts.
Cj, = Concentration of the internal standard spiking mixture, ppbv
JRRF = Mean relative response factor from the initial calibration.
DF= Dilution factor calculated as described in section 2. If no dilution is performed, DF
-1.
{Note: The equation above is valid under the condition that the volume (~500 fiL) of internal standard
spiking mixture added in oilfield and QC analyses is the same from run to run, and that the volume (~500 mL)
of field and QC sample introduced into the trap is the same for each analysis.]
10.8.5 Technical Acceptance Criteria.
[Note: If the most recent valid calibration is an initial calibration, internal standard area responses andRTs
in the sample are evaluated against the corresponding internal standard area responses andRTs in the mid
level standard (10 ppbv) of the initial calibration.]
10.8.5.1 The field sample must be analyzed on a GC/MS system meeting the BFB tuning, initial
calibration, and continuing calibration technical acceptance criteria at the frequency described in Sections 10.4,
10.5 and 10.6.
10.8.5.2 The field samples must be analyzed along with a laboratory method blank that met the blank
technical acceptance criteria.
10.8.5.3 All of the target analyte peaks should be within the initial calibration range.
10.83.4 The retention time for each internal standard must be within ±0.33 minutes of the retention time
of the internal standard in the most recent valid calibration.
10.8.6 Corrective Action. If the on-column concentration of any compound in any sample exceeds the
initial calibration range, an aliquot of the original sample must be diluted and reanalyzed. Guidance in
performing dilutions and exceptions to this requirement are given below.
• Use the results of the original analysis to determine the approximate dilution factor required to get the
largest analyte peak within the initial calibration range.
• The dilution factor chosen should keep the response of the largest analyte peak for a target compound in
the upper half of the initial calibration range of the instrument
[Note: Analysis involving dilution should be reported with a dilution factor and nature of the dilution gas.]
10.8.6.1 Internal standard responses and retention times must be evaluated during or immediately after
data acquisition. If the retention time for any internal standard changes by more than 20 sec from the latest daily
(24-hour) calibration standard (or mean retention time over the initial calibration range), the GC/MS system must
be inspected for malfunctions, and corrections made as required
10.8.6.2 If the area response for any internal standard changes by more than ±40 percent between the
sample and the most recent valid calibration, the GC/MS system must be inspected for malfunction and
January 1999 Compendium of Methods for Toxic Organic Air Pottutants Page 15-29
-------
Method TO-1S ; VOCs
corrections made as appropriate. When corrections are made, reanalysis of samples analyzed while the system
was malfunctioning is necessary,
10.8.63 If, after reanalysis, the area responses or the RTs for all internal standards are inside the control
limits, then the problem with the first analysis is considered to have been within the control of the Laboratory.
Therefore, submit only data from the analysis with SICPs within the limits. This is considered the initial analysis
and should be reported as such oa all data deliverables.
11. Requirements for Demonstrating Method Acceptability for VOC Analysis from Canisters
1 • i
11.1 Introduction
11.1.1 There are three performance criteria which must be met for a system to qualify under Compendium
Method TO-15. These criteria are: the method detection limit of sO.5 ppbv, replicate precision within 25 percent,
and audit accuracy within 30 percent for concentrations normally expected in contaminated ambient air (0.5 to
25 ppbv).
11.1 Jt Ether SIM or SCAN modes of operation can be used to achieve these criteria, and the choice of mode
will depend on the number of target compounds, the decision of whether or not to determine tentatively identified
compounds along with other VOCs on the target list, as well as on the analytical system characteristics.
11 J.3 Specific criteria for each Title H compound on the target compound list must be met by the analytical
system. These criteria were established by examining summary data from EPA's Toxics Air Monitoring System
Network and the Urban Air Toxics Monitoring Program network. Details for the determination of each of the
criteria follow.
113 Method Detection Limit
11.2.1 The procedure chosen to define the method detection limit is that given in the Code of Federal
Regulations (40 CFR 136 Appendix B).
11J2.2 The method detection limit is defined for each system by making seven replicate measurements of the
comrjound of interest at a concentration near (within a factor of five) the expected detection limit, computing the
standard deviation for the seven replicate concentrations, and multiplying this value by 3.14 (i.e., the Student's
t value for 99 percent confidence for seven values). Employing this approach, the detection limits given in
Table 4 were obtained for some of the VOCs of interest.
113 Replicate Precision
11.3.1 The measure of replicate precision used for this program is the absolute value of the difference
between replicate measurements of the sample divided by the average value and expressed as a percentage as
follows:
|xt - x-I
percent difference = * _ ^ x 100
x
j
where: x(« First measurement value.
X2= Second measurement value.
x= Average of the two values.
Page 15-30 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-1S
11.3.2 There are several factors which may affect the precision of the measurement The nature of the
compound of interest itself such as molecular weight, water solubility, polarizability, etc., each have some effect
on the precision, for a given sampling and analytical system. For example, styrene, which is classified as a polar
VOC, generally shows slightly poorer precision than the bulk of nonpolar VOCs. A primary influence on
precision is the concentration level of the compound of interest in the sample, i.e., the precision degrades as the
concentration approaches the detection limit A conservative measure was obtained from replicate analysis of
"real world" canister samples from the TAMS and UATMP networks. These data are summarized in Table 5
and suggest that a replicate precision value of 25 percent can be achieved for each of the target compounds.
11.4 Audit Accuracy
11.4.1 A measure of analytical accuracy is the degree of agreement with audit standards. Audit accuracy is
defined as the difference between the nominal concentration of the audit compound and the measured value
divided by the audit value and expressed as a percentage, as illustrated in the following equation:
..... ,. Spiked Value - Observed Value ,nn
Audit Accuracy, % = — x 100
Spiked Value
11.4.2 Audit accuracy results for TAMS and UATMP analyses are summarized in Table 6 and were used
to form the basis for a selection of 30 percent as the performance criterion for audit accuracy.
12. References
1. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method TO-
14A, Second Edition, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA 600/625/R-
96/010b, January 1997.
2. Winberry, W. T., Jr., et al., Statement-of-Work (SOW) for the Analysis of Air Toxics From Superfimd Sites,
U. S. Environmental Protection Agency, Office of Solid Waste, Contract Laboratory Program, Washington, D.C.,
Draft Report, June 1990.
3. Coutant R.W., Theoretical Evaluation of Stability of Volatile Organic Chemicals and Polar Volatile
Organic Chemicals in Canisters, U. S. Environmental Protection Agency, EPA Contract No. 68-DO-0007,
Work Assignment No. 45, Subtask 2, Battelle, Columbus, OH, June 1993.
4. Kelly, T.J., Mukund, R_, Gordon, S.M., and Hays, Ml., Ambient Measurement Methods and Properties of
the 189 Title M Hazardous Air Pollutants, U. S. Environmental Protection Agency, EPA Contract No. 68-DO-
0007, Work Assignment 44, Battelle, Columbus, OH, March 1994.
5. Kelly T. J. and Holdren, M.W., "Applicability of Canisters for Sample Storage in the Determination of
Hazardous Air Pollutants," Atmos, Environ., Vol. 29,2595-2608, May 1995.
6. Kelly, T.J., Callahan, P.J., Pleil, J.K., and Ivans, G.E., "Method Development and Field Measurements for
Polar Volatile Organic Compounds in Ambient Air," Environ. Sci. Technol., Vol. 27,1146-1153, 1993.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 15-31
-------
Method TO-15 ; VOCs
7, McCIenny, W.A., Oliver, K.D. and Daughtrey, E.H.., Jr. "Dry Purging of Solid Adsorbent Traps to Remove
Water Vapor Before Thermal Desorption of Trace Organic Gases,™ J. Air and Waste Manag, Assoc., Vol.
45,792-800, June 1995.
8. Whitaker, DA, Fortmann, R.C. and Lindstrom, A.B. "Development and Testing of a Whole Air Sampler for
Measurement of Personal Exposures to Volatile Organic Compounds," Journal of Exposure Analysis and
Environmental Epidemiology, Vol. 5, No. I, 89-100, January 1995.
9. Pleil, JJD. and Lindstrom, A.B., "Collection of a Single Alveolar Exhaled Breath for Volatile Organic
Compound Analysis," American Journal of Industrial Medicine, Vol. 28, 109-121, 1995.
4
: ' !
10. Pleil, J.D. and McCIenny, W.A., "Spatially Resolved Monitoring for Volatile Organic Compounds Using
Remote Sector Sampling," Atmos. Environ., Vol. 27A, No. 5,739-747, August 1993.
11. Holdren, M.W., et al., Unpublished Final Report, EPA Contract 68-DO-Q007, Battelle, Columbus, OH.
Available from ID. Pleil, M044, U. S. Environmental Protection Agency, Research Triangle Park, NC, 27711,
919-541-4680.
I
12. Morris, C.M., Burkley, R.E. and Bumgamer, J.E., "Preparation of Multicomponent Volatile Organic
Standards Using Dilution Bottles," Anal. Letts., Vol. 16(A20), 1585-1593, 1983.
13. Pollack, A.J., Holdren, M.W., "Multi-Adsorbent Preconcentration and Gas Chromatographic Analysis of
Air Toxics With an Automated Collection/Analytical System," in the Proceedings of the 1990 EPA/A&WMA
International Symposium of Measurement of Toxic and Related Air Pollutants, U. S. Environmental Protection
Agency, Research Triangle Park, NC, EPA/600/9-90-026, May 1990.
14. Stephenson, J.H.M., Allen, F., Slagle, T., "Analysis of Volatile Organics in Air via Water Methods" in
Proceedings of the 1990 EPA/A&WMA International Symposium on Measurement of Toxic and Related Air
Pollutants, U. S. Environmental Protection Agency, Research Triangle Park, NC, EPA 600/9-90-026, May 1990.
i
15. Oliver, K. D., Adams, J. R., Davehtrey, E. H., Jr., McCIenny, W. A., Young, M. J.I and Parade, M. A.,
Techniques for Monitoring Toxices VOCs in Air Sorbent Preconcentration Closed-Cycle Cooler Cryofocusing,
and GC/MS Analysis," Environ. ScL Technol., Vol. 30,1938-1945,1996.
Page 15-32 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-15
APPENDIX A.
LISTING OF SOME COMMERCIAL WATER
MANAGEMENT SYSTEMS USED WITH AUTOGC SYSTEMS
Tekmar Dohrman Company
7143 East Kemper Road
Post Office Box 429576
Cincinnati, Ohio 45242-9576
(513)247-7000
(513) 247-7050 (Fax)
(800)543-4461
[Moisture control module]
Entech Laboratory Automation
950 Enchanted Way No. 101
Simi Valley, California 93065
(805) 527-5939
(805) 527-5687 (Fax)
[Mieroseale Purge and Trap]
Dynatherm Analytical Instruments
Post Office Box 159
Kelton, Pennsylvania 19346
(215) 869-8702
(215) 869-3885 (Fax)
[Thermal Desorption System]
XonTech Inc.
6862 Hayenhurst Avenue
VanNuys,CA 91406
(818)787-7380
(818) 787-4275 (Fax)
[Multi-adsorbent trap/dry purge]
Graseby
500 Technology Ct
Smyrna, Georgia 30082
(770)319-9999
(770) 319-0336 (Fax)
(800)241-6898
[Controlled Desorption Trap]
Varian Chromatography System
2700 Mitchell Drive
Walnut Creek, California 94898
(510)945-2196
(510) 945-2335 (FAX)
[Variable Temperature Adsorption Trap]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-33
-------
Method TO-15 VOCs
j
APPENDIX B.
i
COMMENT ON CANISTER CLEANING PROCEDURES
The canister cleaning procedures given in Section 8.4 require that canister pressure be reduced to <0.05mm Hg
before the cleaning process is complete. Depending on the vacuum system design (diameter of connecting tubing,
valve restrictions, etc.) and the placement of the vacuum gauge, the achievement of this value may take several
hours. In any case, the pressure gauge should be placed near the canisters to determine pressure. The objective
of requiring a low pressure evacuation during canister cleaning is to reduce contaminants. If canisters can be
routinely certified (<0.2 ppbv for target compounds) while using a higher vacuum, then this criteria can be
relaxed. However, the ultimate vacuum achieved during cleaning should always be <0.2mm Hg.
I
Canister cleaning as described in Section 8.4 and illustrated in Figure 10 requires components with special
features. The vacuum gauge shown in Figure 10 must be capable of measuring 0.05mm Hg with less than a
20% error. The vacuum pump used for evacuating the canister must be noncontaminating while being capable
of achieving the 0.05 mm Hg vacuum as monitored near the canisters. Thermoelectric vacuum gauges and
turbomolecular drag pumps are typically being used for these two components.
An alternate to achieving the canister certification requirement of <0.2 ppbv for all target compounds is the
criteria used in Compendium Method TO-12 that the total carbon count be <10ppbC. This check is less
expensive and typically more exacting than the current certification requirement and can be used if proven to be
equivalent to the original requirement This equivalency must be established by comparing the total nonmethane
organic carbon (TNMOC) expressed in ppbC to the requirement that individual target compounds be <0,2 ppbv
for a series of analytical runs.
Page 15-34 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-15
APPENDIX C
LISTING OF COMMERCIAL MANUFACTURERS AND RE-SUPPLIERS OF
SPECIALLY-PREPARED CANISTERS
BRC/Rasraussen
17010 NW Skyline Blvd.
Portland, Oregon 97321
(503) 621-1435
Meriter
1790 Potrero Drive
San Jose, CA 95124
(408) 265-6482
Restek Corporation
110 Benner Circle
Bellefonte, PA 16823-8812
(814)353-1300
(800) 356-1688
Scientific Instrumentation Specialists
P.O. Box 8941
815 Courtney Street
Moscow, ID 83843
(208)882-3860
Graseby
500 Technology Ct
Smyrna, Georgia 30082
(404) 319-9999
(800) 241-6898
XonTech Inc.
6862 Hayenhurst Avenue
VanNuys,CA 91406
(818)787-7380
January 1999 Compendium of Methods for Toxic Organic Air Pottutants Page 15-35
-------
Method TO-1S '' VOCs
APPENDIX D.
i
LISTING OF COMMERCIAL SUPPLIERS OF PERMEATION TUBES AND SYSTEMS
Kin-Tck
504 Laurel St
Lamarquc, Texas 77568
(409)938-3627
(800) 326-3627
Vici Metronics, Inc.
299 ICorvin Drive
Santa Clara, CA 95051
(408)737-0550
Analytical Instrument Development, Inc.
RL 4 land Newark Rd.
Avoodale,PA 19311
(215)268-3181
•
Ecology Board, toe.
9257 Independence Ave.
Chatsworth, CA 91311
(213)882-6795
I
Tracer, Inc.
6500 Tracer Land
Austm,TX
(512)926-2800
i
Mclrooics Associates, Inc.
3201 Porter Drive
Staadford Industrial Park ' .
Palo Alto, CA 94304
(415)493-5632 -
Page 15-36 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
TABLE 1. VOLATILE ORGANIC COMPOUNDS ON THE TITLE III CLEAN AIR AMENDMENT LIST-
MEMBERSHIP IN COMPENDIUM METHOD TO-14A LIST AND THE SOW-CLP LIST OF VOCs
Q
to
\£)
ve
f
I
a-
I
8-
«
l-i
tft
WiiSiKiiMXi^S^Smimijm:
Methyl chloride (chloromethane); CH3C1
Carbonyl sulfide; COS
Vinyl chloride (cHoroethene); C2H3C1
Diazomethane; CH2N2
Formaldehyde; CH2O
l,3-Butadiene;C4H6
Methyl bromide (bromomethane); CH3Br
Phosgene; CC12O
Vinyl bromide (bromoethene); C2H3Br
Ethylene oxide; C2H4O
Ethyl chloride (chloroethane); C2H5C1
Acetaldehyde (etlmnal); C2H4O
Vinylidene chloride (1,1-dichloroethylene); C2H2C12
Propylene oxide; C3H6O
Methyl iodide (iodomethane); CH3I
Methylene cWoride; CH2C12
Methyl isocyanate; C2H3NO
Allyl chloride (3-chloropropene); C3H5C1
Carbon disulfide; CS2
Metliyl tert-butyl ether; C5H12O
Propionaldehyde; C2HSCHO
Bthylidene dichloride (1,1-dichloroethane); C2H4C12
iiliilliii
74-87-3
463-58-1
75-01-4
334-88-3
50-00-0
106-99-0
74-83-9
75-44-5
593-60-2
75-21-8
75-00-3
75-07-0
75-354
75-56-9
74-88-4
75-09-2
624-83-9
107-05-1
75-15-0
1634-044
123-38-6
75-34-3
-23.7
-50.0
-14.0
-23.0
-19.5
-4.5
3.6
8.2
15.8
10.7
12.5
21.0
31.7
34.2
42.4
40.0
59.6
44.5
46.5
55.2
49.0
57.0
Ililiilflf
3.8 x 10
3.7 x 10
3.2x10
2,8 x 10
2.7 x 10
2.0x10
1.8x10
1.2x10
1.1x10
1,1x10
1.0x10
952
500
445
400
349
348
340
260
249
235
230
lillll
llMWft;'
50.5
60.1
62.5
42.1
30
54
94.9
99
107
44
64.5
44
97
58
141.9
84.9
57.1
76,5
76
86
58.1
99
;:f^v:;r:i:;:;:;:v:Si:;^^::;;;x;:i:;
m®mMWt
X
X
X
X
X
X
X
X
^l;ti:K|:;;iili||:;
llJKPi-SQWIH
X
X
X
X
X
X
X
X
I
H
-------
TABLE!, (continued)
Ul
Ul
00
!
8-
I
f
R-
Compound
Chloroprene l2-chloro-l,3-butadiene); C4H5C1
Chloromethyl methyl ether; C2H5CIO
Acrolein (2-propenal); C3H40
1 ,2-Epoxybutane (1,2-butyIene oxide); C4H8O
Chloroform; CHC13
Ethyleneimine (aziridine); QH5N
1,1-Dimethylhydrazine; C2H8N2
Hexane; C6HI4
1,2-Propyleneimine (2-methyl«ziridine); C3H7N
Acrylonitrile (2-propenenitrile); C3H3N
Methyl chloroform {1,1,1-trichloroethane); C2H3CI3
Methanol; CH4O
Carbon tetrachloride; CC14
Vinyl acetate; C4H602
Methyl ethyl ketone (2-butanone); C4H8O
Benzene; C6H6
Acetonitrile (eyanomethane); C2H3N
Ethylene dichloride (1,2-dichloroethane); C2H4C12
Triethylamine; C6H15N
Methylhydraztne; CH6N2
Propylene dichloride (1,2-dichloropropane); C3H6C12
2,2,4-Trimethyl pentane C8H18
1,4-Dioxane (1 ,4-Diethylene oxide); C4H8O2
Bis(chloromethyl) ether; C2H4C120
Ethyl acrylate; C5H8O2
CAS No.
126-99-8
107-30-2
107-02-8
106-88-7
67-66-3
151-56-4
57-14-7
110-54-3
75-55-8
107-13-1
71-55-6
67-56-1
56-23-5
108-05-4
78-93-3
71-43-2
75-05-8
107-06-2
121-44-8
60-34-4
78-87-5
540-84-1
123-91-1
542-88-1
140-88-5
BP(0C)
59.4
59.0
52.5
63.0
61.2
56
63
69.0
66.0
77.3
74.1
65.0
76.7
72.2
79.6
80.1
82
83.5
89,5
87.8
97.0
99.2
101
104
100
v.p.
(mmHg)1
226
224
220
163
160
160,0
157.0
120
112
100
100
92.0
90.0
83.0
77.5
76.0
74.0
61.5
54.0
49.6
42,0
40.6
37.0
30.0
29.3
MW1
88.5
80.5
56
72
119
43
60.0
86.2
57.1
53
133.4
32
153.8
86
72
78
41.0
99
101.2
46.1
113
114
88
115
100
TCM4A
X
X
X
X
X
X
X
X
CLP-SOW
X
X
X
X
X
X
X
X
X
X
X
I
cr
8.
tn
£?
-------
TABLE 1. (continued)
I
•5,
8-
§
S-
9
Methyl methacrylate; C5H8O2
1,3-Dichloropropene; C3H4C12 (cis)
Toluene; C7H8
Trichloroethylene; C2HC13
1,1,2-Trichloroethane; C2H3C13
Tetrachloroethylene; C2C14
Epichlorohydrin (l-ehloro-2,3-epoxy propane); C3H5C1O
Ethylene dibromide (1,2-dibromoethane); C2H4Br2
N-Nitroso-N-methylurea; C2H5N3O2
2-Nitropropane; C3H7NO2
Chlorobenzene; C6H5C1
Ethylbenzene; C8H10
Xylenes (isomer & mixtures); C8H10
Styrene; C8H8
p-Xylene; C8H10
m-Xy!ene; C8H10
Methyl isobutyl ketone (hexone); C6H12O
Bromoform (tribromomethane); CHBr3
1,1,2,2-Tetrachloroethane; C2H2C14
o-Xylene; C8H10
Dimethylcarbamyl chloride; C3H6C1NO
N-Nitrosodimethylamine; C2H6N2O
Beta-Propiolaetone; C3H4O2
80-62-101
542-75-6
108-88-3
79-01-6
79-00-5
127-18-4
106-89-8
106-93-4
684-93-5
79-46-9
108-90-7
100-41-4
1330-20-7
100-42-5
106-42-3
108-38-3
108-10-1
75-25-2
79-34-5
95-47-6
79-44-7
62-75-9
57-57-8
gWi^jSwSffigsJSSjjC
101
112
111
87.0
114
121
117
132
124
120
132
136
142
145
138
139
117
149
146
144
166
152
Decomposes at
162
si?8i*|i;i>Pi
ifltngSl)*!
28.0
27.8
22.0
20.0
19.0
14.0
12.0
11.0
10.0
10,0
8.8
7.0
6.7
6.6
6.5
6,0
6.0
5.6
5.0
5.0
4.9
3.7
3.4
100.1
111
92
131.4
133.4
165.8
92.5
187.9
103
89
112.6
106
106.2
104
106.2
106.2
100.2
252.8
167.9
106.2
107.6
74
72
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
o
I
H
-------
I
>-»
3E
TABLE 1. (continued)
I
fr
I
S-
Jb-
*?
Compound >
Cumsne (iiwpropylbenzene); C9H12
Acrylic «cid; C3H4O2
N.N-Dimethylformamide; C3H7NO
1,3-Propane sultone; C3H6O3S
Acetoplienone; C8H8O
Dimelhyl sulfale; C2H6O4S
Benzyl chloride (a-chlorotoluene); C7H7C1
1 ,2-Dibromo-3-chloropropane; C3H5Br2Cl
Bls(2-Chloroethyl)ether; C4H8C12O
Chloroacetic acid; C2H3CIO2
Aniline (aminobenzene); C6H7N
1,4-Dichlorobenzene (p-); C6H4C12
Ethyl carbamate (urethane); C3H7NO2
Acrylamide; C3H5NO
N,N-Dimethylaniline; C8H11N
Hexaehloroethane; CZC16
Hexachlorobutadiene; C4C16
Isophoronej C9H14O
N-Nitrosomorpholine; C4H8N2O2
Styrene oxide; C8H8O
Diethyi sulfate; C4H10O4S
Cresylic acid (oresol isomer mixture) ;C7H8O
o-Cresol; C7H8O
Catechol (o-hvdroxYphenol); C6H6O2
CAS No,
98-82-8
79-10-7
68-12-2
1120-71-4
98-86-2
77-78-1
100-44-7
96-12-8
111-44-4
79-11-8
62-53-3
106-46-7
51-79-6
79-06-1
121-69-7
67-72-1
87-68-3
78-59-1
59-89-2
96-09-3
64-67-5
1319-77-3
95-48-7
120-80-9
BP CC)
153
141
153
180/30mm
202
188
179
196
178
189
184
173
183
125/25 mm
192
Sublimes at 186
215
215
225
194
208
202
191
240
V.p.
(mmHg)1
3.2
3.2
2.7
2.0
1.0
1,0
1.0
0.80
0,71
0.69
0.67
0.60
0.54
0.53
O.SO
0.40
0.40
0.38
0.32
0.30
0.29
0.26
0.24
0.22
MW1
120
72
73
122.1
120
126.1
126.6
236.4
143
94.5
93
147
89
71
121
236.7
260.8
138.2
116.1
120.2
154
108
108
110
TO-14A
X
X
X
CLP-SOW
X
X
X
I
I
H
9
§
p
-------
0
I
s;
1
I
5?
TABLE 1. (continued)
loll 1
-
•.-rvivx-:-:-:-:*:*:*'**:-"-1':*:-: :•:•:•
Catechol (o-hydroxyphenol); C6H602
120-80-9
240
0,22
110
Phenol; C6H60
108-95-2
182
0.20
94
1,2,4-Trichlorobenzene; C6H3CB
120-82-1
213
0.18
181.5
X
Q8-QS-T
n is
z
'Vapor pressure (v.p.), boiling point (BP) and molecularweight (MW) data from:
(a)D. L, Jones and I. bursey, "Simultaneous Control of PM-10 and Hazardous Air Pollutants H: Rationale for Selection of Hazardous
Air Pollutants as Potential Paniculate Matter," Report EPA-452/R-93/013, U. S. Environmental Protection Agency, Research Triangle
Park.NC. October 1992;
(b)R, C. Weber, P. A. Parker, and M. Bowser. Vapor Pressure Distribution of Selected Organic Chemicals, Report EPA-600/2-81-021,
U, S. Environmental Protection Agency, Cincinnati, OH, February 1981; and
(c)R. C. Weast, ed., "CRC Handbook of Chemistry and Physics," 59th edition, CRC Press, Boca Raton, 1979.
o
a
M
cn
-------
Method TO-15
VOCs
TABLE 2. CHARACTERISTIC MASSES (M/Z) USED FOR QUANTIFYING
THE TITLE III CLEAN AIR ACT AMENDMENT COMPOUNDS
Compound " ' :;F:' '•:'.' '•:'--'-v-;;-->"v:' -;::v:>v^"'&%f::ife:f:f;
Methyl chloride (chloromcthane); CH3CI
Cat bony! nilfidc; COS
Vinyl chloride (chloroethene); C2H3C1
Diizomethane; CH2N2
Formaldehyde; cmo
1.3-Butadiene; C4H6
Methyl bromide (bromomethane); CHSBr
Phosgene; CC12O
Vinyl bromide (bromocthcne); C2H3Br
Elhykne oxide; C2H4O
Ethyl chloride (chloraethane); C2H5C!
Aeetaldehyde (ethanai); C2H4O
Vinylidene chloride (Ll-dichloroethylene); C2H2C12
Propylenc oxide; C3H6O
Melhyl iodide (iodomethane); CH3I
Melhylene chloride; CH2C12
Melhyl isocyanate; C2H3NO
Allyl chloride (3-chloropropene); C3H5C1
Carbon disulfide; CS2
Melhyl tat-butyl ether, C5H12O
Proptormldehydc; C2H5CHO
Ethytidenc dfehloride (1,1-diohloroethane); C2H4C12
Chloroprene (2-chloro-l,3-butadiene); C4H5CI
Chkxomethyl methyl ether, C2H5CKD
Acrotein (2-propcnaI); C3H4O
1,2-Epoxy butane (1.2-butylene oxide); C4H8O
Chlorofomu CHC13
Ethylcneimine (aziridine); C2H5N
U-DimethyUiydrazine; C2HBN2
Hcxine; C6H14
lJ2-Propylencimine (2-methylazindine); C3H7N
Acrykmitrile (2-propenenitrile); C3H3N
Methyl chloroform (1,1,1 trichloroethane); C2H3CB
Mcthtnol; CH4O
Cwton tetrachloridc; CC14
Vinyl acetate; C4H6O2
Methyl ethyl ketone (2-botanoneV, C4H8O
L^fcAsiirl.'
74-87-3
463-S8-1
7S-01-4
334-88-3
50-0(W
106-99-0
74-83-9
75-^4-5
593-60-2
75-21-8
75-00-3
75^37-0
75-35^1
75-56-9
74-88^1
75-09-2
624-83-9
107-05-1
75-15-0
1634-04-4
123-38-6
75-34-3
126-99-8
107-30-2
107-02-8
106-88-7
67-66-3
151-56-4
57-14-7
110-54-3
75-55-8
107-13-1
71-55-6
67-56-1
56-23-5
108-05-4
78-93-3
PrirrmiyldB
50
60
62
42
29
39
94
63
106
29
64
44
61
58
142
49
57
76
76
73
58
63
88
45
56
42
83
42
60
57
56
53
97
31
117
43
43
.• Se
-------
VOCs
Method TO-15
TABLE 2. (continued)
Benzene; C6H6
Acetonitrile (cyanomethane); C2H3N
Ethylene dichloride (1,2-dichIoroethane); C2H4C12
Triethylamine; C6H15N
MethyUiydiBzine; CH6N2
Propylene dichloride (1,2-dichloropropane); C3H6C12
2,2,4-Trimethyl pentane; C8H18
1.4-DIoxane (1,4 Diethylene oxide); C4B8O2
Bis(chtoroniethyl) ether, C2H4C12O
Ethyl acrylate; C5H8O2
Methyl methacrylate; C5H8O2
13-Dichloropropenr, C3H4CI2 (cis)
Toluene; C7H8
Trichloethyiene; C2HC13
1,1^-Tiichloroethane; C2H3CJ3
Tetrachloroethylene; C2C14
Epichlorohydrin (l-chloro-2,3-epoxy propane); C3H5CIO
Ethylene dibromide (1,2-dibromoethane); C2H4Br2
N-Nitrso-N-methylurea; C2H5N3O2
2-NMropropane; C3H7NO2
Chlorobenzene; C6H5C1
Ethylbenzene; C8H10
Xylenes (isomer & mixtures); C8H10
Styrene; C8H8
p-Xy!ene; C8H10
m-Xylene; C8H10
Methyl isobutyl ketone (hexone); C6H12O
Bromoform (tribromomethane); CHBr3 . •
l,U>TetrachIoroethanr, C2H2O4
o-Xylene; C8H10
Dimethylcarbamyl chloride; C3H6C1NO
N-Nitrosodimethylamine; C2H6N2O
Beta-Propiolactonr, C3H4O2
Cumcnc (isopropylbenzene); C9H12
Acrylic acid; C3H4O2
NJ^-Dimethylformamide; C3H7NO
I J-Propane sultone; C3HBO3S
iiliiliil
71-43-2
75-05-8
W7-0&-2
121^4-8
60-34^
78-87-5
540-84-1
123-91-1
542-88-1
140-88-5
80-62-6
542-75-6
108-88-3
79-01-6
79-00-5
127-18-4
106-89-8
106-93-4
684-93-5
79-46-9
108-90-7
100-41-4
1330-20-7
100-42-5
106-42-3
108-38-3
108-10-1
75-25-2
79-34-5
95-47-6
79-44-7
62-75-9
57-57-8
98-82-8
79-10-7
68-12-2
1120-71-4
-.vlUniMy:;!^
78
41
62
86
46
63
57
88
79
55
41
75
91
130
97
166
57
107
60
43
112
91
91
104
91
91
43
173
83
91
72
74
42
105
72
73
58
^•ieMSiarf:Safea
77,50
40
64,27
58, 101
31,45
41,62
41,56
58
49,81
73
69, 100
39,77
92
132, 95
83,61
164, 131
49,62
109
44,103
41
77, 1 14
106
106
78, 103
106
106
58, 100
171, 175
85
106
107
42
43
120
45,55
42,44
65, 122
TABLE 2. (continued)
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-43
-------
JVfethod TO-15
VOCs
Compound • ' .; ''':"'• .f^^-':.: •
Acctophenorw. C8H8O
Dimethyl miUkte; C2H6O4S
Benzyl chloride (a-chlorotaluene); C7H7C1
1 i-Dibromo-3-chloropropane; C3H5Bi2Cl
Bii(2-Chk>rocthyl)cthcr, C4H8C12O
Chlofoacetfc acid; C2H3C1O2
Aniline (aminobcnzene); C6H7N
1,4-Dtchterobcnzene (p-); C6H4C12
Ethyl carbamatc (urcthane); C3H7NO2
Aerytamide; C3H5NO
N-N-Dimethylanilinc; C8H1 IN
Haaehlorecthane; C2C16
Hoochlorobutadlene; C4C16
bophoronr, C9H14O
N-NitrosomorphoIInc; C4H8N2O2
Styrtne oxide; C8H8O
Dielhyi sulfate; C4H10O4S
Cresylic acid (cresol isotner mixture); C7H8O
o-Creso!; C7H8O
Catechol (o-hydroxyphcnol); C6H6O2
Phenol; C6H6O
lJ2,4-TrichIorobcnzenr, C6H3C13
Mtrobenamc; C6H5NO2
'CAS No.
98-86-2
77-78-1
100-44-7
96-12-8
111-44-4
79-11-8
62-53-3
106-46-7
51-79-6
79-06-1
121-69-7
67-72-1
87-68-3
78-59-1
59-89-2
96-09-3
64-67-5
1319-77-3
95-48-7
120-80-9
108-95-2
120-82-1
98-95-3
Primary Ion
105
95
91
57
93
50
93
146
31
44
120
201
225
82
56
91
45
108
110
94
180
77
Secondary loJt'.:;:
77,120
66,96
126
155, 157
63,95
45,60
66
148,111
44,62
55,71
77, 121
199,203
227,223
138
86,116
120
59, 139
107
64
66
182, 184
51, 123
Page 15-44
Compendium of Methods for Toxic Organic Air Pottutants
January 1999
-------
VOCs
Method TO-1S
TABLE 3. REQUIRED BFB KEY IONS AND
ION ABUNDANCE CRITERIA
JiP'Stv- WPSSIIIJ:
50
75
95
96
173
174
175
176
177
:::i£:x':;:t: '££*•:?£ j;i1'::i;*x*:^
ilQO:?ADunaanc«'^ten^||p;p|¥c&M%^^M^?^Pi'
8.0 to 40.0 Percent of m/e 95
30.0 to 66.0 Percent of m/e 95
Base Peak, 100 Percent Relative Abundance
5.0 to 9.0 Percent of m/e 95 (See note)
Less than 2.0 Percent of m/e 174
50.0 to 120.0 Percent of m/e 95
4.0 to 9.0 Percent of m/e 174
93.0 to 10 1.0 Percent of m/e 174
5.0 to 9:0 Percent of m/e 176
'All ion abundances must be normalized to m/z 95, the
nominal base peak, even though the ion abundance of m/z
174 may be up to 120 percent that of m/z 95.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-45
-------
Method TO45
VOCs
TABLE 4. METHOD DETECTION LIMITS
TO-14A.List
Benzene
Bcnzvl Chloride
Carbon tetraehloride
Chloro benzene
Chloroform
1 ,3-DichIorobenzene
1 ,2-Dtbromoethane
1 T4-DichIorobenzene
1 ,2-DichIorobenzerie
1 T 1-Dichloroethane
1 .2-Dichloroethane
1 , 1 -Diohloroethene
cis- 1 .2-Dichloroethcne
Methvlene chloride
1 J2-Dichloropropane
cis-l-3-Dichloropropene
trans-! 3-Diehloropropene
Ethvibenzene
Chloroethane
Trichlorofluoromethane
l.l^-Trichloro-l^^-trifluoro«thanc
1 ,2-DiehIoro-l »I .2.2-tetraihioroethane
Dichlorodifluoromethane
Hexachlorobutadiene
Bromomethane
Chloromcthanc
Styrenc
1 .IJ^-Tetrachlorocthane
Tetrachloroethene
Toluene
1 ,2.4-Trichlorobenzenc
1,1,1 -Trichloroethane
1 . 1 ,2-Trichloroethane
Trichloroethene
lJ2.4-Trimethvlbenzene
1 34-Trimethvlbenzene
Virtvl Chloride
m.p-Xylene
o-X^ene
Lab »l, SCAN
0.34
—
0.42
0.34
0.25
0.36
_
0.70
0.44
0.27
0.24
_
_
1.38
0.21
0.36
0.22
0.27
0.19
_
_
_
«
0.53
0.40
1.64
0.28
0.75
0.99
_
0.62
0.50
0.45
__
—
0.33
0.76
0.57
'l^b#2,S]M
0.29
— .
0.15
0.02
0.07
0,07
0.05
0.12
—
0.05
w*
0.22
0.06
0.84
—
— .
.
0.05
_
_
—
~ .
-.
_
0.06
0.09
0.10
0.20
_
0.21
_
0.07
— *
—
0.48
0.08
0,28
'Method Detection Limits (MDLs) are defined as the product of the standard
deviation of seven replicate analyses and the students "t" test value for 99%
confidence. For Lab #2, the MDLs represent an average over four studies.
MEDLs are for MS/SCAN for Lab # 1 and for MS/SIM for Lab #2.
Page 15-46
Compendium of Methods for Toxic Organic Aii- Pollutants
January 1999
-------
VOCs
Method TO-15
TABLE 5. SUMMARY OF EPA DATA ON REPLICATE PRECISION (RP)
FROM EPA NETWORK OPERATIONS1
1
;:$I§iHt£83jilg;;G|Jm|^^ ;
Dichlorodifluoromethane
Methylene chloride
1 ,2-Dicoloroethane
1,1,1-Trichloroethane
Benzene
Trichloroethene
Toluene
Tetrachloroethene
Chlorobenzene
Ethylbenzene
m-Xylene
Styrene
o-Xylene
p-Xylene
1 ,3-Dichlorobenzene
1 ,4-DicMorobenzene
liiiiiiii
—
16.3
36.2
14.1
12.3
12.8
14.7
36.2
20.3
14.6
14.7
22.8
_
—
49.1
14.7
iis^ir^ilSil^
07
31
44
56
08
76
12
21
32
75
59"
06
14
iltlfplli
«.
4.3
1.6
1.0
1.6
1.3
3.1
0.8
0.9
0.7
4.0
1.1
_
0.6
6.5
r,«x-'; •:•-:• ::.','"'~' " •' • -:;:- -:-:•:":•:
13.9
19.4
—
10.6
4.4
_
3.4
—
—
5.4
5.3
8.7
6.0
_
—
ifi^MSli
47
47
—
47
47
„
47
—
_.
47
47
47
47
—
—
0.9
0.6
—
2.0
1.5
—
3.1
_
_
0.5
1.5
0.22
0.5
—
—
'Denotes the number of replicate or duplicate analysis used to generate the statistic. The replicate precision is
defined as the mean ratio of absolute difference to the average value.
2Sfyrene and o-xylene coelute from the GC column used in UATMP. For the TAMS entries, both values were
below detection limits for 18 of 47 replicates and were not included in the calculation.
TABLE 6. AUDIT ACCURACY (AA) VALUES1 FOR SELECTED
COMPENDIUM METHOD TO-14A COMPOUNDS
•::;Y:>:y.*:::**~:^^
Vinyl chloride
Bromomethane
Trichlorofluoromethane
Methylene chloride
Chloroform
1 ,2-Dichloroethane
1,1,1 -Trichloroethane
Benzene
Carbon tetracbloride
1 ,2-Dichloropropane
Trichloroethene
Toluene
Tetrachloroethene
Chlorobenzene
Ethylbenzene
o-Xylene
p-Ei^iTlilsjilttililii
4.6
6.4
8.6
6.8
18.6
10.3
12.4
8.8
8.3
6.2
10.5
12.4
16.2
lll^8liiilli|p)|^3i?
17.9
6.4
_
31.4
4.2
11.4
11.3
10.1
9.4
6.2
5.2
12.5
_
11.7
12.4
21.2
'Audit accuracy is defined as the relative difference between the audit measurement result and its nominal value divided by
the nominal value. N denotes the number of audits averaged to obtain the audit accuracy value. Information is not available
for other TO-14A compounds because they were not present in the audit materials.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 15-47
-------
Method TO-15
VOCs
Wel
•~1.fi Uetert
(-5 ft)
To AC
To AC
Figure I. Sampler configuration for subalmospheric pressure or pressurized canister sampling.
Page 15-48
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-15
tis v
TIMER
SWITCH
— Q
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(a). Simple Circuit for Operating Magnefatch Valve
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KaiUcr »i and »» - OS wHL SK lottrarcc
(b). Improved Circuit Designed to Handle Power Interruptions
Figure 2. Electrical pulse circuits for driving Skinner magnelatch solenoid valve with
mechanical timer.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-49
-------
Method TO-1S
VOCs
1 Aintilliory
Vacuum
Pump
Intel
To AC
FIgu» 3. Alternative sampler configuration for pressurized canister sampling.
Page 15-50
Compendium, of Methods for TOXK Organic Air Pollutants January 1999
-------
VOCs
Method TO-15
STAGE 1; SAMPLE TRANSFER TO THE PRECONCENTRATION TRAP
CANISTER
SORB6NTTUBE
SAMPLER INLET
AIR SAMPLE IN
ADSORBENTTRAP
AT NEAR AMBIENT
TEMPERATURE
SAMPLE GAS
FLOW CARRIER
GAS IN
STAGE 2: DRY PURGING
DRY HELIUM
ADSORBENTTRAP
PURGE QAS
rr
ATNEARAMBJENT
TEMPERATURE I
PURGE GAS
PLUS WATER
CARRIER
GAS IN
STAGE 3: TRAP DESORPTION - ANALYTE TRANSFER TO GC COLUMN
CARRIER GAS IN*
ADSORBENT TRAP
J
(HOT)
Figure 4. Illustration of three stages of dry purging of adsorbent trap.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-51
-------
Method TO-15
VOCs
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-------
VOCs
Method TO-15
GC
Column
Effluant
ton
Source/
Filament
Figure 6. Simplified diagram of a quadrupole mass spectrometer.
GC
Column
Effluent
End Cap
Ring
Btoctrode
End Cap
Supplementary
rf Voltage
C 1 Etoctnm Multiplier
Figure 7. Simplified diagram of an ion trap mass spectrometer.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 15-53
-------
*
f
g-
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o) Reol Time
-FID-ECD-PtD
or CC-MS
o
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Cylinder
Moss Flow
Controller
(0-50 ml/mln)
Inlernol
Baffles
Teflon
Filter
Zero Air
C-UmJsr
Moss Flow
Controller
(0-50 l/min)
Vacuum/Pressure
Cougs
Heated Calibration Manifold
Toflon
Fillir
Shut OH
Pump
(b) Eyocuotid or Pressurizad
Canister Sampling System
Flow
Control
Valve
500 ml
Round-Bottom
Flask
(c) Canister Transfer
Standard
Humidifier
Figure S, Schematic diagram of calibration system and manifold for
(a) analytical system calibration, (b) testing canister sampling system and (c) preparing canister transfer standards.
£?
-------
VOCs
Method TO-15
COMPENDIUM METHOD TO-15
CANISTER SAMPLING FIELD TEST DATA SHEET
A.GENERAL INFORMATION
SITE LOCATION:
SITE ADDRESS:
SHIPPING DATE:
CANISTER SERIAL NO.:
SAMPLER ID:
SAMPLING DATE:
OPERATOR:
CANISTER LEAK
CHECK DATE:
B. SAMPLING INFORMATION
TEMPERATURE
PRESSURE
START
STOP
INTERIOR
AMBIENT
MAXIMUM
MINIMUM
:^':':^t-;Ji;:-::::^S^:::'?^^^'S:;'
CANISTER PRESSURE
|;|ill|iS|I|
SAMPLING TIMES
FLOW RATES
START
STOP
LOCAL TIME
ELAPSED TIME
METER READING
MANIFOLD
FLOW RATE
CANISTER
FLOW RATE
FLOW
CONTROLLER
READOUT
SAMPLING SYSTEM CERTIFICATION DATE:
QUARTERLY RECERTIFICATION DATE:
C LABORATORY INFORMATION
DATA RECEIVED:
RECEIVED BY:
INITIAL PRESSURE:
FINAL PRESSURE:
DILUTION FACTOR:
ANALYSIS
GC-FID-ECDDATE: _
GC-MSD-SCAN DATE:
GC-MSD-SMDATE: _
RESULTS*: '
GC-FID-ECD: _
GC-MSD-SCAN:
GC-MSD-SIM: _
SIGNATURE/nTLE
Figure 9. Canister sampling field test data sheet (FTDS).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 15-55
-------
Method TO-1S
VOCs
Pressure
Regulator
Exhaust
Vacuum Pump
Shut Oil Vofve
Vacuum
Pump
>^<
Cryogenic
Trap Coaler
(Liquid Argon)
Trap
Vacuum
Shut Off
Valve
Zero
Shut OH
Valve
Exhaust
Vacuum
Gauge
Shut Off
Valve
Sample \ / Sample
Canister/ I Canister
Cryogenic
Trap Cooler
(Liquid Argon)
Humidifier
Uanilold
Optional
Isothermal
Oven
_ J
Figure 10. Canister cleaning system.
Page 15-56
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-15
Cantor
Gu
V»nt
Watt Management
System and
Main Preconcenttator
Optional
Pressure
Gouge
p n
Mass Fkm
I T <
' ' < Flam* kmbMlon I
] ^ Detector (RO) J
OV-1 Capfllary Column
(0.32mnx5Om>
Low Dead- Vofume
I
I I Row Resttctor
Ij (Opttoral)
Mass Spednmietar
h SCAN or SIM Mod*
Figure 11. Canister analysis utilizing GC/MS/SC AN/SIM analytical system with optional flame ionization detector
with 6-port cfaromatographic valve in the sample desorption mode.
[Alternative analytical system illustrated in Figure 16.]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-57
-------
Method TO-15
VOCs
TIME
(o). Certified Sampler
(b). Contaminated Sampler
Figure 12. Example of humid zero air test results for a clean sample canister
(a) and a contaminated sample canister (b).
Page 15-58
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-15
PRECONCENTRATOR
(-160° CJ
GC/MS
CRYOTRAP
V».25ee
LOOP
INSULATED INTERNAL STANDARD
VALVE BOX {45 ± 2° C)
INT. STD.
Figure 13. Diagram of design for internal standard addition.
January 1999
Compendium, of Methods for Toxic Organic Air Pottutants
Page 15-59
-------
Method TO-15
VOCs
FL08METER.
NITROGEN
Figaro 14. Water method of standard preparation in canisters.
Page
Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-15
Humidifier
Exhaust
11
Calibration Manifold i
Calibration Zero Air
Gas Cylinder Cylinder
T = Thermocouple
F a Zero Dead Vol. Fit
FC = Flow Controller
S - Solenoid Valve
To
Auto. Temp
Control
Figure 15, Diagram of the GC/MS analytical system.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 15-61
-------
Page 15-62 Compendium of Methods for Toxic Organic Air Pollutants January 1999
5 STATUS:
TRAP 1: SwipUnfl
TRAP 2: Dasorttna
CLOSED JL OPEN J
MFC PUMP Mp_
SAMPLE PUMP
«4^l ! "I ' T1 '
1 ^T^£3. ! ! OP^N -— P-» ••," — ?
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pwq r» cva mfc ^x \«o*x*^ •*
IfVi 1 \p*"' t->-rn>7>T*.
PURGE s ntHiiinflnnn '• —
1 " SOyDSORBENT CONCENTRATOR . I 1 STIRLING CYCLE .COOLER \
figure 16. Sample flow diagram of a commercially available concentrator showing the combination of nmltisorbent tube and cooler
(Trap 1 sampling; Trap 2 desoibing).
I
o
o.
O
H- I
01
8
-------
EPA/62S/R-%/01Gb
Compendium of Methods
for the Determination of Toxic
Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-16
Long-Path Open-Path Fourier
Transform Infrared Monitoring
Of Atmospheric Gases
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-16
Acknowledgements
i
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition, (EPA/625/R-96/010b), which was prepared under
Contract No. 68-C3-0315, WA No. 3-10, by Midwest Research Institute (MM), as a subcontractor to Eastern
Research Group, Inc. (ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA).
Justice A. Manning, John Burckle, and Scott Hedges, Center for Environmental Research Information (CERI),
and Frank F. MeEIroy, National Exposure Research Laboratory (NERL), all in the EPA Office of Research and
Development, were responsible for overseeing the preparation of this method. Additional support was provided
by other members of the Compendia Workgroup, which include:
John Burckle, U.S. EPA, ORD, Cincinnati, OH
« James L. Cheney, Corps of Engineers, Omaha, MB
Michael 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. McCIenny, U.S. EPA, NERL, RTF, NC
» Frank F. Mcllroy, U.S. EPA, NERL, RTF, NC
Heidi Schultz, ERG, Lexington, MA
William T. "Jerry" Winberry, Jr., EnviroTech Solutions, 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)
* George M. Russwurm, ManTech Environmental Technology, Inc., Research Triangle Park, NC
Peer Reviewers
• Robert L. Spellicy, Radian International, Austin, TX
• William F. Herget, Radian International, Austin, TX
• Judith O. Zwicker, Remote Sensing Air Inc., St. Louis, MO
« William W. Vaughn, Remote Sensing Air Inc., St. Louis, MO
Robert J. Kricks, RJK Consultant, Cranford, NJ
• Robert H. Kagaan, AIL Systems Inc., Deer Park, NY
J.D. Tate, Dow Chemical, Freeport, TX
Lauren Drees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kauftnan, Debbie Bond, Cathy Whitaker, and Kathy Johnson
of Midwest Research Institute's Administrative Services staff whose dedication and persistence during the
development of this manuscript has enabled it's production.
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 TO-16
Long-Path Open-Path Fourier Transform Infrared
Monitoring Of Atmospheric Gases
TABLE OF CONTENTS
1. Scope ....................... . ............................... 16-1
2. Summary of Method ..... .... .................................... 16-2
3. Significance [[[ 16-3
4. Applicable Documents ............................................ 16-4
4.1 ASTM Standards ......................... ...................
4.2 EPA Documents ........................... . . ...............
5. Definitions ....... . ........... . ............. ..... .............. 16-4
6. Apparatus and System Requirements ....... ............................ 16-7
6.1 Summary . . ............................................... 16-7
6.2 FT-ER Sensor Requirements ..................................... 16-7
6.3 Computer Requirements ...... ................ . ................ 16-8
6.4 Software Requirements ........................................ 16-8
7. Materials and Supplies ........................... . ................ 16-8
8. Standard Procedures for Processing of Infrared Spectra .......... . ............ 16-9
8.1 Summary ... ................ . ............................. 16-9
8.2 Suggested Order of Generation of FT-IR Concentration Data ............... 16-9
8.3 Selection of Wave Number Regions for Analysis in the Presence of
Interfering Species ............. . ............................. 16-10
8.4 Generation of a Background Spectrum .............................. 16-12
8.5 Production of a Water Vapor Reference Spectrum ...................... 16-14
8.6 Subtraction of Stray Light or Black Body Radiation ...................... 16-16
8.7 Generation of an Absorbance Spectrum ....................... . ..... 16-18
8.8 Correction for Spectral Shifts ...... . .................. . .......... 16-18
8.9 Analysis of the Field Spectra for Concentration ........... . ............ 16-20
8.10 Post-Analysis Review of the Data .... ..... . ....................... 16-21
9. Quality Assurance ............................................... 16-22
9.1 Summary ................................................. 16-22
9.2 The Determination of Method Noise or Method Noise Equivalent Absorption ..... 16-22
9.3 The Measurement of the Return Beam Intensity ........................ 16-23
9.4 The Measurement of Stray Light .................................. 16-25
9.5 The Measurement of Black Body Radiation ................. .... ...... 16-26
9.6 The Determination of the Detection Limit .................. . ..... .... 16-27
-------
TABLE OF CONTENTS (continued)
9.8 The Determination of Accuracy .................................. 16-29
9.9 The Measurement of Resolution .................................. 16-31
9, 10 The Determination of Nonlinear Instrument Response . ............. ...... 16-32
9.11 The Determination of Water Vapor Concentration . .......... . ...... ..... 16-34
10. References ......... . .......................................... 16-35
IV
-------
METHOD TO-lfi
Long-Path Open-Path Fourier Transform Infrared
Monitoring Of Atmospheric Gases
1. Scope
1.1 Fourier transform infrared (FT-DR.) spectroscopy used for open-path monitoring of atmospheric gases is
undergoing a vigorous development and growth period; Until now the developmental effort and the most of the
data acquisition have been performed by highly trained individuals experienced in the fields of instrument
development and spectroscopy. La the future, operators trained at the technician level will be required to perform
the operation routinely. This method is intended to address that need Specifically, the method is intended to
allow trained technicians to acquire data in a standardized way and to process that data to obtain atmospheric gas
concentrations. The primary intent is that the results will be obtained in a consistent fashion.
1.2 This method is intended for the use of an FT-ER system that acquires data using a long, open air path and
does not require the acquisition of a sample for subsequent analysis. The system produces data that is a time
sequence of the path-averaged atmospheric concentrations of various gases. Because the FT-IR can potentially
measure the concentration of a large number of atmospheric gases, this method does not address the requirements
for measuring a particular gas or a set of gases. Rather, it is intended to be a generalized method.
13 The method is intended to be instrument independent in that it discusses the processing of spectra so that gas
concentrations can be obtained. The primary geometric configurations of FT-ER. instruments that are
commercially available are the monostatic configuration and the bistatic configuration. These configurations are
shown schematically in Figures 1 and 2. This method can be used to process data from either of these types. It
is assumed that the FT-IR is under computer control and that the controlling software will allow the manipulation
of the spectra. This method is specifically designed to process spectra that will be analyzed by the commonly
called classical least-squares technique. If the classical least-squares technique is to be used, the spectra must
be processed in a specific way, and this document describes the steps of that processing. Although there are other
ways to analyze the spectra, such as partial least squares, iterative least squares, spectral subtraction, principal
component analysis, and peak height and peak drea calculations, the use of these techniques requires that the
spectra be processed in a different way than is described here. While some of the procedures given here are
applicable to the other analysis techniques, this method addresses only the classical least-squares technique.
1.4 The method is not intended as a tutorial for the use of the computer software or the instruments themselves.
Inclusion of this type of explanation would make this document excessively long. When certain features from
the software packages are called for, it is assumed that the user has read or can read the appropriate description
in the specific manual. As far as the instruments are concerned, it is assumed that the operator has participated
in instrument training provided by the specific instrument manufacturer and that this training has been sufficient
to enable the operator to produce spectra and to save them on a disk.
1.5 Since this method in this document is considered to be a set of operational procedures, the document does
not contain an in-depth explanation about the origin or the rationale for the inclusion of particular steps. For a
more complete and rigorous discussion of the FT-IR technique, the user of this method is referred to EPA's FT-IR
Open-Path Monitoring Guidance Document (1).
1.6 The intent of this document is to provide the operator with stepwise procedures producing concentration data
from spectra taken with an FT-IR. To accomplish this, items such as background spectra, water vapor reference
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 16-1
-------
Method TO-16 VOCs
spectra, and stray light are discussed. In keeping with the concept of a procedure, these quantities must be
specified directly. However, the entire area of FT-DR. remote sensing of the atmosphere is undergoing rapid
change, and parts of these procedures will without doubt need revision in the future. Throughout this document
the user must keep in mind that for each procedure in the TO-16 method there may be other equally valid
procedures that are currently being used that are not described here.
1.7 Finally, a statement about computer automation of these procedures is in order here. The method does not
address the problem of automation directly and implies that an operator is available to perform the individual
steps. Some operational software packages already exist that incorporate many of these routines in an automatic
way. It is felt that each procedure potentially can be automated, but the steps listed here are those that need to
be incorporated in any automated procedure.
2. Summary of Method
2.1 For the purpose of this document the operation of an FT-IR remote sensor is divided into two parts. The first
is initial data acquisition after the system has been set up by the manufacturer and the second is what is
considered to be routine data acquisition. The first of these data acquisition periods is intended to produce data
that will form the basis of a quality assurance data set The second is devoted to the production of time sequences
of atmospheric gas concentration data.
23 There are several items that need to be determined before the FT-ER. system can be put into routine service.
These items have been selected to determine how the system is functioning initially and include the shortest path
length that will saturate the detector, the ambient black body radiation level for the bistatic configuration, the
stray light inside the instrument for the monostatic configuration, and the return intensity as a function of
distance. Beyond these steps there is a survey set of data that should be acquired. Data from this survey set will
form the basis of the routinely monitored quality control checks for the instrument
2.3 In addition to the FT-DR. data it is required that the ambient temperature and the relative humidity be
monitored on a continuous basis so that the water vapor concentration as a function of time can be determined.
It is to be clearly understood that relative humidity measurements alone are not relevant to this operation but the
amount of water is. These data should be acquired at the site where the FT-IR data is taken. Use of data taken
at airports miles away is not appropriate.
2.4 The initial step in the procedure for determining the concentration data for various gases is the production
of a set of interferograms, and it should be the interferograms that are saved as the primary data. The various
procedures given in Section 8 of this document use the single beam spectrum that is created from the
intcrferogram. A single beam spectrum taken with a monostatic system over a 414-ra path length is illustrated
in Figure 3. Various atmospheric constituents as well as a stray light component are pointed out. However, it
is |he interferograms that are considered the most important data. If they are not saved they cannot accurately
be reproduced by simply performing the inverse Fourier transform. Once a set of target gases has been selected,
the wave number regions to be used in the analysis are chosen. For the monostatic instrument geometry, the stray
light component must next be subtracted from each single beam spectrum. For the bistatic case, the black body
radiation spectrum must be subtracted from each single beam spectrum. One spectrum from this set is then
chosen to be the background, or 70, spectrum, and this can be turned into a synthetic background spectrum. A
second spectrum is then used to create a water vapor reference spectrum, and all the remaining spectra are then
Page 16-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TQ-16
converted to absorbance spectra. All the spectra to be analyzed are then checked for wave number shifts. Finally,
the absorbance spectra are analyzed by the classical least-squares technique.
2.5 It is suggested that, if possible, twice each day a short cell filled with a known quantity of gas should be
inserted in the infrared beam, and four spectra should then be recorded The instrument must be operating in
exactly the same manner as it is when it is routinely acquiring data but this time with the cell. These spectra are
analyzed in the same way as all other spectra, but for the particular gas in the cell. This data is then added to the
appropriate control charts. No exact procedure for using this cell and no specifications for the ceU are provided
at this time within this document Not all the instruments that are commercially available can accommodate a
cell, and many gases cannot be easily used in such a cell.
2.6 A subset of each day's spectra is then selected and the following two items are determined: the root mean
square (RMS) noise in three wave number regions and the return beam intensity at two wave numbers. The range
of water vapor concentrations over the time period dining which the subset of data was taken is calculated. These
data are also then added to the appropriate control charts.
2.7 The remainder of the data can then be checked as described in Section 8 and then against the data quality
objectives provided by the monitoring program.
3. Significance
3.1 VOCs enter the atmosphere from a variety of sources, including petroleum refineries, synthetic organic
chemical plants, natural gas processing plants, and automobile exhaust. Many of these VOCs are acutely toxic;
therefore, their determination in ambient air is necessary to assess human health impacts.
3.2 The environmental impacts from the release of airborne VOCs is a topic of great interest among air pollution
scientists. It is important that measurement methods be developed to accurately assess the impact of airborne
chemical emissions on the environment. Until now, traditional air sampling/analytical techniques (i.e., solid
adsorbents, treated canisters, portable gas chromatographs, etc.) have been used to characterize emission impacts
of airborne toxic chemicals in the environment.
3.3 The method of trace gas monitoring using FT-IR-based, long-path, open-path systems has a number of
advantages that are significant over traditional methods. Some of these advantages are related to the path
monitoring aspect of this method which, by its very nature, distinguishes the method from all point monitoring
methods. The main advantages of these systems are the following:
* Integrity of the sample is assured since no sampling actually occurs.
* Multi-gas analysis is possible with a single field spectrum.
* Path-integrated pollutant concentrations are obtained.
• Spatial survey monitoring of industrial facilities is possible if scanning optics are used.
» Coadding of spectra to improve detection capabilities is easily performed.
January 1999 Compendium of Methods for Toxic Organic Air Pottutants Page 16-3
-------
Method TO-16 VQCs
• Rapid temporal scanning of line-of-sight or multiple lines-of-sight is possible.
*
^' '
* Monitoring of otherwise inaccessible areas is possible.
3.4 Applications include the monitoring of atmospheric gases along the perimeters of industrial facilities or, from
an elevated, centrally located platform, monitoring over the industrial facility to infrared sources or retroreflectors
placed along the facility edge. Other applications include monitoring (1) at hazardous waste sites during
remediation or removal operations to provide warnings of high concentrations and to verify that back-to-work
conditions have been achieved; (2) in response to accidental chemical spills or releases; (3) in workplace
environments to develop concentration profiles at the worker level; and (4) in the ambient air for some
compounds. It is theoretically applicable to the measurement of all gaseous compounds that exhibit absorption
spectra in the mid-infrared region of the electromagnetic spectrum.
3.5 Significant advances have been made in recent years to develop the FT-IR systems into practical remote
sensing tools, particularly in the understanding of the importance of water vapor interference associated with FT-
IR methodology. As indicated in this method, the generation of a background spectrum for a given measurement
and the generation of water vapor spectra to account to water vapor interference in mid-infrared measurements
are features of the FT-IR measurement technique that deserve more attention. The significance of Compendium
Method TO-16 is that it is the first such method to address all the features that are required to make a field
measurement using FT-IR-based systems. As such, it provides a guide to field measurement as weU as a basis
for improvement and further consideration.
3.6 The ultimate significance of remote sensing with FT-IR systems is a matter of cost effectiveness and of
technological advances. Technological advances are required in at least two important areas: (1) the
improvement in the characteristics of the instrumentation itself and (2) the development of "intelligent" software.
The software is required to improve the means for short-term adjustment of background and water vapor spectra
to account for the continual variation of ambient conditions that can adversely affect the accuracy and precision
of FT-IR based systems.
4. Applicable Documents
4.1 ASTM Standards
« Method D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis.
4.2 EPA Documents
• Tcdtnlcal Assistance Document for Sampling and Analysis of Toxic Organic Compounds in Ambient Air,
U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
* Quality Assurance Handbook for Air Pollution Measurement Systems, U. S. Environmental Protection
Agency, EPA-6QO/R-94-Q38b, May 1994.
• Open-Path Monitoring Guidance Document, U. S. Environmental Protection Agency,
EPA 600/4-96-040, April 1996.
Page 16-4 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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5. Definitions
[Note: This section contains a portion of the glossary of terms from the guidance document (l)for remote
sensing that is applicable to Compendium Method TO-16. When possible, definitions of terms have been drawn
from authoritative texts or manuscripts in the fields of remote sensing, air pollution monitoring, spectroscopy,
optics, and analytical chemistry. In some cases, general definitions have been augmented or streamlined to
be more specific to long-path, open-path monitoring applications and to Compendium Method TO-16. These
definitions were intended to remain scientifically rigorous and still be generally applicable to the variety ofFT-
IR open-path remote-sensing issues that must be addressed by the operator, J
5.1 Absorbance—the negative logarithm of the transmission. A = -ln(I/Is), where / is the transmitted intensity
of the light and/0 >s the incident intensity. Generally, the logarithm to the base 10 is used, although the quantity
/really diminishes exponentially with/4.
5.2 Apodization—a mathematical transformation carried out on data received from an interferometer to alter
the instrument's response function. There are various types of transformation; the most common are boxcar,
triangular, Happ-Genzel, and Beer-Norton functions.
5.3 Background Spectrum—1. With all other conditions being equal, that spectrum taken in the absence of
the particular absorbing species of interest. 2. Strictly, (hat radiant intensity incident on the front plane of the
absorbing medium. 3. A spectrum obtained from the ambient black body radiation entering the system. This
background must be considered in FT-IR systems, in which the IR beam is not modulated before it is transmitted
along the path. For FT-IR systems that do not use a separate source of infrared energy, the background is the
source of infrared energy.
5.4 Beer's Law—Beer's law states that the intensity of a monochromatic plane wave incident on an absorbing
medium of constant thickness diminishes exponentially with the number of absorbers in the beam. Strictly
speaking, Beer's law holds only if fee foEowing conditions are met: perfectly monochromatic radiation, ao
scattering, a beam that is strictly eoUimated, negligible pressure-broadening effects (2,3).
5.5 Bistatic System—a system in which the receiver is some distance from the transmitter. This term is actually
taken from the field of radar technology. For remote sensing, this implies that the light source and the detector
are separated and are at the ends of the monitoring path.
5.6 Fourier Transform—a mathematical transform that allows an aperiodic function to be expressed as an
integral sum over a continuous range of frequencies (4). The Fourier transform of the interferogram produced
by the Michelson interferometer in an FT-IR is the intensity as a function of frequency.
5.7 FT-IR—an abbreviation for "Fourier transform infrared" A spectroscopic instrument using the infrared
portion of the electromagnetic spectrum. The working component of this system is a Michelson interferometer.
To obtain the absorption spectrum as a function of frequency, a Fourier transform of the output of the
interferometer must be performed. A brief overview of the FT-IR is provided in FT-IR Theory (5). An in-depth
description of the FT-IR can be found in Fourier Transform Infrared Spectrometry (6).
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5,8 Intensity—the radiant power per unit solid angle. When the term "spectral intensity" is used, the units are
watts per steradian per nanometer. In most spectroscopic literature, the term "intensity" is used to describe the
power in a collimated beam of light in terms of power per unit area per unit wavelength.
5.9 Interference—the physical effects of superimposing two or more light waves. The principle of
superposition states that the total amplitude of the electromagnetic disturbance at a point is the vector sum of the
individual electromagnetic components incident there. For a two-component system of collinear beams of the
same amplitude, the mathematical description of the result of addition is given by I(p) - 2Ie( I + cosfAJ), where
/, is the intensity of either beam, and A is the phase difference of the two components. The cosine term is called
the "interference term" (7,8). See also "Spectral Interference."
5.10 Interferogram—the effects of interference that are detected and recorded by an interferometer; the output
of an FT-DR. and the primary data that is collected and stored (6,8).
5.11 Interferometer—any of several kinds of instruments used to produce interference effects. The Michelson
interferometer used in FT-ER. instruments is the most famous of a class of interferometers that produce
interference by the division of an amplitude (9).
5.12 Light—strictly, light is defined as that portion of the electromagnetic spectrum that causes the sensation
of vision. It extends from about 25,000 cm"1 to about 14,300 cm"1 (4).
5.13 Minimum Detection Limit—the minimum concentration of a compound that can be detected by an
instrument with a given statistical probability. Usually die detection limit is given as 3 times the standard
deviation of the noise in the system. In this case, the minimum concentration can be detected with a probability
of 99.7% (10,11).
5.14 Monitoring path—the actual path in space over which the pollutant concentration is measured and
averaged.
5.15 Monostatic System—a system with the source and the receiver at the same end of the path. For FT-ER
systems, the beam is generally returned by a retroreflector.
5.16 Reference Spectra—spectra of the absorbance versus wave number for a pure sample of a set of gases.
The spectra are obtained under controlled conditions of pressure and temperature and with known concentrations.
Formost instruments.,the pure sample is pressure-broadened with nitrogen so that the spectra are representative
of atmospherically broadened lines. These spectra are used for obtaining the unknown concentrations of gases
in ambient air samples.
5.17 Relative Absorption Strength—a term used exclusively in Compendium Method TO-16 to describe the
relation of absorption due to interfering species to the absorption of the target gas.
5.18 Resolution—the minimum separation that two spectral features can have and still, in some manner, be
distinguished from one another. A commonly used requirement for two spectral features to be considered just
resolved is the Raleigh criterion. This states that two features are just resolved when the maximum intensity of
one falls at the first minimum of the other (5,6). This definition of resolution and the Raleigh criterion are also
valid for the FT-IR, although there is another definition in common use for this technique. This definition states
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VOCs . Method TO-16
that the minimum separation in wave numbers of two spectral features that can be resolved is the reciprocal of
the maximum optical path difference (in centimeters) of the two interferometer mirrors employed.
5.19 Retroreflector—the CDE (Commission Internationale de I'Eclairage) defines refrorefleetion as "radiation
returned in directions close to the direction from which it came, this property being maintained over wide
variations of the direction of the incident radiation." Retroreflector devices come in a variety of forms and have
many uses. The one commonly described by workers in remote sensing uses total internal reflection from three
mutually perpendicular surfaces. This kind of retroreflector is usually called a corner cube or prismatic
retroreflector (12).
5.20 RMS Noise—this quantity is actually the statistical quantity rms deviation. In Compendium Method TO-
16 the rms noise (deviation) is calculated by using a least squares fit to the baseline. Because of this calculation,
the rms noise in Compendium Method TO-16 uses the quantity N-2 in the denominator rather than N-l as
normally described.
5.21 Single Beam Spectrum—that spectrum which results from performing the Fourier transform on the
interferogram. It is not a transmission spectrum. The term "single beam" is a holdover from older instruments
that were double beam instruments.
5.22 Source—the device that supplies the electromagnetic energy for the various instruments used to measure
atmospheric gases. These generally are a Nemst glower or globar for the infrared region or a xenon arc lamp for
the ultraviolet region.
5.23 Spectral Intensity—see Section 5.8.
5,24 Spectral Interference—when the absorbance features from two or more gases cover the same wave
number regions, the gases are said to exhibit spectral interference. Water vapor produces the strongest spectral
interference for infrared spectroscopic instruments that take atmospheric data.
5.25 Synthetic Background—a spectrum that is made from a field spectrum by choosing points along the
baseline and connecting them with a high-order polynomial or short, straight lines. The synthetic background
is then used to find the absorbance spectrum.
5.26 Wave Number—the number of waves per centimeter. This term has units of reciprocal centimeters (cm"1).
6. Apparatus and System Requirements
6.1 Summary
6.1.1 Compendium Method TO-16 is a procedure that deals with how spectra taken with an FT-IR are to
be processed in order to obtain various atmospheric gas concentrations. General requirements for FT-DR.
instrumentation is being prepared by a committee of L'Orgarusation Internationale de Metrologie Legate (OML)
and will be available in the very near future.
6.1.2 The instrument requirements listed here are limited to those that will define a rudimentary but
operational system. The requirements are delineated into three categories: those of the FT-IR sensor itself (see
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Method TO-16 ; VOCs
Section 6,2), the computer associated with it (see Section 6.3), and the software that allows for data analysis (see
Section 6.4).
6.2 FT-IR Sensor Requirements
6,2.1 The system should be capable of making spectral absorption measurements along an open air optical
path.
6.2.2 The system can be either of the monostatic or the bistatic geometry.
6.2.3 The system must be able to produce and save an interferogram and a single beam spectrum.
6.2.4 The system must be able to operate with a resolution of at least 1 cm"' over the mid-infrared region
(7QO-4200 cm'1).
6,2,5 The system must be capable of acquiring data by co-adding individual interferogram scans in one-scan
increments. As a minimum, the system must be able to acquire data from a one-scan interferogram to an
interferogram made up of sufficient co-added scans so that at least 5-min concentration averages can be obtained.
6.2.6 The system must be able to perform the mathematical procedure of Fourier transformation on the
interferogram, thereby producing a so-called single beam spectrum. The transform can be performed as part of
post-acquisition processing or in quasi-real time. If performed in quasi-real time the process of transformation
should not add significantly to the data acquisition time.
6.2.7 Although there is no agreed upon procedure for the use of a gas cell with these systems, the system may
have provisions for installing an ancillary gas cell in the optical beam. If that is the case, the installation must
allow for the entire beam to pass through the cell. The cell can be of any of several designs: short, either single
or double pass; multi-pass capable of producing a relatively long optical path; or a multi-chambered cell with the
individual chambers interconnected and in parallel with one another.
6.3 Computer Requirements
6.3.1 The computer must be capable of acquiring data in the form of interferograms with sufficient speed
so that the system is able to operate in quasi-real time.
632 The computer must have provisions for storing of the data acquired in one 24-h period. The storage
must accommodate the interferograms.
"6,3.3 the computer must have sufficient RAM to operate the controlling software and the data manipulation
software.
6.4 Software Requirements
6.4.1 The software must have provisions for manipulating the spectra so that all the individual procedures
listed here can be accomplished
6.4.2 The software must be able to perform the analysis for concentration using classical least squares.
7. Materials and Supplies
7,1 Only a small number of materials are required in addition to the basic instrument for this method. However,
the basic instrument operation may have specific material requirements such as liquid nitrogen or nitrogen, etc,
A listing of any specific instrument's requirement for material must be obtained from the manufacturer.
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7.2 A set of gases may have to be purchased in order to acquire spectra with a ceil. This set of gases is intended
to allow the operator to determine the precision and accuracy of the data obtained from the field spectra, but at
the present time no procedure using a cell has been developed. The specific gases required are dependent on the
particular monitoring program. If necessary, the gases can be purchased as pure gases, which are then diluted
with nitrogen for use, or they can be a mixture of gases that are properly mixed at purchase. The dilution step
can be quite cumbersome and it is recommended that appropriate mixtures of gas be acquired directly whenever
possible. The required concentrations of the gases are dependent on the anticipated concentration of the target
gas in the atmosphere and the ratio of the actual path length used to the length of the cell. Many applications will
require that these gases be purchased with certifications traceable to the National Institute of Standards and
Technology.
7.3 The only other material that may be required is a set of screens of varying mesh that will be used when
determining whether the system is responding linearly. This screening can be regular aluminum window screen
or made of other opaque metallic materials. The size of the mesh is not really important, but the screen should
be large enough to cover the entire beam. The mesh itself should be chosen so as to change the transmitted
intensity by an easily measured amount (on the order of 25% or more). The screen must not be made of any
plastic materials as they transmit infrared energy. This in itself is not a problem but the plastic materials
introduce absorbance at specific wave numbers and may not provide the desired result.
8. Standard Procedures for Processing of Infrared Spectra
3.1 Summary
The specific procedures that are required to produce atmospheric gas concentration data are included in this
section. They start with the general operations procedure that describes how the other individual procedures
should follow one another.
8.2 Suggested Order of Generation of FT-IR Concentration Data
8.2.1 This section provides the FT-IR operator with a systematic approach to the generation of FT-IR
concentration data. These procedures are recommended for operators with little experience with FT-IR operation.
As the operator gains more experience with the production of FT-IR concentration data, he may want to reorder
the sequence of events to better fit his experimental schedule.
8.2.2 Assumptions
8.2.2.1 Compendium Method TO-16, in general, does not describe the general planning that is necessary
to conduct a field program. It is felt that each data acquisition program is different and all programs cannot be
covered in depth with a single procedure. For example, the time for acquiring a single spectrum can vary from
a single scan of a few seconds up to a half hour. The actual time required for any one program is dependent on
that program and therefore is not discussed further in this procedure. Much of the planning for the acquisition
of data is connected to the generation of a detailed quality assurance/quality control (QA/QC) program plan, and
this method is not considered to be such a plan. Section 9 presents individual items that should be addressed as
a minimal quality assurance eflfort The procedures in Section 8 cover only the production of concentration data.
8.2.2.2 It is also assumed that water vapor concentration data for the data acquisition period is available.
This method does not discuss how to acquire that data, however. The water vapor concentration data is used for
post-analysis review and for some of the QA/QC cheeks.
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Method TO-16 : VQCs
8,2.2.3 From this point on, it is assumed that the individual spectra have already been acquired. It is
assumed that the interferograms have been converted to single beam spectra. It is further assumed that no other
data manipulation has occurred.
8.2.3 The suggested order for the production of concentration data utilizing FT-IR is given below.
• Selection of wave number regions for analysis in the presence of interfering species (see Section 8.3).
• Generation of a background spectrum (see Section 8.4).
* Production of a water vapor reference spectrum (see Section 8.5),
• Subtraction of stray light or black body radiation (see Section 8.6).
• Generation of an absorbance spectrum (see Section 8,7).
• Correction for spectral shifts (see Section 8.8).
* Analysis of field spectra for concentration (see Section 8.9).
• Post-analysis review of the data (see Section 8.10).
8,3 Selection of Wave Number Regions for Analysis in the Presence of Interfering Species
83.1 Purpose. This section instructs the operator on how to select the wave number regions that are to be
used in the analysis of field spectra. This section includes the process of working with interfering species because
the absorbance spectrum of any one particular gas frequently overlaps with the absorbance of another species.
This section also provides the operator with a measure of the strength of the interference.
8.3.2 Assumptions. One of the most important requirements when utilizing classical least squares as an
analysis technique is the identification of all possible compounds whose absorption spectrum can interfere with
the absorption feature being analyzed. It is therefore imperative that the operator has as complete knowledge as
he can of the compounds that are expected to be present during the measurement period. The assumption made
here is not only that this knowledge exists but that reference spectra for all the potentially present compounds
also exist. The operator should be aware that absorption spectra from unexpected chemical compounds may
appear during the data acquisition phase and that these must be accounted for in the analysis for the most accurate
data.
8.3,3 Additional Sections Referenced. Section 9.2 is referenced in this section.
8.3.4 Methodology. While FT-IR spectra can in fact be acquired before it is known exactly what wave
number region to use for any particular gas in the analysis, this is never a good idea. If on-line analysis is a
requirement then the wave number regions must be selected first.
When starting, the operator must be aware that this is likely to be an iterative procedure and some wave
number regions may be rejected in the process. The selected wave number region can be quite narrow, but
there are some dangers in selecting a very narrow region. It is best if the operator at first selects the entire
absorbing band structure, using the end points as the 1 % absorbance values relative to the peak. If narrowing
the wave number region becomes necessary, the operator should be aware that the selected wave number
region should always encompass the largest possible range in absorbance.
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This procedure starts by an examination of the absorption spectrum of the target gas and selection of the
absorption feature that has the highest absorption coefficient and is outside the strong absorption regions of
water vapor and carbon dioxide. The wave number region to use is the region that is covered by the entire
peak under study. It is not necessary to include any wave number region whose relative absorbance is less
than 1% of the peak. The absorption coefficient is calculated and the expected absorbance is calculated by
using the anticipated concentration at the site. This absorbance is compared to the noise equivalent absorbance
obtained from Section 9.2. If the expected absorbance is not 3 times higher than the noise equivalent
absorbance, then that wave number region should be rejected. It is likely that if the anticipated absorbance
does not meet this criterion then measurement of that particular gas will have to be rejected because the
remaining absorption coefficients will be too small.
If that test is passed the procedure continues. The absorption features of all the other gases known to be
present at the measurement site are then compared to the target gas for possible interferences. If the total
interference is thought to be too strong, the wave number region is rejected and the process is started over with
a different absorption feature. If all of the features in the target gas are rejected, the gas concentration cannot
be measured by FT-IR.
To calculate the absorption coefficient for any particular feature, the operator must measure the absorbance
of the feature being used at the peak of the feature. This is done by using the reference spectrum. Then by
using the expression a = Aid the absorption coefficient a is determined. The A in this expression is the peak
absorbance measured from the reference spectrum, and the c/ is the concentration-path length product also
obtained from the reference spectrum.
Once a is obtained, an estimate of the peak absorbance can be made as follows. Use the expression A = otcl,
where the c is the anticipated concentration at the site and / is the anticipated path length. The c and the / used
here must have the same units (e.g., ppm, meters) as the reference spectra. The calculated A is then the
anticipated peak absorbance at the site.
To judge whether a particular gas is a possible interfering species, a comparison of the absorption features
must be made. This is initially done by simply comparing the spectra of all the other compounds known to
be present at the site with the absorption feature under study. If any overlap between the two spectra exists
the gas must be considered an interfering species.
To judge the strength of any interfering species the absorption coefficients of the interfering species must be
calculated as above and an estimate of the anticipated absorbance at the measuring site made. In measuring
ihe correct absorbance to use for the interfering species, the operator should use the highest absorbance of the
interfering species spectrum within the overlapping wave number region. Note that the actual peak absorbance
of the interfering gas may very well fall outside the overlap region. The absorption coefficient and the
anticipated absorbance at the site for the interfering species is then determined exactly as described above.
Then the fractional overlap of the spectra must be determined and the estimated impact on the actual
measurement is made.
To determine the fractional overlap, measure the wave number region of the overlap in the spectra and then
divide that by the entire wave number region selected for the target gas. The measurement should be made
by using the 1% relative absorbance wave numbers of the interfering species.
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Method TO-16 t VQCs
To estimate the strength of the overlapping absorbing feature, multiply the fractional overlap of the interfering
species by the anticipated absorbance at the site (for the interfering species). Then divide that product by the
anticipated absorbance at the site for the target gas. The total interfering strength is then the sum of all the
strengths for the individual interfering species.
The classical least squares technique is a very powerful tool for analysis and can determine the presence of
very small quantities of gas in the presence of a fairly large interference. While no hard rule can be given,
the operator should be concerned and at least attempt to find another wave number region if the total strength
of the interfering species is more than 5 times the anticipated absorption of the target gas at the site.
If the operator rejects the wave number region, then the process is repeated with the next highest absorption
coefficient and so on until a suitable wave number region is found. The operator is advised to record a table
of these wave number regions hi a permanent notebook for the specific gases that he is working with. It is
likely that these calculations will have to be done only once for any particular target gas.
8,3.5 Procedure
83 J.I Examine the reference spectrum of the target gas and select the absorbance feature with the highest
absorbance that is outside the strong absorbance of water and carbon dioxide.
833,2 Sccord the wave number region using the relative 1% absorbance peaks as the end points.
8.353 Calculate the absorption coefficient a using the peak absorbance.
8.3.5.4 Calculate the anticipated absorbance at the field site using the a from Section 8.3.5.3, the
concentration anticipated at the field site, and the path length anticipated at the field site.
8.355 Compare the result of Section 8.3.5.5 with 3 times the RMS noise calculated from Section 9,2.
835.6 Compare the absorfaance spectra of all the gases known to be present in the atmosphere at the site.
Record any overlaps with the selected region.
8.35,7 Calculate the following.
8.3.5.7.1 The absorption coefficient a of the interfering species using the peak absorbance hi the overlap
region.
8.3.5.7.2 The fractional overlap.
8.3.5.7.3 The anticipated strength of the interfering species.
8.3.5.7.4 The sum of the interfering strengths.
835.8 Accept or reject the wave number regioa
835.9 If necessary repeat Sections 8.3.5.1 through 8.3.5.8 with the next highest absorbance peak.
8.4 Generation of a Background Spectrum
8.4.1 Purpose
8.4.1.1 This section instructs the operator on how to generate a background spectrum that can then be used
as /, in Beer's law. A background spectrum can be generated by several methods. These methods are (a) the
upwind background, (b) the cross-path background, (c) the zero target gas background, and (d) the synthetic
background The first three backgrounds are generally used with no further processing, but the synthetic
background has to be made. Each is briefly discussed below.
8.4.1.2 Since the synthetic background is the only one that requires computer processing, it is the one for
which the actual steps are given in this procedure.
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8.4.2 Assumptions
8.4 J.I The wave number regions for the analysis have previously been chosen.
8.4.2.2 Field spectra have been acquired, and one of them is to be used for a synthetic background.
8.4.2.3 Software is available that allows a synthetic background to be made.
8.4.3 Additional Sections Referenced. No other sections are referenced.
8.4.4 Methodology. In the derivation of Beer's law, one calculates how much the intensify of the infrared
source diminishes as the energy traverses an absorbing medium. To calculate the concentration of the gas, the
operator must compare the initial intensity obtained in the absence of the target gas with the measured intensity
obtained when the target gas is present. This initial intensity is called the background, and it is the response of
the instrument to the infrared source in the absence of any absorbance due to the target gas. A variety of
phenomena are responsible for the shape of the background curve. A number of these phenomena are related to
the instrument, but the predominant atmospheric process that shapes the background is the absorbance due to
water vapor.
If any absorbance due to the target gas remains in the background, the absolute values of the gas concentration
cannot be measured. In this case, only values relative to the concentration in the background will be obtained.
The upwind background is one that is predominantly used at smaller sites, where it is fairly simple to move
the system from one side to another. Once the wind direction is known, the system is set up so that the path
is along the upwind side and a spectrum that is to be used as a background is acquired. This procedure is
normally done twice a day (morning and evening), and these spectra are generally used as backgrounds with
no further processing.
The argument is made that an upwind background will contain only target gas concentrations from upwind
sources. The remaining downwind field spectra will men give correct values from gases at the site alone.
While this is a valid argument, it is not a very strong argument for the use of an upwind spectrum, and any
variability in die upwind sources may erroneously be interpreted as variability of the target gas concentration
at the site itself. Also to be noted when using such a spectrum is mat it may not be valid for the entire time
period the operator intends. As the water vapor concentration changes, the curvature of the baseline in the
spectra changes also. This will give rise to high error bars (as calculated from classical least squares) and to
variability in the target gas concentration mat follows that of water. When that occurs, this background (or
any background) may no longer be valid.
The cross-path background is taken with an optical path placed along one side of the site and with the wind
velocity parallel to it. This background is generally used when the geometry of the site allows it, and it
supposedly has no target gas concentration. This type of background may also pose some unwanted problems.
If the wind is very light, then the gases from the site can indeed diffuse into the optical path. Target gas
concentrations from elsewhere may be present, and interpretation may present the same problems described
above.
Some researchers have obtained a background spectrum by simply waiting long enough for the gas
concentration to go to zero. This method will not work for gases that are always present in the atmosphere,
such as methane or carbon monoxide. This procedure may be used if there is sufficient time in the program
for the waiting period and if real-time analysis is not an immediate requirement, but it is not clear whether the
water vapor concentration will be hi a satisfactory range. Also, the operator should not expect any one
background to remain valid for more than a few days, and then a new background must be obtained.
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If the measurement program merely requires a "yes" or "no" response to the question of whether a compound
is present, then any spectrum that is taken may possibly be used for a background. If possible, the operator
should use a spectrum that has a minimum of the target gas, but that is not necessary if the analysis software
allows negative numbers. (Note that it is the difference of the concentration hi the two spectra that will be
measured.)
If, however, the absolute values of the concentration of the target gas hi the optical path are required by the
measurement program and no applicable spectrum can be found that is void of the target gas absorption, a
synthetic background must be used. A synthetic background is one that is made from a single beam field
spectrum, and it may have some of the target gas in it. Once a field spectrum has been selected, a new
baseline is made to replace all the absorbance features in the wave number region used for analysis with a new
curve that resembles the instrument baseline as closely as possible. This new baseline is made by connecting
the data points along the original baseline with straight line segments, or by some other appropriate fitting
procedure, thereby removing any absorbance features. The difficulty with this method is knowing where the
baseline actually is. No points within any absorbance feature of the original spectrum can be used. A portion
of a field spectrum and the synthetic background made from it by connecting the data points with very short
straight line segments is illustrated in Figure 4. The original field spectrum has absorption lines due to water
vapor in it.
Selecting the points for the baseline for a synthetic background may be quite difficult when large wave number
regions are used or when the curvature of the baseline is high. This is a problem with the wave number region
used for the analysis of ozone, for example.
8.4.5 Procedure
8,4.5.1 From the set of available spectra, select one spectrum by using the following criteria.
8.4.5.1.1 The target compound concentration should be near a minimum.
8.4.5.1.2 The interfering species concentration should be at a minimum.
8.4.5.1.3 The vapor pressure concentration should be in the mid range of water vapor concentrations
during the period for which the background is to be used.
8.4.5.1.4 The return intensity at 987 cm"1, 2520 cm"1, and 4400 cm"' should be normal for this instrument
and for the particular path length used.
8.4.5.2 Once the candidate spectrum has been selected, use the available software to create a synthetic
background.
8.5 Production of a Water Vapor Reference Spectrum
8.5.1 Purpose This section instructs the FT-IR operator on how to create a water vapor reference spectrum
from a single beam field spectrum. Absorption due to water vapor represents an interference to the spectral
region of the target gas, and these interferences must be accounted for in whatever analysis routines that are
finally used. Water vapor presents the predominant absorption features in the spectra acquired by the FT-IR, and
the operator can expect it to interfere with the target gas spectrum. It is essentially impossible to create a water
vapor reference spectrum in the laboratory by using a cell because the concentrations required are not normally
attainable, and measuring the amount of water vapor in the cell is very difficult Therefore, the water vapor
reference spectrum has to be made from the acquired field spectra. Fairly large changes in the atmospheric
concentrations of water vapor can occur rapidly, and that generally implies that a new water vapor reference
spectrum has to be created.
8.5.2 Assumptions
8.5.2.1 The wave number regions for the analysis of the remaining spectra have previously been chosen.
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VOCs . Method TO-16
8.5.2.2 Field spectra have been acquired, and one of them is to be used for a water vapor reference
spectrum.
8.5.3 Additional Sections Referenced. Activities and evaluations performed in Section 8.4 are referred to
in this section.
8.5.4 Methodology. The first step in the process of creating a water vapor reference is the selection of a
single beam spectrum from the set available. The selection is based on a number of criteria. During the process,
any absorbance due to the target gas must be subtracted from the water vapor reference. This can be done in a
number of ways, but until the operator gains some familiarity with the FT-IR analysis process, it is best to do this
by starling with a spectrum that contains a reasonable amount of the target gas and any other interfering species.
In this way it may be possible for the operator to see the absorbance feature and do the subtraction interactively.
Otherwise, the concentration of the target gas needs to be measured by using an analysis routine and then
subtracted by using the library reference spectrum.
There is also some argument that can be made to specifically acquire a spectrum with a large number of scans
and to use that as a water vapor reference spectrum. The large number of scans ostensibly gives a smaller
noise value. This argument is not generally true with the FT-IR systems because the calculated RMS noise
is not usually generated by the system electrical noise. The majority of the calculated RMS noise seems rather
to be die result of slight changes in the water vapor concentration and other atmospheric constituents from one
spectrum to the other.
From the set of available spectra, one spectrum must be selected by using the following criteria.
• The target compound concentration should not be near a minimum. As the operator gains more
experience at creating a water vapor reference he may want to minimize the target gas absorption if
possible.
* The interfering species concentrations should not be near minim^
• The vapor pressure concentration should be in the mid range of water vapor concentrations during the
period for which this particular water vapor reference spectrum is to be used. It should be remembered
that many of the water vapor lines may be saturated as far as the instrument response is concerned. That
implies that the time period that can be covered with any one water vapor spectrum must be carefully
chosen. However, at the present time no explicit guidance concerning the length of time that a single
water vapor reference is valid can be given. Perhaps the best advice is to compare the curvature of the
baselines of the single beam spectra. If that is changing rapidly, a new water vapor reference spectrum
may have to made.
» The return intensity at 987 cm"1, 2520 cm"', and 4400 cm"1 should be normal for this instrument and for
the particular path length used. Any spectrum that has been acquired in foggy or rainy conditions should
not be used.
The last criterion is included as a check to determine that the instrument is operating correctly.
Once the candidate spectrum has been chosen, it must be turned into an absorption spectrum by using the
background spectrum created in Section 8.4.
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Method TO-16 VOCs
The new water vapor absorbance spectrum must now be analyzed for the presence of absorbance due to the
target gas. To accomplish this, the normal analysis procedure can be used if an older version of the water
vapor reference spectrum already exists. It is likely that using the older water vapor reference will result in
somewhat higher error bars from the analysis. At the present time this can be ignored. The results of this
analysts should be zero, but it can give a positive result if there is an absorbance due to the target gas in the
newly created water vapor reference. If a positive value exists then that amount of the target gas must be
subtracted from the water vapor reference spectrum. The exact procedure to use for the subtraction process
will depend on the software mat the operator has.
If no other water vapor reference exists, the following procedure must be used. A set of 15 pairs of spectra
must be acquired with the FT-IR. They should be taken so that no time elapses between them. They should
be acquired with the same number of scans and the same resolution as the newly created water vapor reference
spectrum. The individual 15 pairs are used to create 15 absorbance spectra. These spectra should not contain
any of the target compound absorbance because they have been taken back-to-back, and it is hoped that each
will contain the same amount of the target gas absorption. These spectra must then be analyzed for the target
compound by using me newly created water vapor reference.
The average value of the results of this analysis should be zero. If it is not but some positive or negative bias
exists, some amount of the target compound absorbance is still fa the water vapor reference spectrum.
There are two possibilities to consider if a bias exists. The first is that the baseline of the newly created water
vapor reference is not quite correct, and the second is that some of the target compound must be subtracted
from the newly created reference spectrum. (This can give rise to either a negative or a positive bias.) At the
present time no procedure exists to correct for curvature of the baseline. If the operator decides that baseline
curvature is the primary problem, then there is little that he can do to correct the problem.
If a bias exists that is not from a baseline curvature then the operator must subtract some of the target gas from
the newly created water vapor reference. If an interactive software mode for subtraction exists, the subtraction
can be done in an interactive mode using the target gas reference spectrum as the subtrahend. If an "interactive
software mode is not available, the target gas reference can be used as follows. The target gas reference
spectrum can be multiplied by an appropriate factor and the result subtracted from the newly created water
vapor reference. The path length at which the water vapor reference spectrum was acquired is known and the
target gas concentration is known in parts per million from the analysis above. The reference spectrum
absorbance is given in terms of parts per million meters. So the operator must divide the absorbance of the
spectrum by the path length in meters and by the ratio of the concentrations (reference/calculated). The
resulting spectrum can then be subtracted from the created water vapor reference.
Repeat the analysis procedure and this process until the target gas concentration is zero.
85.5 Procedure
8,5.5.1 Select the single beam spectrum that is to be used for a water vapor reference using the criteria
listed above.
$££.2 Create an absorbance spectrum using the appropriate background spectrum.
8,55.3 Analyze the newly created water vapor reference for the target gas,
8,5.5,4 If necessary, subtract the proper amount of the target gas absorption from the water vapor
reference.
8.5.5.5 Reanalyze the water vapor spectrum.
8.5.5.6 Repeat Sections 8.5.5.3 through 8.5.5.5 until the target gas concentration is zero.
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8,6 Subtraction of Stray Light or Black Body Radiation
8.6.1 Purpose. This section instructs the operator how to subtract the stray light or black body radiation
measured by the instrument from the field spectra. This procedure can be used by operators using either the
monostatic or the bistatic instrument configurations. The subtraction for either configuration is performed by
using single beam spectra.
8.6.2 Assumptions. Assumptions. For both the stray light component and the black body radiation
component measurement the instrument must be operating at its equilibrium conditions. That is, the FT-IR must
have been allowed to warm up. As long as the operating conditions are not changing rapidly, the spectra should
be acquired by using a large number of scans so as to provide a good signal-to-noise ratio. Since these spectra
have to be subtracted from the field spectra, noise will be added to the analysis, and a longer acquisition time
minimizes the electrical noise. Acquiring data for up to one half hour is satisfactory. Not much is gained in the
signal-to-noise ratio by acquisition times longer than that
8.6.3 Additional Sections Referenced. No other sections are referenced.
8.6.4 Methodology. The procedure for subtracting stray light is primarily to be used for the removal of a
spurious signal from FT-IR instruments using the monostatic configuration with a second beam splitter. While
it is possible to have scattered light that gives rise to unwanted signals in instruments using the other geometric
configurations, this component is very difficult to measure and is considered to be a difficulty that the
manufacturer has to deal with. This type of stray light subtraction will not be discussed further in this method.
Instrument manufacturers strive to have the stray light as small as possible compared to the intensity returning
from the retroreflector, but to remove it all can be a formidable task, and it should therefore be measured and
subtracted. It is fairly simple to show mathematically that, whatever percentage of the return intensity the stray
light intensity represents, that percent error will be carried through to the final result in the analysis. The presence
of stray light can sometimes be detected visually in the single beam spectrum as is shown in Figure 3. Therefore,
it has to be subtracted from the spectra if the errors in the data are to be minimized. The intent of the specific
program may indicate it is not necessary to subtract the stray light spectrum from the field spectra; an example
is when only the identification of compounds is necessary.
Once the stray light intensity is known and measured it should not change unless some component of the optical
system is changed or reoriented. Therefore, the stray light spectral subtraction can easily become part of the
routine analysis. Since the stray light component is generated inside the instrument, its intensity is not path-
length dependent. This means that the stray light will change its intensity relative to the return intensity as the
path length changes. It can easily be measured by simply slewing the instrument away from the retroreflector
and acquiring a spectrum.
The need to subtract the black body radiation arises only in bistatic systems that have an unmodulated source
at one end of the physical path. It is convenient to think that the black body radiation conies from the fact that
the field of view of the receiving telescope is larger than the angle that me infrared source subtends; therefore,
the instrument allows the infrared energy from the surroundings into the system. This is only partially true,
and if the instrument is at the same temperature as the surroundings, the black body radiation can be thought
of as coming entirely from the instrument enclosure. That is because all black body radiators at the same
temperature radkte the same amount of energy per unit area. Therefore, the easiest way to measure the black
body spectrum is to turn the source off and then acquire a spectrum.
There is an additional problem with the black body radiation curve that occurs when the instrument is pointed
at the sky. When this situation occurs it is very likely that there will be an emission spectrum superimposed
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Method TO-16 VQCs
on the black body curve. The emission spectrum arises from several atmospheric gases and is quite variable.
Even the smallest amount of cloud cover will dramatically change the intensity of this spectrum. That fact
makes it almost impossible to subtract the emission spectrum totally. It is advisable to avoid pointing the
instrument so that it has the sky in the field of view. If that cannot be avoided, the operator should be aware
that higher than normal errors can occur in the data in the region below about 1050 cm"1.
Small changes in the ambient temperature (10 °K) are not thought to be significant in the black body radiation,
and thus one spectrum should be usable for an extended period. These spectra should be subtracted from the
field spectra after the single beam spectra have been obtained. If the interferograras are subtracted and the
single beam is then calculated, a different result is obtained. The reason for that is not fully understood at this
time.
8.6,5 Procedure
t 8.6.5.1 Measure the stray light in the instrument by slewing the instrument off the retroreflector.
8.6.5.2 Subtract this spectrum from each single beam field spectrum before proceeding with the analysis.
8.6.5.3 Measure the black body radiation spectrum by turning the source off.
8.6,5.4 Subtract this spectrum from each single beam field spectrum before proceeding with the analysis.
8.7 Generation of an Abso rbance Spectrum
8.7.1 Purpose. This section instructs the operator on how to generate an absorbance spectrum from the field
spectra and an appropriately chosen background spectrum.
8.7.2 Assumptions. The following assumptions are made.
8.7.2.1 An appropriate background spectrum is available.
8.7.2.2 AH the field spectra have been converted to single beam spectra.
8,7.2,3 All the field spectra have been corrected for stray light and the black body radiation if necessary.
8.7,3 Additional Sections Referenced. No other sections are referenced.
8.7.4 Methodology. Beer's law is the underlying physical law that governs the way the least squares analysis
is performed. Mathematically, Beer's law is written as J(v) = J8(v)exp(-aCL). In order to calculate C, the
concentration of the gas in the atmosphere, one must divide by /, and take the logarithm of the result. That gives
ln(JJI) m O.CL. The spectrum described by the term \n(I,/I) is called the absorbance spectrum. The FT-IR
analysis is actually done by using the logarithm to the base 10, but this is normally transparent to the operator.
All software packages that are available for least squares analysis allow the generation of an absorbance
spectrum. The operator is generally asked to supply the background spectrum, but then the process is
mathematically performed by the computer. It is important to understand that some correction may be
necessary to the field spectra before they are converted to absorbance spectra.
8.73 Procedure. Use the available software to create the absorbance spectra.
8.8 Correction for Spectral Shifts
8.8.1 Purpose. This section instructs the operator on how to align two spectra so as to minimise the errors
involved with spectral shifts.
883. Assumptions. The field spectra have been acquired and are in the single beam format A water vapor
reference that is to be used for analysis is available. A background spectrum has been prepared and is available
for use. In order to check for a shift between the field spectrum and the reference spectrum, an absorbance
spectrum must be used if the reference spectrum is an absorbance spectrum.
8.8.3 Additional Sections Referenced. No other sections are referenced.
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8.8,4 Methodology. There are three ways that a spectral shift will affect the FT-IR data analysis. The first
is when a spectral shift between the field absorbance spectrum and the water vapor reference spectrum exists.
The second is when a spectral shift between the field absorbance spectrum and the library reference spectrum for
the target gas exists. The third is when a nonsynthetic background is used and a spectral shift exists between the
background and the field spectra. A spectral shift compared to the instrument may also be noticed when new
reference spectra are purchased or produced on an instrument other than the one used for data acquisition. The
first two of these comparisons are done using absorbance spectra, but the third must be done with single beam
spectra.
When a synthetic background is used, any spectral shift between the field spectrum (single beam) and the
background spectrum (single beam) is irrelevant. That is because the synthetic background generation process
does away with all spectral features of interest.
A question arises as to what sort of a shift is really important to the analysis. Some researchers discuss this
in terms of absolute quantity of wave numbers. This is not really satisfactory because then apparently small
shifts are important for some spectral features while at other times they are not. If a Gaussian shape is used
to describe the absorption line shape, then it is possible to show mathematically that when the absorption
feature of interest shifts by about 10% of the line width (FWHH), a 5% error occurs in the least-squares
analysis. If a Lorentzian line is used to describe the actual line shape, the shift can be about 15% of the line
width (FWHH) before a 5% error occurs when least-squares analysis is used. Experimentally, if a 5% error
is acceptable, it is only seldom that line shifts will be important. However, lfa.1% error is all that is allowed
by data quality objectives, then the same calculations show that a 0.5% shift (FWHH) of the line is all that can
be tolerated. This really implies that wave number shifts will probably not be important when broad absorption
features (such as presented by ozone) are used but will be crucial for narrow absorption features (such as
presented by carbon monoxide). The predominant spectral feature in the FT-IR open path field spectra is
water vapor, and the pressure-broadened lines of water have a line width (FWHH) of about 0.2 cm"1. Since
water is the predominant feature, the errors produced by the classical least-squares technique will be primarily
caused by how well water is handled in the analysis. That means that water vapor must always be checked
for shifts.
Experience has shown mat when a spectral shift occurs, the magnitude of the shift is different in the C-H
(2900-3000 cm"1) stteteh region than it is in the fingerprint region. This implies that all line shifts are caused
by some change in the interferometer and/or the system optics. If that is truly the case, then the shift is linear
in wave number, and a linear correction must be applied when the correction is made throughout the field
spectrum. Some computer software automatically identifies a wave number shift and then shifts the entire
spectrum by the proper amount. If that software is available it should be used.
The best place to determine whether a shift has occurred is in the low-wavelength or high-wave-number end
(in the region of the C-H stretch) of the spectrum. It may also be possible to automatically determine during
the acquisition phase whether a shift has occurred and then shift each individual spectrum as it is being
acquired. To do that, some known spectral feature present hi every spectrum must exist. Thus it may be
possible to select some water vapor line that is present in all the spectra covering a particular time period and
compare all the spectra with that particular line. A shift of that Mnd guarantees that all the field spectra are
aligned one to the other but does not automatically guarantee that the field spectra and the reference spectra
wiU be aligned. At any rate, at the present time no such line has been agreed upon, and it may not be possible
to select a single line for all occasions.
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Method TO-16 VOCs
If shifting software is not available, two problems are presented to the operator. The first is how to recognize
a shift and the second is how to correct for it over the entire wave number region.
Recognizing that a shift has occurred can be facilitated by subtracting one spectrum from another. If a small
(less than the line width) shift has occurred, the difference will appear as an "S"-shaped curve. This kind of
curve is closely related to the first derivative of the line shape if the shift is small. Determining the absolute
magnitude of the shift can be a difficult task, and no simple mathematical relation exists between the features
of the S-sfaaped curve and the magnitude of the shift. At the present time, the best estimate of the magnitude
of the shift is obtained from measuring the difference of the peak positions of the two lines. However, this
is best done on spectra that have been interpolated to increase the number of data points. Or, if the operator
so chooses, he may zero fill the interferogram by a factor of 2 or 4 in order to increase the number of data
points.
Since the correction for a shifted spectrum is most likely linear in wave number, the shift must be done in steps
if appropriate software is not available. A shift between the individual library reference spectra and the field
absorbance spectra can be overcome because the library spectra can be individually shifted. It may also be
possible (depending on the software available) to rename the water vapor reference spectrum so mat mere are
two or three of them, each with its own shift, and then do all the analysis simultaneously. The same procedure
can be used to overcome a shift between the field spectra and the background spectrum when a synthetic
background is not used. However, if the shift is small (less than the data point spacing) but significant, then
all the spectra may have to be interpolated or zero filled to correct for the shift.
•* 8.8.5 Procedure (applicable when shifting software is not available).
8.8.5.1 Subtract the two spectra and examine the residual for an S-shaped curve. Do the background and
the field spectra first because these have to be done with single beam spectra.
8.8.5.2 Determine the magnitude of the shift by comparing the peaks of the individual lines.
8.853 Shift one spectrum with respect to the other. This will have to be done in the target gas analysis
regions and may have to be done several times,
8.8,5.4 Create absorbance spectra from the field spectra and the background and repeat Sections 8.8.5.1
through 8.8.5.3.
8.8£J5 Perform a correction for shift to the water vapor reference spectrum, the reference spectrum, and
the background if necessary. The field spectra should not be shifted, as this requires the most time.
8 J Analysis of the Field Spectra for Concentration
8 J.I Purpose. This section instructs the user on the procedures used for the analysis of FT-IR absorbance
spectra in order to produce gas concentration values.
8.9.2 Assumptions. The spectra have been converted to absorbance spectra and aU changes and corrections
listed in the above sections have been made to them. A set of reference (library) spectra that includes the target
gas, the interfering gases, and a water vapor reference is available for use. A software package that is capable
of performing least squares analysis on the spectra is available.
8.93 Additional Sections Referenced. No other sections are referenced.
8 3.4 Methodology. There are a number of ways to analyze the spectra in order to obtain concentration data.
These include peak height or peak area analysis, spectral subtraction, partial least squares, iterative least squares,
principal component analysis, etc. While these methods are all usable, this procedure uses classical least squares
as described mathematically by Haaland and Easterling (13). The use of classical least squares requires that the
spectra be prepared in a specific way for the analysis to work efficiently and effectively. Thus the majority of
Compendium Method TO-16 is concerned with preparation of the spectra.
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VOCs Method TO-16
It is likely that, when the other techniques cited above are used, the data will have to be prepared in a different
manner. Under those conditions the steps of this procedure that deal with spectral preparation are not usable.
Whatever software is available to perform the classical least-squares technique, it must be able to perform the
analysis of a single target gas in the presence of interfering species. It is only seldom that the range of wave
numbers used for the analyses will be free of absorbances due to interfering species. This is particularly true
of water, and the analysis routines must be able to perform a multiple linear regression of the field spectra.
There are a number of software packages that are in use that perform classical least-squares analysis of the
spectra. These all have somewhat different user interfaces and operating conditions, but in all cases the
mathematical algorithms are transparent to the user. Therefore, the software packages are not described in
detail here. Since the classical least-squares analysis is a multiple linear regression, it must have certain items
available for it to function. The items that are common to all available analysis packages include the target
gas reference spectrum, the background (or /,) spectrum, the water vapor reference spectrum, and whatever
interfering gas reference spectra are necessary. Most software packages are, however, only available with
the FT-IR instrument itself. The primary concern for this procedure is that the analysis itself follows the
classical least squares described mathematically by Haaland and Easterling (13).
8.9,5 Procedure. The individual steps in this section are dependent on the specific software available to the
operator. Since the individual packages are not described here, the specific steps required for any one package
are not either.
8.10 Post-Analysis Review of the Data
8.10.1 Purpose. The purpose of this section is to provide the operator with a way to check the data for
possible problems. This procedure primarily makes use of plotted data in the form of the concentration of one
gas plotted against the other and of time sequence plots. There is one statistical determination that can be used
to determine if correlations exist between pairs of data. The primary tool used here is for the operator to look
for trends in the data where none should exist. The specific tests of the data are described below.
8.10.2 Assumptions. The only assumption is that all of the spectra have been analyzed by use of the least-
squares analysis software.
8.10.3 Additional Sections Referenced. No other sections are referenced.
8.10.4 Methodology. The operator should make several plots of the concentration data. The first should
be a set of plots of target gas concentration versus time. These plots should be examined for any expected trends
in time. For example, ozone in rural areas generally follows a diurnal pattern with a minimum at about 0600
hours and a maximum at about 1500 hours. The concentration values should not go negative to any great extent;
although around zero concentration the values may go slightly negative, the average value over time should be
zero. Suppression of negative values should never be done in the analysis because then a zero average can never
be achieved. If values go negative with time in a regular fashion, then something is amiss with the data. The
most likely case is that there is a small remaining absorbance due to the target gas in the water vapor reference
spectrum. If the concentration values are much higher than the anticipated values, there may also be a problem
with the water vapor reference spectrum. In this case there may have been too much of the target gas absorbance
subtracted from the water vapor reference. If that is so, the water vapor reference should be fixed and then the
data reanalyzed.
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Method TO46 VOCs
Plots should be made of Ae target gas concentration versus the water vapor. If the variability of the target gas
and the water vapor are correlated and this is not expected, the water vapor reference spectrum must, in most
cases, be corrected.
• :,
The next step is to plot the concentration values of those gases whose concentrations are expected to be
correlated. This includes any gases that are derived from the same source. If the variability of these gases
is not correlated, the data must be carefully examined for the cause. There are no good guidelines to judge
what is causing that problem, but a nonlinear response of the instrument for one of the gases is a possibility.
If that is suspected, the operator must carefully examine the QA data for possible clues.
Another check of the instrument can be made by analyzing the spectra for N2O. Nitrous oxide is present
naturally in the atmosphere with a concentration very close to 300 ppb. The variability in this concentration
should be less than ± 10%. If this is not the case then all the data must be suspect. Another gas that is always
present in the atmosphere is methane. The variability of methane can be foirly large, particularly in the
proximity of landfills. That means it is somewhat more difficult to use as a quality check of the data but it can
still be used. The value of the atmospheric concentration of methane should never fall to less than about
1.7'ppm.
If the FT-IR instrument is a bistatic one and there is any possibility mat the instrument was admitting energy
from the sky when the black body radiation measurement was made, there might be a problem with the
observed detection limits. If that occurs, it is possible that the analysis is flawed because of emission spectra
in the black body radiation.
Another check for the quality of the data can be obtained by examining the errors calculated by the least-
squares analysis routine. If there is an abrupt change in the relative error and no obvious reason such as an
abrupt change in the water vapor concentration, it may be that a new interfering species, not accounted for
in the analysis, has been measured.
Once these checks have been made on the data, the operator must follow the data quality checks that have been
written for the specific program that is being studied.
8.10.5 Procedure.
8.10.5.1 Plot the data as a function of time and check for unexpected trends.
- • 8.10.5.2 Plot the target gas data concentration as a function of water and determine if the variability is
correlated
8.10.5,3 Determine whether N2O and CH4 have been correctly measured.
'.' 8.10.5.4 Determine whether correlation of the data exists where correlation is expected,
8.10.5.5 Review all the QA/QC data taken in compliance with the specific data quality objectives.
9. Quality Assurance
9.1 Summary
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The section provides guidance to the operator In determining how well fee FT-IR sensor is operating. While
this section is labeled "quality assurance", it is by no means adequate to serve as a quality assurance project
plan or program plan. Project and program plans are meant to address the specific data quality objectives of
a monitoring program, and the final use of the FT-IR data and cannot be adequately covered hi this document.
Some of the procedures are limited in scope because a satisfactory procedure has not been developed at this
time.
9.2 The Determination of Method Noise or Method Noise Equivalent Absorption
9.2.1 Purpose. The purpose of this section is to allow the operator to determine the method noise. This
determination should form part of the routine quality assurance checks made of the instrument It should be made
at least once a day for extended programs and every time the instrument is moved or otherwise changed This
procedure is used to judge whether the instrument is operating properly but not as a gauge of the quality of the
data.
9.2.2 Assumptions
9.2.2.1 This procedure assumes that spectra have been acquired with the same operating parameters
(number of co-added scans, resolution, etc.) as the field spectra. The one exception is that the spectra used to
determine the method noise should be taken so that no time elapses between them.
9.2,2.2 It is also assumed that software exists that will allow this determination to be made automatically
by computer.
9.2.3 Additional Sections Referenced. No other sections are referenced.
9.2.4 Methodology. Instrumental noise is generally considered to be the random fluctuations in the recorded
signal. That is not exactly true for the FT-IR system when the data are acquired along a long, open path.
Evidently, the time required to allow small but measurable changes in the gaseous atmospheric constituents is
short compared to the normal acquisition time of the spectra. Because of that, when two spectra are used to create
an absorbance spectrum there is a variability in the result that is not electronic noise alone. This is defined here
as the method noise. It is important because it cannot easily be done away with and will contribute to the error
of the measurement
The determination of method noise uses the statistical quantity called the RMS deviation. The mathematical
routine normally used for this calculation performs a linear least-squares fit (linear regression) using the data
points over a specified wave number region and calculates the RMS deviation from that line. The RMS
deviation is defined as the square root of the sum of the differences squared divided by the quantity N-2. The
number N is the total number of data points. The differences are calculated by taking the difference between
the actual data point and the line; they are then squared and added.
The actual range of wave numbers mat can be used changes with resolution, but the number of data points does
not. The number of data points used should be 80 points. Thus for a l-cmf' resolution, the range of wave
numbers is 40, because the instrument acquires a data point every half resolution unit. Since this measurement
is considered to be the determination of an instrument parameter, the wave number region or regions should
be chosen to minimize the effect of water vapor. The water vapor concentrations along the path are known
to change rapidly, and that will perhaps cause most of the variability in the signal.
The two single beam spectra that are used to measure the noise should be taken without any time lapse between
them. These two spectra are then used to create an absorbance spectrum. Which of the two that is used as
the so-called background is irrelevant Three wave number regions are then used for this determination. For
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Method TO-16 ; VOCs
this procedure, the regions are based on a l-cm"1 resolution and are 968-1008, 2480-2520, and 4380-4420 cm"
', respectively. Other regions may be used, but the operator should try to cover the range of wave numbers
that are being measured. The 80 data points used in the measurement should also be adhered to. This data
should then be recorded and plotted on a quality control chart for comparison purposes.
9.2.5 Procedure
9.2.5.1 Record two spectra with the same operational parameters that will be used for the acquisition of
the field spectra. Do not allow any time to elapse between these spectra.
i 9,2.5.2 Create an absorbance spectrum by using either of the two spectra taken in Section 9.2.5.1 as a
background.
9.2.5.3 Analyze this absorbance spectrum for the RMS deviation in the three wave number regions
968-1008 cm"1,2480-2520 cm"1, and 4380-^420 cm'1.
; 9.2.5,4 Record this data in a notebook and plot it on a quality control chart
9.3 The Measurement of the Return Beam Intensity
^9,3.1 Purpose. This section provides guidance to the measurement of the return beam intensity in the case
of the monostatic system or the intensity of the ER source at the FT-DR. in the case of the bistatic system. This
procedure needs to be done only once as long as the detector or the infrared source does not change.
™ 9.3.2 Assumptions. In order that these measurements be realistic, the stray light component or the black
body radiation should be subtracted from the spectra. This means those measurement results should be available
to the operator or should be made in conjunction with this measurement.
9.33 Additional Sections Referenced. Refer to Section 9,4, Measurement of Stray Light, and Section 9,5,
The Measurement of Black Body Radiation, if applicable.
93.4 Methodology. The return beam intensity determines the operational signal-to-noise ratio of the FT-IR
system. This intensity is a variable and depends on the path length chosen, the water vapor in the atmosphere,
and other atmospheric conditions. The primary atmospheric conditions that make the return beam intensity
change are fog, rain, snow, and sleet. Of these, fog has by far the largest effect Another cause for a change in
the return beam intensity is pollen in the atmosphere. This happens in the spring in areas where there are a large
number of pine trees. Finally, for the monostatic geometry, which uses a retroreflector, condensation on the
mirror can make dramatic changes in the return beam intensity. There are also instrumental causes of changes
in the return beam intensity but they are beyond the scope of this document.
For these reasons, it is prudent to include in a quality assurance program the measurement of the return beam
intensity. If the return energy has been degraded by an unacceptable amount, the operator must change the
length of the path. Whether the return is acceptable or not is dependent on the data quality objectives from
the quality assurance program plan.
This procedure is separated into two parts. The first is a procedure for measuring the return beam intensity
as a function of path lengm. The second is the measurement of return beam Intensity as a function of time.
There are two reasons to measure the return beam intensity as a function of path length. The first is to
determine when the energy becomes intense enough to saturate the detector. The second is to determine when
the infrared energy becomes too small to measure. These measurements then determine experimentally the
rninirnum and maximum usable path length. There are a number of reasons why the return beam intensity
should be monitored as a function of time. The primary one is that the return beam intensity will change
according to varying weather conditions. The operator must become familiar with the magnitude and the
rapidity of these changes.
•IS ' " ; ,
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9.3,5 Procedure
9.3.5.1 Return Beam Intensity as a Function of Path Length.
9.3.5.1.1 Place the light source or the retroreflector at a short distance, say 25 meters, from the
detector.
9.3.5.1.2 Align the system to maximize the return signal.
9.3.5.1.3 Record a spectrum and convert this spectrum to a single beam spectrum.
9.3.5.1.4 Record the intensity levels in the 987-cm'1 region and in the 2,500-cm"1 and the 4,400 cm"1
regions. The reason the wave numbers are not given specifically is that the operator should select a maximum
in the baseline return intensity in these regions.
9.3.5.1.5 Examine the detector cutoff region at about 650 cm'1. If a dip occurs in this region or the
baseline is elevated above zero, then the detector is already saturated.
9.3.5.1.6 If there is no indication of saturation, move the light source or the rettoreflector so that the
distance separating it and the detector is smaller. Repeat Sections 9.3.5.1.1 through 9.3.5.1.5.
9.3.5.1.7 Continue this process by cutting the distance in half until the single beam spectrum exhibits
saturation as described above in the 650-cm"1 region. Record this distance. This distance represents the
minimum path length that can be used with this particular instrument without altering the instrument.
9.3.5.1.8 Next, move the light source or retroreflector to a distance of 100 m.
9.3.5.1.9 Realign the "instrument to maximize the signal.
9.3.5.1.10 Record a spectrum and convert it to a single beam spectrum.
9.3.5.1.11 Record the intensity levels at the same wave numbers as used above.
9.3.5.1.12 Repeat Sections 9.3.5.1.8 through 9.3.5.1.11 by increasing the path length in 50-m
increments until the intensity levels no longer change. For the monostatie geometry mode, mis will occur
when all the energy being recorded comes from the stray light hi the instrument. For the bistatic mode, the
return signal will diminish to zero in the 4000-cm"1 region and then will evolve into the black body radiation
spectrum.
9.3.5.1.13 Plot a graph of the return intensity versus path length.
9.3,5.2 Measurement of the Return Beam Intensity as a Function of Time. At least once every day of
operation the return beam intensity should be recorded at the wave number regions given above. More frequent
measurements should be made when the atmospheric or other conditions listed in Section 9.3.4 occur. The
atmospheric conditions should also be recorded. Water vapor plays an important role in the recorded beam
intensity so that the partial pressure of water should also be calculated and recorded. A continuous plot of these
data should be made showing the intensity as a function of time. The graph should include notations for the
various atmospheric conditions listed above.
9.4 The Measurement of Stray Light
9.4.1 Purpose. The monostotic FT-IR systems are prone to having stray light in the instrument To obtain
the best possible accuracy, this stray light component must be subtracted from the field spectra before the analysis
is performed. This section describes how to measure the stray light component and is applicable to only the
monostatie geometries that modulate the beam with the interferometer before the infrared energy is transmitted
along the path and that use a second beam splitter to direct the beam. There are other sources for stray light that
arise from overfilled optical components. These are a problem for the manufacturer and are not addressed in this
document
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Method TO-16 ' VOCs
9.4.2 Assumptions. The primary assumption for this procedure is that the FT-DR. system being used is of
the monostatic geometry. The system has been operating sufficiently long to be past any warm-up periods and
it is using the same resolution as when it is acquiring the normal field spectra.
9.4.3 Additional Sections Referenced. No other sections are referenced.
9.4.4 Methodology. The easiest way to measure the stray light with a monostatic system that modulates
the beam before the energy is transmitted along the path is to simply slew the system away from the retroreflector.
Once this is done, the operator should acquire a spectrum using a large number of co-added scans. If the time
required to acquire this spectrum cannot be at least 4 times the length of time to acquire the field spectra, he
should then use the longest time possible. The issue here is one of electronic noise, and the electronic noise
should diminish as the square root of the time needed to acquire the spectrum. Changes in the atmospheric
constituents play no role in this measurement
This spectrum should be saved as a single beam spectrum with an appropriate name, and it must be subtracted
from the single beam field spectra before they are converted to absorbance spectra.
A second way to measure die stray light is to cover the receiving telescope with some opaque, non-reflecting
material. Any material that is reflecting acts as a mirror and will give erroneous readings. Any material that
is not opaque will allow some of the beam returning from the retroreflector to be transmitted to the detector.
This method is not recommended.
This measurement must be done at the beginning of operation and every time the instrument is altered in any
way. For those programs that are short-term field programs, the measurement should be made at the
beginning of each field program.
9.4.5 Procedure.
9,4.5.1 Set up the instrument fa exactly the same way as it will be used to acquire field spectra.
- 9,4,5.2 Slew the transmitting telescope off the retroreflector so that there is no beam return signal.
9.4.5.3 Acquire a spectrum.
9.5 The Measurement of Black Body Radiation
9.5.1 Purpose. FT-DR. systems generally have a field of view larger than the solid angle that the light source
or the retroreflector subtends at the far end of the path. The bistatic systems (or those that do not transmit the
beam through the interferometer before it transmitted along the path), therefore, admit radiation to the detector
from the surrounding background These systems also respond to any radiation coming from the instrument itself
(the instrument is also a radiator of energy). This radiation is commonly referred to as the black body radiation
and it must be subtracted from the single beam spectra before the analysis is performed. This procedure describes
how to measure that radiation.
9.5.2 Assumptions. The instrument must be set up in the same manner and with the same background that
will be in its field of view during the acquisition of the field spectra.
9.5 J Additional Sections Referenced, No other sections are referenced.
9,5.4 Methodology. The FT-IR systems available today use some form of a heated element as a source of
inJCrared energy. These elements generally have a temperature in the vicinity of 1500°K. The terrestrial
surroundings in which the FT-IR operates generally have a temperature around 3QO°K, All things above absolute
zero radiate energy according to their temperature and have a very well known energy distribution in wave
number. The distribution of energy peaks at a wave number that is temperature dependent with the cooler body
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VQCs . Method TO-M
having a peak at lower wave numbers. Also, the energy distribution of a cooler body is lower in intensity at all
wave numbers than the distribution of a hotter body. The question arises of what the ratio of intensities is of
these two sources. This ratio at the peak of the 300 degree source is about 5. That is, the surroundings can
represent about 20% of the energy of the source. Therefore, it must be subtracted from the spectra before the
analysis is performed.
The simplest way to acquire a black body spectrum is to set up the instrument in exactly the same way it will
be run to take the field spectra. A spectrum should then be acquired with the light source turned off. This
spectrum should be saved with an appropriate name.
This spectrum does not appear to change dramatically when me Instrument is pointed at terrestrial targets such
as buildings or trees. Nor does it change dramatically with slight changes in the ambient temperature
(±10°K). A 10% change in temperature will shift the peak by 10%, and mat may become important.
Remember, however, that a 10% change in temperature is about 30°C. The black body spectrum does,
however, change dramatically if the sky is included in the instrument's field of view. In this case an emission
spectrum appears from me atmosphere, and this is very difficult to handle. The black body spectrum can also
change dramaticaUy if hot sources other than the primary light source are allowed into the field of view of the
instrument. The operator is advised to take precautions so that these conditions are avoided.
In order to minimize the noise introduced by the subtraction process, the number of scans used to acquire the
spectrum should be large. An acquisition time of more than 15 minis probably excessive. It is prudent to run
such a spectrum at least once every day during the study. These spectra should be Investigated for changes,
particularly when there are large swings in temperature. This is possible during the early fall, when the
temperature can range from cold at night to quite warm in me daytime.
9.5.5 Procedure
93.5.1 Set up the FT-IR along the same path that will be used to acquire the field spectra.
9.5.5.2 Acquire a spectrum over a long acquisition time with the infrared source off.
93.5.3 Store the spectrum with an appropriate name.
9.6 The Determination of the Detection Limit
9,6.1 Purpose. The purpose of this routine is to provide the operator with a mechanism for determining the
detection limits for the various gases. The definition of the detection limit is given here as the minimum
concentration of the target gas that can be detected in the presence of all the usually encountered spectral
interferences.
9.6.2 Assumptions. The instrument is operating with the same parameter settings as those used for
collecting the field spectra. That is, the path length, resolution, number of co-added scans, and the apodization
function are the same in both cases. If the instrument has an ancillary gas cell, this must be empty.
9.6.3 Additional Sections Referenced. No other sections are referenced.
9.6.4 Methodology. The detection limit of the FT-IR systems is a dynamic quantity that will change as the
atmospheric conditions change. The variability of the target gas, water vapor, and all of the other interfering
species concentrations contributes to the variability of this measurement Some researchers have suggested that
the/0 spectrum used to create the absorption spectrum when measuring the detection limits be the same as that
used for the field spectra. However, that cannot be done if a synthetic background is used since the field spectra
are expected to contain some quantity of the target gas. If any other arbitrary background is used the
measurement will certainly reflect the variability of the target gas, at least. To overcome most of the effects of
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Method TO-16 VOCs
this problem, the operator should use spectra whose acquisition times are no longer than about five minutes. If
the field spectra are acquired at shorter times then the shorter time should be used. If the field spectra are
acquired at longer times because the anticipated variability of the target gas is small, then it is appropriate to use
the longer times.
The detection limit as determined in this procedure is the result of a calculation using a set of 15 individual
absorption spectra. The 16 individual single beam spectra used for mis determination are acquired in 5-min
intervals and no time is allowed to elapse between them. The absorption spectra are then created by using the
first and the second single beam spectra, the second and the third, and the third and the fourth, and so on until
the 15 absorption spectra are obtained. These absorption spectra are analyzed in exactly the same way that
all field spectra are to be analyzed and over the same wave number region. The analysis should result in a
set of numbers that are very close to zero because most of the effects of the gas variability have been removed.
The numerical results should be both positive and negative and for a very large set of data should average to
zero. Three times the standard deviation of this calculated set of concentrations is defined to be the detection
limit.
There is reason to believe that this procedure gives the most optimistic (lowest) value for the detection limit
because it removes most of the effects of the interfering species. However, the other suggested procedures
seem to introduce as much uncertainty, and this procedure may actually be used for further diagnostics of the
post-analysis review of the data (see Section 8.10).
9.6.5 Procedure.
9,6.5.1 Acquire a set of 16 single beam spectra in exactly the same manner that will be used for the field
spectra.
9.6.5.2 Use the first spectrum as a background to create an absorbance spectrum from the second
spectrum.
9.6.5.3 Use the second spectrum as the background and create an absorbance spectrum from the third
spectrum.
f 9.6.5.4 Continue this process until all 15 absorbance spectra have been created,
9.63.5 Analyze each of the spectra for the target gas concentration.
9.6.5.6 Calculate the standard deviation of the set of concentration values.
9.6.5.7 Multiply the result of Section 9.6.5.6 by 3 to obtain the detection Emit.
9.7 The Determination of Precision
9.7.1 Purpose. Precision is a measure of the FT-IR system's ability to make repeatable measurements when
challenged with the same sample. This section provides guidance to the operator on how to make that
determination for some gases.
'9.7.2 Assumptions. The FT-IR system has the capability for installing a gas cell in the beam so that the
entire beam passes through it This is something that the manufacturer has to build into the design of the system
and is not under the control of the operator. While the measurements are being made, the instrument is operating
in the same way that it is used to collect the field spectra.
9.7.3 Additional Sections Referenced. No other sections are referenced.
9.7.4 Methodology. The precision with which a measurement is made with the FT-IR instruments is, at the
present time, very difficult to measure. The best method that has been suggested is one that uses a cell of some
sorFthat is filled with a high concentration of gas and is then placed in the beam. However, this process is quite
error-prone and it has not been shown to work well with a mixture of gases. A second difficulty is that it cannot
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VOCs Method TO-16
be used for all the gases that can be potentially measured with the FT-IR. The primary reason is that the
concentration of the gas in the cell has to be high in order to produce a measurable absorption. Many gases have
a vapor pressure that is too low to achieve these concentrations. No procedure has been established for making
these measurements of polar compounds. Additionally, not all the .commercially available instruments have at
the present time been designed to accept a cell in an appropriate position of the optical path.
However, for those instruments and for those gases that can be measured, the procedure is as follows. A cell
whose length is short compared to the pam length is filled with a high concentration of gas. The cell is placed
in the infrared beam so that all of the energy passes through the cell. Then a set of spectra is acquired and
these are converted to absorption spectra. These absorption spectra are analyzed for the target gas. The
relative standard deviation of this set of measurements is given as the precision.
This procedure is also quite similar to the procedure for the measurement of accuracy. The measurement of
precision, however, does not require an exact knowledge of the concentration of the gas, but rather the gas
concentration must remain constant. Thus the gas concentrations used can be made up in the field at a lower
cost to the monitoring program.
Determining the precision of the FT-IR monitoring system is complicated by the feet that the measurements
are made over an open path in the atmosphere. It cannot be assumed that the concentration of the various
atmospheric gases will be constant in time, and this feet will impact the precision measurements. This
procedure calls for the precision measurements to be made by using the same path length that is generally used
for acquiring field spectra. Therefore, the precision will vary in time and will be dependent on the variability
of not only the target gas but also the variability of the interfering species. The precision measurement
described is therefore a method precision and includes all of the parameters that must be considered in the field
spectra analysis.
The cell can be filled in a number of ways, but the preferred way is to use a gas of the appropriate
concentration from a prepared cylinder that has been purchased for this purpose. The proper mixture can be
calculated as follows:
• The absorption coefficient of the gas can be calculated from the reference spectrum by using a = A/cl,
where A is the absorbance at the peak of the reference spectrum and d Is the concentration-path length
product, which is supplied with the reference spectrum for the reference gas.
• Next, the desired absorbance when the cell is filled is selected. This can be set at 0.05,
« Then c is calculated from c = A/a/, where A = 0.05, a is the absorption coefficient calculated above,
and / is the length of the cell in meters if the reference gas has a concentration-path length product in
parts per million per meter.
• The concentration calculated above has units of parts per million if the concentration-path length product
for die reference gas has units of parts per million per meter. This is the concentration to use when
purchasing a cylinder of gas. The fill gas of the cylinder must not absorb in the infrared, and the gas
preferred for this is nitrogen.
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Method TO-16 VQCs
Before the target gas is introduced into the cell, the cell should be flushed with nitrogen until at least five
volumes of the cell have passed through it. At the present time me preferred method for introducing the target
gas Is with a flowing system. The gas should remain flowing during the measurement.
9.7J Procedure.
9.7.5.1 Calculate the appropriate concentration for the target gas and obtain a cylinder of that
concentration. ~ "
9.7.5.2 Set up the instrument as it will be used to acquire the field spectra.
r~" 9.7.5.3 Place the cell in the instrument and flush it with dry nitrogen so that at least five volumes of the
cell have passed through it
9.7.5.4 Flow the target gas through the cell, and after three volumes of the cell have passed through,
acquire a set of 15 spectra.
» 9.7.5.5 Analyze these spectra for the target gas.
; 9.7.S.6 Express the relative standard deviation of this set of concentrations as the precision.
9.8 The Determination of Accuracy
j).8.1 Purpose. Accuracy is a measure of the ability of the FT-IR to measure a known concentration of gas.
This procedure may allow the operator to determine the accuracy of the FT-DR. measurements for some gases.
This measurement is very difficult to make and no exact procedure has been accepted.
9.8.2 Assumptions. The FT-ER must have the capability for installing a gas cell that is short compared to
the path length in the instrument so that the entire infrared beam passes through it. This must be included in the
manufacturer's design of the instrument, and whether or not the cell can be placed in the beam is not under the
control of the operator. The measurements for accuracy should be made with the instrument operating in the
same way as it is when acquiring normal field spectra.
9.83 Additional Sections Referenced. No other sections are referenced.
9.8.4 Methodology. The general procedure to be used for the determination of accuracy is essentially
identical to the procedure for the determination of precision. The difference is that for the measurement of
accuracy the concentration of the gas in the ceU must be known. Obtaining this knowledge poses some special
problems, and preparation of the sample gas by the individual operators is not recommended at this time. Rather,
whenever possible a cylinder of prepared gas should be purchased; for convenience, this prepared mixture is
called the reference gas for the rest of this procedure. However, the vapor pressure of some gases is too low to
allow the purchase of appropriate concentrations. Even if a cylinder is purchased, there is some difficulty with
knowing what the concentration in the cell is, particularly for the polar compounds.
If a cell is to be used for this measurement then the first step is to calculate the concentration that is required.
It is anticipated that the accuracy of the measurement is dependent on the concentration that is being measured.
Therefore, the operator must make some judgement of what that concentration is to be. To obtain the
concentration in the cell, the operator must multiply the anticipated concentration by the ratio of the path length
used for the monitoring program to the cell length. Thus if the path length to be used in the acquisition phase
is 100 m and the cell length is 20 cm, then the operator must multiply the anticipated concentration by 500 to
get the required concentration of the reference gas in the cell.
Once the proper mixture of gas has been obtained, the operator must introduce it into the cell. At the present
time it is recommended that the gas should be flowed through the cell continually during the measurement.
Before the measurement is attempted, the gas should be allowed to flow through the cell until at least five
volumes of the ceil have passed through it.
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VOCs Method TO-16
At the beginning of this measurement the cell should be flushed with dry nitrogen and then a spectrum should
be acquired. The reference gas is then flowed through the cell and a second spectrum acquired while the gas
is flowing. The cell should then be flushed with dry nitrogen again and a third spectrum recorded.
The average value of the target gas concentration found from the first and third spectra is subtracted from the
value determined for the target gas from the second spectrum. This value is then used as the recorded value
for the measurement. This procedure is repeated five times in a day, and the average value of these five
measurements is used as the accuracy measurement The percent accuracy is then defined as the average value
found above divided by the known concentration of the cylinder gas value times 100, This value should be
recorded and plotted on a control chart made for that purpose.
If a flowing system is used, the flow rate must be small so that there is no measurable pressure change in the
cell. Flow rates of a few cubic centimeters per minute are acceptable and would require no measurement of
the pressure. When the cell is purged to remove the target gas, the volume of purge gas used should be at least
5 times the volume of the cell.
The procedure described here has not been studied in depth, and little written material exists in the literature.
Questions such as what the material of the lead lines are to be made of, whether the pressure must be measured
in the cell, and whether the lines have to be heated have not been answered at this time. It is also not clear
whether this procedure can be used with a mixture of gas or if only a single species must be used at a time.
It seems possible that, in the future, a procedure using the water in the atmosphere can be used for mis
measurement. Absorbance due to water is in every important part of the spectrum that is used with FT-ER
measurements, and it will be in every spectrum. Water can also be measured independently with techniques
other than the FT-DR. so that a verification step can be performed. However, the use of water has not been
explored at all.
9.8.5 Procedure.
9.8.5.1 Calculate the required concentration of the reference gas and obtain a cylinder with that
concentration.
9.8.5.2 Set up the FT-ER. with the same operating conditions used to acquire the field spectra.
9,8.5.3 Install the cell in the beam if necessary and flush it with dry nitrogen.
9.8.5.4 Acquire a spectrum.
9.8.5.5 Flow the reference gas through the cell so that at least five volumes of the cell pass through it.
9.8.5.6 Acquire a second spectrum with the reference gas flowing.
9.8.5.7 Flush the cell with dry nitrogen again and acquire a third spectrum.
9.8.5.8 Analyze all three spectra for the target gas by using the same background as used for the field
spectra..
9.8.5.9 Find the concentration of the reference gas from the result of analyzing the second spectrum minus
the average value of the first and third spectra.
9.8.5.10 Repeat Sections 9.8.5.3 through 9.8.5.9 five times in any one day of operation.
9.8.5.11 Determine the percent accuracy as the average value of the five measurements divided by the
known concentration of the reference cell times 100.
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Method TO-16 VOCs
"i-1, . ... :. in- (
9.9 The Measurement of Resolution
93.1 Purpose. The purpose of this procedure is to provide the operator with a means for measuring the
resolution of the FT-IR instrument
9.9.2 Assumptions. The spectra used to make this determination have been acquired with the same
instrumental parameters as those used for the field spectra. Particularly, the apodization function and the path
length must be the same,
9.9.3 Additional Sections Referenced. No other sections arc referenced.
9.9.4 Methodology. The resolution of the FT-IR is an important parameter in that it determines the
specificity of the measurements. The instrument resolution does not exhibit dramatic changes from day to day
and needs to be measured infrequently. However, whenever any change is made to the instrument optics,
including the light source, the resolution must be remeasured. The resolution can also change when the path
length changes if the instrument does not have an appropriate field stop to clearly define the field of view
regardless of the optical path length. If that is the case, the resolution should be measured at whatever path
lengths are used. The FT-IR resolution is also dependent on the apodization function that is used when single
beam spectra are created from interferograms, and if more than one apodization function is used then the
resolution should be measured for each. The operator needs to be aware of the instrument resolution for a number
of reasons. The spectra from two instruments cannot be compared if the resolutions are not the same. The use
of reference spectra at resolutions different from that of the instrument creates problems with accuracy.
Subtracting one spectrum from another with different resolutions is also a problem. The manufacturers of these
devices list the nominal resolution, but a listed resolution of, for example, I cm'1 should not be interpreted as an
exact number.
To measure the resolution, an absorption spectrum must be used. An absorption line that is narrow in
comparison to the instrument's line function must be used, and the spectral line used must be a single line.
If changes in the instrument resolution occur, they should be noticeable in the high-wave-number region first.
Six primary atmospheric constituents are present in every spectrum. They are water vapor, methane, carbon
dioxide, nitrous oxide, ozone, and carbon monoxide. Of these, only the absorption features of water vapor
and carbon monoxide can be used to measure the instrument resolution. If the path length is great enough and
the water vapor concentration is large enough, then the atmospheric constituent deuterated water can also be
used.
In addition to these, absorption features from other gases in high concentrations, in conjunction with a short
cell can be used. The important feature of any line that is selected for resolution measurements is that it be
a single line and be narrow compared to tie instrument's nominal operating resolution. Thus methane cannot
b« used because the lines are not single lines. Whatever feature is chosen, it must not be impacted by any
interfering species, as this has the same effect as having double lines. The absorption features of ammonia
or hydrogen chloride can be used. HC1 is actually a good choice because it absorbs in the high-wave-number
region. However, it is not generally present in high enough quantities in the atmosphere to be measured in
every spectrum.
There are a number of lines that can be used in the water vapor spectrum that can be used for this
measurement. They are at the wave numbers 1014.2, 1149.46, 1187.02, and 2911.88. It should be noted that
many of the water lines are already saturated as far as the instrument response is concerned at a vapor pressure
of 3 torr. So any line used must be checked to make sure it is not saturated. For carbon monoxide there is
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VOCs Method TO-16
at least one line at 2168.9 that can be used. These lines should easily be observed in spectra that have been
taken with path lengths greater than 100 m (total).
The resolution for the FT-IR is defined as the full width at half maximum (FWHM) for either of the these
lines. Thus to determine the instrument's resolution, an absorbance spectrum must be created with a synthetic
background. The operator needs to have a large number of data points across the line in order to make this
measurement, and it should be remembered that the system takes only two data points per nominal resolution
element The best way to create this absorption spectrum is to record an interferogram and then zero fill by
at least a factor of 4 before computing the Fourier transform. If that is not possible, then the absorbance
spectrum must be interpolated to increase the number of data points.
The absorbance at the peak must be measured, and any non-zero baseline value must be subtracted from that
measurement The result of this subtraction is the peak height Then the entire width of the line at one-half
the peak absorbance is measured in wave numbers. This is the required measure of the resolution of the
instrument.
9.9.5 Procedure.
9.9.5,1 Obtain an interferogram with the FT-IR operating at the same path length as will be used for the
acquisition of the field spectra.
9.9.5.2 Zero fill the interferogram by at least a factor of 4.
9.9.5.3 Perform the Fourier transform on the interferogram.
9.9.5.4 Create an absorbance spectrum using a synthetic background.
9.9.53 Isolate one of the lines and measure the peak height
9.93.6 Subtract any non-zero baseline measurement
9.9.5.7 Measure the full width of the line at one half the absorbance measured in Section 9.9.5.6. This is
the resolution.
9.10 The Determination of Nonlinear Instrument Response
9.10.1 Purpose. The FT-ER instrument can respond noniinearly to changes in the light intensity for several
reasons. There are two instrumental conditions that must be guarded against, and these are discussed here. The
first is that the electrical gain is set too high, and this can cause the analog-to-digital (A/D) converter to be
saturated. The second is that the light source itself is too intense, and this causes the detector response to become
nonlinear. This procedure is intended to give the operator a means for determining when either of these
conditions exist.
9.10.2 Assumptions. The instrument is operating under the same conditions as it will be to acquire the field
spectra. •
9.10«5 Additional Sections Referenced. No other sections are referenced.
9.10.4 Methodology. A nonlinear response can be caused by excessive source intensity or amplifier gain.
All of the FT-IR systems mat are used for remote sensing use A/D converters to convert the analog detector signal
to a digitized form. Most use either a 16 bit or an 18 bit converter, and that defines the range of voltages that can
be monitored. If the source intensity and amplifier gain combination is too high, then the A/D converter can be
saturated. This manifests itself as a sudden drop in the signal being recorded when the source or the retrorefleetor
is moved closer to the detector. When this happens, the system gain must be lowered, if that possibility exists,
or the path length must be changed.
The second type of nonlinear response is somewhat more difficult to determine. This occurs if too much light
falls on the detector. The detector converts the incident light photons to an electrical signal. There is a limit
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 16-33
-------
Method TO-16 VOCs
for how many photons can be converted to electrons, and when this limit is exceeded the detector response
becomes nonlinear.
There may also be a nonlinear response from the feet that HgCdTe detectors exhibit nonlinear behavior in their
response to infrared energy. This circumstance is not covered here and should be corrected by the
manufacturer.
In everyday operation, the easiest way to detect the second kind of nonlinearity is to examine the portion of
the single beam spectrum at wave numbers below the detector cutoff. This is in the 65Q-€80-cm"1 region for
most HgCdTe detectors. If a dip below zero occurs in that region or if the signal is above zero at wave
numbers below that region, the system's response may be nonlinear.
There are two ways to check the system's response. Both involve the use of screens to diminish the light
intensity while the response is being viewed. If the screens have meshes that reduce the intensity by known
amounts, the response should be diminished by that amount also. If the instrument responds differently, the
system is nonlinear.
Wire screens caiTbe purchased in a number of mesh sizes, and the mesh size determines how much light will
get blocked. Plastic screens should not be used because they may exhibit selective absorption. Aluminum
screening that is used for window screening is satisfactory but may not reduce the intensity enough. It is best
to use screens of different mesh when using the procedure described below rather than two layers of screening
with the same mesh.
The following procedure needs to be done only if the operator suspects that the system is operating in a
nonlinear way.
9.10.5 Procedure.
9.10£.1 Set the FT-K. system up as it will be used for acquisition of the field spectra.
9.10.5,2 Mfove the source or the retroreflector to twice the original distance.
i. 9.1053 Examine the signal. If a sudden increase in the signal strength occurs, then the A/D converter is
salurated.
9.10.5,4 With the source on and the retroteflector at the distance used for the field spectra, acquire a single
beam field spectrum and examine the intensity in the detector cutoff region. If a dip occurs, the detector may be
saturated.
9.10.5.5 If the dip that is described in Section 9.10.5.4 occurs, insert a wire screen in the beam so that it
covers the entire beam and record the signal level.
i 9.10.5.6 insert a second screen in the beam and record the signal again. If the screens are the same, each
should dimmish the beam in the same ratio. If that does not happen, the system is nonlinear in response and the
infrared energy must be decreased by some means such as increasing the path length, closing the iris in the
instrument, etc.
9.11 The Determination of Water Vapor Concentration
9.11.1 Purpose. It is suggested that the water vapor content in the atmosphere be monitored independently
of the FT-ER. measurements. This is not an individual procedure like the preceding portions of this method in that
it docs not explain the siting criteria for making water vapor measurements. It is rather a discussion as to why
the measurement is important
9.11.2 Assumptions. There are no assumptions about the FT-IR system associated with this process.
Page 16-34 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-16*
9.11.3 Additional Sections Referenced. No other sections are referenced.
9.11.4 Methodology. Absorption due to water vapor is the predominant feature in the spectra acquired by
the FT-ER remote sensor. It also seems to be one of the most difficult compounds to deal with in the analysis.
There are measurable changes in the observed water vapor from spectrum to spectrum. Data from a local airport
weather service is not satisfactory to understand the changes and their effects on the analysis. Large and abrupt
changes in the water vapor content can be expected When mat occurs it is likely that the background spectrum
and the water vapor reference spectrum will have to be remade. But the only way to know that these changes have
occurred is to measure the water independently.
Some argument can be made that the water vapor concentration can be obtained by simply adding water to the
list of analyzed gases. However, it is not simple to make that measurement. Many of the water vapor lines
are very strongly absorbing when the vapor pressure is 3 or 4 torr. The atmospheric vapor pressure in most
areas is at least 5 times higher than that That makes line selection for analysis quite problematic.
Since the water vapor can easily be measured in a continuous fashion it seems prudent to make the
measurement independently of the FT-IR. One post-analysis check of the data is to look for a correlation
between the concentrations of the target gas and water vapor. To accomplish that, the operator must determine
what the water vapor concentration is. The following discussion describes a way of doing that.
The water vapor concentration can be obtained by measuring the relative humidity and the ambient
temperature. These values, along with the Smithsonian psychrometric tables, are then used to calculate the
water vapor concentration. The psychrometric tables can be found in the Handbook of Chemistry and Physics
(14), which is published yearly.
There are solid-state devices available today that allow reliable measurements of the relative humidity and the
ambient temperature. These devices give results to within a few percent of relative humidity and a few tenths
of a degree for the temperature. The operator will need a way to record the output from these devices. This
can be accomplished with a data logger that allows for multichannel, multiday recording.
The sensors can be placed anywhere along the path but must be shielded from the sun. A complete description
of how to configure the placement of these devices is well outside the scope of this document. For a complete
discussion of these measurements, the operator should consult the following document: Quality Assurance
Handbook for Air Pollution Measurements, Volume IV—Meteorological Measurements (15). Once the water
vapor concentration is known, it should be plotted as a function of time and then compared with the target gas
concentration as discussed hi the procedure for post-analysis data checking (see Section 8.10). The operator
should pay particular attention to the periods where abrupt changes in the water vapor occur.
10. References
1. Russwurm, G. M., and Childers, J.W., FT-IR Open-Path Monitoring Guidance Document., U. S.
Environmental Protection Agency, Research Triangle Park, NC, EPA/6QO/R-96/040, April 1996.
2. Pfeiffer, H. G., and Liebhafsky, H. A., "The Origins of Beer's Law," J. Chem. Educ,, Vol. 28:123-125,
1951.
3. Lothian, G. F., "Beer's Law aad Its Use in Analysis," Analyst, Vol. 88:678, 1963.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 16-35
-------
Method TO-16 VQCs
4. Champeney, D. C., Fourier Transforms and Their Physical Applications, Academic Press, London, 1973.
5. Nicolet Analytical Instruments, FT-IR Theory, Nicolet Analytical Instruments, Madison, WI, 1986.
6. Griffiths, P. R., and deHaseth, J. A., Fourier Transform Infrared Spectrometry, John Wiley and Sons,
New York, 1986.
7, Halliday, D., and Resnicfc, R. Fundamentals of Physics, Wiley and Sons, New York, 1974.
8. Stone, J. M., Radiation and Optics, McGraw-Hill, New York, 1963.
9. Tolansky, S., An Introduction to Interferometry, John Wiley and Sons, New York^ 1962.
10. Calvert, J. G,, "Glossary of Atmospheric Chemistry Terms (Recommendations 1990)," Pure Appl.
Ghent, Vol. 62(11):2167-2219, 1990.
11. Long, G. L., and Winefordner, J. D., "Limit of Detection: A Closer Look at the RJPAC Definition,"
Anal, Chem., Vol. 55(7):712A-724A, 1983.
12. _ Rennilson.jf, J.j_"Retroreflection Measurements: A Review," Appl. Opt., Vol. 19:1234, 1980.
13. Haaland, D. M., and Easterling, R. G., "Application of New Least-Squares Methods for the
Quantitative Infrared Analysis of Multicomponent Samples," Appl. Spectrosc., 36(6):665-673, 1982.
14. Handbook of Chemistry and Physics, CRC Press, Cleveland, OH.
15. Quality Assurance Handbook for Air Pollution Measures, Volume IV—Meteorological Measurements,
U. S. Environmental Protection Agency, EPA-600/R-94-Q38b, Research Triangle Park, NC, May 1994.
Page 16-36 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs
Method TO-16
Detector
Receiving
Optics
*
.* *
f
9
i^tt *
\
**<
«
t
IRPath
t
»
»
*
t
.. — g.
t
t
tf
Qpdcs
W8rtWSra8ter
-*** ID
Source
Absorbing Medium
X
B
InterferDrnater
Receiving
Optics
IR Path
IR
Source
Detector
Figure 1. The bistatic configuration of an FT-ER. Astern.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 16-37
-------
Method TO-liS
VOCs
/«^g- »•»»« ;C12v--«.- - *V"- —•>—
/Transmiting IRjPath
^i..-..,.... V**.'*
i tt{ ; \
,.*srr *—-,^"
; Return 1R Path i--'
\
Translating
Retroref lector
Absorbing Medium
Transmitting
Optics
Receiving •
Optics
Interferometer
.--" IR
Source
Detector
IRPath
Additional
Beamsplitter
Transmiting/
Receiving
Optics
\:
IntBrferomflter
Retroreflector *;
tt
X*
Detector
Source
, r Figure 2. The monostatic configuration of an FT^-IR system.
Page 16-38
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-16
CO
I
i
m
0)
*O)
JC
CO
400
1000
2000 3000
Wave Number (cm-1)
4000
Figure 3. Single-beam spectrum acquired by using a raonostatic system and a 414-m path.
; S indicates stray light.]
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 16-39
-------
Method TO-16
VOCs
Original Spectrum
900 927 954 981 1008 1035 1062 1089 1116
"• > Wave Number (crrr1)
Figure 4, Synthetic Ig spectrum for an FT-IR absorbance.
The peak at 1110 cm"1 has intentionally been left in as a fiducial point.}
Page 16-40
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
EPA/625/R-96/QlQb
Compendium of Methods
for the Determination of Toxic
Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-17
Determination of Volatile Organic
Compounds in Ambient Air Using Active
Sampling Onto Sorbent Tubes
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
-------
Method TO-17
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/010b), which was prepared under
Contract No. 68-C3-0315, WA No. 3-10, 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, John O. Burckle, and Scott Hedges, Center for Environmental Research
Information (CERT), and Frank F. McElroy, National Exposure Research Laboratory (NERL), aU in the EPA
Office of Research and Development, were responsible for overseeing the preparation of this method.
Additional support was provided by other members of the Compendia Workgroup, which include:
John O. Burclde, U.S. EPA, ORD, Cincinnati, OH
• James L. Cheney, Corps of Engineers, Omaha, NB
• Michael Davis, U.S. EPA, Region 7, KG, KS
• Joseph B. EUdns Jr., U.S. EPA, OAQPS, RTP, NC
1 • RobertG. 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 Schujtz, ERG, Lexington, MA
William T. "Jerry" Winberry, Jr., EnviroTech Solutions, 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)
• Elizabeth A. Woolfenden, Perkin Elmer Corp., Wilton, CT
• William A. McClenny, U.S. EPA, NERL, RTP, NC
(•«•„•
Peer Reviewers
I • Joan T.Bursey, ERG, Morrisville, NC
• • Martin ffirper.SKC Inc., Eighty-Four, PA
• Irene D. DeGraff, Supelco, Inc., Bellefonte, PA
r « Joseph E. Bumgarner, U. S. EPA, NERL, RTP, NC
; « Lauren JJrees, U.S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufinan, Debbie Bond, Cathy Whitaker, and Kathy
Johnson of Midwest Research Institute's Administrative Services staff whose dedication and persistence
during the development of this manuscript has enabled it's production.
: -z : DISCLAIMER
This Compendium has bean 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
no? constitute endorsement or recommendation for use.
-------
METHOD TO-17
Determination of Volatile Organic Compounds in Ambient Air
Using Active Sampling Onto Sorbent Tubes
TABLE OF CONTENTS
Page
1. Scope 17-1
2. Summary of Method 17-2
3. Significance 17-3
4. Applicable Documents 17-4
4.1 ASTM Standards 17-4
4.2 EPA Documents 17-4
4.3 Other Documents . 17-4
»
5. Definitions . . .- 17-5
6. Overview of Methodology . 17-6
6.1 Selection of Tube and Sorbent 17-7
6.2 Conditioning the Tube 17-7
6.3 Sampling Apparatus 17-7
6.4 Sampling Rates 17-7
6.5 Preparing for Sample Collection 17-8
6.6 Set the Flow Rates 17-8
6.7 Sample and Recheck Flow Rates 17-8
6.8 Reseal the Tubes 17-8
6.9 Selection of Thermal Desorption System 17-8
6.10 Dry Purge the Tubes and Prepare for Thermal Desorption 17-9
6.11 Check for System Integrity 17-9
6.12 Repurge of Tube on the Thermal Desorber/Addition of Internal Standard 17-9
6.13 Thermally Desorb the Packing . 17-9
6.14 Trap Desorption and GC/MS Analysis 17-9
6.15 Restoring the Tubes and Determine Compliance with Performance Standards .... 17-9
6.16 Record and Store Data 17-10
7. Interferences and Limitations 17-10
7.1 Interference from Sorbent Artifacts 17-10
7.2 Minimizing Interference from Water 17-11
7,3 Atmospheric Pollutants not Suitable for Analysis by this Method 17-12
7.4 Detection Limits and Maximum Quantifiable Concentrations of Air Pollutants .... 17-12
7.5 Suitable Atmospheric Conditions 17-12
in
-------
TABLE OF CONTENTS (continued)
'"HI >li •*.
> • i
Page
8. Apparatus Selection and Preparation 17-13
8.1 Sample Collection 17-13
8.2 Apparatus 17-14
8.3 Tube Conditioning Apparatus 17-15
9. Reagents and Materials 17-16
r 9.1 Sorbent Selection Guidelines 17-16
- 9.2 Gas Phase Standards 17-17
9.3 Liquid Standards . 17-17
9.4 Gas Phase Internal Standards 17-19
9.5 Commercial, Preloaded Standard Tubes 17-19
9.6 Carrier Gases 17-19
10. Guidance on Sampling and Related Procedures 17-20
10.1 Packing Sorbent Tubes 17-20
*• 10.2 Conditioning and Storage of Blank Sorbent Tubes 17-21
i 10,3 RecordJKeeping Procedures for Sorbent Tubes 17-21
-• 10.4 Pump Calibration and Tube Connection 17-22
10.5 Locating and Protecting the Sample Tube 17-22
10.6 Selection of Pump Flow Rates and Air Sample Volumes 17-22
"^ 10,7 Sampling Procedure Verification - Use of Blanks, Distributed Volume Pairs,
rj BackUoJCubes, and Distributed Volume Sets 17-23
• 10.8 DeSmMng araf Validating Safe Sampling Volumes (SSV) 17-24
' 10,9 Resealing Sorbent Tubes After Sample Collection 17-25
10.10 Sample Storage 17-25
11^ AnalyticalJProcedure 17-25
11.1 Preparation for Sample Analysis 17-25
11,2 Predesorption System Checks and Procedures 17-25
11.3 Analytical Procedure 17-26
K-'. ' im 49 • • •"•• ' ' • ••> ~t: t \ _ .,
12. Calibration of Response i 17-27
13, Quality Assurance 17-27
13.1 Validating the Sample Collection Procedure 17-27
13.2 Performance Criteria for the Monitoring Pump 17-28
14. Performance Criteria for the Solid Adsorbent Sampling of Ambient Air 17-28
14.1 Introduction 17-28
14.2 Method Detection Limit 17-28
14.3 Analytical Precision of Duplicate Pairs 17-29
" 14.4 Precision for the Distributed Volume Pair 17-29
14.5 Audit Accuracy 17-29
151 References . . : 17-30
IV
-------
METHOD TO-17
Determination of Volatile Organic Compounds in Ambient Air Using
Active Sampling Onto Sorbent Tubes
1. Scope
1,1 This document describes a sorbent tube/thermal desorption/gas chromatographic-based monitoring method
for volatile organic compounds (VOCs) in ambient air at 0.5 to 25 parts per billion (ppbv) concentration levels.
Performance criteria are provided as part of the method in Section 14. EPA has previously published
Compendium Method TO-1 describing the use of the porous polymer Tenax® GC for sampling nonpolar VOCs
and Compendium Method TO-2 describing the use of carbon molecular sieve for highly volatile, nonpolar
organics (1). Since these methods were developed, a new generation of thermal desorption systems as well as
new types of solid adsorbents have become available commercially. These sorbents are used singly or in
multisorbent packings. Tubes with more than one sorbent, packed in order of increasing sorbent strength are used
to facilitate quantitative retention and desorption of VOCs over a wide volatility range. The higher molecular
weight compounds are retained on the front, least retentive sorbent; the more volatile compounds are retained
farther into the packing on a stronger adsorbent. The higher molecular weight compounds never encounter the
stronger adsorbents, thereby improving the efficiency of the thermal desorption process.
1,2 A large amount of data on solid adsorbents is available through the efforts of the Health and Safety
Laboratory, Health and Safety Executive (HSE), Sheffield, United Kingdon (UK). This group has provided
written methods for use of solid adsorbent packings in monitoring workplace air. Some of their documents on
the subject are referenced in Section 2.2. Also, a table of information on safe sampling volumes from their
research is provided in Appendix 1.
13 EPA has developed data on the use of solid sorbents in multisorbent tubes for concentration of VOCs from
the ambient air as part of its program for methods development of automated gas chromatographs. The
experiments required to validate the use of these sorbent traps include capture and release efficiency studies for
given sampling volumes. These studies establish the validity of using solid adsorbents for target sets of VOCs
with minimal (at most one hour) storage time. Although questions related to handling, transport and storage of
samples between the times of sampling and analysis are not addressed, these studies provide information on safe
sampling volumes. Appendix 2 delineates the results of sampling a mixture of humidified zero air and the target
VOCs specified in the Compendium Method TO-14 (2) using a specific multisorbent.
1.4 An EPA workshop was convened in November of 1995 to determine if a consensus could be reached on the
use of solid sorbent tubes for ambient air analysis. The draft method available at the workshop has evolved
through several reviews and modifications into the current document The method is supported by data reported
in the scientific literature as cited in the text, and by recent experimental tests performed as a consequence of the
workshop (see Table 1).
1,5 The analytical approach using gas chromatography/mass spectroscopy (GC/MS) is identical to that
mentioned in Compendium Method TO-15 and, as noted later, is adapted for this method once the sample has
been thermally desorbed from the adsorption tube onto the focusing trap of the analytical system.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-1
-------
Method TO-I7 VOCs
1.6 Performance criteria are given in Section 14 to allow acceptance of data obtained with any of the many
variations of sampling and analytical approaches.
2. Summary of Method
2.1 The monitoring procedure involves pulling a volume of air through a sorbent packing to collect VOCs
followed by a thermal desorption-capillary GC/MS analytical procedure.
2.2 Conventional detectors are considered alternatives for analysis subject to the performance criteria listed in
Section 14 but are not covered specifically in this method text
2.3_Key steps of this method are listed below.
2.3,1 Selection of a sorbent or sorbent mix tailored for a target compound list, data quality objectives and
sampling environment
2.3.2 Screening the sampling location for VOCs by taking single tube samples to allow estimates of the
nature and amount of sample gases.
2.33 Initial sampling sequences with two tubes at nominally I and 4 liter total sample volumes (or
appropriate proportional scaling of these volumes to fit the target list and monitoring objectives).
2.3,4 Analysis of the samples and comparison to performance criteria.
235 Acceptance or rejection of the data.
" 23.6 If rejection, then review of the experimental arrangement including repeat analysis or repeat analysis
with backup tubes and/or other QC features.
[Note: EPA requires the use of distributed volume pairs (see Sectionl4.4) for monitoring to insure high quality
data. However, in situations where acceptable data have been routinely obtained through use of distributed
volume pairs and the ambient air is considered well characterized, cost considerations may warrant single tube
sampling. Any attendant risk to data quality objectives is the responsibility of the project's decision maker.]
II / ,.-•: :« w ' y ':• !'.' . " ' '"- r "'1'
2.4 Key steps in sample analysis are listed below.
""2.4.1 Dry purge of the sorbent tube with dry, inert gas before analysis to remove water vapor and air. The
sorbeut tube can be held at temperatures above ambient for the dry purge.
2.4.2 Thermal desorption of the sorbent tube (primary desorption).
2.43 Analyte refocusing on a secondary trap.
2.4.4 Rapid desorption of the trap and injection/transfer of target analytes into the gas chromatograph
(secondary desorption).
*-2.4.5 Separation of compounds by high resolution capillary gas chromatography (GC).
2.4.6 Measurement by mass spectrometry (MS) or conventional GC detectors (only the MS approach is
explicitly referred to in Compendium Method TO-17; an F1D/ECD detector combination or other GC detector
can be used if Section 14 criteria are met. However, no explicit QA guidelines are given here for those
alternatives). ~ "~ ' ' " " ' ~
Page 17-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-17
2 J The target compound list (TCL) is the same as listed in Compendium Method TO-15 (i.e., subsets of the 97
VOCs listed as hazardous pollutants in Title in of the Clean Air Act Amendments of 1990). Only a portion of
these compounds has been monitored by the use of solid adsorbents. This method provides performance criteria
to demonstrate acceptable performance of the method (or modifications of the method) for monitoring a given
compound or set of compounds.
3. Significance
3.1 This method is an alternative to the canister-based sampling and analysis methods that are presented in
Compendium Methods TO-14 and TO-15 and to the previous sorbent-based methods that were formalized as
Compendium Methods TO-1 and TO-2. AE of these methods are of the type that include sampling at one
location, storage and transport of the sample, and analysis at another, typically more favorable site.
3.2 The collection of VOCs in ambient air samples by passage through solid sorbent packings is generally
recognized to have a number of advantages for monitoring. These include the following:
* The small size and light weight of the sorbent packing and attendant equipment.
• The placement of the sorbent packing as the first element (with the possible exception of a filter or
chemical scrubber for ozone) in the sampling train so as to reduce the possibility of contamination from
upstream elements.
* The availability of a large selection of sorbents to match the target set of compounds including polar
VOC.
• The commercial availability of thermal desorption systems to release the sample from the sorbent and
into the analytical system.
* The possibility of water management using a combination of hydrophobia sorbents (to cause water
breakthrough while sampling); dry gas purge of water from the sorbent after sampling; and splitting of
the sample during analysis.
* The large amount of literature on the use of sorbent sampling and thermal desorption for monitoring of
workplace air, particularly the literature from the Health and Safety Executive in the United Kingdom.
3.3 Accurate risk assessment of human and ecological exposure to toxic VOCs is an important goal of the U.
S. Environmental Protection Agency (EPA) with increased emphasis on their role as endocrine disrupters.
Accurate data is fundamental to reaching this goal. The portability and small size of typical sampling packages
for sorbent-based sampling and the wide range of sorbent choices make this monitoring approach appealing for
special monitoring studies of human exposure to toxic gases and to use in network monitoring to establish
prevalence and trends of toxic gases. Mieroenvironmental and human subject studies are typical of applications
for Compendium Method TO-17.
3.4 Sorbent-based monitoring can be combined with canister-based monitoring methods, on-site autoGC
systems, open path instrumentation, and other specialized point monitoring instruments to address most
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-3
-------
Method TO-17 ; ; ; VOCs
monitoring needs for volatile organic gases. More than one of these approaches can be used simultaneously as
a means to check and insure the quality of the data being produced.
3,5 In the form specified ia Compendium Method TO-17, sorbent sampling incorporates the distributed volume
pair approach that provides inherently defensible data to counter questions of sample integrity, operator
performance, equipment malfunction during sampling, and any other characteristic of sample collection that is
not linear with sampling volume.
3.6 In keeping with the consensus of EPA scientists and science advisors, the method is performance-based such
that performance criteria are provided. Any modification of the sorbent approach to monitoring for VOCs can
be used provided these criteria are met
4, Applicable Documents
4.1 ASTM Standards
• Method D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis
• Method E260 Recommended Practice for General Gas Chromatography
** Method E355 Practice for Gas Chromatography Terms and Relationships
•I I I" III ll II illlllil , • :', , >' : ,1 . • • ; , . „„
4.2 EPA Documents* J i
« Technical Assistance Document for Sampling and Analysis Toxic Organic Compounds in Ambient Air,
U. S. Environmental Protection Agency, EPA-600/4-83-027, June 1983.
• Quality Assurance Handbook for Air Pollution Measurement Systems, U. S. Environmental Protection
- Agency, EPA-€00/R-94-038b, May 1994.
« Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Methods
TO-1 and TO-2, U. S. Environmental Protection Agency, EPA 600/4-84-041, April 1984.
ys. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-14, Second Supplement, U. S. Environmental Protection Agency, EPA 600/4-89-018, March 1989.
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-15, U. S. Environmental Protection Agency, EPA 625/R-96-010b, January 1997.
4.3 Other Documents
• MDHS 3 - Generation of Test Atmospheres of Organic Vapors by the Syringe Injection Technique,
Methods for the Determination of Hazardous Substances (MDHS), Health and Safety
Laboratory, Health and Safety Executive, Sheffield, UK.
» MDHS 4 - Generation of Test Atmospheres of Organic Vapors by me Permeation Tube Method,
Methods for the Determination of Hazardous Substances (MDHS), Health and Safety
Laboratory, Health and Safety Executive, Sheffield, UK.
;„• MDHS 72 - Volatile Organic Compounds in Air, Methods for the Determination of Hazardous
* ~ Substances (MDHS), Health and Safety Laboratory, Health and Safety Executive,
Sheffield, UK.
" . • • • mr m * f
Page 17-4 Compendium of Methods for Toxic Organic Air Pottutants January 1999
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VOCs Method TO-17
• TAD - Technical Assistance Document (TAD) on the Use of Solid Sorbent-based Systems for
Ambient Air Monitoring, Perkin Elmer Corp., 50 Danbury Rd., Wilton, CT 06897,
USA.
5. Definitions
Definitions used in this document and any user-prepared Standard Operating Procedures (SOPs) should
be consistent with those used in ASTMD1356. All abbreviations and symbols are defined within this document
at the point of first use.]
5.1 Thermal Desorption-the use of heat and a flow of inert (carrier) gas to extract volatiles from a solid or
liquid matrix directly into the carrier gas and transfer them to downstream system elements such as the analytical
column of a GC. No solvent is required,
5.2 Two-stage Thermal Desorption-the process of thermally desorbing analytes from a solid or liquid matrix,
reconcentrating them on a focusing tube and then rapidly heating the tube to "inject" the concentrated compounds
into the GC system in a narrow band of vapor compatible with high resolution capOIary gas chromatography.
53 Sorbent Tube (Also referred to as 'tube* and 'sample tube')-stainless steel, glass or glass lined (or fused
silica lined) stainless steel tube, typically 1/4 inch (6 mm) O.D. and of various lengths, with the central portion
packed with greater than 200 mg of solid adsorbent material, depending on density and packing bed length. Used
to concentrate VOCs from air.
5.4 Focusing Tube-narrow (typically <3mm I.D.) tube containing a small bed of sorbent, which is maintained
near or below ambient temperature and used to refocus analytes thermally desorbed from the sorbent tube. Once
all the VOCs have been transferred from the sorbent tube to the focusing tube, the focusing tube is heated very
rapidly to transfer the analytes into the capillary GC analytical column in a narrow band of vapor.
5.5 Cryogen (Also referred to as * cryogenic fluid')-typically liquid nitrogen, liquid argon, or liquid carbon
dioxide. In the present context, eryogens are used in some thermal desorption systems to cool the focusing tube.
5.6 High Resolution Capillary Column Chromatography-eonventionally describes fused silica capillary
columns with an internal diameter of 320 gm or below and with a stationary phase film thickness of 5 um or less.
5.7 Breakthrough Volume (BV)- volume of air containing a constant concentration of anaiyte which may be
passed through a sorbent tube before a detectable level (typically 5%) of the anaiyte concentration elutes from
the nonsampling end. Alternatively, the volume sampled when the amount of anaiyte collected in a back-up
sorbent tube reaches a certain percentage (typically 5%) of the total amount collected by both sorbent tubes.
These methods do not give identical results. For purposes in the document the former definition will be used.
5.8 Retention Volume (RV)-the volume of carrier gas required to move an anaiyte vapor plug through the short
packed column which is the sorbent tube. The volume is determined by measuring the carrier gas volume
necessary to elute die vapor plug through the tube, normally measured at the peak response as the plug exits the
tube. The retention volume of methane is subtracted to account for dead volume in the tube.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-5
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Method TO-17 ' VOCs
5.9__Safe Sampling Volume (SSV)-usually calculated by halving the retention volume (indirect method) or
taking two-thirds of the breakthrough volume (direct method), although these two approaches do not necessarily
give identical results. The latter definition is used in this document
' , •; '," ; ' ; .;:' ; - ,, ,! ;. • „
5.10 Sorbent Strength—term used to describe the affinity of sorbents for VOC analytes. A stronger sorbent
is ooe which offers greater safe sampling volumes for most/all VOC analytes relative to another, weaker sorbent.
Generally speaking, sorbent strength is related to surface area, though there are exceptions to this. The SSVs of
most, if not all, VOCs will be greater on a sorbent with surface area " 1 On" than on one with a surface area of "n".
As a general rule, sorbents are described as "weak" if their surface area is less than 50 m2g"! (includes Tenax®,
Carbopack™/trap C, and Anasorb® GCB2), "medium strength" if the surface area is in the range 100-500 m2g"'
(includes Carbopack™/trap B, Anasorb® GCBI and all the Porapaks and Chromosorbs listed in Tables I and
2) and "strong" if the surface area is around 1000 nrg"1 (includes Spherocarb®, Carbosieve™ S-in, Carboxen™
1000, and Anasorb® CMS series sorbents.)
5.11 Total Ion Chromatogram (TIQ-chromatogram produced from a mass spectrometer detector operating
in full scan mode.
«•».« ••••'(' i pi tig : - v , .'- j ; • - - • ' V • : • • i
ma "- - '* % • , ' a
5,12 MS-SCAN-mode of operation of a GC mass spectrometer detector such that all mass ions over a given
mass range are swept over a given period of time.
5.13 MS -SIM-mode of operation, of a GC mass spectrometer detector such that only a single mass ion or a
selected number of discrete mass ions are monitored.
mv , • .-* - imm p,,., - ,:J -.»*,>-,
5.14 Standard Sorbent (Sample) Tube-stainless steel, glass or glass lined (or fused silica lined) stainless steel
tube, 1/4 inch (6 mm) O.D. and of various lengths, with the central portion packed with 2200 mg of solid
adsorbent material depending on sorbent density. Tubes should be individually numbered and show the direction
of flow.
m-v" : .. f« m • 5 ••: ..:_.' . .: , . , ., ;;,; |,, . ;
5.15 Time Weighted Average (TWA) Monitoring-if air is sampled over a fixed time period - typically 1,3,
8 or 24 hours, the time weighted average atmospheric concentration over the monitoring period may be calculated
from the total mass of analyte retained and the specific air volume sampled. Constraints on breakthrough
volumes make certain combinations of sampling time and flow rates mutually exclusive.
6. Overview of Methodology
[Note: The following is intended to provide a simple and straightforward method description including the
example of a specific sampling problem. Although specific equipment is listed, the document is intended only
asjsn example and equipment mentioned in the text is usually onfy one of a number of equally suitable
components that can be used. Hence trade names are not meant to impfy exclusive endorsement for sampling
and analysis using solid sorbents. Later sections in the text give guidance as to what considerations should be
made far a number of VOC monitoring applications.]
Page 17-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-17
6.1 Selection of Tube and Sorbent
6.1.1 Select a tube and sorbent packing for the sampling application using guidance from Tables 1 and 2 on
sorbent characteristics as well as guidance from Appendix 1 and Table 3 on safe sampling volumes and
breakthrough characteristics of sorbents.
6,1.2 As an example, assume the TCL includes a subset of the compounds shown in Table 3. In this case,
the multisorbent tube chosen consists of two sorbents packed in a 1/4 inch O.D., 3.5" long glass tube in the
following order and amounts: 160 mg of Carbopack™ graphitized carbon black (60/80 mesh) and 70 mg of
Carboxen™-1000 type carbon molecular sieve (60/80 mesh). This is an example of Tube Style 2 discussed
Section 9.1.3.2.
6.1.3 Pack the tube with the adsorbent by using the guidance provided in Section 10.1 or buy a prepacked
tube from a supplier. In the example, tubes were purchased from Supelco Inc., Supelco Park, Bellefonte, PA
16823-0048.
6.2 Conditioning the Tube
6.2.1 Condition newly packed tubes for at least 2 hours (30 mins for preconditioned, purchased tubes) at
350°C while passing at least 50 mL/min of pure helium carrier gas through them.
@M&: Other sorbents may require different conditioning temperatures - see Table 2 for guidance.]
Once conditioned, seal the tube with brass, 1/4 inch Swagelok* -type fittings and PTFE ferrules. Wrap the
sealed tubes in uncoated aluminum foil and place the tubes in a clean, airtight, opaque container.
6.2.2 A package of clean sorbent material, e.g. activated charcoal or activated charcoal/silica gel mixture,
may be added to the container to ensure clean storage conditions.
6.2.3 Store in a refrigerator (organic solvent-free) at 4°C if not to be used within a day. On second and
subsequent uses, the tubes will generally not require further conditioning as above. However, tubes with an
immediate prior use indicating high levels of pollutant trace gases should be reconditioned prior to continued
usage.
6.3 Sampling Apparatus
6.3,1 Select a sampling apparatus with accommodations for two sampling tubes capable of independent
control of sampling rate at a settable value in the range 10 to 200 mL/min. Laboratory and field blanks must also
be included in the monitoring exercise.
633, Backup tabes may be required to determine the cause of any problem if performance criteria, outlined
in Section 14, are not met
6.4 Sampling Rates
6.4.1 Select sampling rates compatible with the collection of 1 and 4 liter total sample volume (or of
proportionally lower/higher sampling volumes).
6.4.2 Air samples are collected over 1 hour with a sampling rate of 16.7 mL/min and 66.7 mL/min,
respectively.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-7
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Method TO-17 VOCs
6.5 Preparing for Sample Collection
6JS.1 At the monitoring location, keep the tubes in their storage and transportation container to equilibrate
T with ambient temperature.
6.5.2 Using clean gloves, remove the sample tubes from the container, take off their caps and attach them
to the sampling lines with non-outgassing flexible tubing. Uncap and immediately reseal the required number
g of field blank tubes.
S 6.5.3 Place ihe'field" blank tubes back in the storage container. If back-up tubes are being used, attach them
to the sampling tubes using clean, metal Swagelok® type unions and combined PTFE ferrules.
6.6 Set the Flow Rates
6.6.1 Set the flow rates of the pump using a mass flow monitor.
6.6.2 The sampling train includes, from front to back, an in-line particulate filter (optional), an ozone
scrubber (optional), a sampling tube, a back-up tube if any is being used, and a flow controller/pump
combination.
6.6.3 Place the mass flow monitor in line after the tube. Turn the pump on and wait for one minute.
•• Establish the approximate sampling flow rate using a dummy tube of identical construction and packing as the
sampling tube to be used. Record on Field Test Data Sheet (FTDS), as illustrated in Figure I.
6.6.4 Place the sampling tubes to be used on the sampling train and make final adjustments to the flow
controller as quickly as possible to avoid significant errors in the sample volume.
6.6.5 Adjust the flow rate of one tube to sample at 16.7 mL/min. Repeat the procedure for the second tube
and set the flow rate to 66.7 mL/min. Record on FTDS.
If lBii. .'.• 3U: >Wit *H •- '. «fv . ** ', >• ;, < '*••'•
6.7 Sample and Recheck Flow Rates *
6.7.1 Sample over the selected sampling period (i.e., 1-hour). Recheck all the sampling flow rates at the end
of the monitoring exercise just before switching off each pump and record on FTDS.
6.7.2 Make notes of aU relevant monitoring parameters including locations, tube identification numbers,
pump flo%v rates, dates, times, sampled volumes, ambient conditions etc. on FTDS.
6.8 Reseal the Tubes
•: •»! ? ..--.,--, ._.,..,!, ......
* • •» - • •••• • •> . - 11
> . ^6,8.1 Immediately remove the sampling tubes with clean gloves, recap the tubes with Swagelok® fittings
" using PTFE ferrules, rewrap the tubes with uncoated Al foil, and place the tubes in a clean, opaque, airtight
container. __^ ' •
6.8 2 If not to be analyzed during the same day, place the container in a clean, cool (<4SCJ, organic solvent-
free environment and leave there until time for analysis.
6.9 Selection of Thermal Desorptiou System
S.9,1 Select a thermal desorption system using the guidance provided in Section 8.
6.9.2 Place the thermal unit in a ready operational status.
Page 17-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-17
6.10 Dry Purge the Tubes and Prepare for Thermal Desorption
6.10.1 Remove the sampling tubes, any backup tubes being used, and blanks from the storage area and allow
the tubes to come to room temperature. Using clean gloves, remove the Swagelok®-type fittings and dry purge
the tubes with a forward (sampling direction) flow of, for example, 50 mL/min of dry helium for 4 minutes (see
Section 7.2 concerning dry purging).
/Mate-* Do not dry purge the laboratory blanks.]
6.10.2 Reseal the tubes with Teflon® (or other) caps compatible with the thermal desorber operation. Place
the sealed tubes on the thermal desorber (e.g., Perkin Elmer Model ATD 400 Automated System or equivalent).
Other thermal desorbers may have different arrangements for automation. Alternatively, use equivalent manual
desorption.
6.11 Check for System Integrity
6.11.1 Check the air tightness of the seals and the integrity of the flow path.
6.11.2 Guidance is provided in Section 11.2 of this document
6.12 Repurge of Tube on the Thermal Desorber/Addition of Internal Standard
6.12.1 Because of tube handling after dry purge, it may be necessary to repurge each of the tubes with pure,
dry helium (He) before analysis in order to eliminate any oxygea
6.12.2 If the initial dry purge can be performed on the thermal desorber so as to prevent any further exposure
of the sorbent to air, then this step is not necessary. Proceed with the addition of an internal standard to the
sorbent tube or the focusing tube.
6.13 Thermally Desorb the Packing
6.13.1 Reverse the flow direction of He gas, set the flow rate to at least 30 mL/min, and heat the tube to
325 °C (in this case) to achieve a transfer of VOCs onto a focusing tube at a temperature of27°C. Thermal
desorption continues until all target species are transferred to the focusing trap. The focusing trap is typically
packed with 20 mg of Carbopack™ B (60/80 mesh) and 50 rag of a Carboxen™ 1000-type sorbent (60/80
mesh).
6.14 Trap Desorption and GC/MS Analysis
6.14.1 After each tube is desorbed, rapidly heat the focusing trap (to 325 °C in this example) and apply a
reverse flow of at least 3 mL/min of pure helium carrier gas. Sample splitting is necessary to accommodate the
capillary column. Analytes are transferred to the column in a narrow band of vapor.
6.14.2 The GC run is initiated based on a time delay after the start of thermal desorption. The remaining
part of the analytical cycle is described in Section 3 of Compendium Method TO-15.
6.15 Restoring the Tubes and Determine Compliance with Performance Standards
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-9
-------
Method TO-17
VOCs
6.15.1 When tube analysis is completed, remove the tubes from the thermal desorber and, using clean gloves,
replace the Teflon1® caps with Swagelok fittings and PTFE ferrules, rewrap with aluminum foil, repiace in the
clean, airtight container, and re-store the tubes in a cool environment (<4°C) until the next use.
6.15.2 Using previously prepared identification and quantification subroutines, identify the target compounds
and document the amount of each measured compound (refer to the Section 3 of Compendium Method TO- 1 5).
Compare the results of analysis for the distributed volume pair taken during each sampling run and use the
comparison to determine whether or not the performance criteria for individual sampling events have been met.
Also examine thejesults ojfany laboratory blanks, field blanks, and any backup tube being used. Accept or reject
the data based on the performance criteria (see Section 14).
•r if*w.-2 m* '.ai -v,,.,, -,.r ,-,.,. .. ' ^ . ...
Ill- 1J>( -ii i-T IBB - ' -„ . . : i;~ ;' .**'''
2 * , f - ¥ |
6.16 Record and Store Data
6.16.1 Accurately retrieve field data (including the tube identification number) from the FTDS. The data
should include a sampling site identifier, time of sample initiation, duration of sampling., air pump identification,
flow rate, and other information as appropriate.
6.16 2. Store GC/MS data in a permanent form both in hard copy in a notebook and in digital form on a disk.
Also store the data sheet with the hard copy.
Sections 7 through 14 below elaborate on the method by providing important information and guidance
appropriate to explain the method as outlined in Section 6 and also to generalize the method for many
applications. Section 14 gives the performance criteria for the method.]
7. Jnterferences and Limitations
7.1 Interference from Sorbent Artifacts
-7.1.1 Minimizing; Artifact Interference.
ff -t taiJBtw map iJSE, , - ,_
7.1.1.1 Stringent tube conditioning (see Section 10.2.1) and careful tube capping and storage procedures
(see Section 10.2.2) are essential for minirnizing artifacts. System and sorbent tube conditioning must be carried
out using more stringent conditions of temperature, gas flow and time than those required for sample analysis.
7.1.1.2 A reasonable objective is to reduce artifacts to 10% or less of individual analyte masses
retained during sampling. A summary of VOC levels present in a range of different atmospheric environments
and the masses of individual components collected from 1,2 or 10 L samples of air in each case is presented in
Table 4.
— 7.1.1.3 Given that most ambient air monitoring is carried out in areas of poor air quality, for example in
urban, indoor and factory fenceline environments where VOC concentrations are typically above 1 ppb, Table 4
demonstrates that the mass of each analyte retained will, therefore, range from ~5 ng to —10 /^g in most
monitoring situations. Even when monitoring 'ultraclean' environments, analyte masses retained will usually
exceed 0. Ing (3).
I 7.1.1.4 Typical artifact levels for 1/4 inch O.D. tubes of 3.5" length range from 0.01 ng and 0.1 ng for
carbonaceous sorbents and Tenax® respectively. These levels compare well with the masses of analytes collected
- even from sub-ppb atmospheric concentrations (see Table 4), Artifact levels are around 10 ng for
Chromosorb® Centtny series and other porous polymer sorbents. However, these types of sorbents can still be
used for air monitoring at low ppb levels if selective or mass spectrometer detectors are used or if the blank
profile of the tube demonstrates that none of the sorbent artifacts interfere analytically with the compounds of
interest
Page 17-10
'•**•*'• • . »5 .- r *!»• s, ."<
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
T t
-------
VOCs _ Method TO-17
7.1.1.5 Some varieties of charcoal contain metals which will catalyze the degradation of some organic
analytes during thermal desorption at elevated temperatures thus producing artifacts and resulting in low analyte
recoveries.
7.1.2 Artifacts from Long-term Storage of Blank Tubes.
7.1.2.1 Literature reports of the levels of artifacts on (a) Carbotrap/pack™ C, Carbotrap/pack™ B and
Carbosieve™ SHI multi-bed tubes and (b) Tenax® GR tubes, by workers sealing the tubes using metal
SwagelokdMype caps and PTFE ferrules with multi-tube, glass storage jars are reported to be between 0.01 ng
[after 1-2 months (4)] and 0. 1 ag [after 6 months (5)] for (a) and (b) respectively.
7.1.2.2 Artifact levels reported for other porous polymers are higher - for example 5 ng for Chromosorb
106 after 1 week (5). More information is given in the Technical Assistance Document (TAD) referred to in
Section 4.3.
7.1.3 Artifacts Generated During Sampling and Sample Storage.
7.1.3.1 Benzaldehyde, phenol and acetophenone artifacts are reported to be formed via oxidation of the
polymer Tenax® when sampling high concentration (100-500 ppb) ozone atmospheres (6).
7.1.3.2 Tenax® should thus be used with an ozone scrubber when sampling low levels (<10 ppb) of these
analytes in areas with appreciable ozone concentrations. Carbotrap™/pack type sorbents have not been reported
to produce this level of artifact formation. Once retained on a sorbent tube, chemically stable VOCs, loaded in
laboratory conditions, have been shown to give good recoveries, even under high ozone concentrations for storage
of a year or more (7-9).
7.2 Minimizing Interference from Water
7.2.1 Selection of Hydrophobic Sorbents
7,2.1.1 There are three preferred approaches to reducing water interference during air monitoring using
sorbent tubes. The first is to minimize water collection by selecting, where possible, a hydrophobic sorbent for
the sample tube.
7.2.1.2 This is possible for compounds ranging in volatility from n-C5 (see SSVs listed in Appendix 1).
Tenax®, Carbotrap™ or one of the other hydrophobic sorbents listed in Table 2 should be used.
It is essential to ensure that the temperztture of the sorbent lube is the same and certainly not lower than
ambient temperature at the start of sampling or moisture will be retained via condensation, however
hydrophobic the sorbent. J
7.2.2 Sample Splitting
7.2.2.1 If the sample loading is high, it is usually possible to eliminate sufficient water to prevent analytical
interference by using sample splitting (10).
7.2.2.2 Sample may be split either (1) between the focusing trap and the capillary column (single splitting)
during trap (secondary) desorption or (2) between both the tube and the focusing trap during primary (tube)
desorption and between the focusing trap and the column during secondary (trap) desorption (see Section 8.2.3)
(double splitting). It may, in fact, be necessary to split the sample in some cases to prevent overloading the
analytical column or detector.
7.2.3 Dry Purge
73. 3.1 The third water management method is to "dry purge" either the sorbent tube itself or the focusing
trap or both (1 1-13). Dry purging the sample tube or focusing trap simply involves passing a volume of pure,
dry, inert gas through the tube from the sampling end, prior to analysis.
January 1999 Compendium, of Methods for Toxic Organic Air Pollutants Page 17-11
-------
Method TO-17 VQCs
^7.2,3.2 Theftibecaii be toted while dry purging at siightly elevated temperatures (11), A trap packing
combination and a near ambient trapping temperature must be chosenlsuch that target analytes are quantitatively
retained while water is purged to vent from either the tube or trap.
73 Atmospheric Pollutants not Suitable for Analysis by this Method
73.1 Inorganic gases not suitable for analysis by this method are oxides of carbon, nitrogen and sulfur, O3
and other permanent gases. Exceptions include CS2 and N2O.
7.3.2 Other pollutants not suitable are particulate pollutants, (i.e., fumes, aerosols and dusts) and compounds
too labile (reactive) for conventional GC analysis.
7.4 Detection Limits and Maximum Quantifiable Concentrations of Air Pollutants
7.4.1 Detection limits for atmospheric monitoring vary depending on several key factors. They are:
• Minimum artifact levels.
* GC detector selection.
2,, ypJumetojf_au:>sMpled. The volume of air sampled is to turn dependent upon a series of variables
*"' Including SSVs (see Section 10,8, Table 1 and Appendix 1), pump flow rate limitations and time-
weighted-average monitoring time constraints.
7.4.2 Generally speaking, detection limits range from sub-part-per-trillion (sub-ppt) for halogenated species
such as CCJ4 and the freons using an electron capture detector (ECD) to sub-ppb for volatile hydrocarbons in 1
L air samples using the GC/MS operated in the full SCAN mode.
7,4,3 Detection limits are greatly dependent upon the proper management of water for GC capillary analysis
of volatile organics in air using sorbeat technology (14).
7.5 Suitable Atmospheric Conditions
up, • r,^rr ,m ^ _. . i }
7.5.1 Temperature range.
7.5.1.1 The normal working range for sorbent packing is 0-40°C (8).
~: 7.5.1.2 In general, an increase in temperature of 10°C will reduce the breakthrough volume for sorbent
packings by a factor of 2.
7.5.2 Humidity.
IIP t »•• '* nt*^ ':*•• i c^» —• .'.'
~" 7.5.2.1 The capacity of the analytical instrumentation to accommodate the amount of water vapor
collected on tubes is usually die limitation in obtaining successful results, particularly for GC/MS applications.
This limitation can be extreme, requiring the use of a combination of water management procedures (see Section
7.2). ..-..-.--.-.. . .... ....
7.5.2.2 The safe sampling volumes of VOCs on hydrophobic adsorbents such as Tenax®, other porous
polymers, Carbotrap™ and Carfaopack™ are relatively unaffected by atmospheric humidity. Spherocarb® or
carbonized molecular sieve type sorbents such as Carbosieve™ SHI and the Carboxens® are affected by high
humidity, however, and SSVs should typically be reduced by a factor of 10 at 90-95% RH (8). Hydrophilic
zeolite molecular sieves cannot be used at all at high humidity.
{7.5.3* Wind speeds. ' - • -. .
Kl • :" ' ' '•:.!"!::. :i".. !"«0qi
H r 7.5.3.1 Air movement is not a factor indoors or outdoors at wind speeds below 10 miles per hour (<20
km per hour). , , ,_
Page 17-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
"I1 . 1*. "» ••< : - ,, ,
• • • '
-------
VOCs Method TO-17
7.5,3.2 Above this speed, tubes should be orientated perpendicular to the prevailing wind direction and
should be sheltered from the direct draft if wind speeds exceed 20 miles per hour (30-40 km per hour) (see
Section 10.5). -
7.5.4 High concentrations of particulates.
7.5,4.1 It may be necessary to connect a particulate filter (e.g., a 2 micron Teflon® filter or short clean
tube containing a loose plug of clean glass wool) to the sampling end of the tube in areas of extremely high
particulate concentrations.
7.5.4.2 Some compounds of interest may, however, be trapped on the Teflon® or on the glass wool.
Particulates trapped on the sorbent tube have the potential to act as a source or sink for volatiles, and may remain
on the tube through several cycles of sampling and desorption. Frequent replacement of the particulate filter is
therefore recommended.
8. Apparatus Selection and Preparation
8.1 Sample Collection
8.1.1 Selection of Tube Dimensions and Materials.
8.1.1.1 The most extensively used sorbent tubes are 1/4 inch O.D, stainless steel or 6 mm O.D. stainless
steel or glass. Different suppliers provide different size tubes and packing lengths; however, 3.5 inch long tubes
with a 6 cm sorbent bed and 1/4 inch O.D. stainless steel (see Figure 2) were used to generate the SSV
information presented in Appendix 1.
8.1.1.2 As an approximate measure, for sorbents contained in equal diameter tubes the breakthrough
volume is proportional to the bed-length (weight) of sorbenL Therefore, doubling the bed-length would
approximately double the SSV (15).
8.1,1.3 Stainless steel (304 or "GC" grade) is the most robust of the commonly available tube materials
which include, in addition, glass, glass-lined, and fused silica lined tubing. Tube material must be chosen to be
compatible with the specifics of storage and transport of the samples. For example, careful attention to packaging
is required for glass tubes.
8.1.2 Tube Labeling.
8.1.2.1 Label sample tubes with a unique identification number and the direction of sampling flow.
Stainless steel tubes are most conveniently labeled by engraving. Glass tubes are best labeled using a temperature
resistant paint. If empty sample tubes are obtained without labels, it is important to label and condition them
before they are packed with adsorbent.
8.1.2.2 Recondition prepacked, unlabeled tubes after the tube labeling process and record the blank
chromatogram from each tube. Record in writing the details of the masses and/or bed lengths of sorbent(s)
contained in each tube, the maximum allowable temperature for that tube and the date each tube was packed or
repacked.
8.1.3 Blank and Sampled Tube Storage Apparatus.
8.13.1 Seal clean, blank sorbent tubes and sampled tubes using inert, Swagelok®-type fittings and PTFE
ferrules. Wrap capped tubes individually in uncoated aluminum foil. Use clean, scalable glass jars or metal cans
containing a small packet of activated charcoal or activated charcoal/silica gel for storage and transportation of
multiple tubes. Store the multi-tube storage container in a clean environment at 4°C.
8.13.2 Keep the sample tubes inside the storage container during transportation and only remove them
at the monitoring location after the tubes have reached ambient temperature. Store sampled tubes in a refrigerator
at 4°C inside the multi-tube container until ready for analysis.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-13
-------
Method TO-17 VOCs
: The atmosphere Inside the refrigerator must be clean and free of organic solvents. J
8.1.4 Selection of Sampling Pumps.
::; 8.1.4.1 The selected monitoring pump(s) should be capable of operating in the range 10 to 200 mL/min.
Label the pumps with a unique identlCcatron number and operate them according to manufacturer's guidelines.
8,1.4.2 Constant mass flow type pumps are ideal for air monitoring as they deliver a constant flow rate
for ajwjde range of tube impedances. They thus compensate for moderate impedance variations between the
sortotjubesja use. The pump should meet US criteria for intrinsic safety where applicable. Connect the pump
to the non-sampling end of the sample tube by means of flexible, nonoutgassing tubing.
8.1.5 Parallel Sampling onto Multiple Tubes with a Single Pump.
- 8.1.5.1 Select a sample collection system for collecting samples onto 2 tubes in parallel.
8.1.5.2 If a single pump is used for both tubes, ensure that the flow rates will be controlled at a constant
flow rate during sampling and that the two flow rates can be independently controlled and stabilized.
8.1 6 Apparatus for Calibrating the Pumped Air Flow.
8,1.6.1 Calibrate the pump with the type of sorbent tube to which it will be connected during the
monitoring exercise. ~Use the actual sampling tube to fine tune the sampling flow rate at the start of sample
collection.
^ 8.1.6.2^ Use a flow meter certified traceable to MIST standards.
8.1.7 Sorbent^Tufae Protection During Air Sample Collection.
8.1.7.1 Protect sorbent tubes from extreme weather conditions using shelters constructed of inert
materials. The shelter must not impede the ingress of ambient air.
_ 8.1.7.2 If the atmosphere under test contains significant levels of particulates - fume, dust or aerosol,
connect a Teflon® 2-micron filter or a (metal, glass, glass-lined or fused silica lined stainless) tube containing
a short plug of clean glass wool prior to the sampling end of the tube and using inert, Swagelok®-type fittings
anoPTFE ferrules for fitting connections.
• ' ! i,1 '"•!]!,, '",{1 " ' '.' , iji , i,
8.2 Apparatus
8.2.1 Essential Sample Protection Features of the Thermal Desorption Apparatus.
8.2.1.1 As thermal desorption is generally a one shot process, (i.e., once the sample is desorbed it cannot
readily be reinjected or retrieved), stringent sample protection measures and thorough preanalysis system checks
mujsffprm an integral part of the thermal desorption-GC procedure and should be systematically carried out
« 8.2.1.2 The sample integrity protection measures and preanalysis checks required include:
I* Sealed tuJaes.^SampIe tubes awaiting analysis on an automated desorption system must be completely
if I ;sededj3efore thermal desorption^ to prevent ingress of VOC contaminants from the laboratory air and
to prevent losses of weakly retained analytes from the tube.
« Inert andjieated .sample flow path. To eliminate condensation, adsorption and degradation of analytes
within the analytical system, the sample flow path of iromtal and automated thermal desorbers should
be uniformly heated (minimum temperature range 50° - 150° Q between the sample tube and the GC
— analytical column. The components of the sample flow path should also, as far as possible, be
Z , constructed of inert materials, i.e., deactivated fused silica, glass lined tubing, glass, quartz and PTFE.
* Tjibg leak testing. This activity must not jeopardize sample integrity.
_« |Leak tesjjng of the sample flow path. This activity must not jeopardize sample integrity.
* System purge. Stringent, near-ambient temperature carrier gas purge to remove oxygen.
• Analytical system. "Ready" status checks.
Page 17-14 Compendium of Metliods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-17
8.2.2 Thermal Desorption Apparatus.
8.22.1. Two-stage thermal desorption is used for the best high resolution capillary chromatography (ie.,
analytes desorbed from the sorfaent tube must be refocused before being rapidly transferred to the GC analytical
column). One type of analyte refocusing device which has been successfully used is a small sorbent trap (17).
One cryogen-free trap cooling option is to use a multistage Peltier electrical cooler (18,19).
8.2.2.2 Closed cycle coolers are also available for use. At its low temperature, the trap must provide
quantitative analyfce retention far target compounds as well as quantitative and rapid desorption of target analytes
as high boiling as n-C12. The peak widths produced must be compatible with high resolution capillary gas
chromatography.
8,2.2.3 Typical key components and operational stages of a two-stage desorption system are presented
in Figure 3(a) - (f) and a stepwise description of the thermal desorber operation is presented in Section 11.3.
8.2.3 Sample Splitting Apparatus.
8,2.3.1 Sample splitting is often required to reduce water vapor interference, for the analysis of relatively
high concentration (>10 ppb level) air samples, when large volume air samples are collected, or when sensitive
selective detectors are in use.
8.2.3.2 Sample splitting is one of the three key approaches to water management detailed in this method
(see Section 7,2). Moisture management by sample splitting is applicable to relatively high concentrations (210
ppb) or large volume air samples or to analyses employing extremely sensitive detectors - for example, using the
BCD for low levels of tetrachloroethylene. In these cases the masses of analytes retained by the sorbent tube
when monitoring such atmospheres is large enough to allow, or even require, the selection of a high split ratio
(>10:1) during analysis to avoid overloading the analytical column or detector. The mass of water retained by
the sorbent tube during sample collection may be sufficiently reduced by the split alone to eliminate the need for
further water management steps.
8.2.4 The Thermal Desorber - GC Interface.
8.2.4.1 Heat the interface between the thermal desorber and the GC uniformly. Ensure that the interface
line is leak tight and lined with an inert material such as deactivated fused silica.
8,2.4.2 Alternatively, thread the capillary column itself through the heated transfer line/interface and
connected directly into the thermal desorber.
[Note: Use of a metal syringe-type needle or unheated length ofjused silica pushed through the septum of a
conventional GC injector is not recommended as a means of interfacing the thermal desorber to the
chromatograph. Such connections result in cold spots, cause band broadening and are prone to leaks.}
8.2.5 GC/MS Analytical Components. This method uses the GC/MS description as given in Compendium
Method TO-15, Section 7.
8.3 Tube Conditioning Apparatus
8.3.1 Tube Conditioning Mode
83.1.1 Condition freshly packed tubes using the analytical thermal desorption apparatus if it supports
a dedicated 'tube conditioning mode' (i.e., a mode in which effluent from highly contaminated tubes is directed
to vent without passing through key parts of the sample flow path such as the focusing trap).
8.3.2 Stand Alone System
8.3.2.1 If such a tube conditioning mode is not available, use separate stand-alone tube conditioning
hardware.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-15
-------
Method TO-17 VOCs
SK •' ih milt ~ '• • •*•' '><•&••
!!» ":r" " ' '."••..„..;-„ .'Sri ,: J ' : '• ;! : "if*">H *;! vllf* •'• 3"--i • ' •'•••• . : ) .. .-".;a
8.3.2.2 The tube conditioning hardware must be leak-tight to prevent air ingress, allow precise and
reproducible temperature selection (±5°C), offer a temperature range at least as great as that of the thermal
desorber and support inert gas flows in the range of 50 to 100 mL/min.
[Note: Whether conditioning is carried out using a special mode on the thermal desorber or using separate
hardwire, pass effluent gases fivm freshly packed or highfy contaminated tubes through a charcoal filter during
the process to prevent desorbed VOCs polluting the laboratory atmosphere.]
9. Reagents and Materials
*"'"'*"1" ;"air !i* - ' ' : '.'• ' i I . , f: ; • :j. , , i ,f
9.1 Sorbent Selection Guidelines
.9.1.1 Selection of Sprbent Mesh Size.
9.1.1.1 Sieved sorbents of particle size in the range 20 to 80 mesh should be used for tube packing.
». 9.1.1.2 Specific surface area of different sorbents is provided in Table 2.
*9.l4. Sorbent Strength and Safe Sampling Volumes.
9.1.2.1 Many well-validated pumped and diffusive sorbent tube sampling/thermal desorption methods
havejbeea published at the relatively high atmospheric concentrations (i.e., mid-ppb to ppm) typical of workplace
air and industrial/mobile source emissions (8,20-30).
. .9.1.2.2 Thesejnethods show that SSVs are unaffected by analyte concentrations far in excess of the 25
ppb"upp*er limit of this method. The effect of humidity on SSVs is discussed in Section 7.5 and Table 2.
9.1.2.3" Select a sorbent or series of sorbents of suitable strength for the analytes in question from the
information given in Tables 1 and 2 and Appendices 1 and 2. Where a number of different sorbents fulfill the
basic safe sampling volume criteria for the analytes in question, choose that (or those) which are hydrophobic
and least susceptible to artifact formation. Keep the fleld sampling volumes to 80% or less of the SSV of the
least well-retained analyte. Using one of the two procedures given in Section 10.8, check the safe sampling
volumes for the most volatile analytes of interest on an annual basis or once every twenty uses of the sorbent
tubes whichever occurs first
9.1.3 Three General-Purpose 1/4 Inch or 6 mm O.D. Multi-Bed Tube Types.
[Note: The three general-purpose lubes presented in this section are packed with sorbents in the mesh size
range of 20-80 mesh. The difference in internal diameter between standard glass and stainless steel tubes will
result in different bed volumes (weights) for the same bed length.]
9.13.1 Tube Style 1 consists of 30 mm Tenax®GRpIus 25 mm of Carbopack™ B separated by 3 mm
of unsUanized, preconditioned glass or quartz wool. Suitable for compounds ranging in volatility from n-Cs to
n-C20 for air volumes of 2 L at any humidity. Air volumes may be extended to 5 L or more for compounds
ranging in volatility from n-C;.
I" 9.1.3.2 Tube Style 2 consists of 35 mm Carbopack™ B plus 10 mm of Carbosieve™ Sffl or Carboxen™
1000 separated by glass/quartz wool as above. Suitable for compounds ranging in volatility from n-C3 to n-C12
(such as "Compendium Method TO-14 air toxics") for air volumes of 2 L at relative humidities below 65% and
temperatures below 30 °C. At humidities above 65% and ambient temperatures above 30 °C, ah- volumes should
be reduced to 0.5 L. Air volumes may be extended to 5 L or more for species ranging in volatility from n-C4.
A dry purge procedure or a large split ratio must be used during analysis when humid air has been sampled on
these tubes.
Page 17-16 Compendium of Methods for Toxic Organic Air Pottutants January 1999
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VOCs Method TO-17
9.1,3.3 Tube Style 3 consists of 13 mm Carbopack™ C, 25 mm Carbopack™ B plus 13 mm of
Carbosieve™ SM or Carboxen™ 1000 all separated by 3 mm plugs of glass/quartz wool as above. Suitable for
compounds ranging in volatility from n-Q to n-C16 for air volumes of 2 L at relative humidities below 65 percent
and temperatures below 30°C. At humidities above 65 percent and ambient temperatures above 30°C, air
volumes should be reduced to 0,5 L. Air volumes may be extended to 5 L or more for compounds ranging in
volatility from n-C4. A dry purge procedure or a large split ratio must be used during analysis when humid air
has been sampled on these tubes.
[Note: These multi-bed tubes are commercially available prepacked and preconditioned if required.}
[Hole.: These general purpose multi-bed tubes are onfy recommended for monitoring unknown atmospheres
or wide volatility range sets of target anafytes. Most routine monitoring of industrial air (for example at factory
fencelfnes) onfy involves monitoring a few specific target anafytes such as benzene, toluene, ethylbenzene, and
xylenes (BTEX), carbon disulfide (CSJ or 1,1,1-trichloroethane. Single-bed sorbent tubes selected from the
options listed in Appendix 1 are typically used in these cases.]
[Note: In the interests of minimizing water retention it is advisable to stick to hydrophobic (i.e., weak and
medium strength) sorbents whenever possible; this generally is the case when components more volatile than
n-Cs are not of interest.]
9.2 Gas Phase Standards
9.2.1 Standard Atmospheres.
9.2.1.1 Standard atmospheres must be stable at ambient pressure and accurate (±10%). Analyte
concentrations and humidities should be similar to those in the typical test atmosphere. Standard atmospheres
must be sampled onto conditioned sorbent tubes using the same pump flow rates as used for field sample
collection.
9.2.1.2 If a suitable standard atmosphere is obtained commercially, manufacturer's recommendations
concerning storage conditions and product lifetime should be rigidly observed.
9.2.2 Concentrated, Pressurized Gas Phase Standards.
922.1 Use accurate (± 5%), concentrated gas phase standards in pressurized cylinders such that a 0.5 -
5.0 mL gas sampling volume (GSV) loop contains approximately the same masses of analytes as will be collected
from a typical air sample. Introduce the standard onto the sampling end of conditioned sorbent tubes using at
least ten times the loop volume of pure helium carrier gas to completely sweep the standard from the GSV.
9.2,2.2 Manufacturer's guidelines concerning storage conditions and expected lifetime of the concentrated
gas phase standard should be rigidly observed.
9.3 Liquid Standards
9.3.1 Solvent Selection.
9.3.1.1 If liquid standards are to be loaded onto sorbent tubes for calibration purposes, select a solvent
for the standard that is pure (contaminants <10% of minimum analyte levels) and that, if possible, is considerably
more volatile than the target analytes. This then allows the solvent to be purged and eliminated from the tube
during the standard preparation process.
9.3.1.2 Methanol most commonly fills these criteria. If the target analyte range includes very volatile
components, it will not be possible to do this. In these cases, select a pure solvent which is readily
chromatographicauy resolved from the peaks/components of interest (ethyl acetate is commonly used) or use a
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-17
-------
Method TO-17 _ - : - _ • _ VOCs
fe, ,s! " „,. "--'• *• i *, • ; fg 2 3% v* •=; , i r fe .. - f
gas phase standard Test the purity of the solvent by comparing an analysis of the prepared standard with an
analysis of pure solvent under identical chromatographic conditions.
9.3.2 Liquid Standard Concentrations.
i 9j5_2j[ Liquid standards should be prepared so that the range of analyte masses introduced onto the tubes
is in the same order as the range of masses expected to be collected during sampling.
* 93.2 J Concentrations of benzene in urban air may be expected to range from 0.5-25 ppb. Thus if 5 L
air samples were to be collected at approximately 25 °C, the masses of benzene collected would range from
around 8 ng (0.5 ppb level) to around 400 ng (25 ppb level).
"Hie above calculation was derived from Style 's law ft.e., 1 mole of gas occupies around 25Lat25°C
and 760 mm Hg).
* 25 L of pure benzene vapor contains 78 g benzene
• 5 L of pure benzene vapor contains 15.6 g benzene
"• 5 L of a 1 ppm benzene atmosphere contains 15.6 ^ug benzene
s 5 L of a 100 ppb benzene atmosphere contains 1560 ng benzene
• 5 L of a 1 ppb benzene atmosphere contains 15. 6 ng benzene./
«! jj». •-:•.• i v. « ,. . » aim • - .-..,.. . , ,„ , t
£.3.3 Loading Liquid Standards onto Sorbent Tubes.
93.3.1 Introduce 0. 1 - 10 (jL aliquots of the liquid standards onto the sampling end of conditioned sorbent
tubes using a conventional 1/4 inch GC packed column injector and a 1, 5 or 10 /j.L syringe. The injector is
typically unheated with a 100 mJL/min flow of pure carrier gas. The solvent and analytes should completely
vaporize and pass onto the sorbent bed in the vapor phase. It may be necessary to heat the injector slightly
(typically to 50°C) for analytes less volatile than n-C,2 to ensure that all the liquid vaporizes.
tm 9 jjjj The sample tube should remain attached to the injector until die entire standard has been swept
from the injector and onto the sorbent bed. If it has been possible to prepare the liquid standard in a solvent
whkb. will pass through the sorbent while analytes are quantitatively retained (for example, methanol on Tenax®
or Carbopack™ B), the tube should not be disconnected from the injector until the solvent has been eliminated
fiomthe sorbent J>ed - this takes approximately 5 minutes under die conditions specified. Once the tube has been
disconnected from the injector, it should be capped and placed in an appropriate storage container immediately.
In cases where it is possible to purge the solvent from the tube while quantitativefy retaining the
anafytes, a 5-10 t made as this can usualfy be introduced more accurately than smaller
volumes. However, if the solvent, is to be retained in the tube, the injection volume should be as small as
possible (0.5 - LO/£) to minimize solvent interference in the subsequent chromatogram.]
; 9.3.3.3 This method of introducing liquid standards onto sorbent tubes via a GC injector is considered
thejpptimum approach to liquid standard introduction as components reach die sorbent bed in the vapor phase
(i.e., in a way which most closely parallels die normal air sample collection process). Alternatively, liquid
standards may be introduced directly onto the sorbent bed via the non-sampling end of the tube using a
conventional GC syringe.
This approach is convenient and works well in most cases, but it may not be used for multi-bed tubes
or for wide boiling range sets of anafytes and does not allow solvent to be purged to vent.]
Paige 17-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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VOCs Method TO-17
9.4 Gas Phase Internal Standards
9.4,1 The ideal internal standard components are:
• chemically similar to the target analytes
• extremely unlikely to occur naturally in the atmosphere under test
• readily resolved and distinguished analytically from the compounds of interest
• stable in the vapor phase at ambient temperature
• compatible with metal and glass surfaces under dry and humid conditions
* certified stable in a pressurized form for a long time period (i.e., up to 1 year).
9.4.2 Deuterated or fluorinated hydrocarbons usually meet all these criteria and make perfect internal
standards for MS based systems. Typical compounds include deuterated toluene, perfluorobenzene and
perfluorotoluene. Multiple internal standards should be used if the target analytes cover a very wide volatility
range or several different classes of compound.
9.4.3 Obtain a pressurized cylinder containing accurate (±5%) concentrations of the internal standard
components selected. Typically a 0.5 to 5.0 mL volume of this standard is automatically introduced onto the back
of the sorbent tube or focusing trap after the tube has passed preliminary leak tests and before it is thermally
desorbed. The concentration of the gas should be such that the mass of internal standard introduced from the
GSV loop is approximately equivalent to the mass of analytes which will be sampled onto the tube during sample
collection. For example, a 1 L air sample with average analytic concentrations in the order of 5 ppb, would require
a 10 ppm internal standard, if only 0.5 mL of the standard is introduced in each case.
9.5 Commercial, Preloaded Standard Tubes
9.5.1 Certified, preloaded commercial standard tubes are available and should be used for auditing purposes
wherever possible to establish analytical quality control (see Section 14), They may also be used for routine
calibratioa Suitable preloaded standards should be accurate within ±5% for each analyte at the microgram level
and ±10% at the nanogram level.
9.5,2 The following information should be supplied with each preloaded standard tube:
• A chromatogram of the blank .tube before the standard was loaded with associated analytical conditions
and date.
• Date of standard loading
* List of standard components, approximate masses and associated confidence levels
• Example analysis of an identical standard with associated analytical conditions (these should be the same
as for the blank tube)
• A brief description of the method used for standard preparation
• Expiration date
9.6 Carrier Gases
Inert, 99.999% or higher purity helium should be used as carrier gas. Oxygen and organic filters should be
installed on the carrier gas lines supplying the analytical system. These filters should be replaced regularly
according to the manufacturer's instructions.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-19
-------
Method TO47 _ * _ VOCs
It ' ' ""If . if! Si! • ' ' ' :!: ». -i Ijiji ii' "'ij1'11 '' ' : '• i'
mi, . iv ., ..out- »!» , • , ., . "i ,
10. Guidance on Sampling and Related Procedures
10.1 Packing Sorbent Tubes
1.0.1.1 Commercial Tubes
-: 10.1.1.1 Sorfaent tubes are commercially available either prepacked and preconditioned or empty.
10.1.1.2 When electing to purchase empty tubes and pack/condition them as required, careful attention
must be paid to the appropriate manufacturer's instructions.
10.1.2 Tube Parameters
j. ™~, ., -"? -4 ,.---s^a.»Tf- s . . iiiapg,- = t • , * ^y* '
10.1.2.1 Key parameters to consider include: "
* Sorhent bed positioning within the tube. The sampling surface of the sorbent bed is usually
positioned at least 15 mm from the sampling end of the tube to minimize sampling errors due to
- diffusive ingress. The position of the sorbent bed must also be entirely within that section of the tube
which is surrounded by the thermal desorpnon oven during tube desorption.
• gorbent bed length. The sorbent bed must not extend outside mat portion of the tube which is directly
^ heated by the thermal desorption oven.
• Sorbent mesh size. 20 to 80 mesh size sorbent is recommended to prevent excessive pressure drop
across the tube which may cause pump failure. It is always recommended that sorbents be sieved to
,*•. remove "fines" (undersized particles) before use.
« Use of appropriate sorbent bed retaining^ hardware inside the tube. Usually 100 mesh stainless
= sied gauzes and retaining springs are used in stainless steel tubes and unsilanized, preconditioned glass
or quartz wool in glass tubes.
~* Correct conditioning procedures. See Table 2 and Section 10.2.
JJ , Red separation. If a single tube is to be packed with two or three different sorbents, these must be kept
in discreet beds separated by "3 mm length plugs of unsilanized, preconditioned glass or quartz wool
or glass fiber disks and arranged in order of increasing sorbent strength from the sampling end of the
HI,, .tube. Do i not use sorbents i of widely different maximum temperatures in one tube or it will be difficult
~~ " to condition the more stable sorbents without exceeding the maximum recommended temperature of the
less stable sorbents.
flfate; Silanized glass or quartz wool may be used for labile species such as suljur or nitrogen containing
compounds but should not be taken to temperatures above 250 °C,J
^f bed. The sorbent bed must not be compressed while packing the tube. Compression
of the sorbentjan lead to excessive tube impedance and may produce "fines"
fr.':... ';.'•', M 3 "".-;. I; j -.f-'j il ; . ;Hv :; ;. . a.;^.-, •«& r^s .-.- u &,- ^ ."*.
10.1.2.2 Tubes packed with porous polymer sorbents (Chromosorbs®, Porapaks® and Tenax®) should
be repacked after 100 thermal cycles or if the performance criteria cannot be met. Tubes packed with
carbonaceous sorbents such as Spherocarb®, Carbotrap™, Carbopack™, Carbosieve™ SHI and Carboxens®
should be repacked every 200 thermal cycles or if the safe sampling volume validation procedure fails.
Page 17-20 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-17
10.2 Conditioning and Storage of Blank Sorbent Tubes
10.2.1 Sorbent Tube Conditioning.
10.2.1.1 The success of sorbent tube sampling for ppb and sub-ppb level air monitoring is largely
dependent on artifact levels being at significantly lower levels (<10%) than the masses of analytes collected
during air monitoring. A summary of recommended conditioning parameters for various individual sorbents and
multibed tubes is given in Table 2. 1/4 inch O.D. sorbent tubes may be adequately conditioned using elevated
temperatures and a flow of ultra-pure inert gas. Washing or any other preconditioning of the bulk sorbent is not
usually necessary. Appropriate, dedicated tube conditioning hardware should be used for tube conditioning unless
the thermal desorption system offers a separate tube conditioning mode.
10.2.1.2 The tube conditioning temperatures and gas flows recommended in Table 2 should be applied
for at least 2 hours when a tube is packed with fresh adsorbent or when its history is unknown.
Sorbent tabes which are:
• desorbed to completion during routine analysis (as is normally the case)
• stored correctly (see Section 10.2.2)
* re-issued for air sampling within 1 month (1 week for Chromosorb®, Tenax* and Porapak* porous
polymers)
« and are to be used for atmospheres with analytes at the 10 ppb level or above
do not usually requite any reconditioning at all before use. However, tubes to be used for monitoring at lower
levels should be both reconditioned for 10-15 minutes using the appropriate recommended conditioning
parameters and put through a "dummy" analysis using the appropriate analytical conditions to obtain blank
profiles of each tube before they are issued for sampling.
10.2.1.3 Analytical system conditioning procedures are supplied by system manufacturers. Generally
speaking, both system and sorbent tube conditioning processes must be carried out using more stringent
conditions of temperature, gas flow and time than those required for sample analysis - within the maximum
temperature constraints of all the materials and equipment involved.
10.2.2 Capping and Storage of Blank Tubes.
10.2.2.1 Blank tubes should be capped with ungreased, Swagelok®-type, metal screw-caps and combined
PTFE ferrules. The screw caps should be tightened by hand and then an extra 1/4 turn with a wrench. If uncoated
aluminum foil is required, tubes should be wrapped individually.
10.2.2.2 Batches of blank, sealed tubes should be stored and transported inside a suitable multi-tube
container.
10.3 Record Keeping Procedures for Sorbent Tubes
Sample tubes should be indelibly labeled with a unique identification number as described in Section 8.1.2.
Details of the masses and/or bed lengths of sorbent(s) contained in each tube, the maxinnim allowable
temperature for that tube and the date each tube was packed should be permanently recorded. A record should
also be made each time a tube is used and each time the safe sampling volume of that tube is retested so that
its history can be monitored. If a tube is repacked at any stage, the records should be amended accordingly.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-21
-------
Method TO-17 VOCs
10.4 Pump Calibration and Tube Connection
10.4.1 Tube Deployment
10.4.1.1 Once at ambient temperature, remove the tabes from the storage container, uncap and connect
them to the monitoring pumps as quickly as possible using clean, non-outgassing flexible tubing. Multi-bed
sorbent tubes must be orientated so that the air sample passes through the series of sorbents in order of increasing
sorbent strength (le., weaker sorbent first). This prevents contamination of the stronger adsorbent with less
volatile components."" ' ' " ' " ••••—.— .. -—. .. ...........
10.4.1.2 In all cases the sampling end of the tube must be clearly identified and recorded
_ 10.4.1.3 A typical sampling configuration for a distributed volume pair of sampling tabes is shown in
Figure 4.
10.4.2 Pump Calibration
l|, JOA2.1 Pumgs should be calibrated according to the manufacturer's instructions, preferably at the
monitoring location, immediately before sampling begins or, alternatively, in a clean environment before the tabes
and pumps are transported to the monitoring site. The apparatus required is described in Section 8.1.6. Details
of the jpump flow rate delivered with a given identified tube and the flow rate, stroke rate or pressure selected on
the pump Itself should be recorded together with the date.
10.4.2.2 The pump flow rate should be retested at the end of each sampling period to make sure that a
constant pump rate was maintained throughout the sample collection period. The flow rate measured at the end
of sampling should agree within 10% with that measured at the start of the sampling period for the sample to be
considered valid and the average value should be used.
10.5 Locating and Protecting the Sample Tube
The sampling points of individual sorbent tubes or sequential tube samplers should not be unduly influenced
by nearby emission sources unless the emission source itself is specifically being monitored. Common sense
generally determines the appropriate placement Field notes on the relative location of known emission sources
should be part of the permanent record and identified on the FIDS. Some shelter or protection from high
winds (see Section 8.1.7) other extreme weather conditions and high levels of particulates is required for the
sample tube if it is to be left unattended during the monitoring period.
10.6 Selection of Pump Flow Rates and Air Sample Volumes
10.6.1 Flow Rate Selection
10.6.1.1 For 1/4 inch O.D, tubes, 50 mL/min is the theoretical optimum flow rate (31). However,
negligible variation in retention volume will in fact be observed for pump flow rates varying from 5 to
200 mL/min. Pump flow rates above 10 mL/min are generally used in order to minimize errors due to ingress
of VjCXIsjrfadiffikioa Flow rates in excess of 200 mL/min are not recommended for standard 1/4-inch sample
tubes unless for short term (e.g. 10 minute) monitoring (21).
[Note: High sampling flow rates can be used longer term for high boiling materials such as low level, vapor
phase pofychlorinated biphenyls (PCBs) and pofycycUc aromatic hydrocarbons (PAHs) in air.]
_ . 10.6.1^jpne_and four Eter air sample volumes are recommended for this method if consistent with
anticipated safe sampling volumes. Adjustments of the flow rates to accommodate low safe sampling volumes
should be made by proportionally reducing both rates with the qualification that the lower flow rate result is no
less than 300 mL total volume. The 300 mL sample gives adequate detection limits (<0.5 ppb per analyte) with
Paige 17-22 " " Compendium of Metiiods far Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-17
full scan mass speetrometry detection for ambient air applications (see Table 4). Sensitivity is generally enhanced
at least ten-fold if conventional GC detectors or selected ion monitoring are applied. However; the pump flow
rate, sampling time and consequently air volume selected may be varied to suit the requirements of each
individual air monitoring exercise.
10.6.1.3 Typical example pump flow rates include:
• 16 mL/min to collect 1 L air samples in 1 hour
« 67 mL/min to collect 4 L air samples in 1 hour
• 10 mL/min to collect 1800 mL air samples over 3 hours
• 40 mL/min to collect 7200 mL air samples over 3 hours
10.6.2 Pump Flow Rate Selection
10.6.2.1 The pump flow rate used is dependent upon:
• Safe sampling volume constraints- The flow rate must be adjusted (within the allowed range) to
ensure that, for the chosen sample collection time, SSVs are not exceeded for any target analyte
• Time weighted average monitoring requfreinentg. If long-term - 3, 8 or even 24 hour - time
weighted average data are required, the pump flow rate must be adjusted to ensure SSVs are not
exceeded during the sample collection period.
• GC detection limits. Within the constraints of safe sampling volumes and pump flow rate limits, air
volumes selected for trace level (ambient) air monitoring, should be maximized such that the largest
possible analyte masses are collected.
10.63.3. Typical VOC concentrations and the associated analyte masses retained from a range of different
air sample volumes in various atmospheres are presented in Table 4.
10.7 Sampling Procedure Verification - Use of Blanks, Distributed Volume Pairs, Back-Up Tubes, and
Distributed Volume Sets
10.7.1 Field and Laboratory Blanks
10.7.1.1 Laboratory blanks must be identically packed tubes, from the same batch, with similar history
and conditioned at the same time as the tubes used for sample collection. At least two are required per monitoring
exercise. They must be stored in the laboratory in clean controlled conditions (<4°C) throughout the monitoring
program and analyzed at the same time as the samples— one at the beginning and one at the end of the sequence
of runs.
10.7.1.2 Field blanks are the same as laboratory blanks except that they are transported to and from the
monitoring site, are uncapped and immediately reseated at the monitoring site, but do not actually have air
pumped through them. One field blank tube is taken for every ten sampled tubes on a monitoring exercise and
no less than two field blanks should be collected, however small the monitoring study. The field blanks should
be distributed evenly throughout the set of sampled tubes to be analyzed. Guidance on acceptable performance
criteria for blanks is given in Section 13.
10.7.2 Distributed Volume Pairs
10.7.2.1 When monitoring for specific analytes using a validated sorbeut tube but in an uneharacterized
atmosphere, it is advisable to collect distributed volume tube pairs - e.g. 1 and 4 L samples - in parallel at every
monitoring location as described in Section 6. If single tube sampling is used to reduce analysis costs, a reduction
in the quality assurance associated with this method has to be assumed.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-23
-------
Method TO-17 _ VOCs
§*.", i:'-»»»i- .Mi .•..; !• " 11 '-1. • » • • «rf , '* 'I , • ' > : ,v, - .= »' • . i
10.7.2.2 Back-up tubes (identical to those used for sample collection) should be used to investigate
situations in which distributed volume pairs do not agree within acceptable tolerance. To use back-up tubes, a
second identical sampling tube is placed in series with a primary (front) tube. The purpose of the backup tube
is to capture compounds that pass through the primary tube because of breakthrough. Analysis of the backup
tube may indicate unexpected breakthrough or give evidence of channeling of sample through the tube because
of loose packing. ~~ ' —
=t 10.7.2.3 A significant volume of literature exists on the use of distributed volume sets to determine the
occurrence of nonlinearities when different sample volumes are taken from the same sample air mix. Ideally, the
quantity of material collected scales linearly with sample volume. If this is not the case, then one of a number
of problems has occurred. The 4-tube distributed volume developed by Walling, Bumgardner, and co-workers
(32,33) is a method by which sample collection problems can be investigated.
10.8 Determining and Validating Safe Sampling Volumes (SSV)
•1 -•••«:.•! "tm m ,.*.'•: . .. .,;,-, ^- • ,•• , sj :, o
10.8.1 Field Test Method for Tube Breakthrough.
Hi lb,8.fj[ If SSV information is not readily available for the analytes under test on the sorbent tube
selected, or if the safe sampling volumes need validating - the following field experiment may be used. Link at
leas! 12 of toe sorbent tubes under test together in series to give 6 pairs of tubes. Use inert, preferably
Swagelok-'Sl-type 1/4-inch metal unions with PTFE fittings. The sampling end of the back up tube should be
connected to the exit end of the front tube in each of the pairs. The tube pairs are then connected to calibrated
kf iii1"111 *W«*" ' ™ *» II il VtiMllllllllllllk iipi'innm » w ™ ....................
monitoring pumps ana used to simultaneously sample at least 3 different air volumes at pump flow rates between
10 and 200 mL/min with 2 replicates at each air sample volume.
10.8.1.2 The experiment should be carried out in the atmosphere to be monitored and, if possible, under
woSt
-------
VOCs Method TO-17
10.8.2.6 Inject a sample of methane to measure the delay time of the system and subtract this from the
analyte retention times determined.
10.8.2.7 Use the flow of nitrogen carrier gas and corrected retention times to calculate the analyte retention
volumes at different sorbent temperatures.
10.8.2.8 A graph of log,0 retention volume vs. l/temp(K) should produce a straight line plot which can
be readily extrapolated to ambient temperatures. Use this plot to obtain the retention volume.
A SSV for the analyte on that sorbent tube is then derived by halving the calculated retention volume at
ambient temperature. When required, this experiment should be carried out for the least well retained
compound(s) of interest.
10.9 Resealing Sorbent Tubes After Sample Collection
Sampled tabes should be recapped with the metal, Swagelok*-type caps and combined PTFE ferrules,
rewrapped in the aluminum foil (if appropriate) and replaced in the storage container immediately after
sampling. They should not be removed from the sampling container until they are in die laboratory and about
to be analyzed.
10.10 Sample Storage
Samples should be refrigerated at <4°C in a clean environment during storage and analyzed within 30 days
of sample collection (within one week for limonene, carene, Ms-cfaloromemyl ether and labile sulfur or
nitrogen-containing volatiles). Samples taken on tubes containing multiple sorbent beds should be analyzed
as soon as possible after sampling unless it is know in advance that storage will not cause significant sample
recovery errors (see also Section 7.1.3 concerning artifacts).
11. Analytical Procedure
11.1 Preparation for Sample Analysis
Follow the description given in Compendium Memod TO-15 for set up of me GC/MS analytical system
including column selection, MS tune requirements, calibration protocols, etc.
11.2 Predesorption System Checks and Procedures
The following sample and system integrity checks and procedures must be carried out manually or
automatically before thermal desorption:
« Pry purge. Dry purge die batch of sampled, back-up and field blank tubes (do not purge lab blanks).
* &}fi. Cap tubes with PTFE 'analytical' caps and place on instrument carousel.
» Leak test the tubes. Each tube must be stringently leak tested at the GC carrier gas pressure, without
heat or gas flow applied, before analysis. Tubes which fail the leak test should not be analyzed, but
should be reseated and stored intact. On automated systems, the instrument should continue to leak test
and analyze subsequent tubes after a given tube has failed. Automated systems should also store a
record of which tubes in a sequence have failed the leak test in battery-protected system memory until
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-25
-------
Method TO-17 _ VOCs
ff!'1 7!3f % '.&'.•;.-•* Mi ( j; ,;•.;•• • • &."~ $: t:fi> .•!>:>• !•;•- - --.- *
tbe error is acknowledged by an operator. These measures prevent sample losses and help ensure data
^ quality.
* Leak test the sample flow path . All parts of the sample flow path should be stringently leak tested
before each analysis without heat or gas flow applied to the sample tube. An automatic sequence of tube
~- desorptions and GC analyses should be halted if any leak is detected in the main sample flow path.
Iji" Purge air. Purge air from the tube and sample flow path at ambient temperature using carrier gas
immediately before tube desorption. It helps to dry the sample and prevents analyte and sorbent
~ ; oxidation thus minimizing artifact formation, ensuring data quality and extending tube lifetimes. The
5 focusing trap should be in-line throughout the carrier gas purge to retain any ultra-volatile analytes
— ."desojbed" from the tube prematurely.
• Check GC/MS analytical system ready status. The "ready" status of the GC, detector(s), data
processor and all parts of the analytical system should be automatically checked by the thermal
desorption device before each tube desorption. It should not be possible to desorb a tube into the
analytical system if it is not ready to accept and analyze samples.
'"•' TnternaTsfandard. Introduce a gas phase "internal standard onto the sorbent tube or focusing trap
before primary (tube) desorption, as an additional check of system integrity (optional).
A series of schematics illustrating these steps is presented in Figure 3, Steps (a) through (f).
113 Analytical Procedure
jjjl.3.1 Steps Required for Reliable Thermal Desorption.
ii3.1.f~A~stepwise summary of the complete thermal desorption procedure is as follows:
_• Predesorption system checks (see Section 11.2).
• Introduction of a fixed volume gas phase internal standard (optional) [see Figure 3, Step (d)].
H*. ^pesorption of the sorbent tube (typically 200-3QO°C for 5-15 minutes with a carrier gas flow of 30-100
mL/min - see Table 2) and refocusing of the target analytes on a focusing trap held at near- ambient or
_ subambient temperatures [see Figure 3, Step (e)].
.* Anatytes should be desorbedjrom the tube in 'backftush'mode, i.e., with the gas flow in the reverse
direction to thai of the airflow during sampling],
, * Splitting the sample as it is transferred from the tube to the focusing trap (Optional). This is only
required to prevent column or detector overload due to excess water accumulation or during the analysis
of high concentration/large volume air samples or when using ultra-sensitive detectors such as the BCD
[see Figure 3, Step (e)].
=i " Rapid desorption of the focusing trap (typically 40 deg/sec. to a top temperature of 250-350° C, with
a 3lpkr Jjmejrf 1-15 mins at the top temperature and an inert/carrier gas flow of 3-100 mL/min) and
mto the* analytical column [see Figure 3, Step (f)],
/M>££." Components should normally be desorbedjrom the focusing trap in 'backflush "mode, L e. , with the gas
flow through the 'cold' trap in the reverse direction to that used during anafyte focusing. J
"* Splitting the sample as VOCs are transferred from the focusing trap to the analytical column.
(Optional). This is only required to prevent column or detector overload due to excess water
II " ': • !: HI a V-'- £•• — * •;. 1. (•:.::.•.-. t?; 5 . ' S ..' r» ,,4 b ««. i.iij* t .iv n .o
Page 17-26 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs , Method TO-17
accumulation or during the analysis of high concentration/large volume air samples or when using
ultra-sensitive detectors such as die ECD [See Figure 3, Step (f)].
* Desorbing the focusing trap initiates the GC run. [See Figure 3, Step (f)].
• All volatiles should be stripped from the sorbent tubes during the thermal desorption process leaving
them clean and ready for reuse. The tubes should be resealed to ensure they are kept clean and ready
for immediate reuse while the sequence of tube desorptions and analyses is completed.
11.3,2 GC/MS Analytical Procedure
11.3.2.1 Once the GC run has been initiated by desorption of the focusing trap, the chromatographic
procedure continues as described in Compendium Method TO-15.
11323. The precision of the analytical system should be tested using six standard tubes all loaded with
a mid-concentration-range standard. This procedure should be carried out whenever the thermal desorption -
GC/MS analytical method is changed and should be repeated once every tenth series of samples run with an
analytical method or once every three months, whichever happens first The report produced from the most recent
precision test should be included with the final batch report generated for each series of samples.
12. Calibration of Response
Descriptions of how to load tubes from standard atmospheres, concentrated gas phase standards or liquid
standards are given in Sections 9.2 and 9.3. Once the tubes are desorbed to the focusing trap and into the
analytical GC/MS system the calibration procedure becomes identical to that presented in Section 3 of
Compendium Method TO-15. The guidance given in Section 3 of Compendium Method TO-15 concerning
multi-level calibration procedures and calibration frequencies should be followed for this Compendium method.
It is also advisable to analyze a single level calibrant (i.e. tubes loaded with analyte masses in the mid-range
of those expected to be collected during sampling) approximately every tenth sample during an analytical
sequence, as a check on system performance. All samples processed that exceed the calibration range will
require data qualifiers to be attached to the analytical results.
13. Quality Assurance
13.1 Validating the Sample Collection Procedure
13.1.1 Blanks.
13.1.1.1 Artifact levels on laboratory and field blanks should be at the low or sub-nanogram level for
carbonaceous sorbents and Tenax® and at the double digit ng level for Porapaks®, Chromosorb® Century series
sorbents and other porous polymers as described in Section 7.1. If artifact levels are considerably above this,
careful attention must be paid to the tube conditioning and storage procedures described in Sections 10.2.1 and
10.2.2. Artifact peaks which are 10% or more of the area of average component peaks should be marked as
artifacts in the final data reports. When monitoring unknown atmospheres, special care must be taken to
distinguish between sorbent artifacts and analytes, using the MS to identify components which are significant in
both blank and sampled tubes.
13.1.1.2 If the same profile/pattern of VOCs is observed on the field blanks as on the sampled tubes and
if the level of these components is 5% or more of the sampled volatiles, careful attention must be paid to the
method of sealing the tubes and other storage procedures in future studies. If the profile of volatiles on the field
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-27
-------
Method TO-17 _ : _ VOCs
blanks matches Jhat ofthe sampled tubes and if the areas of the peaks on the field blank are 10% or more of
sampled rube levels, the sampled tube date are invalidated,
13.1.2 Routine Checking of Sorbent Tube Safe Sampling Volumes.
13.12.1 The SSVs of sorbent tubes should be rctested annually or once every 20 uses (whichever happens
first) using one of the procedures described in Section 10.8.
~ 13.1.2 2 If the SSV of atube (i.e., half the RV or two thirds of the BV) falls below the normal air sample
collection yolumejbr the analvtes in question, the tube should be repacked with fresh adsorbent and
reconditionecL ** —• • •• -•• •- -•••• •-••-.-• • • •-,., ... «.^, ,.-,.. ^
•&.>•**. ,'i s; -%, ,, ; if. .. , ;
13.2 Performance Criteria for the Monitoring Pump
Records of the pump flow rate delivered against the pump flow rate, stroke rate or pressure selected on a
pump should be reviewed at least once per three months. If the performance of any pump has been found to
have changed significantly over that time; for example if completely different pump settings are required to
deliver the same pump flow rate, the pump should be serviced by the manufacturer or their approved agent.
t •£«J p IM PIP IP ^ ••• £• ^ I 11 or: .pjrik . f^]. ,;• , ,rf,, . ...... T|HHM ................................. ......... r
Sampling pump errors can normally be presumed to be in the order of 5% (8). If the pump sampling flow rate
measured at the end of sample collection varies more than 10% from that measured at the beginning of sample
collection, ffienlbat sample is invalidated.
. JLwm i ,« ... ,. • ^ ......
14. Performance Criteria for the Solid Adsorbent Sampling of Ambient Air
14.1 Introduction
There are four performance criteria which must be met for a system to qualify under Compendium Method
TO47. These criteria closely parallel those of Compendium Method TO- 15, The Determination of Volatile
Organic Compounds (VOCsJ in Air Collected in Specially Prepared Canisters and Analyzed by Gas
Oiromatography/Mass Spectrometry (GC/MS) ". These criteria are:
« A method detection Umit sO.5 ppb.
• Duplicate (analytical) precision within 20% on synthetic samples of a given target gas or vapor in a
typical target gas or vapor mix in humidified zero air.
* Agreement within 25% for distributed volume pairs of tubes taken in each sampling set.
• Audit accuracy within 30 percent for concentrations normally expected in contaminated ambient air (0.5
to 25 pptjj. Either mass spec&dmetry as ^emphasized here, or specific detectors can be used for
analysis. Details for the determination of each of the criteria follow,
14.2 Method Detection Limit
The procedure chosen to define the method detection limit is that given in the Code of Federal Regulations
(40CFR136 Appendix B). The method detection limit is defined for each system by making seven replicate
ojeasufements of a concentration of the compound of interest near the expected detection limit (within a factor
of five), computing the standard deviation for the seven replicate concentrations, and multiplying this value
by 3. 14 (the Student's t value for 99 percent confidence for seven values).
Page 17-28 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs , Method TO-17
14-3 Analytical Precision of Duplicate Pairs
The measure of. analytical precision used for this method is the absolute value of the relative difference
between two identical samples (same flow rate over the same time period from with a common inlet to the
sample volume). The analytical precision is expressed as a percentage as follows:
Analytical Precision = | 0X1 - X2|]|
I X J
where:
XI = A measurement value taken from one of the two tubes using in sampling.
X2 = A measurement value taken from the second of two tubes using hi sampling,
X = Average of XI and X2.
The analytical precision is a measure of the precision achievable for the entire sampling and analysts procedure
including the sampling and thermal desorption process mentioned above and the analytical procedure that is
same as the TO-15 analytical finish, although specific detector systems can also be used.
14.4 Precision for the Distributed Volume Pair
The measure of precision used for this method is the absolute value of the relative difference between the
distributed volume pair expressed as a percentage as follows:
percent difference = f P1 " X2!! | 100
( X J
where:
XI = One measurement value (e.g., for a defined sample volume of 1 L).
X2 = Duplicate measurement value (e.g., for a defined sample volume of 4 L taken over the same
time period as the first sample).
X = Average of the two values.
There are several factors that may affect the precision of the measurement as defined above. In fact any factor
that is nonlinear with sample volume may be significant enough to violate the constraint placed on distributed
volume pair precision. These factors include artifact formation, compound reactions on the sorbent,
breakthrough of target compounds, etc.
14.5 Audit Accuracy
A measure of audit accuracy is the degree of agreement with audit standards. Audit accuracy is defined as
the relative difference between the measurement result and the nominal concentration of the audit compound:
A ... A ~, [(Spiked Value - Observed Value)] ,nn
Audit Accuracy, % = — - x 100
y [ (Spiked Value) J
The choice of audit standard is left to the analyst.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-29
-------
Method TO-17 VOCs
Hi" -.'• ,•, • 1.1 >• • . , , , ,
15. References " ' " : " - ! "
1. Riggin, R. M., Compendium, of Methods for the Determination of Toxic Organic Compounds in Ambient
Air: Methods TO-1 and TO-2, U. S. Environmental Protection Agency, Research Triangle Park, NC
E27711, EPA 600/4-84-041, April 1984,
2. Winberry, W. T. Jr., et al., Compendium of Methods for the Determination of Toxic Organic Compounds
IJnAmbient Air: Method TO-14t Second Supplement, U. S. Environmental Protection Agency, Research
^Triangle Park, NC 27711, EPA 600/4-89-018, March 1989.
3. Schmidbauer, N., and Oehme, M., "Comparison of Solid Adsorbent and Stainless Steel Canister
Sampling for Very Low ppt-concenttations of Aromatic Compounds (J^Cg) in Ambient Air From Remote
Areas," Fresenius ZAnal Ghent., 331, pp 14-19, 1988.
•" - ' :-.W.*--. .^*.«,..»-M;,,.^«, ,„.,,, .. . ,, ,^,c ,,!„,, ....^ .„,;.,. ..,.,.
4. Ciccioli, P., Brancaleoni, E., Cecinato, A., Sparapim, R., and Frattoni, M., "Identification and
Determination of Biogenic and Anthropogenic VOCs In Forest Areas of Northern and Southern Europe
• and a Remote Site of ttteJBmalaya Region by High-resolution GC-MS," /. ofChrom., 643, pp 55-69,
"1993. " "~ " ' ' '" —' ••
5. Hafkenscheid, T., Peters, R., NMI, The Netherlands, Private Communications to E. Woolfenden of
Perkin Elmer Corp., Norwalk, Conn.
6. Ciccrof, P.TBrancaleoni^E., Cecinato,1 A., DiPalo, C, Brachetti, A., and Libern, A., "GC Evaluation
of the Organic Components Present In the Atmosphere at Trace Levels with the Aid of Carbopack™ B
for Preconcentration of the Sample," J.ofChrom., 351, pp 433-449, 1986.
7. MDHS 72 (Volatile Organic Compounds in Air), "Laboratory Method. Using Pumped Solid Sorbent
P Tjiibes? ThermMJDesorption and Gas Chromatography," Methods for the Determination of Hazardous
Suoitances (MDHS), UK Health and Safety Executive, Sheffield, UK.
,8. Vapdendriessche, S., and Griepink, B., "The Certification of Benzene, Toluene and m-Xylene Sorbed
:~: onTenax TA inTUbes," CRM-112 CEC, BCR, EUR12308EN, 1989.
9. Lindquist, F., and Balkeren, H., "Stability of Chlorinated Hydrocarbons on Tenax," CEC Commissioned
~ fteporf From TNO, The Netherlands, Rpt. No. R90/268, 1990.
10. Bianchi, A. P., and Varney, M. S., "Sampling and Analysis of VOCs in Estuarine Air by GC-MS," /.
ofChrom,, 643, pp 11-23, 1993.
11. Tipler, A., "Water Management in Capillary Gas Chromatbgraphic Air Monitoring Systems," in
IP; Proceedings of the Air and Waste Management Association Conference: Measurement of Toxic and
^Related Air Pollutants, Air and Waste Management Association, Pittsburgh, PA, May 1994.
Page 17-30 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-17
12. Helmig, D. and Vierling, L., "Water Adsorption Capacity of the Solid Adsorbents Tenax TA, Tenax
GR, Carbotrap, Carbotrap™ C, Carbosieve™ SHI and Carboxen™ 569 and Water Management
Techniques for the Atmospheric Sampling of Volatile Organic Trace Gases," Anal. Chem., Vol. 67, No
23, pp 4380-4386, 1995.
13, McClenny, W. A., Oliver, K. D. and Daughtrey, E, H., Jr. "Analysis of VOCs in Ambient Air Using
Multisorbent Packings for VOC Accumulation and Sample Drying," /. Air and Waste Management
Assoc,, Vol 45, pp 792-800, 1995.
14. Pankow, J. G., "Technique for Removing Water from Moist Headspace and Purge Gases Containing
Volatile Organic Compounds: Application in the Purge with Whole-column Cryotrapping (P/WCC)
Method," Environ. Sci. Technol., Vol 25, pp 123-126, 1991,
15. Harper, M., "Evaluation of Solid Sorbent Sampling Methods by Breakthrough Volume Studies," Ann.
Occup. Hyg., pp 65-88, 1993.
16. Pollack, A. J., Gordon, S. M., Moschandreas, D. J., McClenny, W. A., and Mulik, J. D., "Evaluation
of Portable Multisorbent Air Samplers for Use with an Automated Multitube Analyzer." Project Rpt by
Battelle Columbus Operations for U. S. Environmental Protection Agency, Contract No. 68-DO-0007,
Sept 1992.
17. Broadway, G. M., and Trewern, T., "Design Considerations for the Optimization of a Packed Thermal
Desorption Cold Trap for Capillary Gas Chromatography," Proc. 13th Int'l Symposium on Capil.
Chrom,, Baltimore, MD, pp 310-320, 1991.
18, Broadway, G. M., "An Automated System for use Without Liquid Cryogen for the Determination of
VOC's in Ambient Air," Proc. 14th Int'l. Symposium on Capil. Chrom., Baltimore, MD, 1992.
19. Gibiteh, J., Ogle, L., and Radenheimer, P., "Analysis of Ozone Precursor Compounds in Houston,
Texas Using Automated Continuous GCs," in Proceedings of the Air and Waste Management Association
Conference; Measurement of Toxic and Related Air Pollutants, Air and Waste Management Association,
Pittsburgh, PA, May 1995.
20. MDHS 2 (Acrylonitrile in Air), "Laboratory Method Using Porous Polymer Adsorption Tubes, and
Thermal Desorption with Gas Chromatographic Analysis," Methods for the Determination of Hazardous
Substances (MDHS), UK Health and Safety Executive, Sheffield, UK.
21. MDHS 22 (Benzene in Air), "Laboratory Method Using Porous Polymer Adsorbent Tubes, Thermal
Desorption and Gas Chromatography," Method for the Determination of Hazardous Substances (MDHS),
UK Health and Safety Executive, Sheffield, UK.
22. MDHS 23 (Glycol Ether and Glycol Acetate Vapors in Air), "Laboratory Method Using Tenax Sorbent
Tubes, Thermal Desorption and Gas Chromatography," Method for the Determination of Hazardous
Substances (MDHS), UK Health and Safety Executive, Sheffield, UK.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-31
-------
Method'f 0-17 \ '4 H l " • VOCs
23-L. MPJJS3o_ffojy5"e in air), "Laboratory Method Using Pumped Porous Polymer Adsorbent Tubes,
; Thermal Desorption and Gas Chroma tography," Method for the Determination of Hazardous Substances
~ -*HaX UK I&lffi and Safety Executive, Sheffield, UK.
24. MDHS 60 (Mixed Hydrocarbons (C, to CtQ) in Air), "Laboratory Method Using Pumped Porous Polymer
"* arid CarboU Sorbeiit Tubes, Thermal Desorption and Gas Chromatography," Method for the
Determination of Hazardous Substances (MDHS), UK Health and Safety Executive, Sheffield, UK.
25. Price, J. A., and Saunders, K. J., "Determination of Airborne Methyl Tert-butyl Ether in Gasoline
Atmospheres," Analyst, Vol. 109, pp. 829-834, July 1984.
26. Coker,"D.~T,,"vari den Hoed" N., Saunders, K. J., and Tindle, P. E., "A Monitoring Method for
Gasoline Vapour Giving Detailed Composition," Ann. Occup, Hyg. , Vol 33, No. 11, pp 15-26, 1989.
»'27._ DFGj "Analytische Methoden zur prufing gesundheitsschadlicher Arbeistsstoffe," Deutsche
Forschungsgemeinschaft, Verlag Chemie, Weinheim FRG, 1985.
28. NNJE, "Methods in NVN Series (Dachtkwaliteit; Werkplefcatmasfeer), " Nederlands Normailsatie - Institut,
' Z'Delft,'fhe ...... Neteifends,' ......... iggglsC ....... "' ..................................................
29. "Sampling by Solid Adsorption Techniques," Standards Association of Australia Organic Vapours,
. - ' , 1987.
30. Woolfenden, E. A., "Monitoring VOCs in Air Using Pumped Sampling onto Sorbent Tubes Followed
by Thermal Desotption-capillary GC Analysis: Summary of Reported Data and Practical Guidelines for
Successful Application," /. Air and Waste Management Assoc. , Vol. 47, 1997, pp. 20-36.
31. BrpwOj R^HL^and Purnell, C. J., "Collection and Analysis of Trace Organic Vapour Pollutants in
• Ambient Atmospheres: The Performance of a Tenax-GC Adsorbent Tube," /. ofChrom., Vol 178, pp
79-90, 1979.
' »" &TITk ," si , , «,
* * ~ « W * » £ '-I r. a "J "'•! W ' , 'j
32. Walling, J. F., "The Utility of Distributed Air Volume Sets When Sampling Ambient Air Using Solid
Adsorbents," Mnos. Environ., Vol 18, No 4, 855-859, 1984.
33. WalUng> TTF.TBerMey", R. E., Swanson, D. H. and Toth, F. J., "SampUng Ak for Gaseous Organic
ChemicarUsing Solid ^Adsorbents: Application to Tenax," U. S. Environmental Protection Agency,
Research Triangle ParirNC 27711, EPA 600/5-82-059, May 1982.
Page 17-32 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
TABLE 1. GUIDELINES FOR SORBENT SELECTION
I
§
S'
'fyfasfffSSfffSSsffSfySffSti^SfSfSfff.
?SpiplKx!SBlSgirb«nt;|l
CarbotrapC*
CarbopaekC*
Anasorb* GCB2
Tennx'TA
Tenax OR
Carbotrap*
CarbopaekB*
Anasorb* OCB1
Chroraosorb* 102
Chromosorb 106
Porapak Q
Porapak N
Spherocarb*
CarbosieveSIU**
Carboxen 1000«*
Aimsorb* CMS*
Zeolite
Molecular Sieve I3X**
Coconut Charcoal*
(Coconut charcoal is
rarely used)
lilippfiiiiPl
:»s\WBfHi$*Rwp»
n-C, to n-Ca,
bp lOO'C to 400"C
n-C, to n-C^
bp IOO°C to 450°C
n-C, to n-CM
(n-C4) n-C, to n-Cu
bp 50°e - 2008C
bp 50°C - 200°C
bp 50*C - 200°C
n-Cj to n-C15
bp 50°C - I50"C
n-C, to n-C,
-30° C - ISO'C
Q to n-C,
-60°C to 80°C
-60°C to 80°C
-80"C to 50"C
(miy2tm::m2K
WM&fempm
•x.i-ft(Z-'-f*Fftx**f--<-
*.:*:;»>:I^teJK-s;to Si
>400
350
350
>400
250
250
250
ISO
>400
400
350
>400
:;«a»a:W«S^K*
12
35
35
100
350
750
550
300
1,200
800
> 1,000
Alkyl benzenes and nliphatics ranging in volatility from u-C to n-C ,
Aromatics except bcazcne, Apolur components (bp> IOO°C) und less volatile
polur compouunls (bp> !50°C).
Alkyl benzenes, vapor phase PAHs and PCBs and as above for Tenax TA,
Wide range of VOCs inc. , ketoncs, alcohols, and aldehydes (bp >75°C) and
all apolar compounds within the volatility range specified. Plus
perfluorocarbon tracer gases.
Suits a wide range of VOCs incl, oxygenated compounds and haloforms less
volatile than methylene chloride.
Suits a wide range of VOCs incl. hydrocarbons from n-C to n-C . Also good
for volatile oxygenated compounds
Suits a wide range of VOCs including oxygenated compounds.
Specifically selected for volatile nitrites; acrylonitrile, acetonitrile and
propionitrfle. Also good for pyridine, volatile alcohols from EtOH, MBK, etc.
Good for very volatile compounds such as VCM . ethylene oxide, CS and
CHjCI,, Also good for volatile polurs e.g. MeOrl, BOH and acetone.
Good for ultra volatile compounds such as C C hydrocarbons, volatile
haloforms and freons.
Used specifically for 1,3- butadiene and nitrous oxide.
Rarely used for thermal desorptioa because metal content may catalyze analyte
degradation. Petroleum charcoal and Anasorb* 747 are used with thermal
desportion in the EPA's volatile organic sampling train (VOST), Methods 0030
and 0031.
Q
* These sorbents exhibit some water retention. Safe sampling volumes should be reduced by a factor of 10 if sampling a high (> 90%) relative humidity.
** Significantly hydrophilic. Do not use In high humidity atmospheres unless silicone membrane caps can be fitted for diffusive monitoring purposes.
CarbotrapC™, CarbopackC™, CarbopackB™, Carboxen™ and CarbosJeve Sill™ are all trademarks of Supelco, Inc., USA; Tenax* is a trademark of Enka
Research Institute; Chromosoro* is a trademark of Manville Corp.; Anasorb* is a trademark of SKC, Inc.; Porapak* is a trademark of Waters Corporation.
2
i
H
O
-------
H 1
I
s-
1
i fin 1.1
Sample Tube Sorbent
CarbotnpC*
CarbopackC*
Anasorb* QCB2
Tcnax* TA
Tenax OR
Carbotrap*
CarbopackB*
Anasolrb* GCB1
Chromosorb* 102
Chromosorb 106
Porapak Q
Porapak N
Spherocarb*
CMS such as CSIJI**
Carboxen 1000**
Anasorb* CMS*
Zeolile
Molecular Sieve 13X**
Tenax / CB : comb. Tube
Type 1 (see
Sect. 9.1.3)
Carb B / CMS* comb.
Tube Type 2 (see
Sect. 9.13)
Carb. 300 type*, comb.
Tube Type 3 (see
Sect. 9. 1.3)
Maximum
Temp,, (*C)
>400
350
350
>400
250
250
L 250
180
>400
400
350
350
400
400
Hydro-
phobic {1)
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
No
No
Temp, and Gts Flow for
Conditioning
350'C and 100 mL/min
330*C and 100 mL/min
330°C and 100 mL/min
350°C and 100 mL/min
250°C and 100 mL/min
250° C and 100 mL/min
2500C and 100 mL/min
180'Cand 100 mL/min
4QO°C and 100 mL/min
350° C and 100 mL/min
330° C and 100 mL/min
330°C and 100 mL/min
350° C and 100 mL/min
350" C and 100 mL/min
Temp, tnd Min. GUI
Flow for Daorplion
325°C and 30 mL/min
30Q*C and 30 mL/min
300* C and 30 mL/min
325 "C and 30 mL/min
225 "C and 30 mL/min
250° C and 30 mL/min
225"C and 30 mL/min
180°C and 30 mL/min
390"C and 30 mL/min
325°C and 30 mL/min
300" C and 30 mL/min
300°C and 30 mL/min
325 °C and 30 mL/min
325°C and 30 mL/min
Recommended Focusing Trap Packing
Tenax* or Carbopick C*
Tenax*
Tenax*
Tcnax or Carbopack B*
Dual-bed CB plus CMS trap or Chrom.
102
Dual-bed CB plus CMS trap or Chrom.
106
Dual-bed CB plus CMS trap or Porapak Q
Dual-bed CB plus CMS trap or Porapak N
Dual-bed CB plus CMS trap or
Spherocarb
Dual-bed CB plus CMS trap or CMS
alone
Dual-bed CB plus CMS trap or CMS
alone
Tcnax
Dual-bed CB plus CMS trap
Dual-bed CB plus CMS trap
* These sorbents exhibit some water retention. Safe sampling volumes should be reduced by a factor of 10 if sampling a high (>90%) relative humidity.
** Significantly hydrophilic. Do not use in high humidity atmospheres unless silicone membrane caps can be fitted for diffusive monitoring purposes.
CB is short for Carbopack B and CMS is short for carbonized molecular sieve,
CarbotrapC™, CarbopackC™, CarbopackB™, Carboxen™ and Carbosieve SHI™ are all trademarks of Supelco, Inc., USA; Tenax* is a trademark of Enka
im
I
I
H
9
<5
O
0
-------
VOCs
Method TO-17
TABLE 3 - LIST OF COMPOUNDS WITH BREAKTHROUGH VOLUMES >5L USING
THE AIR TOXICS TUBE STYLE 2 LISTED DM SECTIONS 6. 1.2 AND 9.1.3
OF COMPENDIUM METHOD TO-17
/Mote: The following list of compounds was determined to have breakthrough volumes of greater than 5 liters
of trace levels in humidified zero air for humidities of 20%, 65% and 90% RHat25°C, The tests were
performed immediately prior to the publication of this document at the Research Triangle Institute, Research
Triangle Park, NC as a result of activities leading up to the publication of this document. Compounds with an
* were not tested at 90% RH.J
Halocarbon 114
l,3»5-TrimethyIbenzene
Halocarbon 11
1,2,4-Trimethylbenzene
Halocarbon 113
Dichlorobenzenes
1,1-Dichloroethene
1,2,4-Trichlorobenzene
Methylene Chloride
Hexachloro-1,3, -butadiene
1,1 Dichloroethaue
*1,3 Butadiene
cis-1,2-Dichloroethene
*Aeetonitrile
Chloroform
*Acetone
1,1,1-Trichloroethane
*2-Propanol
Carbon tetrachloride
*Acrylonitrile
Benzene
*Isoprene
1,2-Dichloroethane
*Methyl Acetate
Trichloroethene
*Metiiyl tert-Butyl Ether
1,2-Dichloropropane
*Metfayl Etfayl Ketone
cis-1,3-Dichloropropene
*Ethyl Acrylate
Toluene
*MethyI Aerylate
Trans-1,3-Dichloropropene
*Methyl Isobutyl Ketone
Turfural
Tetrachloroethene
1,2-Dibromoethane
Chlorobenzene
Ethylbenzene
m-Xylene
p-Xylene
o-Xylene
1,1,2,2-Tetrachloroethane
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 17-35
-------
Method TO-17
VOCs
TABLE 4.' iSsfbF°AN"*ANALYTE "'X'" COLLECTED FROM 1," 2 dR "10 L AIR SAMPLES AT'
^DIFFERENT ATMOSPHERIC CONCENTRATIONS
^, ... „"-' ;= (ASSUMING'X1 HAS A MOLAR WEIGHT OF 100 g)
r
i
I .
Sample typ«
Feoeeline/severe urban area
Indoor air sampling
Avg. exposure to benzene
Normal urban area
Normal rural area
Forested area
Mt. Everest/K2 site
Arctic on an ultraclean day
Typical
concentration
10-250 ppb
1-100 ppb
"3 ppb
1-10 ppb
0.1-1 ppb
0.25-2.5 ppb
0.025-7.5 ppb
15-50 ppt
Mass collected in
1 L sample volume
40-1,000 ng
4-400 ng
ling
4-40 ng
0.4-4 ng
1-10 ng
0.1-30ng
60-200jg
Mass collected in
2 L sMnple
'volume
80 ng-2 Mg
8-800 ag
22 me
8-80 ng
0.8-8 ng
2-20 ng
0.2-60 ng
0. 12-0.4 ng
Mass collected in
10 L sample volume
0.4-10wg
40 ng-4^g
110 Dg
40-400 ng
4-40 ng
10-100 ng
1-300 ng
0.6-2 ng^
Page 17-36
Compendium of Methods for Tome Organic Air Pollutants
January 1999
-------
VOCs
Method TO-17
COMPENDIUM METHOD TO-17
FIELD TEST DATA SHEET (FTDS)
I. GENERAL INFORMATION
PROJECT:,
SITE:
LOCATION:
INSTRUMENT MODEL NO.:.
PUMP SERIAL NO.:
DATE(S) SAMPLED:
TIME PERIOD SAMPLED:,
OPERATOR:
CALIBRATED BY:_
RAIN: YES
_NO
ADSORBENT CARTRIDGE INFORMATION:
Tube 1 Tube 2
Type:
Adsorbent:
Serial No.:
Sample No.:
H. SAMPLING DATA
Tube
Identifi-
cation
Sampling
Location
Ambient
Temp.,
op
Ambient
Pressure,
inHg
How Rate (Q),
mL/tnin
Tubel
Tube 2
Samplin
Start
e Period
Stop
Total
Sampling
Time,
inin.
Total
Sample
Volume,
L
DDL FIELD AUDIT
Tube 1 Tube 2
Audit Flow Check Within _
10 % of Set Point (Y/N)? pre-
pre-
post-
post-
CHECKED BY:_
DATE:
Figure 1. Compendium Method TO-17 Reid Test Data Sheet,
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 17-37
-------
Method TO-17
VOCs
•t-.£
Stainless steel tube:
Total volume: - 3 mL
Sorbcnt capacity: 200 -
bed(s)
Maximum 60 mm
PuffipBow
DMorbflow
Stainless stoat
5puza"(-100 mesh)
3.5 inch (-89 mm)
\
Stainless
steel lufao
Stainless steal
gauze (-100 mash}
Minimum 15mm
mmrnmrnmmmmm
'X:
5 mm
taintess steel
gauze retaining spring
Gtaistube:
Total vohima: - 2 mL
Sortoant capacity: 130 - 650 mg
Adsorbent
bed{s)
1_S mm
"
Maximum 60 mm
Oesorti flow ^
» ; "» " ',(11
3^ ifsch (-89 nun)
Unsi Ionized
glass woo I
Glass
tuba
Minimum IS mm
Unsilanized
glass wool
Figure 2. Example of construction of commercially avaiiaoic ausui ucui
Page 17^38
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-17
inlet split
vent closed
Sottenttubeat T
ambient tamp. Cod sorbent trap
_
Carrier gas Pressure Desoibflow
supply dosed transducer vent closed
Carrier
•Detector
GC analytical
column
(a) "Ribe teak check.
biletspll
vent closed
Serbenttube at
ambient temp.
I
Cool sorbent trap
Carrier gas
supply dosed
Pressure
transducer
Desorbltow,
vent closed
Carrier
gas In
(b) Leak check sample flow path.
Detector
GC analytical
column
Figure 3. Sequence of operations to thermally desorb the sample from the sorbent tube and transfer
to the gas chromatograph; (a) tube leak test and (b) leak check flow path.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 17-39
-------
Method TO-17
VOCs
Inlet open
(optional)
Sorbenttube at
ambient temp.
1
Cool sorbent trap
Carrier
gash
Desorb
flow open 1 '
"O"
^•"••••••i*1^ f*+f*i _
Detector
Carter
gas in
GC analytical
column
(c) Purge to remove air.
From pressurized
cyflnderof
standard gas
Ext
Loop
InJet split open
(optfcnaO
Sorbenttubeat A
, T Cool soibent trap
ambient temp.
(ntemal standard
add Bon valve
Dssorb
flow open
•Carrter
gas In
Carrier
gas in
3 ' t :
(d) Gas phase internal standard addllon to sample tube.
• Detector
GC analytical
column
Figure 3 (cont). Sequence of operations to thermally desorb tbe sample from the sorbent tube and
j; brMsfer to th£gas chromatograph: (c) purge to remove air and (d) gas phase internal standard
addition to sample tube.
Page 17-40
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-17
Intet split open
(optional)
Hot surberrt tube
Cool sorbent trap
Canier
gas in
(e) Primary (tube) desofption.
Desort)
flow open
Carrier
a as Iii
Detector
GC analytical
column
Outlet splft
(optional)
Sorfoent tube coofing
Hot soibent trap
L
(f) Secondary (trap) desorptksn.
Detector
GC analytical
column
Figure 3 (cont). Sequence of operations to thermally desorb the sample from the sorbent tube and
transfer to the gas chromatograph: (e) primary (tube) desorption and (f) secondary (trap) desorpn'on.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 17-41
-------
Method TO-17
VOCs
Adsorbent
Tubes
Figure 4. Example of distributive air volume using adsorbent tuDe tecnnoiogy.
Page 17-42
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
VOCs
Method TO-17
APPENDIX 1.
The following list includes safe sampling volume data generated by the UK Health and Safety Executive (4)
on single sorbent bed 1/4 inch O.D. stainless steel tubes and compatible with a thermal desorption - capillary
GC analytical procedure. It is provided as a resource to readers only. The recommendation for Tube Style
2 is based on the specific tube referenced in Section 6.1.2 and Table 3. Where tubes are not listed with safe
sample volumes they have not been tested and their inclusion represents a suggestion only. Application to air
sampling is subject to criteria listed in Section 14 of Compendium Method TO-17.
[Note: Combination tubes 1, 2, and 3 referenced In this Appendix are those adsorbent tubes described in
Section 9.1.3.]
HydrQcayborig
This procedure is suitable for all aliphatic, aromatic and cyclic hydrocarbons less volatile than ethane and
more volatile than n-C20. These include:
n-Butane
n-Pentane
n-Hexane
Benzene
n-Heptane
Toluene
n-Octane
Ethylbenzene
all Xylenes
n-Nonane
Styrene
Isopropylbenzene
n-Propylbenzene
l-Methyl-3-etfaylbenzene
CS m, C 1000, Combination Tubes 2 or 3 or Spherocarb (SSV 820L).
CS m, C 1000, Spherocarb (SSV 30,OOOL), Combination Tubes 2 or 3 or
Chromosorb 106 (SSV 5.5L).
Carbopack™ B, Combination Tubes 1, 2, 3 or Chromosorb 106
(SSV SOL).
Carbopack™ B, Combination Tubes 1, 2, 3 or Chromosorb 106 (SSV 26L)
or Tenax (SSV 6L).
Carbopack™ B, Tenax (SSV 17L), Combination Tubes 1, 2, 3 or
Chromosorb 106 (SSV 160L).
Carbopack™ B, Tenax (SSV 38L), Combination Tubes 1, 2, 3 or
Chroraosorb 106 (SSV 80L).
Carbopack™ B, Tenax (SSV TOOL) Combination Tubes 1, 2, 3 or
Chromosorb 106 (SSV 1000L).
Carbopack™ B, Tenax (SSV 180L), Combination Tubes 1, 2, 3 or
Chromosorb 106 (SSV 360L).
Carbopack™ B, Tenax (SSV 300L), Combination Tubes 1, 2, 3 or
Chromosorb 106 (SSV 770L).
Carbopack™ C/B, Tenax (SSV 700L), Combination Tubes 1, 2 or 3 or
Chromosorb 106 (SSV 7000L).
Carbopack™ C/B, Tenax (SSV 300L) or Combination Tubes 1, 2 or 3.
Carbopack™ C/B, Tenax (SSV 480L) or Combination Tubes 1, 2 or 3.
Carbopack™ C/B, Tenax (SSV 850L) or Combination Tubes 1, 2 or 3.
Carbopack™ C/B, Tenax (SSV 1000L) or Combination Tubes 1, 2 or 3.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 17-43
-------
tlethod TO-17 VQCs
Compound Suitable'sorbents and SSV's •where 'ayaflabjg ~__
l-Methyl-4-ethylbenzene Carbopack™ C/B, Tenax (SSV 1000L) or Combination Tubes 1, 2 or 3.
1,3,5-Trimethylbenzene Carbopack™ C/B, Tenax (SSV 1800L), Combination Tubes 1, 2 or 3 or
Chromosorb 106 (SSV 2800).
Methylstyrene Carbopack™ C/B, Tenax (SSV 1200L) or Combination Tubes 1, 2 or 3.
Methyl-2-ethylbenzene Carbopack™ C/B, Tenax (SSV 1000L) or Combination Tubes 1, 2 or 3.
1,2,4-f rimethylbenzene Carbopack™ C/B, Tenax (SSV 1800L) or Combination Tubes 1, 2 of 3.
n-Decane ~ ~ Carbopack™ C/B, Tenax (SSV 2100L), Combination Tubes 1, 2 or 3 or
Chromosorb 106 (SSV 37.000L).
1,2,3-f rimethylbenzene Carbopack™ C/B, Tenax (SSV 1800L) or Combination Tubes 1, 2 or 3.
n-Undecane Carbopack™ C/B, Tenax (SSV 12.000L) or Combination Tubes 1, 2 or 3.
n-Dodecane "Carbopack™ C, Tenax"(SSV*63',dOl)L5 or Combination Tubes 1 or 3.
M . •;•- : •• . ^Halogenated Hydrocarbons including PCBs
• * HT KB , t-« •";."».IF I3JI«; .jvio j i.< i i .-. .-^i. unit" T>«" U;T. > »;.*• f •
This procedure is suitable for all aliphatic, aromatic and cyclic halogenated hydrocarbons more volatile
than n-C20. Examples include:
DicMoromethane CS IE, C 1000, Spherocarb (SSV 200L) or Combination Tubes 2 or 3.
1,2-Dichloroethane CS ffl, C 1000, Spherocarb, Chrom. 106 (SSV 17L), Carbopack™ B,
Tenax (SSV 5.4L) or Combination Tubes 1, 2 or 3.
1,1.1-Trichloroethane Spherocarb (SSV 8,OOOL), Chrom. 106 (SSV 8L), Carbopack™ B, or
,,••*. mmf . "Combination Tubes 1, 2 or 3.
Carbontetracbjloride Chrom. 106 (SSV 22L), Carbopack™ B, Tenax (SSV 6.2L) or
_, - -•— -- Combination Tubes 1,2 or 3.
Trichloroethylene Chrom. 106, Carbopack™ B, Tenax (SSV 5.6L) or Combination Tubes 1,
2 or 3.
1,1,2-Trichloroethane Chrom. 106, Carbopack™ B, Tenax (SSV 34L) or Combination Tubes 1, 2
— —. .-1 or 3. "' ' ' '
Tetrachloroethylene Chrom. 106, Carbopack™ B, Tenax (SSV 48L) or Combination Tubes 1, 2
Chlorobenzene Chrom. 106, Carbopack™ B, Tenax (SSV 2§L) or Combination Tubes 1, 2
Uii|.™, ti. T i"H J 1 "T ' "HCWHl " f~^n i < Vfc ~ — — — •— - - - -~~~
' ** W*^ V ^~ " * • /%W *5 --.»....... „_ .. - ™* „ , ,.
or j.
'. , , ,",; • „' .„ ., , , ,, • ..
1,1,1,2-Tetrachloroethane Chrom. 106, Carbopack™ B, Tenax (SSV 78L) or Combination Tubes 1, 2
or 3.
1,1,2,2-Tetrachloroethane Chrom. 106, Carbopack™ B, Tenax (SSV 170L) or Combination Tubes 1,
, -/*,=* '-HHil WiH i i * *"t t
" t if flif £• i "K2 or J.
v I 3 f fm ' i „ i* . i. ~, • , .
,^. i^i wi . \ v i « . . •,- »f i ^ ,- r^ - ? M •-;.,' •. . .
If! i" *1; -aft W - «•*•<,.-',;•* »a ,-,-<^ .v^tnw-r i, «.-,.• r-r»ij ,/h,-,wn««-•.«,n« « -., »-r, ,
Page 17-44 Compendium of Methods for Toxic Organic Air Pollutants January 1999
-------
VOCs Method TO-17
Alcohols
This procedure is suitable for alcohols more volatile than n-C20 and sufficiently stable to be analyzed by
conventional GC techniques. Examples include:
Methanol CSm, C1000, Spherocarb (SSV 130L) or Combination Tubes 2 or 3.
Ethanol CSm, C1000, Spherocarb (SSV 3500L) or Combination Tubes 2 or 3.
n-Propanol Porapak N (SSV 20L), Chrom 106 (SSV 8L), Carbopack™ B or
Combination Tubes 1, 2 or 3.
Isopropanol Chrom 106 (SSV 44L), Carbopack™ B or Combination Tubes 1, 2 or 3.
n-ButanoI Chrom 106 (SSV SOL), Carbopack™ B, Porapafc N (SSV 5L), Tenax (SSV
5L) or Combination Tubes 1, 2 or 3.
iso-Butanol Chrom 106 (SSV 30L), Carbopack™ B, Tenax (SSV 2.8L) or Combination
. Tubes 1,2 or 3.
Octanol Tenax (SSV 1400L), Carbopack™ C or Combination Tubes 1 or 3.
Esters and Gyeol Ethers
This procedure is suitable for all esters and glycol ethers more volatile than n-C20 and sufficiently stable
to be analyzed by conventional GC techniques. Examples include:
Methylacetate Chromosorb 106 (SSV 2.6L), Carbopack™ B or Combination Tubes 1,
2 or 3.
Ethylacetate Chromosorb 106 (SSV 20L), Carbopack™ B, Tenax (SSV 3.6L) or
Combination Tubes 1, 2 or 3.
Propylacetate Chromosorb 106 (SSV 150L), Carbopack™ B, Tenax (SSV 18L) or
Combination Tubes 1, 2 or 3.
Isopropylacetate Chromosorb 106 (SSV 75L), Carbopack™ B, Tenax (SSV 6L) or
Combination Tubes 1, 2 or 3.
Butylacetate Chromosorb 106 (SSV 730L), Carbopack™ B, Tenax (SSV 85L) or
Combination Tubes 1, 2 or 3.
Isobutylacetate Chromosorb 106 (SSV 440L), Carbopack™ B, Tenax (SSV 130L) or
Combination Tubes 1, 2 or 3.
Methyl-t-butyl ether Chromosorb 106 (SSV >6L), Carbopack™ B or Combination Tubes 1,
2 or 3.
t-Butylacetate Chromosorb 106 (SSV 160L), Carbopack™ B or Combination Tubes 1,
2 or 3.
Methylacrylate Chromosorb 106, Carbopack™ B, Tenax (SSV 6.5L) or Combination
Tubes 1,2 or 3.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 17-45
-------
Method TO-17
VOCs
If* SBSTS
Compound.
Suitable sorbeiits antl SSV's where available " •
1* r
•IB
Chromosorb 106, Carbopack™ B, Tenax (SSV 60L) or Combination Tubes
1, 2 or 3.
Chromosorb 106, Qtrbopadc™ BTTenax (SSV 27L) or Combination Tubes
, J, 2 or 3.
Chroraosorb 106 (SSV 5L), Carbopack™ B, Tenax (SSV 3L) or
Combination Tubes 1, 2 or 3.
Chromosorb 106 (SSV 75L), Carbopack™ B, Tenax (SSV 5L) or
Combination Tubes 1, 2 or 3.
Chromosorb 106, Carbopack™ B, Tenax (SSV SSL) or Combination Tubes
I, 2 or 3.
Chromosorb 106, Carbopack™1 B, Tenax (SSV I3L) or Combination Tubes
1,2 or 3.
"Chromosorb 106 (SSV 860L), Caxbopack™ B, Tenax (SSV 8L) or
Combination Tubes I, 2 or 3.
Chromosorb 106 (SSV 4000L), Carbopack™ B, Tenax (SSV 15L) or
Combination Tubes 1, 2 or 3.
Chromosorb 106, Carbopack™ B, Tenax (SSV 150L) or Combination
Tubes 1, 2 or 3.
1111111 ' * * " ; si ' ' • , ,
- ~, • Aldehydes and Ketones
This orocedure is suitable for all aldehydes and ketones more volatile than n-C20 and sufficiently stable
to be analyzed using conventional GC techniques. Examples include:
Ethylacrylate
Methyhncthacrylate
Mt'- •••!'."-i. IV
Kfethoxyethanol
Ethoxyethanol
Butoxyethanol
Meihoxypropanol
MKthoxyethyiacetate
Ethoxyethylacetate
Butoxyethylacetate
•IH; I ll'l'l.
Acetone
CSM, C1000, Spherocarb, Chrom 106 (SSV I.5L) or Combination Tubes
Methylethylketone
(2-butanone)
TI1IM «KM PrJUHF "T n-mif . &
n-Butanal
Chromosorb 106 (SSV 10L), Tenax (SSV 3.2L), Porapak N (SSV SOL)
Carbopack™ B or Combination Tubes 1, 2 or 3,
Chromosorb 106, Carbbpack™ B~, Porapak N (SSV SOL) or Combination
Tubes 1, 2 or 3.
t J.j^*^^^y 25QL),'!&£?(S§V 26lL),*Carbopack™ B or
Combination Tubes 1, 2 or 3.
Chromosorb 106, Tenax (SSV 170L), Carbopack™ B or Combination
Tubes 1,2 or 3.
S.S.S-Tranemylcyclohex^ Tenax (SSV 5600L), Carbopack™ B or Combination Tubes 1 or 3.
-enone
Furfural Tenax (SSV 300L), Carbopack™ B or Combination Tubes 1, 2 or 3.
I^thylisobuQ'lketone
Cyclohexanooe
Page 17-46
Compendium of Methods for Toxic OrgmuTAir Pollutants
January 1999
-------
VOCs
Method TO-17
Miscellaneous VOCs
This procedure is suitable for the analysis of most VOCs in air. It is generally compatible with all
organics less volatile than ethane, more volatile than n-C20 and sufficiently stable to be analyzed using
conventional GC techniques. Examples include:
Acetonitrile
Acrylonitrile
Propionitrile
Maleic anhydride*
Pyridine
Aniline
Nitrobenzene
Acetic acid
Phenol
Porapak N (SSV 3.5L), GSM, C1000 or Combination Tubes 2 or 3.
Porapak N (SSV 8L), Carbopack™ B or Combination Tubes 1, 2 or 3,
Porapak N (SSV 11L), Carbopaek™ B or Combination Tubes 1, 2 or 3.
Tenax (SSV 88L), Chrom. 106, Carbopaek™ B or Combination Tubes 1, 2
or 3.
Tenax (SSV 8L), Porapak N (SSV 200L) Chrom. 106, Carbopaek™ B or
Combination Tubes 1, 2 or 3.
Tenax (SSV 220L), Chrom, 106, Carbopaek™ B or Combination Tubes 1,
2 or 3.
Tenax (SSV 14,OOOL) Carbopaek™ C or Combination Tubes 1 or 3,
Porapak N (SSV SOL), Carbotrap™ B or Combination Tubes 1, 2 or 3.
Tenax (SSV 240L) or combination tube 1.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants
Page 17-47
-------
Method TO-17
VOCs
" ""' "~ ' " ' APPENDIX 2. ~
= • :I^EARrrYifKTING OF"C^ SORBENT TUBE^OCUSING TUBE COMBMTION
Introduction
T f 44 I"
Automated gas chromatographs such as those used at network monitoring stations for hourly updates
of volatile organic compounds (VOCs) have a solid adsorbent concentrator for the VOCs. This unit is
comparable to the sorbent tubes being discussed in this document. The table below shows the results of
sampling a synthetic mixture of the Compendium Method TO-14 target list in humidified zero air
(approximately 70% RH at 25°C). Sampling occurred for 6, 12, and 24 min at a rate of 80 mL/min giving
a total sampling volume of 480, 960, and 1920 mL. These results are similar to the determination of safe
sampling volume and the amount of material collected should be related linearly to the sample period. The
fesMte InidBraJe^^^tJbreakthrough has not occurred to any appreciable extent at a sampling volume of
approximately 2 L for the stated experimental conditions. The response measured is the response of chlorine
from an atomic emission detector after chromatographie separation. The sorbent tube mix was Carbotrap™
C/cTrtoMp™"B7Carboxen'M"1000 and the focusing tube mix was Tenax-TA/SOiea Gel/Amoersorb XE-
340/Cbarcoal. The primary tube was 6 mm O.D. with 4 mm I.D., 110 mm in length. The focusing tube was
6 mm O.D., 0.9 mm I.D., 185 mm in length. The packing lengths for the sorbent tube per sorbent type were:
1.27 cm, 2.86 cm, and 3.18 cm, respectively. The packing lengths for the focusing tube per sorbent type
were: 5.08 cm, 2.54 cm, and 1.27 cm.
"" " ' - • ~ '*• • • • . - - . , Linearitytqst
/M?ff' Actual sampling volumes were 490, 980, and 1960 instead of 1/2,1, and 2L as listed for convenience
in the table below. The response is obtained as chlorine response on an atomic emission detector. Compounds
corresponding to the numbered compounds in the table are identified on the following page J
«*.--,». , ,c"
Cpd.
I
2
3
4
6
7
S
9
10
11
12
13
14
15
1/2L
1255.4
711.82
2079.4
978.14
1155.7
3072.8
2337.3
3041.7
1061.7
3800.5
2386.9
2455.4
3972.6
2430.9
1L
2402J
1802.2
4853
2381.3
2357.1
6764.4
4356.1
5986.6
2183.6
7726.7
4877.5
5063.5
8118.4
4947.9
-2L
5337.2
3087
9386
4680.1
4725.2
13662
8697.2
11525
4296.5
15182
9669
9986.6
15985
9756.1
2L/1L
2.22
1.71
1.93
1.97
2.00
2.02
2.00
1.93
1.97
1.96
1.98
1.97
1.97
1.97
2L/(1/2L>
4.25
4.34
4.51
4.78
4.09
4.45
3.72
3.79
4.05
3.99
4.05
4.07
4.02
4.01
1L/(1/2L) .
1.91
2.53
2.33
2.43
2.04
2.20
1.86
1.97
2.06
2.03
2.04
2.06
2.04
2.04
• -%Diff
:<2L/0,5L)vs.
'• 4'
-6.28
-8.42
-12.85
-19.62
-2.22
-11.15
6.97
5.28
-1.17
0.13
-1.27
-1.68
-0.60
-0.33
. — Jf«* A... frfk**.^ /^winomyy* A ft*
January 1999
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VOCs
Method TO-17
ISsKiK-SISS
yftmWfyXx
ililPtlF
liipiiii
16
18
19
20
21
22
23
26
27
31
36
37
38
39
40
41
&%&.$a&i>$$ffi$>i
6155.4
4270.4
2494.8
4023.9
1086.8
793.33
3708.2
5094
1265.1
4434.9
2320.7
441.17
1410.7
2338.7
2640.9
6796.5
Illl^lltliiif*-
Sv*$S£S:ifela&fe
9247.4
9233,8
5115.2
8379.4
2295.4
1670.1
7679
10582
2615,1
9176.4
5015.7
953.09
3015
4974.8
6269.4
14938
16942
18721
10087
16672
4611.7
3375.2
15165
21139
5136.9
17975
9827.3
1894
5895.2
9858.8
12495
29274
1.83
2.03
1.97
1.99
2.01
2.02
1.97
2.00
1.96
1.96
1.96
1.99
1.96
1.98
1.99
1.96
::.^x:-<:;::-::>^x:::-::Xx.;x::-;::.:>.
::':>>0;y;¥:^:;::;-;?:$:-:';":-;v!-:-:-:;:;:
2.75
4.38
4.04
4.14
4.24
4.25
4.09
4.15
4.06
4.05
4.23
4.29
4.18
4.22
4.73
4.31
&$t^\;.y:;^£$8^$<$$;.'
:';:>:""'T':'>;-:-:-;:::::>>:'>:-;':-:-;¥:;>:->::;::
Illlp2lpf
1.50
2.16
2.05
2.08
2.11
2.11
2.07
2.08
2.07
2.07
2.16
2.16
2.14
2.13
2.37
2.20
:;::':'?<*sr>v-:>%>v:::;>-::;>.;:-.,.:.
mmmtmmm
31.19
-9.60
-1.08
-3.58
-6.08
-6.36
-2.24
-3.74
-1.51
-1.33
-5.87
-7.33
-4.47
-5.39
-18.28
-7.68
There arc no values presented in the above table for hydrocarbons and brominated hydrocarbons (compounds numbered 5, 17,
24, 25, 28, 29, 30, 32, 33, 34, and 35) which do not respond to the chlorine detector used to coEect this data.
Compendium Method T
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DISCLAIMER
The information in this document has been compiled wholly or in part by the
United Slates Environmental Protection Agency under contract No, 68-C3-0315,
W.A. 3-10 to Eastern Research Group (ERG). The 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.
It is further noted that the test methods compiled here are working compilations
subject to on-going review and update. It is recommended that the reader refer to
the "AMTIC, Air Toxics" section of EPA's OAQPC Technology Transfer
Network web site at http://www.epa.gov/ttn/amtic/airtox.html to obtain the latest
updates, corrections, and/or comments to these test methods.
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Environmental Protection Agency
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