EPA
United States Atmospheric Research and
Environmental Protection Exposure Assessment Laboratory
Agency Research Triangle Park NC 27711
EPA/600/4-89/018
June 1988
Research and Development
Second Supplement to
Compendium of
Methods for the
Determination of Toxic
Organic Compounds in
Ambient Air
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EPA/600/4-89/018
June 1988
Second Supplement to Compendium of
Methods for the Determination of Toxic
Organic Compounds in Ambient Air
by
William T. Winberry, Jr. and Norma T. Murphy
Engineering-Science
One Harrison Park, Suite 200
401 Harrison Oaks Boulevard
Gary, NC 27513
and
R. M. Riggan
Battelle-Columbus Laboratories
505 King Avenue
Columbus, OH 43201
Contract No. 68-02-3996 (WA 2/020)
and
Contract No. 68-02-3888 (WA44)
EPA Project Managers: FrankF. McElroyand Larry J. Purdue
Quality Assurance Division
Atmospheric Research and Exposure Assessment Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Atmospheric Research and Exposure Assessment Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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Disclaimer
The Information in this document has been funded wholly or in part by the
U. S. Environmental Protection Agency under contract numbers, 68-02-3745,
68-02-3996, and 68-02-3888. 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.
ii
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SECOND SUPPLEMENT TO COMPENDIUM OF METHODS FOR THE
DETERMINATION OF TOXIC ORGANIC COMPOUNDS IN AMBIENT AIR
NOTICE
To holders of Compendium of Methods for the Determination of Toxic Organic
Compounds In Ambient Air (EPA-600/4-84-041). dated April 1984. and its
Supplement (EPA/600/4-87-006), dated September 1986:
The accompanying document is another supplement to the Compendium and
contains the pages necessary to update the Compendium as of June, 1988. The
supplement contains only the new or updated material and is intended to be used
in conjunction with the original Compendium and Supplement published by the U.S.
Environmental Protection Agency, Environmental Monitoring Systems Laboratory,
Quality Assurance Division. Copies of these previous documents may be obtained,
as supplies permit, from:
U. S. Environmental Protection Agency
Center for Environmental Research Information
Compendium Registration
26 W. Martin Luther King Drive
Cincinnati, Ohio 45268
Attention: Distribution Record System
Included in this supplement are all revisions and additions pertinent to
the update, along with instructions for merging the supplementary pages with
the original Compendium and previous Supplement to form a fully integrated and
updated document. Five new methods are added to the Compendium, and a new
title page, Table of Contents, and new Tables 1 and 2 are included to reflect
the added methods. Also, an update to page 1 of Method TO-9 (first Supplement,
EPA-600/4-84-Q41) is provided.
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Any questions, comments, or suggestions regarding this supplement or the
Compendium should be directed to the U. S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Quality Assurance Division, MD^77,
Research Triangle Park, NC, 27711; (919) 541-2665, (FTS: 629-2665).
Instructions for Merging the
Delete
Previous Title Page
Previous Disclaimer, page ii
Previous CONTENTS, page iii
Previous FOREWORD, page iv
Previous INTRODUCTION, page v
Previous TABLE 1, page vi
Previous TABLE 2, pages vii-viii
Previous Page T09-1 (Method T09)
Second Supplement into the Compendium:
Insert
New Title, Page (6/38)
New Disclaimer, page ii (6/88)
New CONTENTS, page iii (6/88)
New FOREWORD, page iv (6/88)
New INTRODUCTION, page v (6/88)
New .TABLE 1, page vi^vii :(6/88) .
New TABLE 2, pages viii-x (6/88)
New Page T09-1 (Method T09, 6/88)
Method T010 ;(6/88) -
Method T011 (6/88) '
Method T012 (6/88) '
Method T013 (6/88):
•Method T014 (6/88)
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CONTENTS
INTRODUCTION .
TABLE 1. Brief Method Description and Applicability
TABLE 2. Method Applicability to Compounds of Primary Interest
METHODS:
6/88
Page
v
vi
vi i i
T01 Determination of Volatile Organic Compounds in Ambient Air
Using Tenax® Adsorption and Gas Chromatograph (GC/MS) T01-1
T02 Determination of Volatile Organic Compounds in Ambient Air
by Carbon Molecular Sieve Adsorption and Gas Chrotnatography/
Mass Spectrometry (GC/MS) . T02-1
T03 Determination of Volatile Organic Compounds in Ambient Air
Using Cryogenic Preconcentration Techniques and Gas Chromatog-
raphy with Flame lonization and Electron Capture Detection .... T03-1
T04 Determination of Organochlorine Pesticides and
Polychlorinated Biphenyls in Ambient Air T04-1
T05 Determination of Aldehydes and Ketones in Ambient
Air Using High Performance Liquid Chromatography (HPLC) T05-1
APPENDIX A - EPA Method 608
T06 Determination of Phosgene in Ambient Air Using
High Performance Liquid Chromatography (HPLC) T06-1
T07 Determination of N-Nitrosodimethylamine in Ambient
Air Using Gas Chromatography T07-1
T08 Determination of Phenol and Methyl phenols (Cresols)
in Ambient Air Using High Performance Liquid
Chromatography (HPLC) . , T08-1
T09 Determination of Polychlorinated Dibenzo-p-Dioxins
(PCDDs) in Ambient Air Using High-Resolution Gas
Chromatography/High-Resolution Mass Spectrometry T09-1
T010 Determination of Organochlorine Pesticides in Ambient
Air Using Low Volume Polyurethane Foam (PUF) Sampling
with Gas Chromatography/Electron Capture Detector (GC/ECD) . . . .T010-1
T011 Determination of formaldehyde in Ambient Air Using
Adsorbent Cartridge Followed By High Performance
Liquid Chromatography (HPLC) . . .T011-1
T012 Determination of Non-methane Organic Compounds (NMOC)
in Ambient Air Using Cryogenic Preconcentration
and Direct Flame lonization Detection (PDFID) T012-1
T013 Determination of Polynuclear Aromatic Hydrocarbons
(PAHs) in Ambient Air Using High Volume Sampling
with Gas Chromatography/Mass Spectrometry (GC/MS)
and High Resolution Liquid Chromatography Analysis .T013-1
T014 Determination of Volatile Organic Compounds (VOCs) in
Ambient Air Using SUMMA® Polished Canister Sampling
and Gas Chromatographic (GC) Analysis T014-1
iii
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FOREWORD
Measurement and monitoring research efforts are designed to anticipate
potential environmental problems, to support regulatory actions by developing
an in-depth understanding of the nature and processes that impact health and
the ecology, to provide innovative means of monitoring compliance with regu-
lations, and to evaluate the effectiveness of health and environmental pro-
tection efforts through the monitoring of long-term trends. The Environmental
Monitoring Systems Laboratory, Research Triangle Park, North Carolina, has
responsibility for: assessment of environmental monitoring technology and
systems; implementation of Agency-wide quality assurance programs for air
pollution measurement systems; and supplying technical support to other groups
in the Agency, including the Office of Air and Radiation, the Office of Toxic
Substances, and the Office of Enforcement.
Determination of toxic organic compounds in ambient air is a complex task,
primarily because of the wide variety of compounds of interest and the lack of
standardized sampling and analysis procedures. This methods Compendium has
been prepared to provide a standardized format for such analytical procedures.
A core set of five methods is presented in the original document. In an effort
to update the original Compendium, four specific methods have been developed
and published in a supplemental document. In addition to the Compendium and
Supplement, five new methods have been prepared for inclusion. With this
addition, the Compendium now contains fourteen standardized sampling and anal-
ysis procedures. As advancements are made, the current methods may be modified
from time to time along with new additions to the Compendium.
Gary J. Foley
Director
Environmental Monitoring Systems Laboratory
Research Triangle Park, North Carolina, 27711
IV
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INTRODUCTION
This Compendium has been prepared to provide regional, state, and local
•environmental regulatory agencies, as well as other interested parties, with
specific guidance on the determination of selected toxic organic compounds in
ambient air. Recently, a Technical Assistance Document (TAD) was published
which provided guidance to such persons (1). Based on the comments received
concerning the TAD, the decision was made to begin preparation of a Compendium
which would provide specific sampling and analysis procedures, in a standard-
ized format, for selected toxic organic compounds.
The current Compendium consists of fourteen procedures which are consid-
ered to be of primary importance in current toxic organic monitoring efforts.
Additional methods will be placed in the Compendium from time to time, as such
methods become available. The original methods were selected to cover as many
compounds as possible (i.e., multiple analyte methods were selected). The
additional methods are targeted toward specific compounds, or small groups of
compounds which, for various technical reasons, cannot be determined by the
more general methods.
Each of the methods writeups is self contained (including pertinent liter-
ature citations) and can be used independent of the remaining portions of the
Compendium. To the extent possible the American Society for Testing and
Materials (ASTM) standardized format has been used, since most potential users
are familiar with that format. Each method has been identified with a revision
number and date, since modifications to the methods may be required in the
future.
Nearly all the methods writeups have some flexibility in the procedure.
Consequently, it is the user's responsibility to prepare certain standard
operating procedures (SOPs) to be employed in that particular laboratory. Each
method indicates those operations for which SOPs are required.
Table 1 summarizes the methods currently in the Compendium. As shown in
Table 1 the first three methods are directed toward volatile nonpolar compounds.
The user should review the procedures as well as the background material provided
in the TAD (1) before deciding which of these methods best meets the requirements
of the specific task.
Table 2 presents a partial listing of toxic organic compounds which can be
determined using the current set of methods in the Compendium. Additional
compounds may be determined by these methods, but the user must carefully
evaluate the applicability of the method before use.
(1) Riggin, R. M., "Technical Assistance Document for Sampling and Analysis
of Toxic Organic Compounds in Ambient Air", EPA-600/4-83-027, U. S.
Environmental Protection Agency, Research Triangle Park, North Carolina,
1983.
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TABLE 1. BRIEF METHOD DESCRIPTION AND APPLICABILITY
Method
Number
Description
Types of
Compounds Determined
TO-1
TO-2
TO-3
TO-4
TO-5
TO-6
TO-7
TO-8
TO-9
Tenax GC Adsorption
and GC/MS Analysis
Carbon Molecular Sieve
Adsorption and GC/MS
Analysis
Cryogenic Trapping
and GC/FID or ECD
Analysis
High Volume PUF
Sampling and GC/ECD
Analysis
Dinitrophenylhydrazine
Liquid Impinger Sampling
and HPLC/UV Analysis
High Performance Liquid
Chromatography (HPLC)
Thermosorb/N Adsorption
Sodium Hydroxide Liquid
Impinger with High Per-
formance Liquid Chromato-
graphy
High Volume Polyurethane
Foam Sampling with
High Resolution Gas
Chromatography/High
Resolution Mass Spec-
trometry (HRGC/HRMS)
Volatile, nonpolar organics
(e.g., aromatic hydrocarbons,
chlorinated hydrocarbons)
having boiling points in the
range of 80° to 200°C.
Highly volatile, nonpolar
organics (e.g., vinyl chloride,
vinylidene chloride, benzene,
toluene) having boiling points
in the range of -15° to +120°C.
Volatile, nonpolar organics
having boiling points in the
range of -10° to +200°C.
Organochlorine pesticides and
PCBs
Aldehydes and Ketones
Phosgene
N-Nitrosodimethyl amine
Crespl/Phenol
Dioxin
VI
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TABLE 1. BRIEF METHOD DESCRIPTION AND APPLICABILITY (Continued)
Method
Number
Description
Types of
Compounds Determined
TO-10
TO-11
TO-12
TO-13
TO-14
Low Volume Polyurethane
Foam (PUF) Sampling With
Gas Chromatography/Electron
Capture Detector (GC/ECD)
Adsorbent Cartridge Followed
By High Performance Liquid
Chromatography (HPLC)
Detection
Cryogenic Preconcentration
and Direct Flame lonization
Detection (PDFID)
PUF/XAD-2 Adsorption
with Gas Chromatography
(GC) and High Performance
Liquid Chromatography
(HPLC) Detection
SUMMA® Passivated Canister
Sampling with Gas Chromatog-
raphy
Pesticides
Formaldehyde
Non-Methane Organic
Compounds (NMOC)
Polynuclear Aromatic
Hydrocarbons (PAHs)
Semi-Volatile and
Volatile Organic
Compounds (SVOC/VOCs)
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TABLE 2. METHOD APPLICABILITY TO COMPOUNDS OF PRIMARY INTEREST
Compound
Acenaphthenfc
Acenaphthylene
Acetaldehyde
Acetone
Acrolein
Acrylonitrile
Appl i cable
Method(s)
TO-14
TO-14
TO-5, TO-11
TO-11
TO-5, TO-11
TO- 2, TO-3
Comments
Extension of TO-11
Extension of TO-11 .
Extension of TO-11
TO-3 yields better recovery
Aldrin
Ally! Chloride
Aroclor 1242, 1254
and 1260
Benzaldehyde
Benzene
Benzyl Chloride
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(e)pyrene
Benzo(g,h,i)perylene
Benzo(k)fluoranthene
Butyraldehyde
Captan
Carbon Tetrachloride
Chlordane
Chlorobenzene
Chloroform
Chloroprene
(2-Chloro-l,3-buta-
diene)
Chlorothalonil
Chlorpyrifos
Chrysene
Cresol
Crotonaldehyde
4,4'-DDE
4,4'-DDT
1,2-Di bromomethane
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
1,1-Dichloroethane
1,2-Dichloroethylene
TO-10
TO-2, TO-3
TO-10
TO-5
TO-1, TO-2, TO-3,
TO-14
TO-1, TO-3, TO-14
TO-13
TO-13
TO-13
TO-13
TO-13
TO-13
TO-11
TO-10
TO-1, TO-2, TO-3
TO-14
TO-10
TO-1, TO-3, TO-14
TO-1, TO-2, TO-3
TO-14
TO-1, TO-3
TO-10
TO-10
TO-13
TO-8
TO-11
TO-4
TO-4
TO-14
TO-14
TO-14
TO-1, TO-3, TO-14
TO-14
TO-14
data than TO-2.
TO-3 yields better recovery
data than TO-2.
TO-.14 yields better recovery
data.
Extension of TO-11
Breakthrough volume is very
low using TO-1.
Breakthrough volume is very
low using TO-1
The applicability of these
methods for chloroprene has
not been documented.
Extension of TO-11
vi ii
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TABLE 2. METHOD APPLICABILITY TO COMPOUNDS OF PRIMARY INTEREST (Continued)
Compound
Applicable
Method(s)
Comments
1,2-Dichloropropane
1,3-Dichloropropane
Dichlorovos
Dicofol
Dieldrin
2,5-Dimethylbenzaldehyde
Dioxln
Endrin
Endrin Aldehyde
Ethyl Benzene
Ethyl Chloride
Ethylene Dichloride
(1,2-Dichloroethane)
4-Ethyltoluene
Fluoranthene
Fluorene
Fol pet
Formaldehyde
Freon 11
Freon 12
Freon 113
Freon 114
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
and a-Hexachloro-
cyclohexane
Hexachlorobutadiene
Hexachlorocyclopenta-
diene
Hexanaldehyde
Indeno(l,2,3-cd)pyrene
Isovaleraldehyde
Lindane (o-BHC)
Methoxychlor
Methyl Benzene
Methyl Chloride
Methyl Chloroform
(1,1,1-Trichloroethane)
Methylene chloride
Mexacarbate
Mirex
Naphthalene
Nitrobenzene
N-Nitrosodimethyl amine
trans-Nonachlor
TO-14
TO-14
TO-10
TO-10
TO-10
TO-11
TO-9
TO-10
TO-10
TO-14
TO-14
TO-1, TO-2, TO-3
TO-14
TO-14
TO-13
TO-13
TO-10
TO-5, TO-11
TO-14
TO-14
TO-14
TO-14
TO-10
TO-10
TO-10
TO-10
TO-14
TO-10
TO-11
TO-13
TO-11
TO-10
TO-10
TO-14
TO-14
TO-1, TO-2, TO-3
TO-14
TO-2, TO-3, TO-14
TO-10
TO-10
TO-13
TO-1, TO-3
TO-7
TO-1 0
Extension of TO-11
Breakthrough volume very low
using TO-1.
Extension of TO-11
Extension of TO-11
Breakthrough volume very low
using TO-1.
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TABLE 2. METHOD APPLICABILITY TO COMPOUNDS OF PRIMARY INTEREST (Continued)
Compound
Applicable
Method(s)
Comments
Non-methane Organic
Compounds
Oxychlordane
Pentachlorobenzene
Pentachlorphenol
p,p'- DDE
p,p'- DDT
Perch!oroethylene
(tetrachloroethylene)
Phenanthrene
Phenol
Phosgene
Polychlorinated bi-
phenyls (PCBs)
Propanal
Proplonaldehyde
Pyrene
Ronnel
1,2,3,4-Tetrachloro-
benzene
1,1,2,2-Tetrachloro-
ethane
o-Tolualdehyde
m-Tolualdehyde
p-Tolualdehyde
To!uene
1,2,3-Trichlorobenzene
I,2,4-Trlchlorobenzene
1,1,2-Trlchloroethane
Trlchloroethylene
2,4,5-Trii chlorophenol
1,2,4-Trimethylbenzene
1,3,5-Tr1methylbenzene
Valeraldehyde
Vinyl Benzene
Vinyl Chloride
Vinyl Trichloride
Vinylidlne Chloride
(1,1-dlchloroethene)
o,m,p-Xylene
TO-12
TO-10
TO-10
TO-10
TO-10
TO-10
TO-1, (TO-2?), TO-3,
TO-14
TO-13
TO-8
TO-6
TO-4, TO-9
TO-5
TO-11
TO-13
TO-10
TO-10
TO-14
TO-11
TO-11
TO-11
TO-1, TO-2, TO-3,
TO-14
TO-10, TO-14
TO-14
TO-14
TO-1, TO-2, TO-3,
TO-14
TO-10
TO-14
TO-14
TO-11
TO-14
TO-2, TO-3, TO-14
TO-14
TO-2, TO-3, TO-14
TO-1, TO-3, TO-14
TO-2 performance has not been
documented for this compound.
Extension of TO-11
Using PUF in combination with
Tenax® GC solid adsorbent.
Extension of TO-11
Extension of TO-11
Extension of TO-11
Using PUF in combination with
Tenax® GC solid adsorbent.
Extension of TO-11
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Revision 1.1
June, 1988
METHOD T09
METHOD FOR THE DETERMINATION OF POLYCHLORINATED DIBENZO-
p-DIOXINS (PCDDs) IN AMBIENT AIR USING HIGH-RESOLUTION GAS
CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY (HRGC/HRMS)
1. Scope
1.1 This document describes a method for the determination of
polychlorinated dibenzo-p-dioxins (PCDDs) in ambient air. In
particular, the following PCDDs have been evaluated in the
laboratory utilizing this method:
° 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD)
° 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (1,2,3,4,7,8-HXCDD)
o Octachlorodibenzo-p-dioxin (OCDD)
° 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)
The method consists of sampling ambient air via an inlet filter
followed by a cartridge (filled with polyurethane foam) and
analysis of the sample using high-resolution gas chromatography/
high-resolution mass spectrometry (HRGC/HRMS). Original laboratory
studies have indicated that the use of polyurethane foam (PUF) or !
silica gel in the sampler will give equal efficiencies for retain-
ing PCDD/PCDF isomers; i.e., the median retention efficiencies
for the PCDD isomers ranged from 67 to 124 percent with PUF and
from 47 to 133 percent with silica gel. Silica gel, however,
produced lower levels of background interferences than PUF.
The detection limits were, therefore, approximately four times
lower for tetrachlorinated isomers and ten times lower for
hexach]orinated isomers when using silica gel as the adsorbent.
The difference in detection limit was approximately a factor of
two for the octachlorinated isomers. However, due to variable
recovery and extensive cleanup required with silica gel, the
method has been written using PUF as the adsorbent.
1.2 With careful attention to reagent purity and other factors, the
method can detect PCDDs in filtered air at levels below 1-5 pg/m3*.
"
Lowest _levets for which the method has been validated. Up to an order of magnitude better
sensitivity should be achievable with 24-hour air samples.
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Revision 1.0
June, 1987
METHOD T010
METHOD FOR THE DETERMINATION OF ORGANOCHLORINE PESTICIDES IN
AMBIENT AIR USING LOW VOLUME POLYURETHANE FOAM (PUF) SAMPLING WITH GAS
CHROMATOGRAPHY/ELECTRON CAPTURE DETECTOR (GC/ECD)
1. Scope
1.1 This document describes a method for sampling and analysis of a
variety of organochlorine pesticides in ambient air. The procedure
is based on the adsorption of chemicals from ambient air on
polyurethane foam (PUF) using a low volume sampler.
1.2 The low volume PUF sampling procedure is applicable to multicom-
ponent atmospheres containing organochlorine pesticide concentrations
from 0.01 to 50 ug/m3 over 4- to 24-hour sampling periods.
The detection limit 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 analysis methodology described in this
document is currently employed by laboratories using EPA Method
608. The sampling methodology has been formulated to meet the
needs of pesticide sampling in ambient air.
2. Applicable Documents
2.1 ASTM Standards
D1356 - Definitions of Terms Related to Atmospheric
Sampling and Analysis.
D1605-60 - Standard Recommended Practices for Sampling
Atmospheres for Analysis of Gases and Vapors.
E260 - Recommended Practice for General Gas Chroma-
tography Procedures.
E355 - Practice for Gas Chromatography Terms and
Relationships.
2.2 EPA Documents
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T010-2
2.2.1 Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, EPA-600/4-84-041,
U.S. Environmental Protection Agency, Research Triangle
Park, NC, April 1984. •
2.2.2 Manual of Analytical Methods for Determination of Pesti-
cides in Humans and Environmental Standards, EPA-
600/8-80-038, U.S. Environmental Protection Agency,
Research Triangle Park, NC, July 1982.
2.2.3 "Test Method 608, Organochlorine Pesticides and PCBs,"
in EPA-600/4-82-057, U. S. Environmental Protection
Agency, Cincinnati, Ohio, July 1982.
2.2.4 R. 6. Lewis, ASTM draft report on standard practice
for sampling and analysis pesticides and polychlorinated
biphenyls in indoor atmospheres, U. S. Environmental
Protection Agency, Research Triangle Park, NC, June 1987.
Summary of Method
3.1 A low volume (1 to 5 L/minute) sampler is used to collect va-
pors on a sorbent cartridge containing PUF. Airborne particles
may also be collected, but the sampling efficiency is not known.
3.2 Pesticides are extracted from the sorbent cartridge with 5%
diethyl ether in hexane and determined by gas-liquid chro-
matography coupled with an electron capture detector (ECD).
For some organochlorine 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.
3.3 Interferences resulting from analytes having similar retention
times during gas-liquid chromatography are resolved by improv-
ing the resolution or separation, such as by changing the
chromatographic column or operating parameters, or by frac-
tionating the sample by column chromatography.
3.4 Sampling procedure is also applicable.to other pesticides
which may be determined by gas-liquid chromatography coupled
with a nitrogen-phosphorus detector (NPD), flame photometric
detector (FPD), Hall electrolytic conductivity detector (HECD),
or a mass spectrometer (MS).
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T010-3
4. Significance
4.1 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.
4.2 Many pesticides exhibit bioaccumulative, chronic health effects;
therefore, monitoring the presence of these compounds in ambient
air is of great importance.
4.3 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.
Moreover, the PUF cartridge used in this method provides for
successful collection of most pesticides.
5. Definitions
Definitions used in this document and in any user-prepared Standard
Operating Procedures (SOPs) should be consistent with ASTM D1356,
01605-60, 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
vapors of interest. %SE is the percentage of the analyte of in-
terest 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.
5.2 Retention efficiency (RE) - ability of sampling medium to retain
a compound added (spiked) to it in liquid solution.
5.2.1 Static retention efficiency - ability of the sampling
medium to retain the solution spike when the
sampling cartridge is stored under clean, quiescent
conditions for the duration of the test period.
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6.
T010-4
5.2.2 Dynamic retention efficiency - ability of the sampling
medium to retain the solution spike when air or nit-
rogen 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.
5.3 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.
5.4 Relative retention time (RRT) - a ratio of RTs for two chemi-
cals for the same chromatographic column and carrier gas flow
rate, where the denominator represents a reference chemical.
Interferences
6.1 Any gas or liquid chromatographic separation of complex mix-
tures of organic chemicals is subject to serious interference
problems due to coelution of two or more compounds. The use
of capillary or narrowbore columns with superior resolution
and/or two or more columns of different polarity will
frequently eliminate these problems.
6.2 The electron capture detector responds to a wide variety of
organic compounds. It is likely that such compounds will be
encountered as interferences during 6C/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 gene-
rally provide positive identification of specific compounds.
6.3 Certain organochlorine pesticides (£.£•> chlordane) are complex
mixtures of individual compounds that can make difficult
accurate quantification of a particular formulation in a multiple
component mixture. Polychlorinated biphenyls (PCBs) may inter-
fere with the determination of pesticides.
-------
T010-5
6.4 Contamination of glassware and sampling apparatus with traces
of pesticides can be a major source of error, particularly at
lower analyte concentrations. Careful attention to cleaning
and handling procedures is required durina 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 (£.£.,
organophosphorus and carbamate classes), can be removed
by column chromatography on alumina. This sample clean-
up will permit analysis of most organochlorine pesticides.
6.5.2 PCBs may be separated from other organochlorine
pesticides by column chromatography on silicic
acid. . . :
6.5.3 Many pesticides can be fractionated into groups by column
chromatography on Florisil (Floridin Corp.).
7. Apparatus
7.1 Continuous-flow sampling pump (Figure 1) - (DuPont Alpha-4
Air Sampler, E.I. DuPont de Nemours & Co., Ino«, Wilimington,
DE, 19898, or equivalent).
7.2 Sampling cartridge (Figure 2) - constructed from a 20 mm (i..d.)
x 10 cm borosilicate glass tube drawn down to a.7 mm;(o.d.)
open connection for attachment to the pump via Tygon tubing
(Norton Co., P.O. Box 350, Akron, OH, 44309, or, equivalent).
The cartridge can be fabricated inexpensively from glass by
Kontes (P.O. Box 729, Vineland, NJ, 08360), 6Fequivalent.
7.3 Sorbent, polyurethane foam (PUF) - .cut 'into a cylinder, 22 mm
in diameter and 7.6 cm long, fitted under slight compression
inside the cartridge. The PUF should be of the polyether type,
(density No. 3014 or 0.0225 g/cm3) used for furniture upholstery,
pillows, and mattresses; it may be obtained from Olympic Products
Co. (Greensboro, NC),. or equivalent source. The PUF cylinders
(plugs) should be slightly larger in diameter than the internal
diameter of the cartridge. They may be cut by one of the
following means:
-------
f010-6 ' • •
0 With a high-speed cutting tool, such as a motorized
cork borer. Distilled water should be used to lub-
ricate the cutting tool. •
0 With a hot wire cutter. Care should be exercised
to prevent thermal degradation of the foam.
0 With scissors, while plugs are compressed between
the 22 mm circular templates.
Alternatively, pre-extracted PUF plugs and glass cartridges
may be obtained commercially (Supelco, Inc., Supelco Park,
Bellefonte, PA, 16823, No. 2-0557, or equivalent),
7.4 Gas chromatograph (GC) with an electron capture detector (ECD)
and either an isothermally controlled or temperature-programmed
heating oven. The analytical system should be complete with all
required accessories including syringes, analytical columns,
gases, detector, and strip chart recorder. A data system is
recommended for measuring peak heights. Consult EPA Method 608
for additional specifications.
7.5 Gas chromatographic column, such as 4- or 2-mm (i.d.) x 183 cm
borosilicate glass packed with 1.5% SP-2250 (Supelco, Inc.)/1.95%
SP-2401 (Supelco, Inc.) on 100/120 mesh Supelcoport (Supelco,
Inc.), 4% SE-30 (General Electric, 50 Fordham Rd., Wilmington, MAS
01887, or equivalent)/6% OV-210 (Ohio Valley Specialty Chemical,
115 Industry Rd., Marietta, OH, 45750, or equivalent) on 100/200 ,
mesh Gas Chrom Q (Al Itec Assoc., Applied Science Labs, 2051
Waukegan Rd, Deerfield, II, 60015, or equivalent) ,3% OV-101
(Ohio Valfey Specialty Chemical ) on UltraBond (Ultra Scientific,
1 Main St., Hope, RI, 02831, or equivalent) and 3% OV-1 (Ohio
Valley Specialty Chemical"). on 80/100 mesh Chromosorb WHP
(Manville, Filtration, and Materials, P.O. Box 5108, Denver
CO, 80271, or equivalent). Capillary GC column, such as 0.32
mm (i.d.) x 30 m DB-5 (J&W Scientific, 3871 Security Park Dr.,
Rancho Cordova, CA, 95670, or equivalent) with 0.25 urn film thick-
ness. HPLC column, such as 4.6 mm x 25 cm Zorbax SIL (DuPont
Co., Concord Plaza, Wilmington, DE, 19898, or equivalent) or
u-Bondapak C-18 (Millipore Corp., 80 Ashby Rd., Bedfore, MA,
01730, or equivalent).
7.6 Microsyringes - 5 uL volume or other appropriate sizes.
-------
TO10-7
8. Reagents and Materials
[Note: For a detailed listing of various other items required for
extract preparation, cleanup, and analysis, consult U.S. Method 608
which is provided in Appendix A of Method TO-4 in the Compendium.]
8.1 Round bottom flasks, 500 ml, I 24/40 joints.
8.2 Soxhlet extractors, 300 ml, with reflux condensers.
8.3 Kuderna-Danish concentrator apparatus, 500 ml, with Snyder
columns.
8.4 Graduated concentrator tubes, 10 ml, with f 19/22 stoppers
(Kontes, P.O. Box 729, Vine!and, NJ, 08360, Cat. No. K-570050,
size 1025, or equivalent).
8.5 Graduated concentrator tubes, 1 ml, with 5 14/20 stoppers
(Kontes, Vineland, NJ, Cat. No. K-570050, size 0124, or
equivalent).
8.6 TFE fluorocarbon tape, 1/2 in.
8.7 Filter tubes, size 40 mm (i.d.) x 80 mm, (Corning Glass Works,
Science Products, Houghton Park, AB-1, Corning, NY, 14831, Cat.
No. 9480, or equivalent).
8.8 Serum vials, 1 ml and 5 ml, fitted with caps lined with TFE
fluorocarbon.
8.9 Pasteur pipettes, 9 in.
8.10 Glass wool fired at 500°C.
8.11 Boiling chips fired at 500°C.
8.12 Forceps, stainless steel, 12 in.
8.13 Gloves, latex or precleaned (5% ether/hexane Soxhlet extracted)
cotton.
8.14 Steam bath.
8.15 Heating mantles, 500 ml.
8.16 Analytical evaporator, nitrogen blow-down (N-Evap®, Organomation
Assoc., P.O. Box 159, South Berlin, MA, 01549, or equivalent).
8.17 Acetone, pesticide quality.
8.18 n-Hexane, pesticide quality.
8.19 Diethyl ether preserved with 2% ethanol (Mallinckrodt, Inc.,
Science Products Division, P.O. Box 5840, St. Louis, MO, 63134,
Cat. No. 0850, or equivalent).
8.20 Sodium sulfate, anhydrous analytical grade.
8.21 Alumina, activity grade IV, 100/200 mesh.
-------
.T010-8
8.22 Glass chromatographic column (2 mm i.d. x 15 cm long).
8.23 Soxhlet extraction system, including Soxhlet extractors
(500 and 300 ml), variable voltage transformers, and
cooling water source.
8.24 Vacuum oven connected to water aspirator.
8.25 Die.
8.26 Ice chest.
8.27 Silicic acid, pesticide quality.
8.28 Octachloronaphthalene (OCN), research grade, (Ultra Scien-
tific, Inc., 1 Main St., Hope, RI, 02831, or equivalent).
8.29 Florisil (Floridin Corp.).
Assembly and Calibration of Sampling System
9.1 Description of Sampling Apparatus
9.1.1 The entire sampling system is diagrammed in Figure 1.
This apparatus was developed to operate at a rate of
1-5 L/minute and is used by U.S. EPA for low volume
sampling of ambient air. The method writeup presents
the use of this device.
9.1.2 The sampling module (Figure 2) consists of a glass
sampling cartridge in which the PUF plug is retained.
9.2 Calibration of Sampling System
9.2.1 Air flow through the sampling system is calibrated by
the assembly shown in Figure 3. The air sampler must
be calibrated in the laboratory before and after each
sample collection period, using the procedure described
below.
9.2.2 For accurate calibration, attach the sampling cartridge
in-line during calibration. Vinyl bubble tubing (Fisher
Scientific, 711 Forbes Ave., Pittsburgh, PA, 15219, Cat.
No. 14-170-132, or equivalent) or other means (js_.£.,
rubber stopper or glass joint) may be used to connect
the large end of the cartridge to the calibration system.
Refer to ASTM Standard Practice D3686, Annex A2 or
Standard Practice D4185, Annex Al for procedures to
calibrate small volume air pumps.
-------
T010-9
10; Preparation of Sampling (PDF) Cartridges
10.1 The PUF adsorbent is white and yellows upon exposure to light.
10.2 For initial cleanup and quality assurance purposes, the PUF
plug is placed in a Soxhlet extractor and extracted with ace-
tone for 14 to 24 hours at 4 to 6 cycles per hour (If commer-
cially pre-extracted PUF plugs are used, extraction with ace-
tone is not required.). This procedure is followed by a 16-hour
Soxhlet extraction with 5% diethyl ether in n-hexane. When
cartridges are reused, 5% ether in n-hexane can be used as the
cleanup solvent.
10.3 The extracted PUF is placed in a vacuum oven connected to a
water aspirator and dried at room temperature for 2 to 4 hours
(until no solvent odor is detected). The clean PUF is placed in
labeled glass sampling cartridges using gloves and forceps. The
cartridges are wrapped with hexane-rinsed aluminum foil and
placed in glass jars fitted with TFE fluorocarbon-lined caps.
The foil wrapping may also be marked for identification using
a blunt probe.
10.4 At least one assembled cartridge from each batch should be an-
alyzed as a laboratory blank before any samples are analyzed.
A blank level of <10 ng/plug for single component compounds is
considered to be acceptable. For multiple component mixtures,
the blank level should be <100 ng/plug.
11. Sampling
11.1 After the sampling system has been assembled and calibrated as
per Section 9, it can be used to collect air samples as described
bel ow.
11.2 The prepared sample cartridges should be used within 30 days of
loading and should be handled only with latex or precleaned
cotton gloves.
11.3 The clean sample cartridge is carefully removed from the alumi-
num 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 horizontally.
The sampler is located in an unobstructed area at least 30 cm
-------
T010-10
from any obstacle to air flow. The PUF cartridge intake is
positioned 1 to 2 m above ground level. Cartridge height above
ground is recorded on the Sampling Data Form shown in Figure 4.
11.4 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 data sheet.
Ambient temperatures and barometric pressures are measured and
recorded periodically during the sampling procedure.
11.5 At the end of the desired sampling period, the power is turned
off and the PUF cartridges are wrapped with the original alumi-
num foil and placed in sealed, labeled containers for transport
back to the laboratory. At least one field blank is returned
to the laboratory with each group of samples. A field blank
is treated exactly like a sample except that no air is drawn
through the cartridge. Samples are stored at -10°C or below
until analyzed.
12. Sample Preparation, Cleanup, and Analysis
[Note: Sample preparation should be preformed under a properly
ventilated hood.]
12.1 Sample Preparation
12.1.1 All samples should be extracted within 1 week after
collection.
12.1.2 All glassware is washed with a suitable detergent;
rinsed with deionized water, acetone, and hexane;
rinsed again with deionized water; and fired in an
oven (450°C).
12.1.3 Sample extraction efficiency is determined by spik-
ing the samples with a known solution. Octachloro-
naphthalene (OCN) is an appropriate standard to use
for pesticide analysis using GC/ECD techniques. The
spiking solution is prepared by dissolving 10 mg of
OCN in 10 ml of 10% acetone in n-hexane, followed by
serial dilution with n-hexane to achieve a final
concentration of 1 ug/mL.
-------
T010-11
12.1.4 The extracting solution (5% ether/hexane) is prepared
by mixing 1900 mL of freshly opened hexane and 100 ml
of freshly opened ethyl ether (preserved with ethanol)
to a flask.
12.1.5 All clean glassware, forceps, and other equipment to
be used are placed on rinsed (5% ether/hexane) aluminum
foil until use. The forceps are also rinsed with 5%
ether/hexane. The condensing towers are rinsed with
5% ether/hexane and 300 ml are added to a 500 ml round
bottom boiling flask.
12.1.6 Using precleaned (.§_.£., 5% ether/hexane Soxhlet extracted)
cotton gloves, the PDF cartridges are removed from the
sealed container and the PDF is placed into a 300
ml Soxhlet extractor using prerinsed forceps.
12.1.7 Before extraction begins, 100 uL of the OCN solution
are added directly to the top of the PUF plug. Addition
of the standard demonstrates extraction efficiency of the
Soxhlet procedure. [Note: Incorporating a known concen-
tration of the solution onto the sample provides a quality
assurance check to determine recovery efficiency of the
extraction and analytical processes.]
12.1.8 The Soxhlet extractor is then connected to the 500 ml
boiling flask and condenser. The glass joints of the
assembly are wet with 5% 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.
12.1.9 The water flow to the condenser towers of the Soxhlet
extraction assembly is checked and the heating unit is.
turned on. As the samples boil, the Soxhlet extractors
are inspected to ensure that they are filling and siphon-
ing properly (4 to 6 cycles/hour). Samples should cycle
for a minimum of 16 hours.
-------
T010-12
12.1.10 At the end of the extracting process, the heating units
are turned off and the samples are cooled to room temper-
ature.
12.1.11 The extracts are concentrated to a 5 ml solution using a
Kuderna-Danish (K-D) apparatus. The K-D is set up and
assembled with concentrator tubes. This assembly is
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 placed in the neck of the K-D.
The Soxhlet extractors and boiling flasks are carefully
removed from the condenser towers and the remaining sol-
vent 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 hex-
ane 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. The sample is removed from the steam bath and
allowed to cool. Each Synder column is rinsed with a
minimum of hexane. Sample volume is adjusted to 10 ml
in a .concentrator tube, which is then closed with a glass
stopper and sealed with TFE fluorocarbon tape. Alterna-
tively, the sample may be quantitatively transferred (with
concentrator tube rinsing) to prescored vials and brought
up to final volume. Concentrated extracts are stored
at -10°C until-analyzed. Analysis should occur no later
than two weeks after sample extraction.
12.2 Sample Cleanup
12.2.1 If only organochlorine pesticides 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, activity grade IV, and rinsed with
approximately 20 mb-of n-hexane. The concentrated sample
-------
T010-13
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.12.3.
12.2.3 If other pesticides are sought, alternate cleanup pro-
cedures may be required (£.£., Florisil). EPA Method 608
identifies appropriate cleanup procedures.
12.3 Sample Analysis
12.3.1 Organochlorine pesticides and many nonchlorinated pesti-
cides are responsive to electron capture detection
(Table 1). Most of these compounds can be determined at
concentrations of 1 to 50 ng/mL by GC/ECD.
12.3.2 An appropriate GC column is selected for analysis of the
extract. (For example, 4 mm i.d. x 183 cm glass, packed
with 1.5% SP-2250/1,95% SP-2401 on 100/120 mesh Supelo-
port, 200°C isothermal, with 5% methane/95% argon carrier
gas at 65 to 85 mL/min). A chromatogram showing a mix-
ture containing single component pesticides determined
by GC/ECD using a packed column is shown in Figure 5.
A table of corresponding chromatographic characteristics
follows in Figure 6.
12.3.3 A standard solution is prepared from reference materials
of known purity. Standards of organochlorine pesticides
may be obtained from the National Bureau of Standards
and from the U.S. EPA.,
12.3.4 Stock standard solutions (1.00 ug/uL) are prepared by
dissolving approximately 10 milligrams of pure material
in isooctane and diluting to volume in a 10 ml volu-
metric flask. Larger volumes can be used at the con-
venience of the analyst. If compound purity is cer-
tified at 96% or greater, the weight can be used with-
out correction to calculate the concentration of the
stock standard. Commerically prepared stock standards
may be used at any concentration if they are certified
by the manufacturer or an independent source.
12.3.5 The prepared stock standard solutions are transferred
to Teflon-sealed screw-capped bottles and stored at -10°C
for no longer than six months. The standard solutions
should be inspected frequently for signs of degradation
-------
T010-14
or evaporation (especially before preparing calibration
standards from them). [Note: Quality control check
standards used to determine accuracy of the calibration
standards are available from the U.S. Environmental
Protection Agency, Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio 45268.]
12.3.6 The standard solutions of the various compounds of
interest are used to determine relative retention
times (RRTs) to an internal standard such as £,£'-DDE,
aldrin, or OCN.
12.3.7 Before analysis, the GC column is made sensitive to the
pesticide samples by injecting a standard pesticide solu-
tion ten (10) times more concentrated than the stock
standard solution. Detector linearity is then determined
by injecting standard solutions of three different concen-
trations that bracket the required range of analyses.
12.3.8 The GC system is calibrated daily with a minimum of
three injections of calibrated standards. Consult EPA
Method 608, Section 7 for a detailed procedure to
calibrate the gas chromatograph.
12.3.9 If refrigerated, the sample extract is removed from the
cooling unit and allowed to warm to room temperature. The
sample extract is injected into the GC for analysis in
an aliquot of approximately 2-6 uL using the solvent-
flush technique (Ref. D3687, 8.1.4.3-8.1.4.5). The actual
volume injected is recorded to the nearest 0.05 uL. After
GC injection, the sample's response from the strip chart
is analyzed by measuring peak heights or determining peak
areas. Ideally, the peak heights should be 20 to 80% of
full scale deflection. Using injections of 2 to 6 uL of
each calibration standard, the peak height or area re-
sponses are tabulated against the mass injected (injec-
tions of 2, 4, and 6 uL are recommended). If the response
(peak height or area) exceeds the line-ar range .of detec-
tion, the extract is diluted and reanalyzed.
-------
T010-15 .,•• • : . ' >'
12.3.10 Pesticide mixtures are quantified by comparison of the
total heights or areas of GC peaks with the correspond-
ing peaks in the best-matching standard. If both PCBs
and organochlorine pesticides are present in the same
sample, column chromatographic separation on silicic
acid is used before GC analysis, according to ASTM
Standards, Vol.14.01. If polar compounds that interfere
with GC/ECD analysis are present, column chromatographic
cleanup on alumina (activity grade IV) is used as per
Section 12.2.2. ;
12.3.11 For confirmation, a second GC column is used such as
4% SE-30/6% OV-210 on 100/200 mesh Gas Chrom Q or 3%
OV-1 on 80/100 mesh Chromosorb WHP. For improved re-
solution, a capillary column is used such as 0.32 mm
(i.d.) x 30 m DB-5 with 0.25 urn film thickness..
12.3.12 A chromatogram of a mixture containing single component
pesticides determined by GC/ECD using a capillary column
is shown ,in Figure 7. A table of the correspondihg :
chromatographic characteristics follows in Figure 8.
12.3.13 Class separation and improved specificity can be achieved
by column chromatographic separation on Florisil as per
EPA: Method 608. For improved specificity, a Hall
electrolytic conductivity detector operated in the
reductive mode;may be substituted for the electron
; capture detector. Limits of detection^Will be reduced
by at least an order of magnitude,.however.
1.3. GC Calibration ; \ ' ;
Appropriate calibration procedures are identified in EPA Method 608,
Section 7. V : ..
14. Calculations
14.1 The concentration of the analyte in the extract solution is
taken from a standard curve where peak height or area is
plotted linearly against concentration in nanograms per milli-
liter (ng/mL). If the detector response is; known to be linear,
a single point is used as a calculation constant.
14.2 From the standard curve, determine the ng of analyte standard
equivalent to the peak height or area for a particular compound.
-------
T010-16
14.3 Determine if the field blank is contaminated. Blank levels
should not exceed 10 ng/sample for organochl orine pesticides
or 100 ng/sample for other pesticides. If the blank has been
contaminated, the sampling series must be held suspect.
14.4 Quantity of the compound in the sample (A) is calculated
using the following equation:
A = 1000
(A, x vp\
V ,vi /
where:
A = total amount of analyte in the sample (ng).
As = calculated amount of material (ng) injected onto the
chromatograph based on calibration curve for injected
standards.
Ve = final volume of extract (ml).
V-j = volume of extract injected (uL).
1000 = factor for converting microliters to milliliters.
14.5 The extraction efficiency (EE) is determined from the recovery
of octachloronaphthalene (OCN) spike as follows:
EE(%) = S_ x 100
Sa
where:
S = amount of spike (ng) recovered.
Sa = amount of spike (ng) added to plug.
14.6 The total amount of nanograms found in the sample is corrected
for extraction efficiency and laboratory blank as follows:
Ac = A - AQ
IFW
where:
AC = corrected amount of analyte in sample (ng).
A0 = amount of analyte in blank (ng).
-------
T010-17
14.7 The total volume of air sampled under ambient conditions is
determined using the following equation:
n
Vfl = i = 1
1000 L/m3
where:
Va = total volume of air sampled (m3).
T-J = length of sampling segment (min) between flow checks.
F-J = average flow (L/min) during sampling segment.
14.8 The air volume is corrected to 25° and 760 mm Hg (STP) as
follows:
Vs =
/ Ph - Pw \ ./298 K\
\ 760 mm Hg/ \ tp, /
where:
Vs = volume of air (m3) at standard conditions.
Va = total volume of air sampled (m3).
Pb = average ambient barometric pressure (mm Hg).
Pw = vapor pressure of water (mm Hg) at calibration temperature,
t/n = average ambient temperature (K).
14.9 If the proper criteria for a sample have been met, concentration
of the compound in a cubic meter of air is calculated as follows:
ng/m3 = Ac x 100
where:
SE = sampling efficiency as determined by the procedure out-
lined in Section 15.
If it is desired to convert the air concentration value to parts
per trillion (wt/wt) in dry air at STP, the following conversion
is used:
ppt = 1.205 ng/m3
-------
k45 /ng/m3 \
I MW I
T010-18
The air concentration is converted to parts per trillion (v/v) in
air .at STP as follows:
pptv = 24.
where:
MW = molecular weight of the compound of interest.
15. Sampling and Retention Efficiencies
15.1 Before using this procedure, the user should determine the sam-
pling efficiency for the compound of interest. The sampling
efficiencies shown in Tables 2 and 3 were determined for approxi-
mately 1 m3 of air at about 25°C, sampled at 3.8 L/min. Sampling
efficiencies for the pesticides shown in Table 4 are for 24 hours
at 3.8 L/min and 25°C. For compounds not listed, longer sampling
times, different flow rates, or other air temperatures, the fol-
lowing procedure may be used to determine sampling efficiencies.
15.2 SE is determined by a modified impinger assembly attached to the
sampler pump (Figure 9). 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.] PUF plugs (22 mm x 7.6
cm) are placed in the primary and secondary traps and are atta-
ched to the pump.
15.3 A standard solution of the compound of interest is prepared
in a volatile solvent (£.£., hexane, pentane, or benzene). A
small, accurately measured "volume (£.£., 1 ml) of the standard
solution is placed into the modified midget impinger. The
sampler pump is set at the rate to be used in 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 12.3.
15.4 The impinger is rinsed with hexane or another suitable solvent
and quantitatively transferred to a volumetric flask or concen-
trator tube for analysis.
-------
T010-19
15.5 The sampling efficiency (SE) is determined using the following
equation:
% SE = WT x 100
W0 - Wp
where:
Wi = 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)
15.6 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, Wg, to Wi, will provide an indication of
the overall sampling efficiency of a tandem-trap sampling system.
The sum of Wj, ^2 (1f any)» and wr must eclual (approximately +_
10%) W0 or the test is invalid.
15.7 If the compound of interest is not sufficiently volatile to vapo-
rize at room temperature, the impinger may be heated in a water
bath or other suitable heater to a maximum of 50°C to aid volati-
lization. If the compound of interest cannot be vaporized at
50°C or without thermal degradation, dynamic retention efficiency
(REd) may be used to estimate sampling efficiency. Dynamic re-
tention efficiency is determined in the manner described in 15.8.
Table 5 lists those organochlorine pesticides which dynamic re-
tention efficiencies have been determined.
15.8 A pair of PDF 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 (e_.£., dessicator).
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 15.9). Prefiltered
nitrogen or ambient air is drawn through the assembly as per
Section 15.3. [Note: Impinger may be discarded.] Each PUF
plug (spiked and static control) is analyzed separately as per
Section 12.3.
-------
T010-20
15.9 % REd is calculated as follows:
Ml x 100
% REd = W0
where:
w"i = amount of compound (ng) recovered from primary plug.
W0 = amount of compound (ng) added to primary plug.
If a residue, V/2, is found on the secondary plug, breakthrough
has occurred. The sum of Wi + W2 must equal" W0, within 25% or
the test is invalid. For most compounds tested by this proce-
dure, % REd values are generally less than % SE values determined
per Section 15.1. The purpose of the static RE
-------
T010-21
16.2 Process, Fields and Solvent Blanks
• 16.2.1 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.
16.2.2 During each sampling episode, at least one PUF cartridge
should be shipped to the field and returned, without draw-
ing air through the sampler, to serve as a field blank.
16.2.3 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 peroid. 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.
16.2.4 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.
16.2.5 Blank levels should not exceed 10 ng/sample for single
components or 100 ng/sample for multiple component mix-
tures (e^.£., for organochlorine pesticides).
16.3 Sampling Efficiency and Spike Recovery
16.3.1 Before using the method for sample analysis, each labo-
ratory must determine its sampling efficiency for the
^component of interest as per Section 15.
16.3.2 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.
-------
T010-22
16.3.3 The sampling system is activated and set at the desired
sampling flow rate. The sample flow is monitored for
24 hours.
16.3.4 The PUF cartridge is then removed and analyzed as per
Section 12.3.
16.3.5 A second sample, unspiked, is collected over the same
time period to account for any background levels of
components in the ambient air matrix.
16.3.6 In general, analytical recoveries and collection effi-
ciencies of 75% are considered to be acceptable method
performance.
16.3.7 Replicate (at least triplicate) determinations of col-
lection efficiency should be made. Relative standard
deviations for these replicate determinations of +15%
or less are considered acceptable performance.
16.3.8 Blind spiked samples should be included with sample sets
periodically as a check on analytical performance.
16.4 Method Precision and Accuracy
1'6.4.1 Several different parameters involved in both the samp-
ling and analysis steps of this method collectively
determine the accuracy 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 com-
ponent 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
accuracy 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.
-------
T010-23
>
16.4.2 The reproducibility of this method has been determined to
range from +5 to +30% (measured as the relative stan-
dard 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 75 to 115% are considered accept-
able. PUF alone may give lower recoveries for more vola-
tile compounds (e_.£., those with saturation vapor pres-
sures >10~3 mm Hg). In those cases, another sorbent or
a combination of PUF and Tenax GC should be employed.
16.5 Method Safety
This procedure may involve hazardous materials, operations, and
equipment. This method does not purport to address all of the
safety problems associated with its use. 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.
-------
T010-24
TABLE 1. 'PESTICIDES DETERMINED BY
GAS CHROMATOGRAPHY/ELECTRON CAPTURE DETECTOR (GC/ECD)
Aldrin
BHC (« - and /3-Hexa-
chlorocyclohexanes)
Captan
Chlordane, technical
Chlorothalonil
Chlorpyrifos
2,4,-D esters
£,£,-DDT
£,£,-DDE
Dieldrin
Dichlorvos (DDVP)
Dicofol
Endrih-
Endrin aldehyde
Folpet
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Lindane (y-BHC)
Methoxychlor
Mexacarbate
Mi rex
trans-Nonachlor
Oxychlordane
Pentachlorobenzene
Pentachlorophenol
Ronnel
254,5-Trichlorophenol
-------
T010-25
TABLE 2. SAMPLING EFFICIENCIES FOR SOME ORGWOCHLORINE PESTICIDES
Compound
a -Hexachl orocycl o-
hexane («-BHC)
y-Hexachl orocycl o-
hexane (Lindane)
Hexachl orobenzene t
Chlordane, technical
£,£' -DDT
£,£'-DDE
Mi rex ,
Pentachl orobenzene "*"
Pentachl orophenol
2,4,5-trichlorophenol
2,4-D Esters:
isopropyl
butyl
i so butyl
i sooctyl
Quantity
Introduced, ug
0.005
0.05-1.0
0.5, 1.0
0-2
0.6, 1.2
0.2, 0.4
0.6, 1.2
1.0
1.0
t 1.0
0.5
0.5
0.5
0.5
Air
Volume,
m3
0.9
0.9
0.9
0.9
0.9
0.9
0.9
0.9
0.9
0.9
3.6
3.6
3.6
3.6
Sampling
Efficiency, ",
mean RSD
115
91.5
94.5
84.0
97.5
102
85.9
94
107
108
92.0
82.0
79.0
>80*
8
8
8
11
21
11
22
12
16
3
5
10
20
i
n
6
5
5
8
12
12
7
5
5
5
12
11
12
* Not vaporized. Value base on %RE = 81.0 (RSD = 10%, n = 6).
t Semi volatile organochlorine pesticides.
-------
T010-26
TABLE 3. -SAMPLING EFFICIENCIES FOR ORGANOPHOSPHORUS PESTICIDES
Compound
Dichlorvos (DDVP) ,
Ronnel
Chlorpyrifos
Diazinon9
Methyl parathion3
Ethyl parathion3
Mai at hi on3
Quantity
Introduced,*5
0.2
-0.2
0.2
1.0
0.6
0.3
0.3
Sampling
Efficiency, %
ug mean RSD n
72.0
f ' ' 106
108
84.0
80.0
75,9
10QC
13 2
• ' '
8 12
9 12
18 18
19 18
15 18
__ --
b
c
Analyzed by gas chromatography with nitrogen phosphorus detector or
flame photometric detector.
Air volume = 0.9 m3. ;
Decomposed in generator; value based on %RE
(RDS = 7, n = 4).
101
-------
T010-27
TABLE 4. EXTRACTION AND 24-HOUR SAMPLING EFFICIENCIES FOR VARIOUS
PESTICIDES AND RELATED COMPOUNDS
Compound
Chlorpyrifos
Pentachlorophenol
Chlordane
Lindane
DDVP
2,4-D methyl ester
Heptachlor
Aldrin
Dieldrin
Rorinel
Di azi non
trans-Nonachlor
Oxychlordane
«-BHC
Chlorothalonil
Heptachlor epoxide
Extraction ^ Sampling
Efficiency, *% 10 ng/m3
mean RSD mean RSD
83
84
95
96
88
• -
99
97
95
80
72
97
100
98
90
100
.3
.0
.0
.0'
.3
-
.0
.7
.0
.¥'
.0
.7
.0
.0
.3
.0
11
22
7
6
20
-
1
4
7
19
21
4
0
3
8
0
•5
.6
.1
•9
.2
-
.7
.0
.•0
.5
.8
•0
.0
.5
14
•°
83
66
96
91
51
75
97
90
82
" 74
,63
96
95
86
76
95
.7
.7
.0
.7
.0
.3
.3
.7
.7
.7
.7
.7
.3
.7
.7
.3
18.0
42.2
1.4
11.6
53.7
6.8
13.6
5.5
7.6
12.1
18.9
,4.2
9.5
13.7
6.1
5.5
Efficiency,
100 ng/m3
mean RSD
92.7
52.3
74.0
93.0
106.0
58.0
103.0
94.0
85.0
60.7
41.3
101.7
94.3
97.0
70.3
97.7
15.1
36.2
8.5
2.6
1.4
23.6
17.3
2.6
11.5
15.5
26.6
15.3.
1.2
18.2
6.5
14.2
t %, at
1000 ng/nv3
mean RSD
83.7
66.7
96.0
91.7
51.0
75.3
97.3
90.7
82.7
74.7
63.7
96.7
95.3
86.7
76.7
95.3
18.0
42.2
1.4
11.6
53.7
6.8
13.6
5.5
7.6
12.2
19.9
4.2
9.5
13.7
6.1
5.5
* Mean values for one spike at 550 ng/plug and two spikes at 5500 ng/plug.
t Mean values for three determinations.
-------
T012-28
Table 5. EXTRACTION AND 24-HOUR SAMPLING EFFICIENCIES FOR VARIOUS
PESTICIDES AND RELATED COMPOUNDS
Compound
Dicofol
Captan
Methoxychlor
Folpet
Extraction
Efficiency, *%
mean RSD
57.0 8.5
73.0 12.7
65.5 4.9
86.7 11.7
Retention Efficiency, t %, at
10 ng/m3 100 ng/m3 1000 ng/m3
mean RSD mean RSD mean RSD
38.0 25.9 65.0 8.7 69.0
56.0 — 45.5 64.3 84.3
- ,..—,. ,,78.5;;..
— — 78.0 -- 93.0
—
16.3
1*4
— T
* Mean Values for one spike at 550 ng/plug and two spikes at 5500 ng/plug.,
t Mean Values for generally three determinations. :, '
-------
T010-29
SAMPLING CARTRIDGE
115V ADAPTER/
CHARGER PLUG
FIGURE 1. LOW VOLUME AIR SAMPLER
-------
T010-30
•I»Hift:.&?iS--gV^^^
FIGURE 2. POLYURETHANE FOAM (PUF) SAMPLING
CARTRIDGE
-------
T010-31
FLOW RATE
METER (0-1 in H20)
If
FLOW RATE
VALVE
500 mL
BUBBLE
TUBE
)
AIR IN
DISH WITH
BUBBLE SOLUTION
PRESSURE DROP
METER (0-50 in H20)
PRESSURE DROP
VALVE
PUMP
FIGURE 3. CALIBRATION ASSEMBLY FOR AIR SAMPLER
PUMP
-------
T010-32
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-------
T010-33
OPERATING CONDITIONS
Column Type: 1.5% SP 2250/1.95% SP 2401,
1/4" glass.
Temperature: 200°C isothermal.
Detector: Electron Capture.
Carrier Gas: 5% Methane/95% Argon.
Flow Rate: 65 to 85 mL/min.
Lindane
Heptachlor
Aldrin
Dibutylchlorendate
SIME
Methoxychlor
FIGURE 5. CHROMATOGRAM SHOWING A MIXTURE OF
SINGLE COMPONENT PESTICIDES DETERMINED BY
GC/ECD USING A PACKED COLUMN
-------
T010-34
EXTERNAL STANDARD TABLE
SINGLE COMPONENT PESTICIDE MIXTURE (5uL) ON
A PACKED COLUMN
RETENTION
TIME
2.77
3.37
4.03
8.90
10.72
14.63
24.87
26.82
. COMPOUND
NAME
gamma-BHC
Heptachlor
Aldrin
Dieldrin
Endrin
p.p.1 -DDT
Di butyl chl
Methoxychl
CONCENTRATION IN PG
ON COLUMN
(Lindane)
orendate*
or
500
500
500
500
500
500
2500
2500
AREA/
HEIGHT
8.2
10.4
12.0
•24.7
30.2
39.0
61.4
57.5
* Internal standard used for earlier pesticide detection.
FIGURE 6. CHROMATOGRAPHIC CHARACTERISTICS OF THE
SINGLE COMPONENT PESTICIDE MIXTURE
DETERMINED BY GC/ECD USING A
PACKED COLUMN
-------
T010-35
OPERATING CONDITIONS
Column Type: DB-5 0.32 capillary,
0.25 urn film thickness
Column Temperature Program: 90°C (4 min)/16°C per min to
154°C/4°C per min to 270°C.
Detector: Electron Capture
Carrier Gas: Helium at 1 mL/min.
Make Up Gas: 5% Methane/95% Argon at 60 mL/min.
Dibutylchlorendate
Methoxychlor
Heptachlor.
Lindane
Aldrin
Endrin
Dieldrin
P,P' DDT
TIME
FIGURE 7. CHROMATOGRAM SHOWING A MIXTURE OF
SINGLE COMPONENT PESTICIDES DETERMINED BY
GC/ECD USING A CAPILLARY COLUMN
-------
T010-36
EXTERNAL STANDARD TABLE
SINGLE COMPONENT PESTICIDE MIXTURE (2uL) ON
ON A CAPILLARY COLUMN
RETENTION
TIME
14.28
17.41
18.96
23.63
24.63
27.24
29.92
31.49
COMPOUND
NAME
CONCENTRATION IN
ON COLUMN
gamma-BHC (Lindane)
Heptachlor
Aldrin
Dieldrin
Endrin
p,p'-DDT
Methoxychlor
Di butyl chl orendate*
PG
200
200
200
200
200
200
1000
1000
AREA/
HEIGHT
5.2
5 "3
.3
5/1
.4
5.8
6.3
5.6
5.5
5*
.4
* Internal standard used for earlier pesticide detection.
FIGURE 8. CHROMATOGRAPHIC CHARACTERISTICS OF THE
SINGLE COMPONENT PESTICIDE MIXTURE
DETERMINED BY GC/ECD USING A
CAPILLARY COLUMN
-------
T010-37
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-------
Revision 1.0
June, 1987
METHOD T011
METHOD FOR THE DETERMINATION OF FORMALDEHYDE IN AMBIENT AIR
USING ADSORBENT CARTRIDGE FOLLOWED BY HIGH PERFORMANCE
LIQUID CHROMATOGRAPHY (HPLC)
1. Scope
1.1 This document describes a method for the determination of
formaldehyde in ambient air utilizing solid adsorbent fol-
lowed 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 Compendium Method T05, "Method For the Determination of
Aldehydes and Ketones in Ambient Air Using High Perform-
ance Liquid Chromatography (HPLC)" involves drawing
ambient air through a midget impinger sampling train con-
taining 10 mL of 2N HC1/0.05% 2,4-dinitrophenylhydrazine
(DNPH) reagent. Aldehydes and ketones readily form a stable
derivative with the DNPH reagent, and the DNPH derivative
is analyzed for aldehydes and ketones utilizing HPLC.
Method T011 modifies the sampling procedures outlined in
Method T05 by introducing a coated adsorbent for sampling
formaldehyde. This current method is based on the specific
reaction of organic carbonyl compounds (aldehydes and
ketones) with DNPH-coated cartridges in the presence of an
acid to form stable derivatives according to the following
equation:
N02
"\ >~\_ H* \
C = 0 + H2N-NH-A >~N02 !± ^ NC = IV
R
,Alr,CARBONYL GROUP 2,4-DINITROPHENYLHYDRAZINE
(ALDEHYDES AND KETONES) (DNPH) DNPH-DERIVATIVE WATER
where R and R1 are organic alkyl or aromatic group (ketones) or
either substituent is a hydrogen (aldehydes).
-------
T011-2
The determination of formaldehyde from the DNPH-formaldehyde
•derivative is similar to Method T05 in incorporating HPLC.
The detection limits have been extended and other aldehydes
and ketones can be determined as outlined in Section 14.
1.3 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 (1-20) 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.
1.4 The sampling flow rate, as described in this document, is
presently limited to about 1.5 L/min. This limitation is
principally due to the high pressure drop across the DNPH-
coated silica gel cartridges. Because of this, the procedure is
not compatible with pumps used in personal sampling equipments.
1.5 The method instructs the user to purchase Sep-PAK chromato-
graphic grade silica gel cartridges (Waters Associates,
34 Maple St., Mil ford, MA 01757) and apply acidified DNPH
in situ to each cartridge as part of the user-prepared
quality assurance program (1,2). Commercially pre-coated DNPH
cartridges are also available. [Caution: Recent studies
have indicated abnormally high formaldehyde background
levels in commercially prepacked cartridges. It is advised
that three cartridges randomly selected from each production
lot, be analyzed for formaldehyde prior to use to determine
acceptable levels.] Thermosorb/F cartridges (Thermedics,
Inc., 470 Wildwood St., P.O. Box 2999, Woburn, MA, 01888-1799)
can be purchased prepacked. The cartridges are 1.5 cm ID x
2 cm long polyethylene tubes with Luer®-type fittings on
each end. The adsorbent is composed of 60/80-mesh Florisil
(magnesium silicate) coated with 2,4-dinitrophenylhydrazine.
The adsorbent is held in place with 100 mesh stainless
steel screens at each end. The precoated cartridges are
used as received and are discarded after use. The cartridges
are stored in glass culture tubes with polypropylene caps
and placed in cold storage when not in use.
-------
T011-3
1.6 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 deter-
mine the applicability of regulatory limitations prior to use.
Applicable Documents
2.1 ASTM Standards
D1356 - Definition of Terms Relating to Atmospheric Sampling
and Analysis
E682 - Practice for Liquid Chromatography Terms and
Relationships
2.2 Other Documents
Existing Procedures (3-5)
Ambient Air Studies (6-8)
U. S. EPA Technical Assistance Document (9)
Indoor Air Studies (10-11)
Summary of Method
3.1 A known volume of ambient air is drawn through a prepacked
silica gel cartridge coated with acidified DNPH at a sampling
rate of 500-1200 mL/min for an appropriate period of time.
Sampling rate and time are dependent upon carbonyl concentra-
tion in the test atmosphere.
3.2 After sampling, the sample cartridges are capped and placed in
borosilicate glass culture tubes with polypropylene caps.
The capped tubes are then placed in a friction-top can con-
taining a pouch of charcoal and returned to the laboratory
for analysis. Alternatively, the sample vials can be placed
in a styrofoam 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 of 6 ml of acetonitrile from a plastic syringe
reservoir to a graduated test tube or a 5 ml volumetric flask.
3.3 The eluate is then topped to a known volume and refrigerated
until analysis. . .
3.4 The DNPH-formaldehyde derivative is determined using isocratic
reverse phase HPLC with an ultraviolet (UV) absorption detector
operated at 360 nm.
-------
T011-4
3.5 A cartridge blank is likewise desorbed and analyzed as per Sec-
tion 3.4.
3.6 Formaldehyde and other carbonyl compounds in the sample are iden-
tified and quantified by comparison of their retention times
and peak heights or peak areas with those of standard solutions.
Significance
4.1 Formaldehyde has been found to be a major promoter in the forma-
tion of photochemical ozone (12). In particular, short term ex-
posure 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
(13). Animal studies indicate that high concentrations can in-
jure the lungs and other organs of the body (14). Formaldehyde
may contribute to eye irritation and unpleasant odors that are
common annoyances in polluted atmospheres.
4.2 Formaldehyde emissions result from incomplete combustion of hydro-
carbons and other organic materials. The major emission sources
appear to be vehicle exhaust, incineration of wastes, and burning
of fuels (natural gas, fuel oil, and coal). In addition, signifi-
cant amounts of atmospheric formaldehyde can result from photo-
chemical reactions between reactive hydrocarbons and nitrogen
oxides. Moreover, formaldehyde can react photochemically to pro-
duce other products, including ozone, peroxides, and peroxyacetyl
nitrate compounds. Local sources of formaldehyde may include
manufacturing and other industrial processes using the chemical.
In particular, formaldehyde emissions are associated with any
industrial process that results in the pyrolysis of organic
compounds in air or oxygen. This test method provides a means
to determine concentrations of formaldehyde and other carbonyl
compounds in emissions sources in various working environment
and in ambient indoor and outdoor atmospheres.
Definitions
5.1 Definitions used in this document and in any user-prepared Stan-
dard Operating Procedures (SOPs) should be consistent with ASTM
Methods D1356 and E682. All abbreviations and symbols within
this document are defined the first time they are used.
-------
T011-5
6. Interferences
6.1 This procedure has been written specifically for the sampling
and analysis of formaldehyde. Interferences in the method are
certain isomeric aldehydes or ketones that may be unresolved by
the HPLC system when analyzing for other aldehydes and ketones.
Organic compounds that have the same retention time and signifi-
cant absorbance at 360 nm as the DNPH derivative of formaldehyde
will interfere. Such interferences can often be overcome by
altering the separation conditions (e.g., using alternative HPLC
columns or mobile phase compositions). However, other aldehydes
and ketones can be detected with a modification of the basic
procedure. In particular, ehromatographic conditions can be
optimized to separate acrolein, acetone, and propionaldehyde
and the following higher molecular weight aldehydes and ketones
(within an analysis time of about one hour) by utilizing two
Zorbax ODS columns in series under a linear gradient program:
Formaldehyde Isovaleraldehyde
Acetaldehyde Valeraldehyde
Acrolein o-Tolualdehyde
Acetone m-Tolualdehyde
Propionaldehyde p-Tolualdehyde
Crotonaldehyde Hexanaldehyde
Butyraldehyde 2,5-Dimethylbenzaldehyde
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. The following gradient
program was found to be adequate to achieve this goal: Upon
sample injection, linear gradient from 60-75% acetom'trile/40-25%
water in 30 minutes, linear gradient from 75-100% acetonitrile/
25-0% water in 20 minutes, hold at 100% acetonitrile for 5 minutes,
reverse gradient to 60% acetonitrile/40% water in 1 minute, and
maintain isocratic at 60% acetonitrile/40% water for 15 minutes.
-------
T011-6
6.2 Formaldehyde contamination of the DNPH reagent is a frequently
encountered problem. The DNPH must be purified by multiple
recrystallizations in UV grade acetonitrile. Recrystalliza-
tion 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 acetonitrile until use. Impurity
levels of carbonyl compounds in the DNPH are determined by HPLC
prior to use and should be less than 0.025 ug/mL.
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), or equivalent C-18, 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
or strip chart recorder (Figure 1).
7.2 Sampling system - capable of accurately and precisely sampling
100-1500 mL/min of ambient air (Figure 2). The dry test meter
may not be accurate at flows below 500 mL/min, and should then .
be replaced by recorded flow readings at the start, finish,
and hourly during the collection. The sample pump consists of
a diaphragm or metal bellows pump capable of extracting an air
sample between 500-1200 mL/min. [Note: A normal pressure drop
through the sample cartridge approaches 14 cm Hg at a sampling
rate of 1.5 L/min.]
7.3 Stopwatch. • •- •
7.4 Friction-top metal can (e.g., 1-gallon paint can) or a styrofoam
box with polyethlyene-air bubble padding - to hold sample vials.
7.5 Thermometer - to record ambient temperature.
7.6 Barometer (optional).
7.7 Suction filtration apparatus - for filtering HPLC mobile phase.
7.8 Volumetric flasks - various sizes, 5-2000 mL.
7.9 Pipets - various sizes, 1-50 mL.
7.10 Helium purge line (optional) - for degassing HPLC mobile phase.
7.11 Erlenmeyer flask, 1 L - for preparing HPLC mobile phase.
-------
T011-7,
7.12 Graduated cylinder, 1 L - for preparing HPLC mobile phase.
7.13 Syringe, 100-250 uL - for HPLC injection.
7.14 Sample vials.
7.15 Melting point apparatus.
7.16 Rotameters.
7.17 Calibrated syringes.
7.18 Special glass apparatus for rinsing, storing and dispensing
saturated DNPH stock reagent (Figure 3).
7.19 Mass flow meters and mass flow controllers for metering/setting
air flow rate through sample cartridge of 500-1200 mL/min. [Note:
The mass flow controllers are necessary because cartridges
have a high pressure drop and at maximum flow 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 1 L/min for atmospheres
not heavily loaded with particulates without any problems.]
7.20 Positive displacement, repetitive dispensing pipets (Lab-Indus-
tries, or equivalent), 0-10 mL range.
7.21 Cartridge drying manifold with multiple standard male Luer® con-
nectors.
7.22 Liquid syringes, 10 mL (polypropylene syringes are adequate) for
preparing DNPH-coated cartridges.
7.23 Syringe rack - made of an aluminum plate (0.16 x 36 x 53 cm)
with adjustable legs on four corners. A matrix (5 x 9) of cir-
cular holes of diameter slightly larger than the diameter of
the 10-mL syringes was symetrically drilled from the center of
the plate to enable batch processing of 45 cartridges for clean-
ing, coating, and/or sample elution.
7*24 Luer® fittings/plugs - to connect cartridges to sampling system
and to cap prepared cartridges.
7.25 Hot plates, beakers, flasks, measuring and disposable pipets,
volumetric flasks, etc. - used in the purification of DNPH.
7.26 Borosilicate glass culture tubes (20 mm x 125 mm) with polypro-
pylene screw caps - used to transport Sep-PAK coated cartridges
for field applications (Fisher Scientific, Pittsburgh, PA, or
equivalent).
7.27 Heated probe - necessary when ambient temperature to be sampled
is below 60°F to insure the effective collection of formaldehyde
as a hydrazone.
-------
T011-8
7.28 Cartridge sampler - prepacked silica gel cartridge, Sep-PAK
(Waters Associates, Milford, MA 01757, or equivalent) coated
jn situ with DNPH according to Section 9.
7.29 Polyethylene gloves - used to handle Sep-PAK silica gel cart-
ridges, best source.
8. Reagents and Materials
8.1 2,4-Dinitrophenylhydrazine (DNPH)- Aldrich Chemical or J.T. Baker,
reagent grade or equivalent. Recrystallize at least twice
with UV grade acetonitrile before use.
8.2 Acetonitrile - UV grade, Burdick and Jackson "distilled-in-
glass," or equivalent.
8.3 Oeionized-distilled water - charcoal filtered.
8.4 Perchloric acid - analytical grade, best source. y
8.5 Hydrochloric acid - analytical grade, best source. x
8.6 Formaldehyde - analytical grade, best source.
8.7 Aldehydes and ketones, analytical grade, best source - use^d
for preparation of DNPH derivative standards (optional).
8.8 Ethanol or methanol - analytical grade, best source.
8.9 Sep-PAK silica gel cartridge - Waters Associates, 34 Maple Si.,
Milford, MA, 01757, or equivalent. \
8.10 Nitrogen,- high purity grade, best source. \
8.11 Charcoal - granular, best source. \
8.12 Helium - high purity grade, best source. \
9. Preparation of Reagents and Cartridges j
9.1 Purification of 2,4-Dinitrophenylhydrazine (DNPH) !
[Note: This procedure should be performed under a properly ;
ventilated hood.]
9.1.1 Prepare a supersaturated solution of DNPH by boiling excess
DNPH in 200 ml of acetonitrile for approximately one hour.
9.1.2 After one hour, remove and transfer the supernatant to a
covered beaker on a hot plate and allow gradual cooling
to 40-60°C.
9.1.3 Maintain the solution at this temperature (40-60°C) until
95% of solvent has evaporated.
-------
T011-9
9.1.4. Decant solution to waste, and rinse crystals twice with
three times their apparent volume of acetonitrile. [Note:
Various health effects are resultant from the inhalation of
acetonitrile. At 500 ppm in air, brief inhalation has pro-
duced 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
vomiting9 chest or abdominal pain, respiratory depression,
extreme weakness, stupor, convulsions and death (dependent
upon concentration and time).]
9.1.5 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.
9.1.6 Repeat rinsing process as described in Section 9.1.4.
9.1.7 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.
9.1.8 The chromatogram illustrated in Figure 4 represents an
acceptable impurity level of <0.025 ug/mL of formaldehyde
in recrystallized DNPH reagent. An acceptable impurity
level for an intended sampling application may be defined
as the mass of the analyte (e.g. DNPH-formaldehyde deriva-
tive) 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
• f . *
(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.
The impurity level of DNPH should be below the sensitivity
(ppb, v/v) level indicated in Table 1 .for the anticipated
sample volume. If the impurity level is not acceptable
for intended sampling application, repeat recrystallization.
A special glass apparatus should be used for the final rinse
and storage according to the following procedure:
-------
T011-10
9,1.8.1 Transfer the crystals to the special glass appa-
ratus (Figure 3).
9.1.8.2 -Add about 25 ml of acetonitrile, agitate gently,
and let solution equilibrate for 10 minutes,
9.1.8.3 Drain the solution by properly positioning the
three-way stopcock. [Note: The purified crystals
should not be allowed to contact laboratory air
except for a brief moment. This is accomplished
by using the DNPH-coated silica cartridge on
the gas inlet of the special glass apparatus.]
9.1.8.4 After draining, turn stopcock so drain tube is
connected to measuring reservoir.
9.1.8.5 Introduce acetonitrile through measuring reservoir.
9.1.8.6 Rinsing should be repeated with 20-mL portions of
acetonitrile until a satisfactorily low impurity
level in the supernatant is confirmed by HPLC an-
alysis. An impurity level of <0.025 ug/mL formal-
dehyde should be achieved, as illustrated in
Figure 4.
9.1.9 If special glass apparatus is not available, transfer the
purified crystals to an all-glass reagent bottle, add
200 ml of acetonitrile, stopper, shake gentl-y, and let
stand overnight. Analyze supernatant by HPLC according
to Section 11. The impurity level should be comparable
to that shown in Figure 4.>
9.1.10 If the impurity level is not satisfactory, pi pet off the
solution to waste^ then add 25 ml of acetonitrile to the
purified crystals- Repeat Section 9.1.8.6.
9.1.11 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.
9.1.12 After purification, purity of the DNPH reagent can be main-
tained by storing in the special glass apparatus.
9.1.13 Maintain only a minimum volume of saturated solution ade-
quate for day to day operation. This will minimize wastage
-------
T011-11
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
9.1.14 Use clean pipets when removing saturated DNPH stock
solution for any analytical applications. Do not pour the
stock solution from the reagent bottle.
9.2 Preparation of DNPH-Formaldehyde Derivative
9.2.1 Titrate a saturated solution of DNPH in 2N HC1 with formal-
dehyde (other aldehydes or ketones may be used if their de-
tection is desirable).
9.2.2 Filter the colored precipitate, wash with 2N HC1 and water
and let precipitate air dry.
9.2.3 Check the purity of the DNPH-formaldehyde derivative by
melting point determination table or HPLC analysis. If
the impurity level is not acceptable, recrystallize the
derivative in ethanol. Repeat purity check and recrystal-
"" : lization as necessary until acceptable level of purity
(e.g. 99%) is achieved.
9.3 Preparation of DNPH-Formaldehyde Standards
9.3.1 Prepare a standard stock solution of the DNPH-formal-
- dehyde derivative by dissolving accurately weighed
amounts in acetonitrile.
9.3.2 Prepare a working calibration standard mix from the
standard stock solution. The concentration of the
r : ; 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
• - c- 10 mg of the solid derivative in 100 ml of acetonitrile.
The individual solution is used to prepare calibra-
tion standards containing the derivative of interest
at concentrations of 0.5-20 ug/L, which spans the
concentration of interest for most ambient air work.]
9.3.3 Store all standard solutions in a refrigerator. They
should be stable for several months.
-------
T011-12
9.4 Preparation of DNPH-Coated Sep-PAK Cartridges
[Note: 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 alde-
hyde free acetonitrile. Contact of reagents with laboratory air
must be minimized. Polyethylene gloves must be worn when handl-
ing the cartridges.]
9.4.1 DNPH Coating Solution
9.4.1.1 Pipet 30 ml of saturated DNPH stock solution to a
1000 ml volumetric flask then add 500 ml acetonitrile.
9.4.1.2 Acidify with 1.0 ml of concentrated HC1. [Note:
The atmosphere above the acidified solution should
preferably be filtered through a DNPH-coated silica
gel cartridge to minimize contamination from labora-
' tory air.] Shake solution then make up to volume
with acetonitrile. Stopper the flask, invert and
shake several times until the solution is homogeneous,
Transfer the acidified solution to a reagent bottle
; with a 0-10 ml range positive displacement dispenser.
9,4.1.3 Prime the dispenser and slowly dispense 10-20 ml
to waste.
9.4.1.4 Dispense an aliquot solution to a sample vial,
and check the impurity level of the acidified
solution by HPLC according to Section 9.1 and
illustrated in Figure 4.
9.4.1.5 The impurity level should be <0.025 ug/mL
formaldehyde similar to that in the DNPH coating
solution.
9.4.2 Coating of Sep-PAK Cartridges
9.4.2.1 Open the Sep-PAK package, connect the short end
to a 10-mL syringe, and place it in the syringe
rack. [Note: Prepare as many cartridges and
syringes as possible.]
9.4.2.2 Using a positive displacement repetitive pipet,
add 10 ml of acetonitrile to each of the syringes.
-------
T011-13
9.4.2.3 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.]
9.4.2.4 Set the repetitive dispenser containing the acidi-
fied DNPH coating solution to dispense 7 mL into
the cartridges.
9.4.2.5 Once the effluent flow at the outlet of the cart-
ridge has stopped, dispense 7 ml of the coating
reagent into each of the syringes.
9.4.2.6 Let the coating reagent drain by gravity through
the cartridge until flow at the other end of the
cartridge stops.
9.4.2.7 Wipe the excess liquid at the outlet of each of
the cartridges with clean tissue paper.
9.4.2.8 Assemble a drying manifold with a scrubber or
"guard cartridge" connected to each of the
exit ports. These "guard cartridges" are
DNPH-coated and serve to remove any trace of
formaldehyde in the nitrogen gas supply.
9.4.2.9 Remove the cartridges from the syringes and con-
nect the short ends to the exit end of the scrub-
ber cartridge.
9.4.2.10 Pass nitrogen through each of the cartridges at
about 300-400 mL/min for 5-10 minutes.
9.4.2.11 Within 10 minutes of the drying process, rinse
the exterior surfaces and outlet ends of the car-
tridges with acetonitrile using a Pasteur pipet.
9.4.2.12 Stop the flow of nitrogen after 15 minutes and
insert cartridge connectors (flared at both
ends 0.25 OD x 1 in Teflon FEP tubing with ID
slightly smaller than the OD of the cartridge
port) to the long end of the scrubber cartridges.
9.4.2.13 Connect the short ends of a batch of the coated
cartridges to the scrubbers and pass nitrogen
at about 300-400 mL/min.
9.4.2.14 Follow procedure in Section 9*4.2.11.
-------
T011-14
9.4.2.15 After 15 minutes, stop the flow of nitrogen,
remove the dried cartridges and wipe the
cartridge exterior free of rinse acetonitrile.
9.4.2.16 Plug both ends of the coated cartridge with standard
polypropylene Luer® male plugs, place the plugged
cartridge in a borosilicate glass culture tube
with polypropylene screw caps.
9.4.2.17 Put a serial number and a lot number label on
each of the individual cartridge glass storage
container and store the prepared lot in the
refrigerator until use.
9.4.2.18 Store cartridges in an all-glass stoppered rea-
gent bottle in a refrigerator until use. [Note:
Plugged cartridges could also be placed in screw-
capped glass culture tubes and placed in a refrig-
erator until use.] Cartridges will maintain their
integrity for up to 90 days stored in refrigerated,
capped culture'tubes.
9.4.2.19 Before transport, remove the glass-stoppered rea-
gent bottles (or screw-capped glass culture tubes)
containing the adsorbent tubes from the refriger-
ator and place the tubes individually in labeled
glass culture tubes. Place culture tubes in a
friction-top metal can containing 1-2 inches of
charcoal for shipment to sampling location.
9.4.2.20 As an alternative to friction-top cans for
transporting sample cartridges, the coated
cartridges could be shipped in their individual
glass containers. A big batch of coated
cartridges in individual glass containers may
be packed in a styrofoam box for shipment to the
field. The box should be padded with clean
tissue paper or polyethylene-air bubble padding.
Do not use polyurethane foam or newspaper as
padding material.
9.4.2.21 The cartridges should be immediately stored in a
refrigerator upon arrival in the field.
-------
T011-15
10. Sampling
10.1 The sampling system is assembled and should be similar
to that shown in Figure 2. [ Note: Figure 2(a) illustrates
a three tube/one pump configuration. The tester should
ensure that the pump is capable of constant flow rate
throughout the sampling period.] The coated cartridges .
can be used as direct probes and traps for sampling
ambient air when the temperature is above freezing.
[Note: For sampling ambient air below freezing, a short
length (30-60 cm) of heated (50-60°C) stainless steel tubing
must be added to condition the air sample prior to
collection on adsorbent tubes.] Two types of sampling
systems are shown in Figure 2. For purposes of discussion,
the following procedure assumes the use of a dry test meter.
[Note: The dry test meter may not be accurate at flows
below 500 mL/min and should be backed up by recorded
flow readings at the start, finish, and hourly intervals
during sample collection.]
10.2 Before sample collection, the system is checked for leaks.
Plug the input end of the cartridge 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.
10,3 The entire assembly (including a "dummy" sampling cartridge)
is installed and the flow rate checked at a value near the
desired rate. In general, flow rates of 500-1200 mL/min
should be employed. The total moles of carbonyl in the
volume of air sampled should not exceed that of the DNPH
concentration ( 2 mg/cartridge). In general, a safe
estimate of the sample size should be 75% of the DNPH
loading of the cartridge. 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 3686 describes an
appropriate calibration scheme that does not require a
sealed flow system downstream of the pump.]
-------
T011-16
10.4 Ideally, a dry gas meter is included in the system to re-
cord total flow. If a dry gas meter is not available, the
operator must measure and record the sampling flow rate at
the beginning and end of the sampling period to determine
sample volume. If the sampling period exceeds two hours,
the flow rate should be measured at intermediate points
during the sampling period. Ideally, a rotameter should
be included to allow observation of the flow rate without
interruption of the sampling process.
10.5 Before sampling, 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.
10.6 Using polyethylene gloves, remove the coated cartridge
from the glass tube and connect it to the sampling system
with a Luer® adapter fitting. Seal the glass tube for
later use, and connect the cartridge to the sampling train
so that its short end becomes the sample inlet. Record the
following parameters on the sampling data sheet (Figure 5):
date, sampling location, time, ambient temperature, baro-
metric pressure (if available), relative humidity (if avail-
able), dry gas meter reading (if appropriate), flow rate,
rotameter setting, cartridge batch number, and dry gas
meter pump identification numbers.
10.7 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.
10.8 The sampler is operated for the desired period, with peri-
odic recording of the variables listed above.
10.9 At the end of the sampling period, the parameters listed
in Section 10.6 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 15%, the sample should be marked as suspect.
-------
T011-17
10.10 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 culture tube. Cap the culture tube, seal it with
Teflon® tape, and place it in a friction-top can contain-
ing 1-2 inches of granular charcoal or styrofoam box with
appropriate padding. Refrigerate the the culture tubes
until analysis. Refrigeration period prior to analysis
should not exceed 30 days. [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.]
10.11 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:
Ql + 0.2 + . . . QN
QA =
N
where:
QA = average flow rate (mL/min).
Ql» Q2> • • • QN = flow rates determined at beginning, end,
and intermediate points during sampling.
N = number of points averaged.
10.12 The total flow rate is then calculated using the following
equation:
(Tg - TI) x QA
Vm - _______ ..
TOUD
where:
Vm = total volume (L) sampled at measured
temperature and pressure.
T2 = stop time (minutes)..
TI = start time (minutes).
T2 - TI = total sampling time (minutes).
QA = average flow rate (mL/min).
-------
T011-18
10.13 The total volume (Vs) at standard conditions, 25°C and
760 mm Hg, is calculated from the following equation:
= V,
m
Pa x 298
60 273" + t"A
where:
Vs = total sample volume (L) at 25°C and
760 mm Hg pressure.
Vm = total sample volume (L) at measured tem-
__ perature and pressure.
j^\ = average ambient pressure (mm Hg).
t/\ = average ambient temperature (°C).
11. Sample Analysis
11.1 Sample Preparation
11.1.1 The samples are returned to the laboratory in a friction-
top can containing 1-2 inches of granular charcoal and
stored in a refrigerator until analysis. Alternatively,
the samples may also be stored alone in their individual
glass containers. The time between sampling and
analysis should not exceed 30 days.
11.2 Sample Desorption
11.2.1 Remove the sample cartridge form the labeled culture tube.
Connect the sample cartridge (outlet end during sampling)
to a clean syringe. [Note: The liquid flow during desorp-
tion should be in the reverse direction of air flow during
sample collection.]
11.2.2 Place the cartridge/syringe in the syringe rack.
11.2.3 Backflush the cartridge (gravity feed) by passing 6 ml
of acetonitrile from the syringe through the cartridge
to a graduated test tube or to a 5-mL volumetric flask.
[Note: A dry cartridge has an acetonitrile holdup volume
slightly greater than 1 ml. The eluate flow may stop be-
fore the acetonitrile in the syringe is completely drained
into the cartridge because of air trapped between the car-
tridge filter and the syringe Luer® tip. If this happens,
displace the trapped air with the acetronitrile in the
syringe using a long-tip disposable Pasteur pipet.]
-------
T011-19
11.2.4 Dilute to the 5-mL mark with acetonitn'le. Label the
flask with sample identification. Pipet two aliquots
into sample vials with Teflon-lined septa. Analyze
the first aliquot for the derivative carbonyls by HPLC.
Store the second aliquot in the refrigerator until
sample analysis.
11.3 HPLC Analysis
11.3.1 The HPLC system is assembled and calibrated as described
in Section 11.4. The operating parameters are as follows:
Column: Zorbax ODS (4.6 mm ID x 25 cm), or
equivalent.
Mobile Phase: 60% acetonitrile/40% water, isocratic.
Detector: ultraviolet, operating at 360 nm.
Flow Rate: 1.0 mL/min.
Retention Time: 7 minutes for formaldehyde with
one Zorbax ODS column.
13 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.
11.3.2 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-um polyester membrane filter
in an all-glass and Teflon® suction filtration appa-
ratus. The filtered mobile phase is degassed by pur-
ging 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.
11.3.3 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
-------
T011-20
allowed to pump for 20-30 minutes before the first analy-
sis. The detector is switched on at least 30 minutes be-
fore the first analysis, and the detector output is dis-
played on a strip chart recorder or similar output device.
11.3.4 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,
and the point of injection is marked on the strip chart
recorder.
11.3.5 After approximately one minute, the injection valve is
returned to the "inject" 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 clean
while the valve is in the "inject" mode.
11.3.6 After elution of the DNPH-formaldehyde derivative
. (Figure 6), data acquisition is terminated and the
component concentrations are calculated as described
in Section 12.
11.3.7 After a stable baseline is achieved, the system can be
used for further sample analyses as described above.
[Note: After several cartridge analyses, buildup on
the column may be removed by flushing with several
column volumes of 100% acetonitrile.]
11.3.8 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.
11.3.9 If the retention time is not duplicated (+10%), as de-
termined by the calibration curve, the acetonitrile/water
ratio may be increased or decreased to obtain the correct
elution time. If the elution time is too long, increase
-------
T011-21
the ratio; if it is too short, decrease the ratio.
[Note: The chromatographic conditions described here
have been optimized for the detection of formaldehyde.
Analysts are advised to experiment with their.HPLC
system to optimize chromatographic conditions for
their particular analytical needs.]
11.4 HPLC Calibration
11.4.1 Calibration standards are prepared in acetonitrile
from the DNPH-formaldehyde derivative. Individual
stock solutions of 100 mg/L are prepared by dissolving
10 mg of solid derivative in 100 ml of mobile phase.
These individual solutions are used to prepare calibration
standards at concentrations spanning the range of interest.
11.4.2 Each calibration standard (at least five levels) is
analyzed three times and area response is tabulated
against mass injected (Figure 7). All calibration
runs are performed as described for sample analyses
in Section 11.3. Using the UV detector, a linear
response range of approximately 0.05-20 ug/L should be
achieved for 25-uL injection volumes. The results may
be used to prepare a calibration curve, as illustrated
in Figure 8. Linear response is indicated where a
correlation coefficient of at least 0.999 for a linear
least-squares fit of the data (concentration versus
area response) is obtained. The retention times for
each analyte should agree within 2%.
11.4.3 Once linear response has been documented, an intermediate
concentration standard near the anticipated levels of
each 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% for analyte concentrations 1 ug/mL or greater
and within 15-20% for analyte concentrations near 0.5 ug/mL.
If greater variability is observed, recalibration may be
required or a new calibration curve must be developed
from fresh standards.
-------
T011-22
11.4.4 The response for each component in the daily calibra-
tion standard is used to calculate a response factor
according to the following equation:
RFr =
where:
RFC = response factor (usually area counts)
for the component of interest in nano-
grams injected/response unit.
Cc - concentration (mg/L) of analyte in the
daily calibration standard.
Vj = volume (uL) of calibration standard injected,
Rc = response (area counts) for analyte in
the calibration standard.
12. Calculations
12.1 The total mass of analyte (DNPH-formaldehyde) is calculated
for each sample using the following equation:
Wd = RFC x Rd x VE/Vi
where:
Wd
RFC
VE
VD
VA
total quantity of analyte (ug) in the sample.
response factor calculated in Section 11.4.4.
response (area counts or other response units)
for analyte in sample extract, blank corrected.
[(As) (VD/VA) - (Ab)(Vb/vs)]
where:
sample.
blank.
blank.
sample.
final volume (ml) of sample extract.
volume of extract (uL) injected into the HPLC
system.
redilution volume (if sample was rediluted).
aliquot used for redilution (if sample was
redi1uted).
As =
Ab =
Vb -
VS -
area counts,
area counts,
volume (ml),
volume (ml),
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T011-23
12.2 The concentration of formaldehyde in the original sample is cal-
culated from the following equation:
Wd
C = -x 1000
_______
Vm (or Vs)
where:
CA = concentration of analyte (ng/L) in the orig-
inal sample.
Wd = total quantity of analyte (ug) in sample, blank
corrected.
Vm = total sample volume (L) under ambient conditions,
Vs = total sample volume (L) at 25°C and 760 mm Hg.
The analyte concentrations can be converted to ppbv using the
following equation:
CA (PPbv) = CA (ng/L) x 24.4
MWA~
where:
CA(ppbv) = Concentration of analyte in parts per
billion by volume.
CA (ng/L) is calculated using Vs.
MWA = molecular weight of analyte.
13. Performance Criteria 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, cali-
bration, and operation of the sampling system, with
make and model of equipment used; (2) preparation,
-------
T011-24
purification, storage, and handling of sampling reagent
and samples; (3) assembly, calibration, and operation
of the HPLC systems 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:
= 5.54
where:
N = column efficiency (theoretical plates).
tr = retention time (seconds) of analyte.
Wi/2 = width of component peak at half height
(seconds).
A column efficiency of >5,000 theoretical plates should
be obtained.
13.2.3 Precision of response for replicate HPLC injections should
be +10% or less, day to day, for analyte calibration
standards at 1 ug/mL or greater levels. At 0.5 ug/mL level
and below, precision of replicate analyses could vary up
to 25%. Precision of retention times should be +2% on
a given day.
13.3 Process Blanks
13.3.1 At least one field blank or 10% of the field samples,
whichever is larger, should be shipped and analyzed with
each group of samples. The number of samples within a
-------
T011-25.
group and/or time frame should be recorded so that a
specified percentage of blanks is obtained for a given
number of field samples. The field blank is treated
.identically to the samples except that no air is drawn
through the cartridge. The performance criteria de-
scribed in Section 9.1 should be met for process blanks.
13.4 Method Precision and Accuracy
13.4.1 At least one duplicate sample or 10% of the field sam-
ples, whichever is larger, should be collected during
each sampling episode. Precision for field replication
should be +20% or better.
13.4.2 Precision for replicate HPLC injections should be +10%
or better, day to day, for calibration standards.
13.4.3 At least one sample spike with analyte of interest or
10% of the field samples, whichever is larger, should
be collected.
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 j+ 10% and
blank levels as outlined in Section 9.1 should be
achieved.
14. Detection of other Aldehydes and Ketones
[Note: 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 alde-
hydes and ketones. Optimizing chromatographic conditions by using two
Zorbax ODS columns in series and varying the mobile phase composition
through a gradient program will enable the analysis of other aldehydes
and ketones.]
-------
T011-26
14.1 Sampling Procedures
Same as Section 10.
14.2 HPLC Analysis
14.2.1 The HPLC system is assembled and calibrated as described
in Section 11. The operating parameters are as follows:
Zorbax ODS, two columns in series
Acetonitrile/water, linear gradient
60-75% acetonitrile/40-25% water in 30
minutes.
75-100% acetonitrile/25-0% water in
20 minutes.
100% acetonitrile for 5 minutes.
60% acetonitrile/40% water reverse gra-
dient in 1 minute.
60% acetonitrile/40% water, isocratic, for
15 minutes.
Ultraviolet, operating at 360 nm
1.0 mL/min
Column:
Mobile Phase;
Step 1.
Step 2,
Step 3.
Step 4.
Step 5.
Detector:
Flow Rate:
Sample Injection Volume: 25 uL
14.2.2 The gradient program allows for optimization of chromato-
graphic conditions to separate acrolein, acetone,
propionaldehyde, and other higher molecular weight alde-
hydes and ketones in an analysis time of about one
hour. Table 1 illustrates the sensitivity for selective
aldehydes and ketones that have been identified using
two Zorbax ODS columns in series.
14.2.3 The chromatographic conditions described here have been
optimized for a gradient HPLC (Varian Model 5000) sys-
tem equipped with a UV detector (ISCO Model 1840 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.
-------
T011-27
The separation of acrolein, acetone, and propionaldehyde
should be a minimum goal of the optimization.
14.2.4 The carbonyl compounds in the sample are identified and
quantified by comparing their retention times and area
counts with those of standard DNPH derivatives. Formal-
dehyde, acetaldehyde, acetone, propionaldehyde, croton-
aldehyde, 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 methyl ethyl
ketone under the stated chromatographic conditions.
Figure 10 illustrates a typical chromatogram obtained
"' with the gradient HPLC system.
14.2.5 The concentrations of individual carbonyl compounds are
determined as outlined in Section 12.
14.2.6 Performance criteria and quality assurance activities
should meet those requirements outlined in Section 13.
-------
T011-28
REFERENCES
1. Silvestre B. Tejada, "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.
2. Silvestre B. Tejada, "Evaluation of Silica Gel Cartridges Coated in
situ with Acidified 2,4-Dinitrophenylhydrazine for Sampling Aldehydes
and Ketones in Air", Intern. J. Environ. Anal. Chem., 26:167-185, 1986.
3. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II - Ambient Air Specific Methods, EPA-600/4-77-027A. U. S.
Environmental Protection Agency, Research Triangle Park, NC, July
1979.
4. J. 0. Levin, 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., 5_7_: 1032-1035, 1985.
5. Compendium of Methods for the Determination of Toxic Organic Compounds
in Ambient Air, EPA-600/4-84-041, U.S. Environmental Protection
Agency, Research Triangle Park, NC, April 1984.
6. J. E. Sigsby, Jr., et al., unpublished report on volatile organic
compound emissions from 46 in-use passenger cars, U.S. Environmental
Protection Agency, Research Triangle Park, NC, 1984.
7. S. B. Tejada and W. D. Ray, unpublished results of study of aldehyde
concentration in indoor atmosphere of some residential homes, U.S.
Environmental Protection Agency, Research Triangle Park, NC, 1982.
8. J. M. Perez, F. Lipari, and D. E. Seizinger, "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.
9. R. M. Riggin, Technical Assistance Document for Sampling and Analysis
of Toxic Organic Compounds in Ambient Air, EPA-600/4-83-027, U.S.
Environmental Protection Agency, Research Triangle Park, NC, June
1983.
10. E. V. Kring, 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., 45_: 318-324, 1984.
-------
T011-29
11. I. Ahonen, E. Priha, and M-L Aijala, "Specificity of Analytical Methods
Used to Determine the Concentration of Formaldehyde in Workroom
Air", Chemosphere, 13:521-525, 1984.
12. J.J. Bufalini and K.L. Brubaker, "The Photooxidation of Formaldehyde
at Low Pressures." In: Chemical Reaction in Urban Atmospheres,
(ed. C.S. Tuesday), (American Elsevier Publishing Co., New York,
1971), pp. 225-240.
13. A.P. Altshuller and I.R. Cohen, Science 7, 1043 (1963).
14. Committee on Aldehydes, Board of Toxicology and Environmental Hazards,
National Research Council, "Formaldehyde and Other Aldehydes" (National
Academy Press, Washington, DC, 1981).
-------
T011-30
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T011-32
OIL-LESS
PUMP
VENT
MASS FLOW
CONTROLLERS
Couplings to
connect
DNPH-coated Sep-PAK
Adsorbent Cartridges
(a) MASS FLOW CONTROL
ROTAMETER
DRY
TP^T
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METER
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(DRY TEST METER SHOULD NOT BE USED
FOR FLOW OF LESS THAN 500 ml/minute)
Coupling to
connect
DNPH-coated
Sep-PAK
Adsorbent
Cartridges
(b) NEEDLE VALVE/DRY TEST METER
FIGURE 2. TYPICAL SAMPLING SYSTEM CONFIGURATIONS
-------
T011-33
DNPH-COATED Si02
DNPH
CRYSTALS
HIGH-POROSITY /
FRIT
THREE-WAY STOPCOCK
FIGURE 3.
SPECIAL GLASS APPARATUS FOR RINSING,
STORING, AND DISPENSING SATURATED
DNPH STOCK SOLUTION
-------
T011-34
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T011-35
PROJECT:
SITE:
SAMPLING DATA SHEET
(One Sample per Data Sheet)
DATE(S) SAMPLED:
LOCATION:
TIME PERIOD SAMPLED:_
OPERATOR:
INSTRUMENT MODEL N0:_
PUMP SERIAL NO:
CALIBRATED BY:
ADSORBENT CARTRIDGE INFORMATION:
, Type: _ :
Adsorbent: _ _
SAMPLING DATA:
Start Time:
Serial Number:_
Sample Number:"
Stop Time:
Time
-• '-s.
Avg.
Dry Gas
Meter
Reading
,'
Rotameter
Reading
Flow
Rate (Q)*,
mL/mi n
Ambient
Temperature,
°C
Barometric
Pressure,
mm Hg
Relative
Humidity,%
Comments
* Flow rate from rotameter or soap bubble calibrator (specify which)
Total Volume Data (Vm) (use data from dry gas meter, if available)
Vm = (Final - Initial) Dry Gas Meter Reading, or
*m
or
Vm =
Qi + Q2
• • • QN
X 1
1000 x (Sampling Time in Minutes)
Liters
Liters
FIGURE 5.
EXAMPLE SAMPLING DATA SHEET
-------
T011-36
OPERATING PARAMETERS
HPLC
Column: Zorbax 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 uL
z
m
I
10
TIME, min
20
FIGURE 6.
CHROMATOGRAM OF DNPH-FORMALDEHYDE
DERIVATIVE
-------
T011-37
OPERATING PARAMETERS
HPLC
Column: Zorbax ODS or C-18 RP
Mobile Phase: 60% Acetonitrile/40% Water
Detector: U'litraviolet, operating at 360 nm
Flow Rate: 1 mL/min.
Retention Time: ~ 7 minutes for formaldehyde
Sample Injection Volume: 25 uL
(a)
(c)
HI
-3
TIME-+
61 ug/mL
1 TIME-*
§ 1.23ug/mL
TIME-*
6.16ug/ml_
CONC
.61 ug/mL
1.23 ug/mL
6.16ug/mU
12.32ug/mL
18.48 ug/mL
AREA
COUNTS
226541
452166
2257271
4711408
6953812
(d)
(e)
ui
-3
TIME->
12.32ug/mL
t
B
18.48ug/mL
FIGURE 7.
HPLC CHROMATOGRAM OF VARYING CON
CENTRATIONS OF DNPH-FORMALDEHYDE
DERJVATIVE
-------
T011-38
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CORRELATION COEFFICIENT:
0.9999
OPERATING PARAMETERS
HPLC
Column: Zorbax ODS or C-1,8 RP
Mobile Phase: 60% Acetonitri(e/40% Water
Detector: Ultraviolet, operating at 360 nm
Flow Rate: 1 mL/min
Retention Time: ~ 7 minutes for formaldehyde
Sample Injection Volume: 25 uL
3 6 9 12 15 18
DNPH-Formaldehyde Derivative (ug/mL)
FIGURE 8.
CALIBRATION CURVE FOR FORMALDEHYDE
-------
Revision 1.0
June, 1987
METHOD T012
METHOD FOR THE DETERMINATION OF-NON-METHANE ORGANIC COMPOUNDS (NMOC)
IN AMBIENT AIR USING CRYOGENIC PRECONCENTRATION AND DIRECT FLAME
IONIZATION DETECTION (PDFID)
1. Scope
1.1 In recent years, the relationship between ambient concentrations
of precursor organic compounds and subsequent downwind concentra-
tions of ozone has been described by a variety of photochemical,
dispersion models. The most important application of such models
is to determine the degree of control of precursor organic com-
pounds that is necessary in an urban area to achieve compliance
with applicable ambient air quality standards for ozone (1,2).
1.2 The more elaborate theoretical models generally require detailed
organic species data obtained by multicomponent gas chromatography (3)
•p The Empirical Kinetic Modeling Approach (EKMA), however, requires
only the total non-methane organic compound (NMOC) concentration
data; specifically, the average total NMOC concentration from 6
a.m. to 9 a.m. daily at the sampling location. The use of total
NMOC concentration data in the EKMA substantially reduces the
cost and complexity of the sampling and analysis system by not
requiring qualitative and quantitative species identification.
1.3 Method TO!, "Method for The Determination of Volatile Organic
Compounds in Ambient Air Using Tenax® Adsorption and Gas
Chromatography/Mass Spectrometry (GC/MS)", employs collection
of certain volatile organic compounds on Tenax® GC with subse-
quent analysis by thermal desorption/cryogenic preconcentration
and GC/MS identification. This method (T012) combines the same
type of cryogenic concentration technique used in Method T01
for high sensitivity with the simple flame ionization detector
(FID) of the GC for total NMOC measurements, without the GC
columns and complex procedures necessary for species separation.
-------
T012-2
1.4 In a flame ionization detector, the sample is injected into a
hydrogen-rich flame where the organic vapors burn producing
ionized molecular fragments. The resulting ion fragments are
then collected and detected. The FID is nearly a universal
detector. However, the detector response varies with the species
of [functional group in] the organic compound in an oxygen atmos-
phere. Because this method employs a helium or argon carrier
gas, the detector response is nearly one for all compounds.
Thus, the historical short-coming of the FID involving varying
detector response to different organic functional groups is
minimized.
1.5 The method can be used either for direct, in situ ambient
measurements or (more commonly) for analysis of integrated
samples collected in specially treated stainless steel canisters.
EKMA models generally require 3-hour integrated NMOC measurements
over the 6 a.m. to 9 a.m. period and are used by State or local
agencies to prepare State Implementation Plans (SIPs) for ozone
control to achieve compliance with the National Ambient Air
Quality Standards (NAAQS) for ozone. For direct, in situ ambient
measurements, the analyst must be present during the 6 a.m. to
9 a.m. period, and repeat measurements (approximately six per
hour) must be taken to obtain the 6 a.m. to 9 a.m. average
NMOC concentration. The use of sample canisters allows the
collection of integrated air samples over the 6 a.m. to 9 a.m.
period by unattended, automated samplers. This method has
incorporated both sampling approaches.
2. Applicable Documents
2.1 ASTM Standards
D1356 - Definition of Terms Related to Atmospheric
Sampling and Analysis
E260 - Recommended Practice for General Gas Chromato-
graphy Procedures
E355 - Practice for Gas Chromatography Terms and
Relationships
-------
T012-3
2.2 Other Documents
U. S. Environmental Protection Agency Technical Assistance
Documents (4,5)
Laboratory and Ambient Air Studies (6-10)
3. Summary of Method
3.1 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 sample canister and analyzed off site.
3.2 The analysis requires drawing a fixed-volume portion of the
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.
3.3 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 cnyogen is removed and the temperature of the trap is
raised to approximately 90°C.
3.4 The organic compounds previously collected in the trap revol-
atilize 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.
3.5 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.
-------
T012-6
Interferences
6.1 In field and laboratory evaluation, water was found to cause a
positive shift in the FID baseline. The effect of this shift
is minimized by carefully selecting the integration termination
point and adjusted baseline used for calculating the area of
the NMOC peak(s).
6.2 When using helium as a carrier gas, FID response is quite
uniform for most hydrocarbon compounds, but the response can
vary considerably for other types of organic compounds.
Apparatus
7.1 Direct Air Sampling (Figure 1)
7.1.1 Sample manifold or sample inlet line - to bring
sample air into the analytical system.
7.1.2 Vacuum pump or blower - to draw sample air through a
sample manifold or long inlet line to reduce inlet
residence time. Maximum residence time should be no
greater than 1 minute.
7.2 Remote Sample Collection in Pressurized Canisters (Figure 2)
7.2.1 Sample canister(s) - stainless steel, Summa®-polished
vessel(s) of 4-6 L capacity (Scientific Instrumentation
Specialists, Inc., P.O. Box 8941, Moscow, ID 83843), used
for automatic collection of 3-hour integrated field
air samples. Each canister should have a unique identi-
fication number stamped on its frame.
7.2.2 Sample pump - stainless steel, metal bellows type
(Model MB-151, Metal Bellows Corp., 1075 Providence
Highway, Sharon, MA 02067) capable of 2 atmospheres
minimum output pressure. Pump must be free of leaks,
clean, and uncontaminated by oil or organic compounds.
7.2.3 Pressure gauge - 0-30 psig (0-240 kPa).
7.2.4 Solenoid valve - special electrically-operated, bistable
solenoid valve (Skinner Magnelatch Valve, New Britain,
-------
T012-7
CT), to control sample flow to the canister with negligi-
ble temperature rise (Figure 3). The use of the Skinner
Magnelatch valve avoids any substantial temperature rise
that would occur with a conventional, normally closed
solenoid valve, which would have to be energized during
the entire sample period. This temperature rise in the
valve could cause outgasing of organics 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 with an electronic timer that can be pro-
grammed for short (5 to 60 seconds) ON periods or with
a conventional mechanical timer and a special pulse
circuit. Figure 3 [a] illustrates a simple electrical
pulse circuit for operating the Skinner Magnelatch
solenoid valve with a conventional mechanical timer.
However, with this simple circuit, the valve may
operate unpredictably 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 3[b],
7.2.5 Stainless steel orifice (or short capillary) - capable
of maintaining a substantially constant flow over the
'sampling period (see Figure 4).
7.2.6 Particulate matter filter - 2 micron stainless steel
sintered in-line type (see Figure 4).
7.2.7 Timer - used for unattended sample collection. Capable
of controlling pump(s) and solenoid valve.
7.3 Sample Canister Cleaning (Figure 5)
7.3.1 Vacuum pump - capable of evacuating sample canister(s)
to an absolute pressure of <5 mm Hg.
7.3.2 Manifold - stainless steel manifold with connections
for simultaneously cleaning several canisters.
7.3.3 Shut off valve(s) - seven required.
7.3.4 Vacuum gauge - capable of measuring vacuum in the manifold
to an absolute pressure of 5 mm Hg or less.
-------
T012-8
7.3.5 Cryogenic trap (2 required) - U-shaped open tubular trap
cooled with liquid nitrogen or argon used to prevent con-
tamination from back diffusion of oil from vacuum pump,
and to provide clean, zero air to sample canister(s).
7.3.6 Pressure gauge - 0-50 psig (0-345 kPa), to monitor
zero air pressure.
7.3.7 Flow control valve - to regulate flow of zero air into
canister(s).
7.3.8 Humidifier - water bubbler or other system capable of
providing moisture to the zero air supply.
7.4 Analytical System (Figure 1)
7.4.1 FID detector system -. including flow controls for the
FID fuel and air, temperature control for the FID, and
signal processing electronics. The FID burner air,
hydrogen, and helium carrier flow rates should be set
according to the manufacturer's instructions to obtain an
adequate FID response while maintaining as stable a flame
as possible throughout all phases.of the analytical cycle.
7.4.2 Chart recorder - compatible with the FID output signal,
to record FID response.
7.4.3 Electronic integrator - capable of integrating the area
of one or more FID response peaks and calculating peak
area corrected for baseline drift. If a separate inte-
grator and chart recorder are used, care must be exer-
cised to be sure that these components do not interfere
with each other electrically. Range selector controls
on both the integrator and the FID analyzer may not pro-
vide accurate range ratios,, so individual calibration
curves should be prepared for each range to be used.
The integrator should be capable of marking the beginning
and ending of peaks, constructing the appropriate base-
line between the start and end of the integration period,
and calculating the peak area.
-------
T012-9
Note: The FID (7.4.1), chart recorder (7.4.2), inte-
grator (7.4.3), valve heater (7.4.5), and a trap heat-
ing system are conveniently provided by a standard lab-
oratory chromatograph and associated integrator. EPA
has adapted two such systems for the PDFID method: a
Hewlett-Packard model 5880 (Hewlett-Packard Corp., Avon-
dale, PA) and a Shimadzu model GC8APF (Shimadzu Scientific
Instruments Inc., Columbia, MD; see Reference 5). Other
similar systems may also be applicable.
7.4.4 Trap - the trap should be carefully constructed from a
single piece of chromatographic-grade stainless steel
tubing (0.32 cm O.D, 0.21 cm I.D.) as shown in Figure 6.
The central portion of the trap (7-10 cm) is packed with
60/80 mesh glass beads, with small glass wool (dimethyldi-
chlorosilane-treated) plugs to retain the beads. The
trap must fit conveniently into the Dewar flask (7.4.9),
and the arms must be of an appropriate length to allow
the beaded portion of the trap to be submerged below
the level of liquid cryogen in the Dewar. The trap should
connect directly to the six-port valve, if possible,
to minimize line length between the trap and the FID. The
trap must be mounted to allow the Dewar to be slipped
conveniently on and off the trap and also to facilitate
heating of the trap (see 7.4.13).
7.4.5 Six-port chromatographic valve - Seiscor Model VIII
(Seismograph Service Corp., Tulsa, OK), Valco Model 9110
(Valco Instruments Co., Houston, TX), or equivalent.
The six-port valve and as much of the interconnecting
tubing as practical should be located inside an oven or
otherwise heated to 80 - 90°C to minimize wall losses
or adsorption/desorption in the connecting tubing. All
lines should be as short as practical.
7.4.6 Multistage pressure regulators - standard two-stage,
stainless steel diaphram regulators with pressure gauges,
for helium, air, and hydrogen cylinders.
7.4.7 Pressure regulators - optional single stage, stainless
steel, with pressure gauge, if needed, to maintain
constant helium carrier and hydrogen flow rates.
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7.4.8 Fine needle valve - to adjust sample flow rate through
trap.
7.4.9 Dewar flask - to hold liquid cryogen to cool the trap,
sized to contain submerged portion of trap.
7.4.10 Absolute pressure gauge - 0-450 mm Hg,(2 mm Hg [scale
divisions indicating units]), to monitor repeatable
volumes of sample air through cryogenic trap (Wallace
and Tiernan, Model 61C-ID-0410, 25 Main Street, Belle-
ville, NJ).
7.4.11 Vacuum reservoir - 1-2 L capacity, typically 1 L.
7.4.12 Gas purifiers - gas scrubbers containing Drierite® or
silica gel and 5A molecular sieve to remove moisture
and organic impurities in the helium, air, and hydrogen
gas flows (Alltech Associates, Deerfield, IL). Note:
Check purity of gas purifiers prior to use by passing
zero-air through the unit and analyzing according to
Section 11.4. Gas purifiers are clean if produce
[contain] less than 0.02 ppmC hydrocarbons.
7.4.13 Trap heating system - chromatographic oven, hot water,
or other means to heat the trap to 80° to 90°C. A simple
heating source for the trap is a beaker or Dewar filled
with water maintained at 80-90°C. More repeatable types
of heat sources are recommended, including a temperature--
programmed chromatograph oven, electrical heating of
the trap itself, or any type of heater that brings the
temperature of the trap up to 80-90°C in 1-2 minutes.
7.4.14 Toggle shut-off valves (2) - leak free, for vacuum valve
and sample valve.
7.4.15 Vacuum pump - general purpose laboratory pump capable
of evacuating the vacuum reservoir to an appropriate
vacuum that allows the desired sample volume to be
drawn through the trap.
7.4.16' Vent - to keep the trap at atmospheric pressure during
trapping when using pressurized canisters.
7.4.17 Rotameter - to verify vent flow.
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7.4.18 Fine needle valve (optional) - to adjust flow rate of
sample from canister during analysis.
7.4.19 Chromatographic-grade stainless steel tubing (Alltech
Applied Science, 2051 Waukegan Road, Deerfield, IL, 60015,
(312) 948-8600) and stainless steel plumbing fittings -
for interconnections. 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.
7.5 Commercially Available PDFID System (5)
7.5.1 A convenient and cost-effective modular PDFID system suit-
able for use with a conventional laboratory chromatograph
is commercially available (NuTech Corporation, Model 8548,
2806 Cheek Road, Durham, NC, 27704, (919) 682-0402).
7.5.2 This modular system contains almost all of the apparatus
items needed to convert the chromatograph into a PDFID
analytical system and has been designed to be readily
available and easy to assemble.
Reagents and Materials
8.1 Gas cylinders of helium and hydrogen - ultrahigh purity grade.
8.2 Combustion air - cylinder containing less than 0.02 ppm hydro-
carbons, or equivalent air source.
8.3 Propane calibration standard - cylinder containing 1-100 ppm
(3-300 ppmC) propane in air. The cylinder assay should be
traceable to a National Bureau of Standards (NBS) Standard Refer-
ence Material (SRM) or.to a NBS/EPA-approved Certified Reference
Material (CRM).
8.4 Zero air - cylinder containing less than 0.02 ppmC hydrocar-
bons. Zero air may be obtained from a cylinder of zero-grade
compressed air scrubbed with Drierite® or silica gel and 5A
molecular sieve or activated charcoal, or by catalytic cleanup
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10
•T012-12
of ambient air. All zero air should be passed through a liquid
argon cold trap for final cleanup, then passed through a hyrdo-
carbon-free water bubbler (or other device) for humidification.
8.5 Liquid cryogen - liquid argon (bp -185.7°C) or liquid oxygen,
(bp -183°C) may be used as the cryogen. Experiments have shown
no differences in trapping efficiency between liquid argon and
liquid oxygen. However, appropriate safety precautions must be
taken if liquid oxygen is used. Liquid nitrogen (bp -195°C)
should not be used because it causes condensation of oxygen and
methane in the trap.
Direct Sampling •
9.1 For direct ambient air sampling, the cryogenic trapping system
draws the air sample directly from a pump-ventilated distribution
manifold or sample line (see Figure 1). The connecting line should
be of small diameter (1/8" O.D.) stainless steel tubing and as
short as possible to minimize its dead volume.
9.2 Multiple analyses over the sampling period must be made to estab-
lish hourly or 3-hour NMOC concentration averages.
Sample Collection in Pressurized Canister(s)
For integrated pressurized canister sampling, ambient air is sampled
by a metal bellows pump through a critical orifice (to maintain
constant flow), and pressurized into a clean, evacuated, Summa®-
polished sample canister. The critical orifice size is chosen so
that the canister is pressurized to approximately one atmosphere above
ambient pressure, at a constant flow rate over the desired sample
period. Two canisters are connected in parallel for duplicate samples.
The canister(s) are then returned to the laboratory for analysis,
using the PDFID analytical system. Collection of ambient air samples
in pressurized canisters provides the following advantages:
o Convenient integration of ambient samples over a specific
time period ' ,
o Capability of remote sampling with subsequent central
laboratory analysis
o Ability to ship and store samples, if necessary
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o Unattended sample collection
o Analysis of samples from multiple sites with one analytical
system
o Collection of replicate samples for assessment of measurement
precision
With canister sampling, however, great care must be exercised in
selecting, cleaning, and handling the sample canister(s) and sampling
apparatus to avoid losses or contamination of the samples.
10.1 Canister Cleanup and Preparation
10.1.1 All canisters must be clean and free of any contaminants
before sample collection.
10.1.2 Leak test all canisters by pressurizing them to approxi-
mately 30 psig [200 kPa (gauge)] with zero air. The
use of the canister cleaning system (see Figure 5) may
be adequate for this task. Measure the final pressure -
close the canister valve, then check the pressure after
24 hours. If leak tight, the pressure should not vary
more than +_ 2 psig over the 24-hour period. Note leak
check result on sampling data sheet, Figure 7.
10.1.3 Assemble a canister cleaning system, as illustrated in
Figure 5. Add cryogen to both the vacuum pump and zero
air supply traps. Connect the canister(s) to the mani-
fold. Open the vent shut off valve and the canister
valve(s) to release any remaining pressure in the canis-
ter. Now close the vent shut off valve and open the
vacuum shut off valve. Start the vacuum pump and evacuate
the canister(s) to £ 5.0 mm Hg (for at least one hour).
[Note: On a daily basis or more often if necessary, blow-
out the cryogenic traps with zero air to remove any
trapped water from previous canister cleaning cycles.]
Id.1.4 Close the vacuum and vacuum gauge shut off valves and
open the zero air shut off valve to pressurize the canis-
ter^) with moist zero air to approximately 30 psig [200
kPa (gauge)]. If a zero gas generator system is used,
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the flow rate may need to be limited to maintain the
zero air quality.
10.1.5 Close the zero shut off valve and allow canister(s) to
vent down to atmospheric pressure through the vent shut
off valve. Close the vent shut off valve. Repeat steps
10.1.3 through 10.1.5 two additional times for a total of
three (3) evacuation/pressurization cycles for each set of
canisters.
10.1.6 As a "blank" check of the canister(s) and cleanup proce-
dure, analyze the final zero-air fill of 100% of the
canisters until the cleanup system and canisters are
proven reliable. The check can then be reduced to a
lower percentage of canisters. Any canister that does
not test clean (compared to direct analysis of humidified
zero air of less than 0.02 ppmC) should not be utilized.
10.1.7 The canister is then re-evacuated tox 5.0 mm Hg, using
the canister cleaning system, and remains in this con-
dition until use. Close the canister valve, remove the
canister from the canister cleaning system and cap
canister connection with a stainless steel fitting. The
canister is now ready for collection of an air sample.
Attach an identification tag to the neck of each
canister for field notes and chain-of-custody purposes.
10.2 Collection of Integrated Whole-Air Samples
10.2.1 Assemble the sampling apparatus as shown in Figure 2.
The connecting lines between the sample pump and the
canister(s) should be as short as possible to minimize
their volume. A second canister is used when a duplicate
sample is desired for quality assurance (QA) purposes
(see Section 12.2.4). The small auxiliary vacuum pump
purges the inlet manifold or lines with a flow of
several L/min to minimize the sample residence time.
The larger metal bellows pump takes a small portion of
this sample to fill and pressurize the sample canister(s).
Both pumps should be shock-mounted to minimize vibration.
Prior to field use, each sampling system should be leak
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tested. The outlet side of the metal bellows pump can
be checked for leaks by attaching the 0-30 psig pressure
gauge to the canister(s) inlet via connecting tubing and
pressurizing to 2 atmospheres or approximately 29.4 psig.
If pump and connecting lines are leak free pressure should
remain at .+2 psig for 15 minutes. To check the inlet
side, plug the sample inlet and insure that there is no
flow at the outlet of the pump.
10.2.2 Calculate the flow rate needed so that the canister(s)
are pressurized to approximately one atmosphere above
ambient pressure (2 atmospheres absolute pressure)
over the desired sample period, utilizing the following
equation:
F = (P)(V)(N)
(T)(60)
where:
F = flow rate (cm3/min)
P = final canister pressure (atmospheres absolute)
= (Pg/Pa) + 1 '
V = volume of the canister (cm3)
N = number of canisters connected together for
simultaneous sample collection
T = sample period (hours)
Pg = gauge pressure in canister, psig (kPa)
Pa = standard atmospheric pressure, 14.7 psig (101 kPa)
For example, if one 6-L canister is to be filled to 2
atmospheres absolute pressure (14.7 psig) in 3 hours,
the flow rate would be calculated as follows:
F = 2 x 6000 x 1 = 67 cm3/mi n
3 x 60
10.2.3 Select a critical orifice or hypodermic needle suitable
to maintain a substantially constant.flow at the cal-
culated flow rate into the canister(s) over the desired
sample period. A 30-gauge hypodermic needle, 2.5 cm
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T012-16
long, provides a flow of approximately 65 cm3/min with
the Metal Bellows Model MBV-151 pump (see Figure 4).
Such a needle will maintain approximately constant flow
up to a canister pressure of about 10 psig (71 kPa),
after which the flow drops with increasing pressure.
At 14.7 psig (2 atmospheres absolute pressure), the
flow is about 10% below the original flow.
10.2.4 Assemble the 2.0 micron stainless steel in-line particu-
late filter and position it in front of the critical
orifice. A suggested filter-hypodermic needle assembly
can be fabricated as illustrated in Figure 4.
10.2.5 Check the sampling system for contamination by filling
two evacuated, cleaned canister(s) (See Section 10.1)
with humidified zero air through the sampling system.
Analyze the canisters according to Section 11.4. The
sampling system is free of contamination if the canisters
contain less than 0.02 ppmC hydrocarbons, similar to
that of humidified zero air.
10.2.6 During the system contamination check procedure, check
the critical orifice flow rate on the sampling system
to insure that sample flow rate remains relatively con-
stant (+10%) up.to about 2 atmospheres absolute pressure
(101 kPa). Note: A drop in the flow rate may occur
near the end of the sampling period as the canister
pressure approaches two atmospheres.
10.2.7 Reassemble the sampling system. If the inlet sample line
is longer than 3 meters, install an auxiliary pump to
ventilate the sample line, as illustrated in Figure 2.
10.2.8 Verify that the timer, pump(s) and solenoid valve are
connected and operating properly.
10.2.9 Verify that the timer is correctly set for the desired
sample period, and that the solenoid valve is closed.
10.2.10 Connect a cleaned, evacuated canister(s) (Section 10.1)
to the non-contaminated sampling system, by way of the
solenoid valve, for sample collection.
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10.2.11 Make sure the solenoid valve is closed. Open the
canister valve(s). Temporarily connect a small rotameter
to the sample inlet to verify that there is no flow.
Note: Flow detection would indicate a leaking (or open)
solenoid valve. Remove the rotameter after leak de-
tection procedure. '
10.2.12 Fill out the necessary information on the Field Data
Sheet (Figure 7).
10.2.13 Set the automatic timer to start and stop the pump
or pumps to open and close the solenoid valve at the
appropriate time for the intended sample period.
.Sampling will begin at the pre-determined time.
10.2.14 After the sample period, close the canister valve(s) and
disconnect the canister(s) from the sampling system.
Connect a pressure gauge to the canister(s) and briefly
open and close the canister valve. Note the canister
pressure on the Field Data Sheet (see Figure 7). The
canister pressure should be approximately 2 atmospheres
absolute [1 atmosphere or 101 kPa (gauge)]. Note: If
the canister pressure is not approximately 2 atmospheres
absolute (14.7 psig), determine and correct the cause be-
fore next sample. Re-cap canister valve.
10.2.15 Fill out the identification tag on the sample canister(s)
and complete the Field Data Sheet as necessary. Note
any activities or special conditions in the area (rain,
smoke, etc.) that may affect the sample contents on the
sampling data sheet.
10.2.16 Return the canister(s) to the analytical system for
analysis.
11. Sample Analysis
11.1 Analytical System Leak Check
11.1.1 Before sample analysis, the analytical system is assembled
(see Figure 1) and leak checked.
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11.1.2 To leak check the analytical system, place the six-port
gas valve in the trapping position. Disconnect and cap
the absolute pressure gauge. Insert a pressure gauge
capable of recording up to 60 psig at the vacuum valve
outlet.
11.1.3 Attach a valve and a zero air supply to the sample
inlet port. Pressurize the system to about 50 psig
(350 kPa) and close the valve.
11.1.4 Wait approximately 3 hrs. and re-check pressure. If
the pressure did not vary more than +_ 2 psig, the
system is considered leak tight.
11.1.5 If the system is leak free, de-pressurize and reconnect
absolute pressure gauge.
11.1.6 The analytical system leak check procedure needs to
be performed during the system checkout, during a series
of analysis or if leaks are suspected. This should be
part of the user-prepared SOP manual (see Section 12.1).
11.2 Sample Volume Determination
11.2.1 The vacuum reservoir and absolute pressure gauge are
used to meter a precisely repeatable volume of sample
air through the cryogenically-cooled trap, as follows:
With the sample valve closed and the vacuum valve open,
the reservoir is first evacuated with the vacuum pump
to a predetermined pressure (e.g., 100 mm Hg). Then
the vacuum valve'is closed and the sample valve is
opened to allow sample air to be drawn through the
cryogenic trap and into the evacuated reservoir until
a second predetermined reservoir pressure is reached
(e.g., 300 nrnHg). The (fixed) volume of air thus
sampled is determined by the pressure rise in the
vacuum reservoir (difference between the predetermined
pressures) as measured by the absolute pressure gauge
(see Section 12.2.1).
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11.2.2 The sample volume can be calculated by:
V = (AP)(VP)
s (Ps)
where:
Vs = volume of air sampled (standard cm3)
AP = pressure difference measured by gauge (mm Hg)
Vr = volume of vacuum reservoir (cm3)
usually 1 L
Ps = standard pressure (760 mm Hg)
For example, with a vacuum reservoir of 1000 cm3 and a
pressure change of 200 mm Hg (100 to 300 mm Hg), the volume
sampled would be 263 cm3. [Note: Typical sample volume
using this procedure is between 200-300 cm3.]
11.2.3 The sample volume determination need only be performed once
during the system check-out and shall be part of the
user-prepared SOP Manual (see Section 12.1).
11.3 Analytical System Dynamic Calibration
11.3.1 Before sample analysis, a complete dynamic calibration
of the analytical system should be carried out at five or
more concentrations on each range to define the calibra-
tion curve. This should be carried out initially and
periodically thereafter [may be done only once during
a series of analyses]. This should be part of the
user-prepared SOP Manual (See Section 12.1). The
calibration should be verified with two or three-point
calibration checks (including zero) each day the analyt-
ical system is used to analyze samples.
11.3.2 Concentration standards of propane are used to calibrate
the analytical system. Propane calibration standards
may be obtained directly from low concentration cylinder
standards or by dilution of high concentration cylinder
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T012-20
standards with zero air (see Section 8.3). Dilution
flow rates must be measured accurately, and the combined
gas stream must be mixed thoroughly for successful cali-
bration of the analyzer. Calibration standards should
be sampled directly from a vented manifold or tee. Note:
Remember that a propane NMOC concentration in ppmC is
three times the volumetric concentration in ppm.
11.3.3 Select one or more combinations of the following parameters
to provide the desired range or ranges (e.g., Otl.O ppmC
or 0-5.0 ppmC): FID attenuator setting, output voltage
setting, integrator resolution (if applicable), and sample
volume. Each individual range should be calibrated sep-
arately and should have a separate calibration curve.
Note: Modern GC integrators may provide automatic ranging
such that several decades of concentration may be covered
in a single range. The user-prepared SOP manual should
address variations applicable to a specific system design
(see Section 12.1).
11.3.4 Analyze each calibration standard three times according
to the procedure in Section 11.4. Insure that flow
rates, pressure gauge start and stop readings, initial
cryogen liquid level in the Dewar, timing, heating, inte-
grator settings, and other variables are the same as
those that will be used during analysis of ambient
samples. Typical flow rates for the gases are: hydrogen,
30 cm3/minute; helium carrier, 30 cm3/minute; burner
air, 400 cm3/minute.
11.3.5 Average the three analyses for each concentration standard
and plot the calibration curve(s) as average integrated peak
area reading versus concentration in ppmC. The relative
standard deviation for the three analyses should be less
-------
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than 3% (except for zero concentration). Linearity should
be expected; points that appear to deviate abnormally
should be repeated. Response has been shown to be linear
over a wide range (0-10,000 ppbC). If nonlinearity is
observed., an effort should be made to identify and correct
the problem. If the problem cannot be corrected, addi-
tional points in the nonlinear region may be needed to
define the calibration curve adequately.
11.4 Analysis Procedure
11.4.1 Insure the analytical system has been assembled properly,
leaked checked, and properly calibrated through a dynamic
standard calibration. Light the FID detector and allow to
stabilize.
11.4.2 Check and adjust the helium carrier pressure to provide the
correct carrier flow rate for the system. Helium is used
to purge residual air and methane from the trap at the
end of the sampling phase and to carry the re-volatilized
NMOC from the trap into the FID. A single-stage auxiliary
regulator between the cylinder and the analyzer may not
be necessary, but is recommended to regulate the helium
: pressure better than the multistage cylinder regulator.
- When an auxiliary regulator is used, the secondary stage
of the two-stage regulator must be set at a pressure
higher than the pressure setting of the single-stage
regulator. Also check the FID hydrogen and burner air
flow rates (see 11.3.4).
11,.4.3. Close the sample valve and open the vacuum valve to
., ; evacuate the vacuum reservoir to a specific predetermined
.:,-•• . value (e.g., 100 mm Hg).
11.4.4 With the trap at room temperature, place the six-port
valve in the inject position.
11.4.5 Open the sample valve and adjust the sample flow rate
needle valve for an appropriate trap flow of 50-100
cm3/min. Note: The flow will be lower later, when the
trap is cold.
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11.4.6 Check the sample canister pressure before attaching it
to the analytical system and record on Field Data
Sheet (see Figure 7). Connect the sample canister or
direct sample inlet to the six-port valve, as shown in
Figure 1. For a canister, either the canister valve
or an optional fine needle valve installed between the
canister and the vent is used to adjust the canister
flow rate to a value slightly higher than the trap
flow rate set by the sample flow rate needle valve.
The excess flow exhausts through the vent, which
assures that the sample air flowing through the trap
is at atmospheric pressure. The vent is connected to
a flow indicator such as a rotameter as an indication of
vent flow to assist in adjusting the flow control
valve. Open the canister valve and adjust the canister
valve or the sample flow needle valve to obtain a
moderate vent flow as indicated by the rotameter. The
sample flow rate will be lower (and hence the vent
flow rate will be higher) when the the trap is cold.
11.4.7 Close the sample valve and open the vacuum valve (if
not already open) to evacuate the vacuum reservoir.
With the six-port valve in the inject position and the
vacuum valve open, open the sample valve for 2-3 minutes
[with both valves open, the pressure reading won't
change] to flush and condition the inlet lines.
11.4.8 Close the sample valve and evacuate the reservoir to
the predetermined sample starting pressure (typically
100 mm Hg) as indicated by the absolute pressure gauge.
11.4.9 Switch the six-port valve to the sample position.
11.4.10 Submerge the trap in the cryogen. Allow a few minutes
for the trap to cool completely (indicated when the
cryogen stops boiling). Add cryogen to the initial
level used during system dynamic calibration. The level
of the cryogenic liquid should remain constant with
respect to the trap and should completely cover the
beaded portion of the trap.
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11.4.11 Open the sample valve and observe the increasing pressure
on the pressure gauge. When it reaches the specific pre-
determined pressure (typically 300 mm Hg) representative
of the desired sample volume (Section 11.2), close the
sample valve.
11.4.12 Add a little cryogen or elevate the Dewar to raise the
liquid level to a point slightly higher (3-15 mm) than
the initial level at the beginning of the trapping.
Note: This insures that organics do not bleed from the
trap and are counted as part of the NMOC peak(s).
11.4.13 Switch the 6-port valve to the inject position, keeping
the cryogenic liquid on the trap until the methane and
upset peaks have deminished (10-20 seconds). Now close
the canister valve to conserve the remaining sample in
the canister.
11.4.14 Start the integrator and remove the Dewar flask containing
the cryogenic liquid from the trap.
11.4.15 Close the GC oven door and allow the GC oven (or alter-
nate trap heating system) to heat the trap at a predeter-
mined rate (typically, 30°C/min) to 90°. Heating the trap
volatilizes the concentrated NMOC such that the FID pro-
duces integrated peaks. A uniform trap temperature rise
rate (above 0°C) helps to reduce variability and facili-
tates more accurate correction for the moisture-shifted
baseline. With a chromatograph oven to heat the trap,
the following parameters have been found to be acceptable:
initial temperature, 30°C; initial time, 0.20 minutes
(following start of the integrator); heat rate, 30°/minute;
final temperature, 90°C.
11.4.16 Use the same heating process and temperatures for both
calibration and sample analysis. Heating the trap too
quickly may cause an initial negative response that
could hamper accurate integration. "Some initial exper-
imentation may be necessary to determine the optimal
heating procedure for each system. Once established,
the procedure should be consistent for each analysis
as outlined in the user-prepared SOP Manual.
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11.4.17 Continue the integration (generally, in the range of
1-2 minutes is adequate) only long enough to include
all of the organic compound peaks and to establish the
end point FID baseline, as illustrated in Figure 8.
The integrator should be capable of marking the begin-
ning and ending of peaks, constructing the appropriate
operational baseline between the start and end of the
integration period, and calculating the resulting
corrected peak area. This ability is necessary because
the moisture in the sample, which is also concentrated
in the trap, will cause a slight positive baseline
shift. This baseline shift starts as the trap warms
and continues until all of the moisture is swept from
the trap, at which time the baseline returns to its
normal level. The shift always continues longer than
the ambient organic peak(s). The integrator should be
programmed to correct for this shifted baseline by
ending the integration at a point after the last NMOC
peak and prior to the return of the shifted baseline to
normal (see Figure 8) so that the calculated operational
baseline effectively compensates for the water-shifted
baseline. Electronic integrators either do this auto-
matically or they should be programmed to make this cor-
rectipn. Alternatively, analyses of humidified zero air
prior to sample analyses should be performed to determine
the water envelope and the proper blank value for
correcting the ambient air concentration measurements
accordingly. Heating and flushing of the trap should
continue after the integration period has ended to
insure all water has been removed to prevent buildup of
water in the trap. Therefore, be sure that the 6-port
valve remains in the inject position until all moisture
has purged from the trap (3 minutes or longer).
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11.4.18 Use the dynamic calibration curve (see Section 11.3)
to convert the integrated peak area reading into
concentration units (ppmC). Note that the NMOC peak
shape may not be precisely reproducible due to vari-
ations in heating the trap, but the total NMOC peak
area should be reproducible.
11.4.19 Analyze each canister sample at least twice and report
the average NMOC concentration. Problems during an
analysis occasionally will cause erratic or incon-
sistent results. If the first two analyses do not
agree within +_ 5% relative standard deviation (RSD),
additional analyses should be made to identify in-
accurate measurements and produce a more accurate
average (see also Section 12.2.).
12. Performance Criteria and Quality Assurance
This section summarizes required quality assurance measures and pro-
vides guidance concerning performance criteria that should be achieved
within each laboratory.
12.1 Standard Operating Procedures (SOPs)
12.1.1 Users should generate SOPs describing and documenting
the following activities in their laboratory: (1)
assembly, calibration, leak check, and operation of the
specific sampling system and equipment used; (2) prepara-
tion, storage, shipment, and handling of samples; (3)
assembly, leak-check, calibration, and operation of the
analytical system, addressing the specific equipment used;
(4) canister storage and cleaning; and (5) all.aspects of
of data recording and processing, including lists of
computer hardware and software used.
12.1.2 SOPs should provide specific stepwise instructions and
should be readily available to, and understood by, the
laboratory personnel conducting the work.
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12.2 Method Sensitivity, Accuracy, Precision and Linearity
12.2.1 The sensitivity and precision of the method is proportional
to the sample volume. However, ice formation in the
trap may reduce or stop the sample flow during trapping
if the sample volume exceeds 500 cm3. Sample volumes
below about 100-150 cm3 may cause increased measurement
variability due to dead volume in lines and valves. For
most typical ambient NMOC concentrations, sample volumes
in the range of 200-400 cm3 appear to be appropriate.
If a response peak obtained with a 400 cm3 sample is
off scale or exceeds the calibration range, a second
analysis can be carried out with a smaller volume. The
actual sample volume used need not be accurately known
if it is precisely repeatable during both calibration
and analysis. Similarly, the actual volume of the
vacuum reservoir need not be accurately known. But the
reservoir volume should be matched to the pressure
range and resolution of the absolute pressure gauge so
that the measurement of the pressure change in the reser-
voir, hence the sample volume, is repeatable within 1%.
A 1000 cm3 vacuum reservoir and a pressure change of
200 mm Hg, measured with the specified pressure gauge,
have provided a sampling precision of +_ 1.31 cm3. A
smaller volume reservoir may be used with a greater
pressure change to accommodate absolute pressure gauges
with lower resolution, and vice versa.
12.2.2 Some FID detector systems associated with laboratory
chromatographs may have autoranging. Others may
provide attenuator control and internal full-scale
output voltage selectors. An appropriate combination
should be chosen so that an adequate output level for
accurate integration is obtained down to the detection
limit; however, the electrometer or integrator must not
be driven into saturation at the upper end of the
calibration. Saturation of the electrometer may be
indicated by flattening of the calibration curve at
-------
T012-27
high concentrations. Additional adjustments of range
and sensitivity can be provided by adjusting the sample
volume used, as discussed in Section 12.2.1.
12.2.3 System linearity has been documented (6) from 0 to 10,000
ppbC.
12.2.4 Some organic compounds contained in ambient air are
"sticky" and may require repeated analyses before they
fully appear in the FID output. Also, some adjustment
may have to be made in the integrator off time setting
to accommodate compounds that reach the FID late in the
analysis cycle. Similarly, "sticky" compounds from
ambient samples or from contaminated propane standards
may temporarily contaminate the analytical system and
can affect subsequent analyses. Such temporary contam-
ination can usually be removed by repeated analyses of
humidified zero air.
12.2.5 Simultaneous collection of duplicate samples decreases
the possibility of lost measurement data from samples
lost due to leakage or contamination in either of the
canisters. Two (or more) canisters can be filled simul-
taneously by connecting them in parallel (see Figure 2(a))
and selecting an appropriate flow rate to accommodate
the number of canisters (Section 10.2.2). Duplicate (or
replicate) samples also allow assessment of measurement
precision based on the differences between duplicate samples
(or the standard deviations among replicate samples).
13. Method Modification
13.1 Sample Metering System
13.1.1 Although the vacuum reservoir "and absolute pressure gauge
technique for metering the sample volume during analysis is
efficient and convenient, other techniques should work also.
13.1.2 A constant sample flow could be established with a vacuum
pump and a critical orifice, with the six-port valve being
switched to the sample position for a measured time period.
-------
T012-28
" A gas volume meter, such as a wet test meter, could
also be used to measure the total volume of sample air
drawn through the trap. These alternative techniques
should be tested and evaluated as part of a user-prepared
SOP manual.
13.2 FID Detector System
13.2.1 A variety of FID detector systems should be adaptable to
the method.
13.2.2 The specific flow rates and necessary modifications for
the helium carrier for any alternative FID instrument
should be evaluated prior to use as part of the user-
prepared SOP manual.
13.3 Range
13.3.1 It may be possible to increase the sensitivity of the
method by increasing the sample volume. However,
limitations may arise such as plugging of the trap by ice.
13.3.2 Any attempt to increase sensitivity should be evaluated
as part of the user-prepared SOP manual.
.*'
13.4 Sub-Atmospheric Pressure Canister.Sampling
13.4.1 Collection and analysis of"canister air samples at sub-
atmospheric pressure is al-so possible with minor modifi-
cations to the sampling and'analytical procedures.
13.4.2 Method TO-14, "Integrated Canister Sampling for Selective
Organics: Pressurized and Sub-atmospheric Collection
Mechanism.," addresses sub-atmospheric pressure canister
sampling. Additional information can be found in the
literature (11-17).
-------
T012-29
1. Uses, Limitations, and Technical Basis of Procedures for Quantifying
Relationships Between Photochemical Oxidants and Precursors, EPA-
450/2-77-21a, U.S. Environmental Protection Agency, Research Triangle
Park, NC, November 1977.
2. Guidance for Collection of Ambient Non-Methane Organic Compound
(NMOC) Data for Use in 1982 Ozone SIP Development, EPA-450/4-80-011,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
June 1980.
3. H..-B. Singh, Guidance for the Collection and Use of Ambient Hydrocarbons
Species Data in Development of Ozone Control Strategies, EPA-450/480-008,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
April 1980.
4. R. M. Riggin, Technical Assistance Document for Sampling and Analysis
of Toxic Organic Compounds in Ambient Air, EPA-600/483-027, U.S.
Environmental Protection Agency, Research Triangle Park, NC, 1983.
5. M. J. Jackson, et_ aj_., Technical Assistance Document for Assembly and
Operation of the Suggested Preconcentration Direct Flame lonization
Detection (P'DF'ID) Analytical System, publication scheduled for late
1987; currently available in draft form from the Qualilty Assurance
Division, MD.-77, U.S. Environmental Protection Agency, Research
Triangle Park, NC 27711.
6. R. K. M. Jayanty, et al., Laboratory Evaluation of Non-Methane Organic
Carbon Determination in Ambient Air by Cryogenic Preconcentration and
Flame lonization Detection, EPA-600/54-82-019, U.S. Evironmerital Protec-
tion Agency, Research Triangle Park, NC, July 1982.
7. R. D. Cox, et^cil_., "Determination of Low Levels of Total Non-Methane
Hydrocarbon Content in Ambient Air", Environ. Sci.. Techno!., JJ5 (1):57,
- 1982.- '...,.
8. F. f. McElroy, et_ a!., A Cryogenic Preconcentration - Direct FID (PDFID)
Method for Measurement of NMOC in the Ambient Air, EPA-600/4-85-063,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
August'1985. .
9. F. W. Sexton, et^ a_]_., A Comparative Evaluation of Seven Automated
Ambient Non-Methane Organic Compound Analyzers, EPA-600/5482-046,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
August 1982.
10. H. 6. Richter, Analysis of Organic Compound Data Gathered During 1980
in Northeast Corridor Cities, EPA-450/4-83-017, U.S. Environmental
Protection Agency, Research Triangle Park, NC, April 1983.
-------
T012-30
11* Cox, R. D. "Sample Collection and Analytical Techniques for Volatile
Organics in Air," presented at APCA Speciality Conference, Chicago, II,
March 22-24, 1983.
12. Rasmussen, R. A. and Khali!, M.A.K. " Atmospheric Halocarbons:
Measurements and Analyses of Selected Trace Gases," Proc. NATO ASI on
Atmospheric Ozone, 1980, 209-231.
13. Oliver, K. D., Pleil J.D. and McClenny, W.A. "Sample Intergrity of
Trace Level Volatile Organic Compounds in Ambient Air Stored in
"SUMMA®" Polished Canisters," accepted for publication in Atmospheric
Environment as of January 1986. Draft available from W. A. McClenny,
MD-44, EMSL, EPA, Research Triangle Park, NC 27711.
14. McClenny, W. A. Pleil J.D. Holdren, J.W.; and Smith, R.N.; 1984.
" Automated Cryogenic Preconcentration and Gas Chromatographic
Determination of Volatile Organic Compounds," Anal . Chem. 56:2947.
15. Pleil, J. D. and Oliver, K. D., 1985, "Evaluation of Various Config-
urations of Nafion Dryers: Water Removal from Air Samples Prior to
Gas Chromatographic Analysis". EPA Contract No. 68-02-4035.
16. Oliver, K. D.; Pleil, and McClenny, W. A.; 1986. "Sample Integrity
of Trace Level Volatile Organic Compounds in Ambient Air Stored in
Summa® Polished Canisters," Atmospheric Environ. 20:1403.
17. Oliver, K. D. Pleil, J. D., 1985, "Automated Cryogenic Sampling and
Gas Chromatographic Analysis of Ambient Vapor-Phase Organic Compounds:
Procedures and Comparison Tests," EPA Contract No. 68-02-4035,
Research Triangle Park, NC, Northrop Services, Inc. - Environmental
Sciences.
-------
T012-31
PRESSURE
REGULATOR
ABSOLUTE
PRESSURE GAUGE
VACUUM
VALVE
VACUUM
PUMP
DEWAR
FLASK
GLASS
BEADS
CANISTER
VALVE
CANSITER
FINE
NEEDLE
VALVE
(SAMPLE FLOW
ADJUSTMENT)
VACUUM
RESERVOIR
6-PORT
GAS
VALVE
SAMPLE
INJECT
DIRECT AIR SAMPLING
CRYOGENIC
TRAP COOLER
(LIQUID ARGON)
VENT
PRESSURIZED (EXCESS)
CANISTER i
SAMPLE
PRESSURE
GAS REGULATOR
PURIFIER
(OPTIONAL FINE
NEEDLE VALVE)
PRESSURE
REGULATOR
INTEGRATOR
RECORDER
FIGURE 1. SCHEMATIC OF ANALYTICAL SYSTEM FOR
MiVtOC--TWO SAMPLING MODES
-------
T012-32
SAMPLE
IN
CRITICAL
ORIFICE
AUXILIARY
VACUUM
PUMP
TIMER
METAL
BELLOWS
PUMP
PRESSURE
GAUGE
SOLENOID
VALVE
CANISTER(S)
FIGURE 2. SAMPLE SYSTEM FOR AUTOMATIC COLLECTION
OF 3-HOUR INTEGRATED AIR SAMPLES
-------
T012-33
TIMER
SWITCH
100K
RED
o—i
115 VAC
40nfd, 450 V DC
100K 01
BLACK
PUMP
WHITE
COMPONENTS
Capacitor C-| and Cz - 40 uf, 450 VDC (Sprague Atom® TVA 1712 or equivalent)
Resister RI and Rj - 0.5 watt, 5% tolerance
Diode DI and D2 - 1000 PRV, 2.5 A (RCA. SK 3081 or equivalent)
MAGNELATCH
SOLENOID
VALVE
FIGURE 3[a]. SIMPLE CIRCUIT FOR OPERATING MAGNELATCH VALVE
TIMER
SWITCH
O
115 VAC
COMPONENTS
Bridge Rectifier - 200 PRV, 1.5 A (RCA, SK 3105 or equivalent)
Diode DI and 02 - 1000 PRV, 2.5 A (RCA, SK 3081 or equivalent)
Capacitor Ci - 200 uf, 250 VDC (Sprague Atom® TVA 1528 or equivalent)
Capacitor Cj - 20 uf, 400 VOC Non-Polarized (Sprague Atom* TVAN 1652 or equivalent)
Relay - 10,000 ohm coil, 3.5 ma (AMF Potter and Brumfield, KCP 5. or equivalent)
Resister RI and R2 - 0.5 watt, 5% tolerance
MAGNELATCH
SOLENOID
VALVE
20 uf
400 Volt
NON-POLARIZED
FIGURE 3[b]. IMPROVED CIRCUIT DESIGNED TO HANDLE POWER INTERRUPTIONS
FIGURE 3. ELECTRICAL PULSE CIRCUITS FOR DRIVING
SKINNER MAGNELATCH SOLENOID VALVE
WITH A MECHANICAL TIMER
-------
TO12-34
T SERIES COMPACT, INLINE FILTER
W/2 pm SS SINTERED ELEMENT
FEMALE CONNECTOR, 0.25 in O.D. TUBE TO
0.25 in FEMALE NPT
HEX NIPPLE, 0.25 in MALE NPT BOTH ENDS
30 GAUGE x 1.0 in LONG HYPODERMIC
NEEDLE (ORIFICE)
FEMALE CONNECTOR, 0.25 in O.D. TUBE TO
0.25 in FEMALE NPT
THERMOGREEN LBI 6 mm (0.25 in)
SEPTUM (LOW BLEED)
0.25 in PORT CONNECTOR W/TWO 0.25 in NUTS
FIGURE 4. FILTER AND HYPODERMIC NEEDLE
ASSEMBLY FOR SAMPLE INLET FLOW
CONTROL
-------
T012-35
ZERO AIR
SUPPLY
-h>£l— -
3-PORT \
GAS
VALVE
^
nxxj — \;
VENT VALVE /
CHECK VALVE
^
V
/
/
CRYOGENIC
' TRAP
VACUUM VACUUM PUMP
PUMP SHUT OFF VALVE VENT VALVE
ZERO AIR
SUPPLY
VENT SHUT OFF
VALVE
X
0-
CRYOGENIC
TRAP
VACUUM SHUT OFF
VALVE
VACUUM
GAUGE
VACUUM GAUGE
SHUT OFF VALVE
VENT SHUT OFF
VALVE
HUMIDIFIER
PRESSURE
GAUGE
ZERO SHUT OFF
VALVE
FLOW
I CONTROL
.VALVE
VENT SHUT OFF
VALVE
[_}H
J-t!
MANIFOLD
fjH CANISTER VALVE
s^~^^
SAMPLE CANISTERS
FIGURE 5. CANISTER CLEANING SYSTEM
-------
T012-36
TUBE LENGTH: -30 cm
O.D.: 0.32 cm
I.D.: 021 cm
CRYOGENIC LIQUID LEVEL
60/80 MESH GLASS BEADS
fTO FIT DEWAR)
FIGURE 6. CRYOGENIC SAMPLE TRAP DIMENSIONS
-------
T012-37
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-------
TO12-38
NMOC
PEAK
ui
w
O
CL
CO
UJ
cc
a
E
START
INTEGRATION
END
INTEGRATION
CONTINUED HEATING
OF TRAP
WATER-SHIFTED
BASELINE
t
OPERATIONAL BASELINE
CONSTRUCTED BY INTEGRATOR
TO DETERMINE CORRECTED AREA
NORMAL BASELINE
TIME (MINUTES)
FIGURE 8. CONSTRUCTION OF OPERATIONAL BASELINE
AND CORRESPONDING CORRECTION OF
PEAK AREA
-------
Revision 1.0
June, 1988
METHOD TO-13
THE DETERMINATION OF BENZO(a)PYRENE [B(a)P] AND OTHER
POLYNUCLEAR AROMATIC HYDROCARBONS (PAH's) IN AMBIENT AIR USING GAS
CHROMATOGRAPHIC (GC) AND HIGH PERFORMANCE LIQUID
CHROMAT.OGRAPHIC (HPLC) ANALYSIS
OUTLINE
1. Scope
2. Applicable Documents
3. Summary of Method
4. Significance
5. Definitions
6. Interferences
7. Safety
8. Apparatus
8.1 Sample Collection
8.2 Sample Clean-up and Concentration
8.3 Sample Analysis
8.3.1 Gas Chromatography with Flame lonization Detection
8.3.2 Gas Chromatography with Mass Spectroscopy Detection
Coupled with Data Processing System (GC/MS/DS)
8.3.3 High Performance Liquid Chromatography System
9. Reagents and Materials
9.1 Sample Collection
9.2 Sample Clean-up and Concentration
9.2.1 Soxhlet Extraction
9.2.2 Solvent Exchange
9.2.3 Column Clean-up
9.3 Sample Analysis
9.3.1 Gas Chromatography Detection
9.3.2 High Performance Liquid Chromatography Detection
10. Preparation of Sampling Filter and Adsorbent
10.1 Sampling Head Configuration
10.2 Glass Fib'er Filter Preparation
10.3 XAD-2 Adsorbent Preparation
10.4 PUF Sampling Cartridge Preparation
11. Sample Collection
11.1 Description of Sampling Apparatus
11.2 Calibration of Sampling System
11.2.1 Calibration of Flow Rate Transfer Standard
11.2.2 Initial Multi-point Calibration of High Volume Sampling System
Utilizing Flow Rate Transfer Standard
11.2.3 Single Point Audit of the High Volume Sampling System
Utilizing Flow Rate Transfer Standard
11.3 Sample Collection
12. Sample Clean-up and Concentration
12.1 Sample Identification
12.2 Soxhlet Extraction and Concentration
12.3 Solvent Exchange
12.4 Sample Clean-up by Solid Phase Exchange and Concentration
12.4.1 Method 610 Clean-up Procedure
12.4.2 Lobar Prepacked Column Procedure
-------
OUTLINE (cont'd)
13. Gas Chromatography (GC) with Flame lonization (FI) Detection
13.1 Analytical Technique
13.2 Analytical Sensitivity
13.3 Analytical Assembly
13.4 GC Calibration
13.4.1 External Standard Calibration Procedure
13.4.2 Internal Standard Calibration Procedure
13.5 Retention Time Window Determination
13.6 Sample Analysis
13.6.1 Sample Injection
13.6.2 Area Counts and Peak Height
13.6.3 Analyte Identification
13.6.4 Analyte Quantification
14. Gas Chromatography (GC) with Mass Spectroscopy (MS) Detection
14.2 Analytical System
14.2 Operation Parameters
14.3 Calibration Techniques
14.3.1 External Standard Calibration
14.3.2 Internal Standard Calibration
14.4 Sample Analysis
14.4.1 Preliminary Screening by GC/FID
14.4.2 Sample Injection
14.4.3 Area Counts
14.4.4 Analyte Identification
14.4.5 Spectrum Comparison
14.4.6 Analyte Quantification
14.5 GC/MS Performance Tests
14.5.1 Daily DFTPP Tuning
14.5.2 Daily 1-point Initial Calibration Check
14.5.3 12-hour Calibration Verification
15. High Performance Lliquid Chromatography (HPLC) Detection
15.1 Introduction
15.2 Solvent Exchange to Acetonitrile
15.3 HPLC Assembly
15.4 HPLC Calibration
15.4.1 Stock Standard Solution
15.4.2 Storage of Stock Standard Solution
15.4.3 Replacement of Stock Standard Solution
15.4.4 Calibration Standards
15.4.5 Analysis of Calibration Standards
15.4.6 Lingar Response
15.4.7 Daily Calibration
15.5 Sample Analysis
15.6 HPLC System Performance
15.7 HPLC Method Modification
16. Quality Assurance/Quality Control (QA/QC)
16.1 General System QA/QC
16.2 Process, Field and Solvent Blanks
16.3 Gas Chromatography with Flame lonization Detection
16.4 Gas Chromatography with Mass Spectroscopy Detection
16.5 High Performance Liquid Chromatography Detection
-------
OUTLINE (cont'd)
17. Calculations
17.1 Sample Volume
17.2 Sample Concentration
17.2.1 Gas Chromatography with Flame lonization Detection
17.2.2 Gas Chromatography with Mass Spectroscopy Detection
17.2.3 High Performance Liquid Chromatography Detection
17.3 Sample Conversion from ng/m3 to ppbv
18. Bibliography
-------
-------
METHOD TO-13
THE DETERMINATION OF BENZO(a)PYRENE [B(a)P] AND OTHER
POLYNUCLEAR AROMATIC HYDROCARBONS (PAHs) IN AMBIENT AIR USING GAS
CHROMATOGRAPHIC (GC) AND HIGH PERFORMANCE LIQUID
CHROMATOGRAPHIC (HPLC) ANALYSIS
1. Scope
1.1 Polynuclear 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 par-
ticular, 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, a reliable sampling and analytical method
has been established. This document describes a sampling and
analysis procedure for B[a]P and other PAHs involving a combination
quartz filter/adsorbent cartridge with subsequent analysis by gas
chromatography (GC) with flame ionization (FI) and mass spectrometry
(MS) detection (GC/FI and GC/MS) or high resolution liquid chroma-
tography (HPLC). The analytical methods are a modification 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 a carcinogenic constituent
of coal tar (1-7). Fluorescent methods are capable of measuring
subnanogram quantities of PAHs, but tend to be fairly non-selective.
The normal spectra obtained tended to be intense and lacked reso-
lution. Efforts to overcome this difficulty led to the use of
ultraviolet (UV) absorption spectroscopy as the detection method
coupled with pre-speciated techniques involving liquid chromatog-
raphy (LC) and thin layer chromatography (TLC) to isolate specific
PAHs, particularly B[a]P (8). 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 flu-
oresence techniques, the possibility of spectra overlap required
complete separation of sample components to insure accurate measure-
ment of component levels. Hence, the use of UV absorption coupled
-------
T013-2
with pre-speciation involving LC and TLC and fluorescence spectro-
scopy has declined and is now being replaced with the more sensitive
high performance liquid chromatography (9) with UV/fluorescence detec-
tion and highly sensitive and specific gas chromatograph with either
flame ionization detector or coupled with mass spectroscopy (10-11).
1.3 The choice of GC and HPLC as the recommended procedures for analysis
of B[a]P and other PAHs are influenced by their sensitivity and
selectivity, along with their ability to analyze complex samples.
This method provides for both GC and HPLC approaches to the deter-
mination of B[a]P and other PAHs in the extracted sample.
1.4 The analytical methodology is well defined, but the sampling pro-
cedures can reduce the validity of the analytical results. Recent
studies (12-15) have indicated that non-volatile PAHs (vapor pres-
sure <10~8 mm Hg) may be trapped on the filter, but post-collection
volatilization problems may distribute the PAHs down stream of the
the filter to the back-up adsorbent. A wide variety of adsorbents
such as Tenax GC, XAD-2 resin and polyurethane foam (PUF) have been
used to sample B[a]P and other PAH vapors. All adsorbents have
demonstrated high collection efficiency for B[a]P in particular.
In general, XAD-2 resin has a higher collection efficiency (16-17)
for volatile PAHs than PUF, as well as a higher retention efficiency.
. However, PUF cartridges are easier to handle in the field and main-
tain better flow characteristics during sampling. Likewise, PUF
has demonstrated its capability in sampling organochlorine pesticides
and polychlorinated biphenyls (Compendium Methods T04 and T010 re-
spectively), and polychlorinated dibenzo-p-dioxins (Compendium
Method T09). However, PUF has demonstrated a lower recovery effi-
ciency and storage capability for naphthalene and B[a]P, respectively,
than XAD-2. There have been no significant losses of PAHs, up to
30 days of storage at 0°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
reactive PAHs. Consequently, while the literature cites weaknesses
and strengths of using either XAD-2 or PUF, this method covers both
the utilization of XAD-2 and PUF as the adsorbent to address post-
collection volatilization problems associated with B[a]P and other
reactive PAHs.
-------
T013-3
1.5 This method covers the determination of B[a]P specific!ally by
both GC and HPLC and enables the qualitative and quantitative
analysis of the other PAHs. They are:
Acenaphthene Benzo(k)fluoranthene
Acenaphthylene Chrysene
Anthracene Dibenzo(a,h)anthracene
Benzo(a)anthracene Fluoranthene
Benzo(a)pyrene Fluorene
Benzo(b)fluoranthene Indeno(l,2,3-cd)pyrene
Benzo(e)pyrene Naphthalene
Benzo(g,h,i)perylene Phenanthrene
Pyrene
The GC and HPLC methods are applicable to the determination of
PAHs compounds involving two-member rings or higher. Nitro-
PAHs have not been fully evaluated using this procedure; therefore,
they are not included in this method. When either of the methods
are used to analyze unfamiliar samples for any or all of the com-
pounds listed above, compound identification should be supported
by both techniques.
1.6 With careful attention to reagent purity and optimized analytical
conditions, the detection limits for GC and HPLC methods range from
1 ng to 10 pg which represents detection of B[a]P and other PAHs
in filtered air at levels below 100 pg/m3. To obtain this detection
limit, at least 100 m3 of air must be sampled.
2. Applicable Documents
•2.1 ASTM Standards
2.1.1 Method D1356 - Definitions of Terms Relating to Atmospheric
Sampling and Analysis.
2.1.2 Method E260 - Recommended Practice for General Gas
Chromatography Procedures.
2.1.3 Method E355 - Practice for Gas Chromatography Terms and
Relationships.
2.1.4 Method E682 - Practice for Liquid Chromatography Terms and
Relationships.
2.1.5 Method D-1605-60 - Standard Recommended Practices for Sampling
Atmospheres for Analysis of Gases and Vapors.
2.2 Other Documents
2.2.1 Existing Procedures (18-25)
2.2.2 Ambient Air Studies (26-28)
-------
T013-4
2.2.3 U.S. EPA Technical Assistance Document (29-32)
2.2.4 General Metal Works Operating Procedures for Model PS-1
Sampler, General Metal Works, Inc., Village of Cleves, Ohio.
3. Summary of Method
3.1 Filters and adsorbent cartridges (containing XAD-2 or PUF) are
cleaned in solvents and vacuum-dried. The filters and adsorbent
cartridges are stored in screw-capped jars wrapped in aluminum
foil (or otherwise protected from light) before careful installa-
tion on a modified high volume sampler.
3.2 Approximately 325 m3 of ambient air is drawn through the filter
and adsorbent cartridge using a calibrated General Metal Works
Model PS-1 Sampler, or equivalent (breakthrough has not shown
to be a problem with sampling volumes of 325 m3).
3.3 The amount of air sampled through the filter and adsorbent car-
tridge is recorded, and the filter and cartridge are placed in
an appropriately labeled container and shipped along with blank
filter and adsorbent cartridges to the analytical laboratory
for analysis.
3.4 The filters and adsorbent cartridge are extracted by Soxhlet
extraction with appropriate solvent. The extract is concentrated
by Kuderna-Danish (K-D) evaporator, followed by silica gel clean-up
using column chromatography to remove potential interferences prior
to analysis.
3.5 The eluent is further concentrated by K-D evaporator, then analyzed
by either gas chromatograhy equipped with FI or MS detection or high
performance liquid chromatography (HPLC). The analytical system is
verified to be operating properly and calibrated with five concen-
tration calibration solutions, each analyzed in triplicate.
3.6 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 necessary, recalibrate
the instrument, adjust the amount of the sample injected, adjust
the calibration solution concentration, and adjust the data proces-
sing system to reflect observed retention times, etc.
3*7 The samples and the blanks are analyzed and used (along with the
amount of air sampled) to calculated the concentratuon of B[a]P in
ambient air.
-------
T013-5
3.8 Other PAHs can be determined both qualitatively and quantitatively
through optimization of the GC or HPLC procedures.
4. Significance
4.1 Several documents have been published which describe sampling and
analytical approaches for benzo[a]pyrene and other PAHs,-as out-
lined in Section 2.2. The attractive features of these methods
have been combined in this procedure. This method has been
validated in the laboratory; however, one must use caution when
employing it for specific applications.
4.2 The relatively low level of B[a]P and other PAHs in the environ-
ment requires use of high volume (M5.7 cfm) sampling techniques
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 adsorbent cartridge which provide for efficient collection
of most PAHs.
5. Definitions
Definitions used in this document and in any user-prepared standard
operating procedures (SOPs) should be consistent with ASTM Methods D1356,
D1605-60, E260, and E255. All abbreviations and symbols are defined with-
in this document at point of use.
5.1 Sampling efficiency (SE) - ability of the sampling medium to trap
vapors of interest. %SE is the percentage of the analyte of in-
terest colleted 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.
5.2 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.
5.3 High Performance Liquid Chromatography - an analytical method
based on separation of compounds of a liquid mixture through a
liquid chromatographic column and measuring the separated com-
ponents with a suitable detector.
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5.4 Gradient elution - defined as increasing the strength of the
mobile phase during a chromatographic analysis. The net effect
of gradient elution is to shorten the retention time of compounds
strongly retained on the analytical column. Gradient elution may
be stepwise on continuous.
5.5 Method detection limit (MDL) - the minimum concentration of a sub-
stance that can be measured and reported with confidence and that
the value is above zero.
5.6 Kuderna-Danish apparatus - the Kuderna-Danish (KD) appartus is a
system for concentrating materials dissolved in volatile solvents.
5.7 Reverse phase liquid chromatography - reverse phase liquid chro-
matography involves a non-polar absorbent (C-18,ODS) coupled with
a polar solvent to separate non-polar compounds.
5.8 Guard column - guard columns in HPLC are usually short ( 5cm)
columns attached after the injection port and before the analytial
column to prevent particles and strongly retained compounds from
accumulating on the analytical column. The guard column should
always be the same stationary phase as the analytical column and
is used to extend the life of the analytical column.
5.9 MS-SIM - the GC is coupled to a select ion mode (SIM) detector
where the instrument is programmed to acquire data for only the
target compounds and to disregard all others. This is performed
using SIM coupled to retention time discriminators. The SIM
analysis procedure provides quantitative results.
5.10 Sublimatio'n - Sublimation is the 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.
5.11 Surrogate standard - A surrogate standard is a chemically inert
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 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.
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5.12 Retention time window - Retention time window is determined for
each analyte of interest and is the time from injection to elution
of a specific chemical from a chromatographic column. The window
is determined by three injections of a single component standard over
a 72-hr period as plus or minus three times the standard deviation
of the absolute retention time for that analyte.
6. Interferences
6.1 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.
6.1.1 Glassware must be scrupulously cleaned (33). Clean all
glassware as soon as possible after use by rinsing with
the last solvent used in it. This should be followed by
detergent washing with hot water, and rinsing with tap
water and reagent water. It should then be drained dry,
solvent rinsed with acetone and spectrographic grade
hexane. After drying and rinsing, glassware should be
sealed 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.
6.1.2 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.
6.1.3 Matrix interferences may be caused by contaminants that
are coextracted from the sample. Additional clean-up by
column chromatography may be required (see Section 12.4).
6.2 The extent of interferences that may be encountered using liquid
chromatographic techniques has not been fully assessed. Although
GC and HPLC 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 clean-up prior to GC or HPLC analysis will eliminate most
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T013-8
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 is run
for each batch of reagents used to determine if reagents are
contaminant-free.
6.3 Although HPLC separations have been improved by recent advances
in column technology and instrumentation, problems may occur with
baseline noises baseline drift, peak resolution and changes in
sensitivity. Problems affecting overall system performance can
arise (34). The user is encouraged to develop a standard operating
procedure (SOP) manual specific for his laboratory to minimize
problems affecting overall system performance.
6.4 Concern during sample transport and analysis is mentioned. Heat,
ozone, N0£ and ultraviolet (UV) light may cause sample degradation.
These problems should be addressed as part of the user prepared
standard operating procedure manual. Where possible, incandescent
or UV-shield fluorescent lighting should be used during analysis.
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 speci-
fied 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
(35-37).
7.2 Benzo[a]pyrene 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
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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 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 (Table 1.0 and Figure 1.0).
7.3 Treat all selective polynuclear aromatic hydrocarbons 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 Because the sampling configuration (filter and backup adsorbent) has
demonstrated greater than 95% collection efficiency for targeted PAHs,
no field recovery evaluation will occur as part of this procedure.
8. Apparatus
8.1 Sample Collection
8.1.1 General Metal Works (GMW) Model PS-1 Sampler, or equi-
valent [General Metal Works, Inc., 145 South Miami Ave.,
Village of Cleves, Ohio, 45002, (800-543-7412)].
8.1.2 At least two Model PS-1 sample cartridges and filters
assembled for PS-1 sampler.
8.1.3 GMW Model PS-1 calibrator and associated equipment -
General Metal Works, Inc., Model GMW-40, 145 South Miami
Ave., Village of Cleves, Ohio, 45002, (800-543-7412).
8.1.4 Ice chest - to store samples at 0°C after collection.
8.1.5 Data sheets for each sample for recording the location and
sample time, duration of sample, starting time, and volume
of air sampled.
8.1.6 Airtight, labeled screw-capped container sample cartridges
(wide mouth, preferrably glass with Teflon seal or other non-
contaminating seals) to hold filter and adsorbent cartridge
during transport to analytical laboratory.
8.1.7 Portable Tripod Sampler (optional) - user prepared (38).
8.2 Sample Clean-up and Concentration
8.2.1 Soxhlet extractors capable of extracting GMW Model PS-1
filter and adsorbent cartridges (2.3" x 5" length), 500 ml
flask, and condenser.
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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.
8.2.3 Glass vial, 40 ml.
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 glass-
ware 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 a muffle furnace at 400°C for 2 to 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 Polyester gloves for handling cartridges and filters.
8.2.6 Minivials - 2 ml, borosilicate glass, with conical reservoir
and screw caps lines with Teflon-faced silicone disks, and
a vial holder.
8.2.7 Stainless steel Teflon® coated spatulas and spoons.
8.2.8 Kuderna-Danish (KD) apparatus - 500 ml evaporation flask
(Kontes K-570001-500 or equivalent), 10 ml graduated con-
centrator tubes (Knotes K-570050-1025 or equivalent) with
ground-glass stoppers, and 3-ball macro Snyder Column (Kontes
K-5700010500, K-50300-0121, and K-569001-219, or equivalent).
8.2.9 Adsorption columns for column chromatography - 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.
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8.2.13 Laboratory refrigerator with chambers operating at 0°C and 4°C.
8.2.14 Boiling chips - solvent extracted, 10/40 mesh silicon car-
bide or equivalent.
8.2.15 Water bath - heated, with concentric ring cover, capable
of temperature control (+_ 5°C).
8.2.16 Vortex evaporator (optional).
8.3 Sample Analysis
8.3.1 Gas Chromatography with Flame lonization Detection (FID).
8.3.1.1 Gas Chromatography: Analytical system complete
with gas Chromatography suitable for on-column
injections and all required accessories, including
detectors, column supplies, recorder, gases, and
syringes. A data system for measuring peak areas
and/or peak heights is recommended.
8.3.1.2 Packed Column: 1.8-m x 2-mm I.D. glass column
packed with 3% OV-17 on Chromosorb W-AW-DMCS
(100/120 mesh) or equivalent (Supelco Inc.,
Supelco Park, Bellefonte, Pa. Supelco SPB-5).
8.3.1.3 Capillary Column: 30-m x 0.25-mm ID fused silica
column coated with 0.25 u thickness 5% phenyl,
90% methyl siloxane (Supelco Inc., Supelco Park,
Bellefonte, Pa.).
8.3.1.4 Detector: Flame lonization (FI)
8.3.2 Gas Chromatograph with Mass Spectroscopy Detection Coupled
with Data Processing System (GC/MS/DS).
8.3.2.1 The GC must be equipped for temperature programming,
and all required accessories must be available, in-
cluding syringes, gases, and a capillary column. The
GC 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 1-3
uL injection volume is used consistently. With some
, GC injection ports, however, 1 uL injections may pro-
duce some improvement in precision and chromatographic
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8.3.3.2 Guard column - 5-cm guard column pack with Vydac
reverse phase C-18 material.
8.3.3.3 Reverse phase analytical column - Vydac or equivalent,
C-18 bonded phase RP column (The Separation Group,
P.O. Box 867, Hesperia, Ca., 92345), 4.6-mm x 25-cm,
5-micron particle diameter.
8.3.3.4 LS-4 fluorescence spectrometer, Perkin Elmer, sepa-
ate excitation and emission, monochromator positioned
by separate microprocessor-controlled flow cell and
wavelength programming ability (optional).
8.3.3.5 Ultraviolet/visible detector, Spectra Physics 8440,
deuterium Lamp, capable of programmable wavelengths
(optional).
8.3.3.6 Dual channel Spectra Physics 4200 Computing Integra-
tor, measures peak areas and retention times from
recorded chromatographs. IBM PC XT will Spectra
Physics Labnet system for data collection and storage
(optional).
9. Reagents and Materials
9.1 Sample Collection
9.1.1 Acid-washed quartz fiber filter - 105 mm micro quartz fiber
binderless filter (General Metal Works, Inc., Cat. No. GMW
QMA-4, 145 South Miami Ave., Village of Cleves, Ohio,
45002 [800-543-7412] or Supelco Inc., Cat. No. 1-62,
Supelco Park, Bellefonte, PA, 16823-0048).
9.1.2 Polyurethane foam (PUF) - 3 inch thick sheet stock,
polyether type (density 0.022 g/cm^) used in furniture
upholstering (General Metal Works, Inc., Cat. No. PS-1-16,
145 South Miami Ave., Village of Cleves, Ohio, 45002 [800-
543-7412] or Supelco Inc., Cat. No. 1-63, Supelco Park,
Bellefonte, PA, 16823-0048).
9.1.3 XAD-2 resin - Supelco Inc., Cat. No. 2-02-79, Supelco
Park, Bellefonte, PA, 16823-0048.
9.1.4 Hexane-rinsed aluminum foil - best source.
9.1.5 Hexane-reagent grade, best source.
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9.2 Sample Clean-up and Concentration
9.2.1 Soxhlet Extraction
9.2.1.1 Methylene chloride - chromatographic grade,
glass-distilled, best source.
9.2.1.2 Sodium sulfate, anhydrous - (ACS) granular
anhydrous (purified by washing with methylene
chloride followed by heating at 400°C for 4 hrs
in a shallow tray).
9.2.1.3 Boiling chips - solvent extracted, approximately
10/40 mesh (silicon carbide or equivalent).
9.2.1.4 Nitrogen - high purity grade, best source.
9.2.1.5 Ether - chromatographic grade, glass-distilled,
best source.
9.2.1.6 Hexane - chromatographic grade, glass-distilled,
best source.
9.2.1.7 Dibromobiphenyl - chromatographic grade, best source.
Used for internal standard.
9.2.1.8 Decafluorobiphenyl - chromatographic grade, best
source. Used for internal standard.
9.2.2 Solvent Exchange
9.2.2.1 Cyclohexane - chromatographic grade, glass-
distilled, best source.
9.2.3 Column Clean-up
Method 610
9.2.3.1 Silica gel - high purity grade, type 60, 70-230
mesh; extracted in a Soxhlet apparatus with
methylene chloride for 6 hours (minimum of 3
cycles per hour) and activated by heating in a
foil-covered glass container for 24 hours at 130°C.
9.2.3.2 Sodium sulfate, anhydrous - (ACS) granular
anhydrous (See Section 9.2.1.2).
9.2.3.3 Pentane - chromatographic grade, glass-distilled,
best source.
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Lobar Prepacked Column
9.2.3.4 Silica gel lobar prepacked column - E. Merck,
Darmstadt, Germany [Size A(240-10) Lichroprep Si
(40-63 urn)].
9.2.3.5 Precolumn containing sodium sulfate - American
Chemical Society (ACS) granular anhydrous (purified
by washing with methylene chloride followed by
heating at 400°C for 4 hours in a shallow tray).
9.2.3.6 Hexane - chromatographic grade, glass-distilled,
best source.
9.2.3.7 Methylene chloride - chromatographic grade, glass-
distilled, best source
9.2.3.8 Methanol - chromatographic grade, glass-distilled,
best source.
9.3 Sample Analysis
9.3.1 Gas Chromatography Detection
9.3.1.1 Gas cylinders of hydrogen and helium - ultra high
purity, best source.
9.3.1.2 Combustion air - ultra high purity, best source.
9.3.1.3 Zero air - Zero air may be obtained from a cylinder
or zero-grade compressed air scrubbed with Drierite®
or silica gel and 5A 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.
9.3.1.4 Chromatographic-grade stainless steel tubing
and stainless steel plumbing fittings - for
interconnections. [Alltech Applied Science,
2051 Waukegan Road, Deerfield, IL, 60015, (312)
948-8600]. [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.]
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9.3.1.5 Native and isotopically labeled PAHs isomers for
calibration and spiking standards-[Cambridge
Isotopes, 20 Commerce Way, Woburn, MA, 01801 (617-
547-1818)]. Suggested isotopically labeled PAH
isomers are:
o perylene - d]^
o chrysene - d^2
o acenaphthene - djg
o naphthalene - ds
o phenanthrene - d^g
9.3.1.6 Decafluorotriphenylphosphine (DFTPP) - best source,
used for tuning 6C/MS.
9.3.2. High Performance Liquid Chromatography Detection
9.3.2.1 Acetonitrile - chromatographic grade, glass-
distilled, best source.
9.3.2.2 Boiling chips - solvent extracted, approximatley
10/40 mesh (silicon carbide or equivalent).
9.3.2.3 Water - HPLC Grade. Water must not have an
interference that is observed at the minimum
detectable limit (MDL) of each parameter of interest.
9.3.2.4 Decafluorobiphenyl - HPLC grade, best source
(used for internal standard).
10. Preparation of Sample Filter and Adsorbent
10.1 Sampling Head Configuration
10.1.1 The sampling head (Figure 2) consist of a filter holder
compartment followed by a glass cartridge for retaining
the adsorbent.
10.1.2 Before field use, both.the filter and adsorbent must be
cleaned to <10 ng/apparatus of B[a]P or other PAHs.
10.2 Glass Fiber Filter Preparation
10.2.1 The glass fiber filters are baked at 600°C for five hours
before use. To insure acceptable filters, they are ex-"
tracted with methylene chloride in a Soxhlet apparatus, sim-
ilar to the cleaning of the XAD-2 resin (see Section 10.3).
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10.2.2 The extract is concentrated and analyzed by either GC or
HPLC. A filter blank of <10 ng/filter of B[a]P or other
PAHs is considered acceptable for field use.
10.3 XAD-2 Adsorbent Preparation
10.3.1 For initial cleanup of the XAD-2, a batch of XAD-2 (approxi-
mately 60 grams) is placed in a Soxhlet apparatus [see Fig-
ure 3(a)] and extracted with methylene chloride for 16
hours at approximately 4 cycles per hour.
10.3.2 At the end of the initial Soxhlet extraction, the spent
methylene chloride is discarded and replaced with fresh
reagent. The XAD-2 resin is once again extracted for 16
hours at approximately 4 cycles per hour.
10.3.3 The XAD-2 resin is removed from the Soxhlet apparatus,
places in a vacuum oven connected to an ultra-purge nitrogen
gas stream and dries at room temperature for approximately
2-4 hours (until no solvent odor is detected).
10.3.4 A nickel screen (mesh size 200/200) is fitted to the bottom
of a hexane-rinsed glass cartridge to retain the XAD-2 resin.
10.3.5 The Soxhlet extracted/vacuum dried XAD-2 resin is placed into
the sampling cartridge (using polyester gloves) to a depth
of approximately 2 inches. This should require approxi-
mately 55 grams of adsorbent.
10.3.6 The glass module containing the XAD-2 adsorbent is wrapped
with hexane-rinsed aluminum foil, placed in a labeled
*
container and tightly sealed with Teflon® tape.
10.3.7 At least one assemble cartridge from each batch must be
analyzed, as a laboratory blank, using the procedures
described in Section 13, before the batch is considered
acceptable for field use. A blank of <10 ng/cartridge of
B[a]P on other PNA's is considered acceptable.
10.4 PUF Sampling Cartridge Preparation
10.4.1 The PUF adsorbent is a polyether-type polyurethane foam
(density No. 3014 or 0.0225 g/cm3) used for furniture up-
holstery.
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10.4.2 The PUF inserts 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 1). During cutting, the die is
rotated at high speed (e.g., in a drill press) and
continuously lubricated with water.
10.4.3 For initial cleanup, the PUF plug is placed in a Soxhlet
apparatus [see Figure 3(a)] and extracted with acetone
for 14-24 hours at approximately 4 cycles per hour.
[Note: When cartridges are reused, 5% diethyl ether in
n-hexane can be used as the cleanup solvent.]
10.4.4 The extracted PUF is placed in a vacuum oven connected to
a water aspirator and dried at room temperature for
approximately 2-4 hours (until no solvent odor is detected)
10.4.5 The PUF is placed into the glass sampling cartridge using
polyester gloves. The module is wrapped with hexane-
rinsed aluminum foil, placed in a labeled container, and
tightly sealed.
10.4.6 At least one assembled cartridge from each batch must be
analyzed, as a laboratory blank, using the procedures
described in Section 13, before the batch is considered
acceptable for field use. A blank level of <10 ng/plug
for single compounds is considered to be acceptable.
11. Sample Collection
11.1 Description of Sampling Apparatus
11.1.1 The entire sampling system can be a modification of a
traditional high volume sampler (see Figure 4) or a portable
sampler (see Figure 5). A unit specifically designed for
this method is commercially available (Model PS-1 -
General Metal Works, Inc., Village of Cleves, Ohio).
11.1.2 The sampling module consists of a glass sampling cartridge
and an air-tight metal cartridge holder, as outlined in
Section 10.1. The adsorbent (XAD-2 or PUF) is retained
in the glass sampling cartridge.
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11.2 Calibration of Sampling System
Each sampler is to 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%; 4) when a different
sample collection media, other than that which the sampler was
originally calibrated to, will be used for sampling; or 5) at the
frequency specified in the user Standard Operating Procedure (SOP)
manual in which the samplers are utilized.
11.2.1 Calibration of Flow Rate Transfer Standard
Calibration of the modified high volume air sampler in
the field is performed using a calibrated orifice flow
rate transfer standard. The flow rate transfer standard
must be certified 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. Recertification
of the orifice flow rate transfer standard is performed
once per year utilizing a set of five (5) multihole re-
sistance plates. [Note: The 5 multihole resistance
plates are used to change the flow through the orifice so
that several points can be obtained for the orifice cali-
bration curve.]
11.2.1.1 Record the room temperature (ti in °C) and barome-
tric pressure (P& in mm Hg) on Orifice Calibra-
tion Data Sheet (see Figure 7). Calculate the
room temperature in °K (absolute temperature)
and record on Orifice Calibration Data Sheet.
in K = 273° +
in °C
11.2.1.2 Set up laboratory orifice calibration equipment
as illustrated in Figure 6. Check the oil level
of the rootsmeter prior to starting. There are
three oil level indicators, one at the clear
plastic end, and two sight glasses, one at each
end of the measuring chamber.
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T013-21
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, then there ,is a leak in the sys-
tem or in the tape. 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 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 bottom of 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 hi-vol motor and let it run for
five minutes to set the motor brushes.
11.2.1.8 Record both manometer readings-orifice water mano-
meter (AH) and rootsmeter mercury manometer (AP).
[Note: AH is the sum of the difference from zero
(0) of the two column heights.]
11.2.1.9 Record the time, in minutes, required to pass a
known volume of air (approximately 200-300 ft3 of
air for each resistance plate) through the roots-
meter by using the rootsmeter's digital volume dial
and a stopwatch.
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 11.2.1.10.
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T013-22
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 elimi-
nate 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.]
11.2.1.14 Correct the measured volumes with the following
formula and record the standard volume on the
Orifice Calibration Data Sheet:
Vstd = Vm h -AP TS^
Pstd TI
where: Vstc( = standard volume (std m3).
Vm = actual volume measured by the
rootsmeter (m3).
P! = barometric pressure during cali-
bration (mm Hg).
AP = differential pressure at inlet
to volume meter (mm Hg).
Pstd = 760 mm Hg.
Tstd = 298 K.
TI = ambient temperature during cali-
bration (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:
Qstd * Vstd
9
where: Qstd = standard volumetric flow rate,
std m3/min.
9 = elapsed time, min.
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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(Pi/Pstd) (298/Ti)
value for each standard flow rate.
11.2.1.19 Plot each VAH(pl/pstd) (?98/Ti) value (y-axi s)
versus its associated standard flow rate (x-axis)
on arithmetic graph paper, draw a line of best
fit between the individual plotted points and
calculate the linear regression slope (M) and
intercept (b).
11.2.1.20 Commercially available calibrator kits are
available [General Metal Works Inc., Model
GMW-40, 145 South Miami Avenue, Village of
Cleves, Ohio, 45002 (1-800-543-7412)].
11.2.2 Calibration of The High Volume Sampling System Utilizing
Calibrated Multi-point Flow Rate Transfer Standard
11.2.2.1 The airflow through the sampling system can be
monitored by a venturi/magnehelic assembly, as
illustrated in Figure 4 or by a u-tube assembly
connected to the high volume portable design as
illustrated in Figure 5. The field sampling sys-
tem must be audited every six months using a
flow rate transfer standard, as described in the
U.S. EPA High Volume Sampling Method, 40 CFR 50,
Appendix B. A single-point calibration must be
performed before and after each sample collec-
tion, using a transfer standard calibrated as
described in Section 11.2.1.
11.2.2.2 Prior to initial multi-point calibration, a
"dummy" adsorbent cartridge and filter are
placed in the sampling head and the sampling
motor is activated. The flow control valve
is fully opened and the voltage variator is
adjusted so that a sample flow rate corresponding
to 110% of the desired flow rate (typically
0.20 - 0.28 m3/min) is indicated on the
Magnehelic gauge (based on the previously
obtained multi-point calibration curve). The
-------
T013-24
motor is allowed to warm up for 10 minutes and
then the flow control valve is adjusted to
achieve the desired flow rate. Turn off the
sampler. The ambient temperature and baro-
metric pressure should be recorded on the Field
Calibration Data Sheet (Figure 9).
11.2.2.3 The flow rate transfer standard is placed on
the sampling head, and a manometer is connected
to the tap on the transfer standard using a
length of tubing. Properly align the retaining
rings with filter holder and secure by tighten-
ing the three screw clamps. Set the zero
level of the manometer. Attach the magnehelic
gage to the sampler venturi quick release
connections. Adjust the zero (if needed)
using the zero adjust screw on the face of
the gage.
11.2.2.4 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.
11.2.2.5 Adjust the flow control valve and repeat until
six or seven uniformally spaced magnehelic
readings are recorded spanning the range of
approximately 40-70 in. Record the readings
on the Field Calibration Data Sheet (see
Figure 9). [Note: Use of some filter/sorbent
media combinations may restrict the airflow
resulting in a maximum magnehelic reading of
60 in. or less. In such cases, a variable
transformer should be placed in-line between
the 110 volt power source and the sampler so
that the line voltage can be increased suf-
ficiently to obtain a maximum magnehelic
reading approaching 70 in.].
-------
T013-25
11.2.2.6 Adjust the orifice manometer reading for standard
temperature and pressure using the following
equation:
X -JAH Pa_ Tst.n
1 Pstd Ta
where: X = adjusted manometer reading to
standard temperature and
pressure (in. water).
AH = observed manometer reading (in
water).
Pa = current barometric pressure (mm Hg).
pstd = 760 mm Hg.
Ta = current temperature (K), (K = °C + 273)
Tstd = standard temperature (298 K).
11.2.2.7 Calculate the standard flow rate for each
corrected manometer reading by the following
equation:
Qstd - ^
where:
Qstd = standard flow rate (m3/min).
M = slope of flow rate transfer
standard calibration curve.
X = corrected manometer reading
from 11.2.2.6 (in water).
b = intercept of flow rate transfer
standard calibration curve.
11.2.2.8 Adjust the magnehelic gage readings to
standard temperature and pressure using the
following equation:
-------
T013-26
;
(M)(Pa)
Pstd T;
where:
Mstd = adjusted magnehelic reading to
standard temperature and pressure
(inches of water).
M = observed magnehelic reading
(inches of water).
Pa = ambient atmospheric pressure (mm Hg).
Pstd = standard pressure (760 mm Hg).
Ta = ambient temperature (K), (K = °C + 273),
Tstd = standard temperature (298 K).
11.2.2.9 Plot each Mstd value (y-axis) versus its
associated Qstd standard (x-axis) on arithmetic
graph paper. Draw a line of best fit between
the individual plotted points. This is the
calibration curve for the venturi. Retain with
sampler.
11.2.2.10 Record the corresponding Qstd for each Mstd
under Qstd column on Field Calibration Data
Sheet, Figure 9.
11.2.3 Single-point Audit of The High Volume Sampling System
Utilizing Calibrated Flow Rate Transfer Standard
11.2.3.1 A single point flow audit check is performed
before and after each sampling period utilizing
the Calibration Flow Rate Transfer Standard
(Section 11.2.1).
11.2.3.2 Prior to single point audit, a "dummy" adsorbent
cartridge and filter are placed in the sampling
head and the sampling motor is activated.
The flow control valve is fully opened and
the voltage variator is adjusted so that a
-------
T013-27
sample flow rate corresponding to 110% of the
desired flow rate (typically 0.20-0.28 m3/min)
is indicated on the magnehelic gauge (based on
the previously obtained multi-point calibration
curve). The motor is allowed to warm up for 5
minutes and then the flow control valve is
adjusted to achieve the desired flow rate.
Turn off the sampler. The ambient temperature
and barometric pressure should be recorded on
a Field Test Data Sheet (Figure 10).
11.2.3.3 The flow rate transfer standard is placed on
the sampling head.
11.2.3.4 Properly align the retaining rings with filter
holder and secure by tightening the three screw
clamps.
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 remain-
ing 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 five
minutes.
11.2.3.8 Record the pressure differential indicated, AH,
in inches of water. Be sure stable AH has been
established.
11.2.3.9 Record the observed magnehelic gauge reading,
in inches of water. Be sure stable M has been
established.
-------
TO13-28
11.2.3.10 Using previously established Flow Rate Transfer
Standard curve, calculate Qstd (see steps
11.2.2.6 - 11.2.2.7).
11.2.3.11 Using previously established venturi calibration
curve, calculate the indicated Q5td (Section
11.2.2.9).
11.2.3.12 A multi-point calibration of the Flow Rate
Transfer Standard against a primary standard,
must be obtained annually, as outlined in
Section 11.2.1.
11.2.3.13 Remove Flow Rate Transfer Standard and dummy ,
adsorbent cartridge and filter assembly.
11.3 Sample Collection
11.3.1 After the sampling system has been assembled and flow check-
ed as described in Sections 11.1 and 11.2, it can be used to
collect air samples, as described in Section 11.3.2.
11.3.2 The samples should be located in an unobstructed area, at
least two 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.
11.3.3 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.
11.3.4 Detach the lower chamber of the rinsed sampling module.
While wearing disposable clean lint-free nylon or powder-
free surgical gloves, remove a clean glass cartridge/sorbent
from its container (wide mouthed glass jar with a Teflon®-
lined lid) and unwrap its aluminum foil covering. The foil
should be replaced back in the sample container to be re-
used after the sample has been collected.
11.3.5 Insert the cartridge into the lower chamber and tightly
reattach it to the module.
11.3.6 Using clean Teflon® tipped forceps, carefully place a clean
fiber filter atop the filter holder and secure in place
by clamping the filter holder ring over the filter using
the three 'screw clamps. Insure that all module connec-
tions are tightly assembled. [Note: Failure to do so
-------
T013-29
could result in air flow leaks at poorly sealed locations
which could affect sample representativeness]. Ideally,
sample module loading and unloading should be conducted
in a controlled environment or at least a centralized
sample processing area so that the sample handling vari-
ables can be minimized.
11.3.7 With the module 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.
11.3.8 Attach a "dummy" sampling module loaded with the exact
same type of filter and sorbent media as that which
will be used for sample collection.
11.3.9 With the sampler off, attach the Magnahelic gage to the
sampler. Turn the sampler on and adjust the flow control
valve to the desired flow (normally as indicated by the
cfm) magnahelic gauge reading and reference by the
calibration chart. [Note: Breakthrough has not been a
problem for all PAHs outlined in Section 1.5 using
this sampling method except anthracene and penanthrene].
Once the flow is properly adjusted, extreme care should
be taken not to inadvertantly alter its setting.
11.3.10 Turn the smpler off and removeiboth the "dummy" module
and the Magnahelic gauge. The sampler is now ready for
field use.
11.3.11 The zero reading of the sampler Magnehelic is checked.
Ambient temperature, barometric pressure, elapsed time
meter setting, sampler serial number, filter number,
and adsorbent sample number are recorded on the Field
Test Data Sheet (see Figure 10). Attach the loaded
sampler module to the sampler.
11.3.12 The voltage variator and flow control valve are placed
at the settings used in Section 11.2.2, and the power
switch is turned on. The elapsed time meter is acti-
vated and the start time is recorded. .The flow (Magne-
helic setting) is adjusted, if necessary, using the
flow control valve.
11.3.13 The Magnehelic reading is recorded every six hours
during the sampling period. The calibration curve
-------
T013-30
(Section 11.2.4) is used to calculate the flow rate.
Ambient temperature, barometric pressure, and Magnehe-
lic reading are recorded at the beginning and end of
the sampling period.
11.3.14 At the end of the desired sampling period, the power is
turned off. Carefully remove the sampling head contain-
ing the filter and adsorbent cartridge to a clean area.
11.3.15 While wearing disposable lint free nylon or surgical
gloves, remove the sorbent cartridge from the lower
module chamber and lay it on the retained aluminum foil
in which the sample was originally wrapped.
11.3.16 Carefully remove the glass fiber filter from the upper
chamber using clean Teflon® tiped forceps.
11.3.17 Fold the filter in half twice (sample side inward) and
place it in the glass cartridge atop the sorbent.
11.3.18 Wrap the combined samples in aluminum foil and place them
in their original glass sample container. A sample label
should be completed and affixed to the sample container.
Chain-of-custody should be maintained for all samples.
11.3.19 The glass containers should be stored in ice and pro-
tected from light to prevent possible photo-decomposi-
tion of collected analytes. If the time span between
sample collection and laboratory analysis is to exceed
24 hours, sample must be kept refrigerated. [Note: Recent
^studies (13,16) have indicated that PUF does not retain,
during storage, B[a]P as effectively as XAD-2. Therefore,
sample holding time should not exceed 20 days.]
11.3.20 A final calculated sample flow check is performed using
the calibration orifice, as described in Section 11.2.2.
If calibration deviates by more than 10% from the initial
reading, the flow data for that sample must be marked
as suspect and the sampler should be inspected and/or
removed from service.
11.3.21 At least one field filter/adsorbent'blank will be re-
turned to the laboratory with each group of samples. A
field blank is treated exactly as a sample except that
no air is drawn through the filter/adsorbent cartridge
assembly.
-------
T013-31
11.3.22 Samples are stored at 0°C in an ice chest until receipt
at the analytical laboratory, after which they are
refrigerated at 4°C.
12. Sample Clean-up and Concentration
[Note: The following sample extraction, concentration, solvent exchange
and analysis procedures are outlined for user convenience in Figure 11.]
12.1 Sample Identification
12.1.1 The samples are returned in the ice chest to the laboratory
in the glass sample container containing the filter and
adsorbent.
12.1.2 The samples are logged in the laboratory logbook according
to sample location, filter and adsorbent 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-hrs., then the samples must be kept
refrigerated. Minimize exposure of samples to fluores-
cence light. All samples should be extracted within one
week after sampling.
12.2 Soxhlet Extraction and Concentration
12.2.1 Assemble the Soxhlet apparatus [see Figure 3(a)]. Immedi-
ately before use, charge the Soxhlet apparatus with 200 to
250 ml of methylene chloride and reflux for 2 hours. Let
the apparatus cool, disassemble it, transfer the methylene
chloride to a clean glass container, and retain it as a
blank for later analysis, if required. Place the adsorbent
and filter together in the Soxhlet apparatus (the use of an
extraction thimble is optional) if using XAD-2 adsorbent in
the sampling module. [Note: The filter and adsorbent are
analyzed together in order to reach detection limits, avoid
questionable interpretation of the data, and minimize cost.]
Since methylene chloride is not a suitable solvent for PUF,
10% ether in hexane is employed to extract the PAHs from
the PUF resin bed separate from the methylene chloride
extraction of the accompanying filter rather than methylene
chloride for the extraction of the XAD-2 cartridge.
12.2.1.1 Prior to extraction, add a surrogate standard to
the Soxhlet solvent. A surrogate standard (i.e.,
a chemically inert compound not expected to
-------
T013-32
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 surrogate standard is used
to monitor for unusual matrix effects, gross
sample processing errors, etc. Surrogate recov-
ery is evaluated for acceptance by determining
whether the measured concentration falls within
the acceptance limits. The following surrogate
standards have been successfully utilized in
determining matrix effects, sample process errors,
etc. utilizing GC/FID, GC/MS or HPLC analysis.
Surrogate
Standard
Concentration
Dibromobiphenyl 50 ng/uL
Dibromobiphenyl 50 ng/uL
Deuterated Standards 50 ng/uL
Decafluorobiphenyl 50 ng/uL
Analytical
Technique
GC/FID
GC/MS
GC/MS
HPLC
[Note: The deuterated standards will be added
in Section 14.3.2. Deuterated analogs of selec-
tive PAHs cannot be used as surrogates for HPLC
analysis due to coelution problems.] Add the
surrogate standard to the Soxhlet solvent.
12.2.1.2 For the XAD-2 and filter extracted together,
add 300 mL of methylene chlorine to the apparatus
and reflux for 18 hours at a rate of at least
3 cycles per hour.
12.2.1.3 For the PUF extraction separate from the filter,
add 300, mL ,of 10 percent ether in hexane to the
apparatus and reflux for 18 hours at a rate of
at least 3 cycles per hour.
12.2.1.4 For the filter extraction, add 300 mL of methylene
chloride to the apparatus and reflux for 18 hours
at a rate of at least 3 cycles per hour.
12.2.2 Dry the extract from the Soxhlet extraction by passing it
through a drying column containing about 10 grams of anhy-
drous sodium sulfate. Collect the dried extract in a
Kuderna-Danish (K-D) concentrator assembly. Wash the
-------
T013-33
extractor flask and sodium sulfate column with 100 - 125 ml
of methylene chloride to complete the quantitative transfer.
12.2.3 Assemble a Kuderna-Danish concentrator [see Figure 3(b)]
by attachi ng a 10 ml concentrator tube to a 500 mL evapora-
tive flask. [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.]
12.2.4 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.
12.2.5 Remove the Snyder column and rinse the flask and its lower
joint into the concentrator tube with 5 ml of cyclohexane.
12.3 Solvent Exchange
12.3.1 Replace the K-D apparatus equipped with a Snyder column
back on the water bath.
12.3.2 Increase the temperature of the hot water bath to 95-100°C.
Momentarily, remove the Snyder column, add a new boiling
chip, and attach a two-ball micro-Snyder column. Prewet
the Snyder column, using 1 ml of cyclohexane. Place the
K-D apparatus on the water bath so that the concentrator
tube is partially immersed in the hot water. Adjust the
vertical position of the apparatus and the water tempera-
ture, as required, to complete concentration in 15-20
minutes. At the proper rate of distillation, the balls
of the column will actively chatter, but the chambers
-------
T013-34
will not flood. When the apparent volume of liquid
reaches 0.5 ml, remove the K-D apparatus and allow it to
drain and cool for at least 10 minutes.
12.3.3 When the apparatus is cool, remove the micro-Snyder
column and rinse its lower joint into the concentrator
tube with about 0.2 mL of cyclohexane. [Note: A 5 ml
syringe is recommended for this operation]. Adjust the
extract volume to exactly 1.0 ml with cyclohexane. Stopper
the concentrator tube and store refrigerated at 4°C, if
further processing will not be performed immediately. If
the extract will be stored longer than 24 hours, it should
be transferred to a Teflon®-sealed screw-cap vial.
12.4 Sample Cleanup By Solid Phase Exchange
Cleanup procedures may not be needed for relatively clean matrix
samples. If the extract in Section 12.3.3 is clear, cleanup may
not be necessary. If cleanup is not necessary, the cyclohexane
extract ( 1 ml) can be analyzed directly by 6C/FI detection, except
the initial oven temperature begins at 30°C rather than 80°C for
cleanup samples (see Section 13.3), or solvent exchange to aceton-
itrile for HPLC analysis. If cleanup is required, the procedures
are presented using either handpack silica gel column as prescribed
in Method 610 (see Section 18.0, citation No. 18 and 22) or the
use of a Lobar prepacked silica gel column for PAH concentration
and separation. Either approach can be employed by the user.
*
12.4.1 Method 610 Cleanup Procedure [see Figure 3(c)]
12.4.1.1 Pack a 6-inch disposable Pasture pipette
(10 mnrl.D. x 7 cm length) with a piece of
glass wool. Push the wool to the neck of the
disposable pipette. Add 10 grams of activated
silica gel in methylene chloride slurry to the
disposable pipette. Gently tap the column to
settle the silica gel and elute the methylene
chloride. Add 1 gram of anhydrous sodium sul-
fate to the top of the silica gel column.
12.4.1.2 Prior to initial use, rinse the column with
methylene chloride at 1 mL/min for 1 hr to
-------
T013-35
remove any trace of contaminants. Preelute the
column with 40 ml of pentane. Discard the eluate
and just prior to exposure of the sodium sulfate
layer to the air, transfer the 1 ml of the cyclo-
hexane sample extract onto the column, using an
additional 2 ml of cyclohexane to complete the
transfer. Allow to elute through the column.
12.4.1.3 Just prior to exposure of the sodium sulfate
layer to the air, add 25 ml of pentane and con-
tinue elution of the column. Discard the pen-
tane eluate. [Note: The pentane fraction
contains the aliphatic hydrocarbons collected
on the filter/ adsorbent combination. If inter-
ested, this fraction may be analyzed for specific
aliphatic organics.] Elute the column with 25 ml
of methylene chloride/pentane (4 + 6) (V/V) and
collect the eluate in a 500 ml K-D flask equipped
with a 10 ml concentrator tube. [Note: This
fraction contains the B[a]P and other moderately
polar PAHs]. Elution of the column should be
at a rate of about 2 mL/min. Concentrate the.
collected fraction to less than 10 ml by the
K-D technique, as illustrated in Section 12.3
using pentane to rinse the walls of the glass-
ware. The extract is now ready for HPLC or GC
analysis. [Note: An additional elution through
the column with 25 ml of methanol will collect
highly polar oxygenated PAHs with more than one
functional group. This fraction may be analyzed
for specific polar PAHs. However, additional
cleanup by solid phase extraction may be required
to obtain both qualitative and quantitative data
due to complexity of the eluant.]
12.4.2 Lobar Prepacked Column Procedure
12.4.2.1 The setup using the Lobar prepacked column con-
sists of an injection port, septum, pump, pre-
column containing sodium sulfate, Lobar prepacked
column and solvent reservoir.
-------
T013-36
12.4.2.2 The column is cleaned and activated according
to the following cleanup sequence:
Fraction Solvent Composition Volume (ml)
1 100% Hexane 20
2 80% Hexane/20% Methylene Chloride 10
3 50% Hexane/50% Methylene Chloride 10
4 100% Methylene Chloride 10
5 95% Methylene Chloride/5% Methanol 10
6 80% Methylene Chloride/20% Methanol 10
12.4.2.3 Reverse the sequence at the end of the run and
run to the 100% hexane fraction in order to
activate the column. Discard all fractions.
12.4.2.4 Pre-elute the column with 40 ml of hexane,
which is also discharged.
12.4.2.5 Inject 1 ml of the cyclohexane sample extract,
followed by 1 ml injection of blank cyclohexane.
12.4.2.6 Continue elution of the column with 20 ml of
hexane, which is also discharged.
12.4.2.7 Now elute the column with 180 mL of a 40/60
mixture of methylene chloride/hexane respectively.
12.4.2.8 Collect approximately 180 ml of the'40/60 methy-
lene chloride/hexane mixture in a K-D concentrator
assembly.
12.4.2.9 Concentrate to less than 10 ml with the K-D
assembly as discussed in Section 12.2.
12.4.2.10 The extract is now ready for either HPLC or
GC analysis.
13. Gas Chromatography Analysis with Flame lonization Detection
13.1 Gas Chromatography (GC) is a quantitative analytical technique
useful for PAH identification. This method provides the user the
flexibility of column selection (packed or capillary) and detector
[flame ionization (FI) or mass spectrometer (MS)] selection. The
mass spectrometer provides for specific identification of B(a)P;
however, with system optimization, other PAHs may be qualitatively
and quantitatively detected using MS (see Section 14.0). This
procedure provides for common GC .separation of the PAHs with
-------
T013-37
subsequent detection by either FI or MS (see Figure 12.0). The
following PAHs have been quantified by GC separation with either
FI or MS detection:
Acenaphthene Chrysene
Acenaphthylene Dibenzo(a,h)anthracene
Anthracene Fluoranthene
• Benzo(a)anthracene Fluorene
Benzo(a)pyrene Indeno(l,2,3-cd)pyrene
Benzo(b)fluoranthene Naphthalene
Benzo(e)pyrene Phenanthrene
Benzo(g,h,i)perylene Pyrene
Benzo(k)f1uoranthene
The packed column gas chromatographic method described here can not
adequately resolve the following four pairs of compounds: anthracene
and phenanthrene; chrysene and benzo(a)anthracene; benzo(b)fluoran-
thene and benzo(k)fluoranthene; and dibenzo(a,h) anthracene and
indeno(l,2,3-cd)pyrene. The use of a capillary column instead of
the packed column, also described in this method, should adequately
resolve these PAHs. However, unless the purpose of the analysis can
be served by reporting a quantitative sum for an unresolved PAH pair,
either capillary gas chromatography/mass spectroscopy (Section 14.0)
or high performance liquid chromatography (Section 15.0) should be
used for these compounds. This section will address the use of
6C/FI detection using packed or capillary columns.
13.2 To achieve maximum sensitivity with the 6C/FI method, the extract
must be concentrated to 1.0 ml, if not already concentrated to 1 ml.
If not already concentrated to 1 mL, add a clean boiling chip to the
methylene chloride extract in the concentrator tube. Attach a two-
ball micro-Snyder column. Prewet the micro-Snyder column by adding
about 2.0 ml of methylene chloride to the top. Place the micro K-D
apparatus on a hot water bath (60 to 65°C) so that the concentrator
tube is partially immersed in the hot water. Adjust the vertical
position of the apparatus and the water temperature as required to
complete the concentration in 5 to 10 minutes. At the proper rate
of distillation the balls will actively chatter but the chambers
will not flood. When the apparent volume of liquid reaches 0.5 ml,
remove the K-D apparatus. Drain and cool for at least 10 minutes.
Remove the micro-Snyder column and rinse its lower joint into the
concentrator tube with a small volume of methylene chloride. Adjust
the final volume to 1.0 ml and stopper the concentrator tube.
-------
T013-38
13.3 Assemble and establish the following operating parameters for
the GC equipped with an FI detector:
Capillary
(A) (B)
Identification
Dimensions
Carrier Gas
Carrier Gas
Flow Rate
Column
Program
Detector
SPB-5 fused silica
capillary, 0.25 urn
5% phenyl, methyl
siloxane bonded
30-m x 0.25-mm ID
Helium
28-30 cm/sec
( 1 cm/minute)
35°C for 2 min;
program at 8°C/min
to 280°C and hold
for 12 minutes
SPB-5 fused silica
capillary, 0.25 urn
5% phenyl, methyl
siloxane bonded
30-m x 0.25-mm ID
Heli urn
28-30 cm/sec
( 1 cm/minute)
Packed
Chromosorb W-AW-DMCS
(100/120 mesh) coated
with 3% OV-17
1.8-m x 2-mm ID
Nitrogen
30-40 cm/minute
80°C for 2 min; Hold at 100°C for
program at 8°C/min 4 minutes; program at
to 280°C and hold 8°C/min to 280°C and
for 12 minutes hold for 15 minutes
Flame lonization Flame lonization Flame lonization
(A) Without column cleanup (see Section 12.4)
(B)
With column cleanup (see Section 12.4.1)
13.4 Prepare and calibrate the chromatographic system using either
the external standard technique (Section 13.4.1) or the internal
standard technique (Section 13.4.2). Figure 13.0 outlines the
following sequence involving GC calibration and retention time
window determination.
13.4.1 External Standard Calibration Procedure - For each analyte
o'f interest, including surrogate compounds for spiking, if
used, prepare calibration standards at a minimum of five
concentration levels by adding volumes of one or more stock
standards to a volumetric flask and diluting to volume with
methylene chloride. [Note: All calibration standards of
interest involving selected PAHs, of the same concentration,
can be prepared in the same flask.]
13.4.1.1 Prepare stock standard solutions at a concentration
of 100 ug/uL by dissolving.0.100 gram of assayed PAH
material in methylene chloride and diluting to vol-
in a 10 ml volumetric flask. [Note: Larger volumes
can be used at the convenience of the analyst.]
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T013-39
13.4.1.2 When compound purity is assayed to be 98% or
greater, the weight can be used without correc-
tion to calculate the concentration of the stock
standard. [Note: Commercially prepared stock
standards can be used at any concentration if
they are certified by the manufacturer or by an
independent source.] Transfer the stock standard
solutions into Teflon®-sealed screw-cap bottles.
13.4.1.3 Store at 4°C and protect from light. Stock
standards should be checked frequently for signs
of degradation or evaporation, especially just
prior to preparing calibration standards from
them. Stock standard solutions must be replaced
after one year, or sooner, if comparison with
check standards indicates a problem.
13.4.1.4 Calibration standards at a minimum of five
concentration levels should be prepared through
dilution of the stock standards with methylene
chloride. One of the concentration levels should
be at a concentration near, but above, the method
detection limit. The remaining concentration
levels should correspond to the expected range
of concentrations found in real samples or
should define the working range of .the GC.
[Note: Calibration solutions must be replaced
after six months, or sooner, if comparison
with a check standard indicates a problem.]
13.4.1.5 Inject each calibration standard using the
technique that will be used to introduce the
actual samples into the gas chromatograph
(e.g., 1- to 3-uL injections). [Note: The
same amount must be injected each time.]
13.4.1.6 Tabulate peak height or area responses against
the mass injected. The results can be used to
prepare a calibration curve for each analyte.
[Note: Alternatively, for samples that are
introduced into the gas chromatograph using a
syringe, the ratio of the response to the amount
-------
T013-40
injected, defined as the calibration factor (CF),
can be calculated for each analyte at each stand-
ard concentration by the following equation:
Calibration factor (CF) = Total Area of Peak
Mass injected (in nanograms)
If the percent relative standard deviation
(%RSD) of the calibration factor is less than
20% over the working range, linearity through
the origin can be assumed, and the average
calibration factor can be used in place of a ;
calibration curve.]
13.4.1.7 The working calibration curve or calibration
factor must be verified on each working day by
the injection of one or more calibration
standards. If the response for any analyte
varies from the predicted response by more
than +20%, a new calibration curve must be
prepared for that analyte. Calculate the
percent variance by the following equation:
Percent variance - R? - RI x 100
Rl
where
R2 = Calibration factor from succeeding analysis
R! = Calibration factor from first analysis.
13.4.2 Internal Standard Calibration Procedure - To use this
approach, the analyst must select one or more internal
standards that are similar in analytical behavior to the
compounds of interest. The analyst must further demon-
strate that the measurement of the internal standard is
not affected by method or matrix interferences. Due to
these limitations, no internal standard applicable to
all samples can be suggested. [Note: It is recommended
that the internal standard approach be used only when the
GC/MS procedure is employed due to coeluting species.]
-------
T013-41
13.4.2.1 Prepare calibration standards at a minimum of
five concentration levels for each analyte of
interest by adding volumes of one or more stock
standards to a volumetric flask,
13.4.2.2 To each calibration standard, add a known con-
stant amount of one or more internal standard
and dilute to volume with methylene chloride.
[Note: One of the standards should be at a
concentration near, but above, the method
detection limit. The other concentrations
should correspond to the expected range of
concentrations found in real samples or should
define the working range of the detector.]
13.4.2.3 Inject each calibration standard using the same
introduction technique that will be applied to
the actual samples (e.g., 1- to 3-uL injection).
13.4.2.4 Tabulate the peak height or area responses against
the concentration of each compound and internal
standard.
13.4.2.5 Calculate response factors (RF) for each compound
as follows:
Response Factor (RF) = (AsC1s)/(A1sCs)
where:
As = Response for the analyte to be measured
(area units or peak height).
A-JS = Response for the internal standard.
(area units or peak height).
Cis = Concentration of the internal standard,
(ug/L).
Cs = Concentration of the analyte to be
measured, (ug/L).
13.4.2.6 If the RF value over the working range is con-
stant (<20% RSD), the RF can be assumed to be
invariant, and the average RF can be used for
calculations. [Note: Alternatively, the results
can be used to plot a calibration curve of
response ratios, As/Ais versus RF.]
-------
T013-42
13.4.2.7 The working calibration curve or RF must be veri-
fied on each working day by the measurement of
one or more calibration standards.
13.4.2.8 If the response for any analyte varies from the
. predicted response by more than +20%, a new cali-
/ ~~
bration curve must be prepared for that compound.
13.5 Retention Time Windows Determination
13.5.1 Before analysis can be performed, the retention time windows
must be established for each analyte.
13.5.2 Make sure the GC system is within optimum operating condi-
tions.
13.5.3 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 throughout the course of a 72-hr period.]
13.5.4 The retention window is defined as plus or minus three
times the standard deviation of the absolute retention
times for each standard.
13.5.5 Calculate the standard deviation of the three absolute
retention times for each single component standard. In
those cases where the standard deviation for a particular
standard is zero, the laboratory must substitute the
standard deviation of a close eluting, similar compound
- to develop a valid retention time window.
13.5.6 The laboratory must calculate retention time windows for each
standard on each GC column and whenever a new GC column
is installed, 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.
13.6 Sample Analysis
13.6.1 Inject 1- to 3-uL of the methylene chloride extract from
Section 13.2 (however, the same amount each time) using
the splitless injection technique when using capillary
column. [Note: Smaller (1.0 uL) volumes can be injected
if automatic devices are employed.]
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T013-43
13.6.2 Record the volume injected and the resulting peak size
in area units or peak height.
13.6.3 Using either the internal or external calibration pro-
cedure, determine the identity and quantity of each com-
ponent peak in the sample chromatogram through retention
time window and established calibration curve. Table 2
outlines typical retention times for selected PAHs, using
both the packed and capillary column technique coupled
with F.I detection, while Figure 14.0 illustrates typical
chromatogram for a packed column analysis.
13.6.3.1 If the responses exceed the linear range of
the system, dilute the extract and reanalyze.
It is recommended that extracts be diluted so
that all peaks are on scale. Overlapping
peaks are not always evident when peaks are off
scale. Computer reproduction of chromatograms,
manipulated to ensure all peaks are on scale
over a 100-fold range, are acceptable if linearity
is demonstrated. Peak height measurements are
recommended over peak area integration when over-
lapping peaks cause errors in area integration.
13.6.3.2 Establish daily retention time windows for each
analyte. Use the absolute retention time for
each analyte from Section 13.5.4 as the midpoint
of the window for that day. The daily retention
time window equals the midpoint _+ three times the
standard deviation determined in Section 13.5.4.
13.6.3.3 Tentative identification of an analyte occurs
when a peak from a sample extract falls within
the daily retention time window. [Note: Con-
firmation may be required on a second GC column,
or by GC/MS (if concentration permits) or by
other recognized confirmation techniques if
overlap of peaks occur.]
13.6.3.4 Validation of GC system qualitative performance
is performed through the use of the midlevel
standards. If the mid-level standard falls out-
side its daily retention time windo«". t'.ie system
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T013-44
is out of control. Determine the cause of the
problem and perform a new calibration sequence
(see Section 13.4).
13.6.3.5 Additional validation of the GC system perform-
ance is determined by the surrogate standard
recovery. If the recovery of the surrogate
standard deviates from 100% by not more than
20%, then the sample extraction, concentration,
clean-up and analysis is certified. If it
exceeds this value, then determine the cause
of the problem and correct.
13.6.4 Determine the concentration of each analyte in the sample
according to Sections 17.1 and 17.2.1.
14. Gas Chromatography with Mass Spectroscopy Detection
14.1 The analysis of the extracted sample for benzo[a]pyrene and other
PAHs is accomplished by an electron impact gas Chromatography/mass
spectrometry (El GC/MS) in the selected ion monitoring (SIM) mode
with a total cycle time (including voltage reset time) of one
second or less. The GC is equipped with an ultra No. 2 fused
silica capillary column (50-m x 0.25-mm I.D.) with helium carrier
gas for analyte separation. The GC column is temperature controlled
and interfaced directly to the MS ion source.
14.2 The laboratory-must document that the El GC/MS system is properly
maintained through periodic calibration checks. The GC/MS system
should have the following specifications:
Mass range: 35-500 amu
Scan time: 1 sec/scan
GC Column: 50 m x 0.25 mm I.D. (0.25 urn film thickness)
Ultra No. 2 fused silica capillary column or equivalent
Initial column temperature and hold time: 40°C for 4 min
Column temperature program: 40-270°C at 10°C/min
Final column temperature hold: 270°C (until benzo[g,h,i] perylene
has eluted)
Injector temperature: 250-300°C
Transfer line temperature: 250-300°C
Source temperature: According to manufacturer's specifications
Injector: Grob-type, splitless
El Condition: 70 eV
Mass Scan: Follow manufacturer instruction for select ion
monitoring (SIM) mode. l
Sample volume: 1-3 uL
Carrier gas: Helium at 30 cm/sec.
-------
T013-45
The GC/MS is tuned using a 50 ng/uL solution of decaf!uorotriphenyl-
phosphine (DFTPP). The DFTPP permits the user to tune the mass spec-
trometer on a daily basis. If properly tuned, the DFTPP key ions
and ion abundance criteria should be met as outlined in Table 3.
14.3 The GC/MS operating conditions are outlined in Table 4. The
GC/MS system can be calibrated using the external standard tech-
nique (Section 14.3.1) or the internal standard technique
(Section 14.3.2). Figure 15.0 outlines the following sequence
involving the GC/MS calibration.
14.3.1 External standard calibration procedure.
14.3.1.1 Prepare calibration standard of B[a]P or other
PAHs at a minimum of five concentration levels
by adding volumes of one or more stock standards
to a volumetric flask and diluting to volume
with methylene chloride. The stock standard
solution of B[a]P (1.0 ug/uL) must be prepared
from pure standard materials or purchased as
certified solutions.
14.3.1.2 Place 0.0100 grams of native B[a]P or other PAHs
on a tared aluminum weighing disk and weigh on
a Mettler balance.
14.3.1.3 Quantitatively, transfer to a 10 ml volumetric
flask. Rinse the weighing disk with several
small portions of methylene chloride. Ensure
all material has been transferred.
14.3.1.4 Dilute to mark with methylene chloride.
14.3.1.5 The concentration of the stock standard solution
of B[a]P or other PAHs in the flask is 1.0 ug/uL
[Note: Commerically prepared stock standards may
be used at any concentration if they are certified
by the manufacturer or by an independent source.]
14.3.1.6 Transfer the stock standard solutions into Teflon®-
sealed screw-cap bottles. Store at 4°C and pro-
tect from light. Stock standard solutions should
be checked frequently for signs of degradation or
evaporation, especially just prior to preparing
calibration standards from them.
-------
T013-46
14.3.1.7 Stock standard solutions must be replaced after
1 yr or sooner if comparison with quality control
check samples indicates a problem.
14.3.1.8 Calibration standards at a minimum of five con-
centration levels should be prepared. [Note:
One of the calibration standards should be at a
concentration near, but above the method detection
limit; the others should correspond to the range
of concenrations found in the sample but should not
exceed the working range of the GC/MS system.]
Accurately pipette 1.0 ml of the stock solution
(1 ug/uL) into another 10 ml volumetric flask,
dilute to mark with methylene chloride. This
daughter solution contains 0.1 ug/uL of B[a]P
or other PAHs.
14.3.1.9 Prepare a set of standard solutions by appropri-
ately diluting, with methylene chloride, accu-
rately measured volumes of the daughter solution
(0.1 ug/uL).
14.3.1.10 Accurately pipette 100 uL, 300 uL, 500 uL, 700 uL
and 1000 uL of the daughter solution (0.1 ug/uL)
into each 10 ml volumetric flask, respectively.
To each of these flasks, add an internal deuterated
standard to give a final concentration of 40
ng/uL of the internal deuterated standard (Section
14.3.2.1). Dilute to mark with methylene chloride.
14.3.1.11 The concentration of B[a]P in each flask is 1 ng/uL,
3 ng/uL, 5 ng/uL, 7 ng/uL, and 10 ug/uL respec-
tively. All standards should be stored at 4°C
and protected from fluorescent light and should
be freshly prepared once a week or sooner if check
standards indicates a problem.
14.3.1.12 Analyze a constant volume (1-3 uL) of each cali-
bration standard and tabulate the area responses
of the primary characteristic ion of each stand-
ard against the mass injected. The results may
be used to prepare a calibration curve for each
compound. Alternatively, if the ratio of response
-------
TQ13-47
to amount injected (calibration factor) is a
constant over the working range (<20% .^relative
standard deviation, RSD), linearity through the
origin may be assumed and the average ratio or
calibration factor may be used in place of a
calibration curve.
14.3.1.13 The working calibration curve or calibration
factor must be verified on each working day
by the measurement of one or more calibration
standards. If the response for any parameter
varies from the predicted response by more than
±20%, the rest must be repeated using a fresh
calibration standard. Alternatively, a new
calibration curve or calibration factor must
be prepared for that compound.
14.3.2 Internal standard calibration procedure.
14.3.2.1 To use this approach, the analyst must select
one or more internal standards that are similar
in analytical behavior to the compounds of inter-
est. For analysis of B[a]P, the analyst should
use perylene ~A\2> T"ne analyst must further demon-
strate that the measurement of the internal standard
is not affected by method or matrix interferences.
The following internal standards are suggested
at a concentration of 40 ng/uL for specific PAHs:
Perylene - di? Acenaphthene - dm
Benzo(a)pyrene Acenaphthene
Benzo(k)fluoranthene Acenaphthylene
Benzo(g,h,i)perylene Fluorene
Dibenzo(a,h)anthracene
Indeno(l,2,3-cd)pyrene Naphthalene - da
Chrysene - di? Naphthalene
Benzo(a)anthracene Phenanthrene -dip
Chrysene
Pyrene Anthracene
Fluoranthene
Phenanthrene
14.3.2.2 A mixture of the above deuterated compounds in
the appropriate concentration range are commer-
cially available (see Section 9.3.1.5).
-------
T013-48
14.3.2.3 Use the base peak ion as the primary ion for
quantification of the standards. If interferences
are noted, use the next two most intense ions
as the secondary ions. The internal standard
is added to all calibration standards and all
, sample extracts analyzed by GC/MS. Retention
time standards, column performance standards,
and a mass spectrometer tuning standard may be
included in the internal standard solution used.
14.3.2.4 Prepare calibration standards at a minimum of
three concentration level for each parameter of
interest by adding appropriate volumes of one
or more stock standards to a volumetric flask.
To each calibration standard or standard mixture,
add a known constant amount of one or more of the
internal deuterated standards to yield a resulting
concentration of 40 ng/uL of internal standard
and dilute to volume with methylene chloride.
One of the calibration standards should be at a
concentration near, but above, the minimum detec-
tion limit (MDL) and the other concentrations
should correspond to the expected range of
concentrations found in real samples or should
define the working range of the GC/MS system.
14.3.2.5 Analyze constant amount (1-3 uL) of each calibra-
tion standard and tabulate the area of the
primary characteristic ion against concentration
for each compound and internal standard, and
calculate the response factor (RF) for each analyte
using the following equation:
RF = (AsC1s)/(AisCs)
Where:
As = Area of the characteristic ion for the
analyte to be measured.
A-jS = Area of the characteristic ion for the
internal standard.
C-jS = Concentration of the internal standard,
(ng/uL).
Cs = Concentration of the analyte to be
measured, (ng/uL).
-------
T013-49
If the RF value over the working range is a con-
stant (<20% RSD), the RF can be assumed to be'
invariant and the average RF can be used for
calculations. Alternatively, the results can
be used to plot a calibration curve of response
ratios, As/Ajs, vs. RF. Table 5.0 outlines key
ions for selected internal deuterated standards.
14.3.2.6 The working calibration curve or RF must be veri-
fied on each working day by the measurement of one
or more calibration standards. If the response
for any parameter varies from the predicted response
by more than _+ 20%, the test must be repeated using
a fresh calibration standard. Alternatively, a
new calibration curve must be prepared.
14.3.2.7 The relative retention times for each compound
in each calibration run should agree within
0.06 relative retention time units.
14.4 Sample Analysis
14.4.1 It is highly recommended that the extract be screened on a
6C/FID or 6C/PID using the same type of capillary column
as in the GC/MS procedure. This will minimize contamina-
tion of the GC/MS system from unexpectedly high concentra-
tions of organic compounds.
14.4.2 Analyze the 1 ml extract (see Section 13.2) by GC/MS.
The recommended GC/MS operating conditions to be used
are specified in Section 14.2.
14.4.3 If the response for any quantisation ion exceeds the
initial calibration curve range of the GC/MS system,
extract dilution must take place. Additional internal
standard must be added to the diluted extract to maintain
the required 40 ng/uL of each internal standard in the
extracted volume. The diluted extract must be reanalyzed.
14.4.4 Perform all qualitative and quantitative measurements as
described in Section 14.3. The typical characteristic ions
for selective PAHs are outlined in Table 6.0. Store the
extracts at 4°C, protected from light in screw-cap vials
equipped with unpierced Tef 1 on®-!ined, for future analysis.
-------
T013-50
14.4.5 For sample analysis, the comparison between the sample and
references spectrum must illustrate:
(1) Relative intensities of major ions in the reference
spectrum (ions >10% of the most abundant ion) should be
present in the sample spectrum.
(2) The relative intensities of the major ions should
agree within +20%. (Example: For an ion with an abundance
of 50% in the standard spectrum, the corresponding sample
ion abundance must be between 30 and 70%).
(3) Molecular ions present in the reference spectrum
should be present in the sample spectrum.
(4) Ions present in the sample spectrum but not in the
reference spectrum should be reviewed for possible back-
ground contaminatiuon or presence of coeluting compounds.
(5) Ions present in the reference spectrum but not in
the sample spectrum should be reviewed for possible sub-
traction from the sample spectrum because of background
contamination or coeluting peaks. Data system library re-
duction programs can sometimes create these discrepancies.
14.4.6 Determine the concentration of each analyte in the sample
according to Sections 17.1 and 17.2.2.
14.5 GC/MS Performance Tests
14.5.1 Daily DFTPP Tuning - At the beginning of each day that
analyses are to be performed, the GC/MS system must be
checked to see that acceptable performance criteria are
achieved when challenged with a 1 uL injection volume
*
containing 50 ng of decafluorotriphenylphosphine (DFTPP).
The DFTPP key ions and ion abundance criteria that must
be met are illustrated in Table 3.0. Analysis should not
begin until all those criteria are met. Background
subtraction should be staightforward and designed only to
eliminate column bleed or instrument background ions.
The GC/MS tuning standard should also be used to assess
GC column performance and injection port inertness.
Obtain a background correction mass spectra of DFTPP 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. The
-------
T013-51 '
performance criteria must be achieved before any samples,
blanks on standards are analyzed. If any key ion abundance
observed for the daily DFTPP mass tuning check differs by
more than 10% absolute abundance from that observed during
the previous daily tuning, the instrument must be retuned
or the sample and/or calibration solution reanalyzed until
the above condition is met.
14.5.2 Daily 1-point Initial Calibration Check - At the beginning
of each work day, a daily 1-point calibration check is
performed by re-evaluating the midscale calibration
standard. This is the same check that is applied during
the initial calibration, but one instead of five working
standards are evaluated. Analyze the one working standards
under the same conditions the initial calibration curve
was evaluated. Analyze 1 uL of each of the mid-scale
calibration standard and tabulate the area response of
the primary characteristic ion against mass injected.
Calculate the percent difference using the following
equation:
% Difference = RFr - RFj x 100
RFj
Where:
RFi = average response factor from initial cali-
bration using mid-scale standard.
RFC = response factor from current verification check
using mid-scale standard.
If the percent difference for the mid-scale level is
greater than 10%, the laboratory should consider this a
warning limit. If the percent difference for the mid-scale
standard is less than 20%, the initial calibration is
assumed to be valid. If the criterion is not met (<20%
difference), then corrective action MUST be taken. [Note:
Some possible problems are standard mixture degradation,
injection port inlet contamination, contamination at the
front end of the analytical column, and active sites in the
column or chromatographic system.] This check must be met
-------
J013-52
15.
before analysis begins. If no source of the problem can be
determined after corrective action has been taken, a new
five-point calibration MUST be generated. This criterion
MUST be met before sample analysis begins.
14.5.3 12-hour Calibration Verification - A calibration standard
at mid-level concentration containing B[a]P or other PAHs
must be performed every twelve continuous hours of analysis.
Compare the standard every 12-hours with the average response
factor from the initial calibration. If the % difference
for the response factor (see Section 14.5.2) is less than
20%, then the GC/MS system is operative within initial cali-
bration values. If the criteria is not met (>20% difference),
then the source of the problem must be determined and a new
five-point curve MUST be generated.
14.5.4 Surrogate Recovery - Additional validation of the GC system
performance is determined by the surrogate standard recovery.
If the recovery of the surrogate standard deviates from 100%
by not more than 20%, then the sample extraction, concentra-
tion, clean-up and analysis is certified. If it exceeds this
value, then determine the cause of the problem and correct.
High Performance Liquid Chromatography (HPLC) Detection
15.1 Introduction
15.1.1 Detection of B[a]P by HPLC has also been a viable tool in
recent years. The procedure outlined below has been writ-
ten specifically for analysis of B[a]P by HPLC. However, by
optimizing chromatographic conditions [(multiple detector
fluorescence - excitation at 240 nm, emission at 425 nm; ul-
traviolet at 254 nm)] and varying the mobile phase composi-
tion through a gradient program, the following PAHs may
also be quantitatified:
DETECTOR1
COMPOUNDDETECTOR1
Acenaphthene UV
Acenaphthylene UV
Anthracene UV
Benzo(a)anthracene FL
Benzo(a)pyrene FL
Benzo(b)fluoranthene FL
Benzoieipyrene FL
Behzo(ghi) peryl ene FL
J-UV= Ultraviolet
FL= Fluorescences
COMPOUND
Benzo(k)fluoranthene FL
Dibenzo(a,h)anthracene FL
Fluoranthene FL
Fluorene UV
Indeno(l,2,3-cd)pyrene FL
Naphthalene UV
Phenanthrene UV
Pyrene FL
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T013-53
15.1.2 This method provides quantitative identification of the se-
lected PAH's compounds listed above by high performance liquid
chromatography. It is based on separating of compounds of
a liquid mixture through a liquid chromatographic column and
measuring the separated components with suitable detectors.
15.1.3 The method involves solvent exchange, with subsequent HPLC
detection involving ultraviolet (UV) and fluoresence (FL)
detection.
15.2 Solvent Exchange To Acetonitrile
15.2.1 To the extract in the concentrator tube, add 4 ml of ace-
tonitrile and a new boiling chip; attach a micro-snyder
column to the apparatus.
15.2.2 Increase temperature of the hot water bath to 95 to 100°C.
15.2.3 Concentrate the solvent as in Section 12.3.
15.2.4 After cooling, remove the micro-Snyder column and rinse its
lower sections into the concentration tube with approxi-
mately 0.2 ml acetonitrile.
15.2.5 Adjust its volume to 1.0 ml.
15.3 HPLC Assembly
15.3.1 The HPLC system is assembled, as illustrated in Figure 10.
15.3.2 The HPLC system is operated according to the following para-
meters:
HPLC Operating Parameters
Guard Column: VYDAC 201 GCCIOYT
Analytical Column: VYDAC 201 TP5415 C-18 RP (0.46 x 25 cm)
Column Temperature: 27.0 +_ 2°C
Mobile Phase: Solvent Composition Time (Minutes)
40% Acetonitrile/60% water 0
100% Acetonitrile 25
100% Acetonitrile 35
40% Acetonitrile/60% water 45
Linear gradient elution at 1.0 mL/min
Detector: Variable wavelength ultraviolet and fluore-
scence.
Flow Rate: 1.0 mL/minute
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T013-54
[Note: To prevent irreversible absorption due to "dirty"
injections and premature loss of column efficiency, a
guard column is installed between the injector and the
analytical column. The guard column is generally packed
with identical material as is found in the analytical
column. The guard column is generally replaced with a
fresh guard column after several injections ( 50) or
when separation between compounds becomes difficult.
The analytical column specified in this procedure has
been laboratory evaluated. Other analytical columns
may be used as long as they meet procedure and separation
requirements. Table 7.0 outlines other columns uses to
determine PAHs by HPLC.]
15.3.3 The mobile phases are placed in separate HPLC solvent
reservoirs and the pumps are set to yield a total of
1.0 mL/minute and allowed to pump for 20-30 minutes
before the first analysis. The detectors are switched on
at least 30 minutes before the first analysis. UV Detec-
tion at 254 nm is generally preferred. The fluorescence
spectrometer excitation wavelengths range from 250 to 800
nanometers. The excitation and emission slits are both
set at 10 nanometers nominal bandpass.
15.3.4 Before each analysis, the detector baseline is checked
to ensure stable operation.
15.4 HPLC Calibration
15.4.1 Prepare stock standard solutions at PAH concentrations of
1.00 ug/uL by dissolving 0.0100 grams of assayed material in
acetonitrile and diluting to volume in a 10 mL volumetric
flask. [Note: Larger volumes can be used at the convenience
of the analyst. When compound purity is assayed to be 98%
or greater, the weight can be used without correction to
calculate the concentration of the stock standard.] Commer-
cially prepared stock standards can be used at any concen-
tration if they are certified by the manufacturer or by an
independent source.
-------
T013-55
15.4.2 Transfer the stock standard solutions into Teflon®-sealed
screw-cap bottles. Store at 4°C and protect from light.
Stock standards should be checked f/requently for signs of
degradation or evaporation, especially just prior to pre-
paring calibration standards from/them.
15.4.3 Stock standard solutions must be/replaced after one year, or
sooner, if comparision with chec/'k standards indicates a problem.
15.4.4 Prepare calibration standards ajt a minimum of five concentra-
tion levels ranging from 1 ng/uil to 10 ng/uL by first diluting
the stock standard 10:1 with acetonitrile, giving a daughter
solution of 0.1 ug/uL. Accurately pipette 100 uL, 300 uL,
500 uL, 700 uL and 1000 uL of the daughter solution (0.1 ug/uL)
into each 10 ml volumetric flask, respectively. Dilute to
mark with acetonitrile. One of the concentration levels
should be at a concentration near, but above, the method
detection limit (MDL). The remaining concentration levels
should correspond to the expected range of concentrations
found in real samples or should define the working range
of the HPLC. [Note: Calibration standards must be replaced
after six months, or sooner, if comparison with check standards
indicates a problem.] '
15.4.5 Analyze each calibration standard (at lease five levels)
three times. Tabulate area response vs. mass injected.
All calibration runs are performed as described for sample
analysis in Section 15.5.1. Typical retetion times for
specific PAHs are illustrated in Table 8.0. Linear response
is indicated where a correlation coefficient of at least
0.999 for a linear least-squares fit of the data (concen-
tration versus area response) is obtained. The retention
times for each analyte should agree within +_ 2%.
15.4.6 Once linear response has been documented, an intermediate con-
centration standard near the anticipated levels for each com-
ponent, but at least 10 times the detection limit, should be
chosen for a daily calibration check. The response for the
various components should be within 15% day to day. If greater
variability is observed, recallbration may be required or a
new calibration curve must be developed from fresh standards. ~
-------
T013-56
15.4.7 The response for each component in the daily calibration
standard is used to calculate a response factor according to
the following equation:
RFC = Cr x VT
RC
Where
RFC = response factor (usually area counts) for the
component of interest in nanograms injected/
response unit.
Cc = concentration (mg/L) of analyte in the daily
calibration standard.
Vj = volume (uL) of calibration standard injected.
Rc = response (area counts) for analyte in the cali-
bration standard.
15.5 Sample Analysis
15.5.1 A 100 uL aliquot of the sample is drawn into a clean HPLC
injection syringe. The sample injection loop (10 uL) is
loaded and an injection is made. The data system, if avai-
ble, is activated simultaneously with the injection and the
point of injection is marked on the strip-chart recorded.
15.5.2 After approximately one minute, the injection valve is
returned to the "load" position and the syringe and valve
are flushed with water in preparation for the next sample
analysis.
15.5.3 After elution of the last component of interest, concen-
trations are calculated as described in Section 16.2.3.
[Note: Table 8.0 illustrates typical retention times asso-
ciates with individual PAHs, while Figure 17 represent a
typical chromatogram associates with fluorescence detection.]
15.5.4 After the last compound of interest has eluted, establish
a stable baseline; the system can be now used for further
sample analyses as described above.
1-5.5.5 If the concentration of analyte exceeds the linear range
of the instrument, the sample should be diluted with mob.ile
phase, or a smaller volume can be injected into the HPLC.
-------
T013-57
15.5.6 Calculate surrogate standard recovery on all samples, blanks
and spikes. Calculate the percent difference by the follow-
ing equation:
% difference = SR-'ST x 100
Si
Where
Sj = surrogate injected, ng.
SR = surrogate recovered, ng.
15.5.7 Once a minimum of thirty samples of the same matrix have been
analyzed, calculte the averge percent recovery (%R) and stand-
ard deviation of the percent recovery (SD) for the surrogate.
15.5.8 For a given matrix, calculate the upper and lower control
limit for method performance for the surrogate standard.
This should be done as follows:
Upper Control Limit (UCL) = (%R) + 3(SD)
Lower Control Limit (LCL) = (%R) - 3(SD)
The surrogate recovery must fall within the control limits.
If recovery is not within limits, the following is required.
o Check to be sure there are no errors in calculations
surrogate solutions and internal standards. Also,
check instrument performance.
o Recalculate the data and/or reanalyze the extract if
any of the above checks reveal a problem.
o Reextract and reanalyze the sample if none of the
above are a problem or flag the data as "estimated
concentration."
15.5.9 Determine the concentration of each analyte in the sample
according to Sections 17.1 and 17.2.3.
15.6 HPLC System Performance
15.6.1 The general appearance of the HPLC system should be
similar to that illustrated in Figure 10.
15.6.2 HPLC system efficiency is calculated according to the
following equation:
N = 5.54 t 2
""1/2
-------
T013-58
where:
N = column efficiency (theoretical plates).
tr = retention time (seconds) of analyte.
wl/2 = width of component peak at half height
(seconds).
A column efficiency of >5,000 theoretical plates should
be obtained.
15.6.3 Precision of response for replicate HPLC injections should
be +10% or less, day to day, for analyte calibration stand-
ards at 1 ug/mL or greater levels. At 0.5 ug/mL level and
below, precision of replicate analyses could vary up to 25%.
Precision of retention times should be +2% on a given day.
15.6.4 From the calibration standards, area responses for each
PAH compound can be used against the concentrations to
establish working calibration curves. The calibration
curve must be linear and have a correlation coefficient
greater than 0.98 to be acceptable.
15.6.5 The working calibration curve should be checked daily with
an analysis of one or more calibration standards. If the
observed response (rp) for any PAH varies by more than 15%
from the predicted response (rp), the test method must be
repeated with new calibration standards. Alternately a new
calibration curve must be prepared. [Note: If rn - rp
>15%, recalibration is necessary.] rp
15.7 HPLC Method Modification
15.7.1 The HPLC procedure has been automated by Acurex Corpora-
tion as part of their "Standard Operating Procedure for
Polynuclear Aromatic Hydrocarbon Analysis by High Perform-
ance Liquid Chromatography Methods," as reported in Refer-
ence 9 of Section 18.
15.7.2 The system consists of a Spectra Physics 8100 Liquid Chromat-
ograph, a micro-processor-controlled HPLC, a ternary gradient
generator, and an autosampler (10 uL injection loop).
15.7.3 The chromatographic analysis involves an automated solvent
program allowing unattended instrument operation. The
-------
T013-59
solvent program consists of four timed segments using
varying concentrations of acetonitrile in water with a
constant flow rate, a constant column temperature, and a
10-minute equilibration time, as outlined below.
AUTOMATED HPLC WORKING PARAMETERS
Solvent
Time Composition Temperature Rate
10 minutes 40% Acetonitrile 27.0 +_ 2°C 1 mL/min
equilibration 60% Water
T=0 40% Acetonitrile
60% Water
T=25 100% Acetonitrile
T=35 100% Acetonitrile
T=45 40% Acetonitrile
60% Water
Table 9.0 outlines the associated PAHs with their minimum
detection limits (MDL) which can be detected employing
the automated HPLC methodology.
15.7.4 A Vydac or equivalent analytical column packed with a CIQ
bonded phase is used for PAH separation with a reverse
phase guard column. The optical detection system consists
of a Spectra Physics 8440 variable Ultraviolet (UV)/Visible
(VIS) wavelength detector and a Perkin Elmer LS-4 Fluores-
cence Spectrometer. The UV/VIS detector, controlled by
remote programmed commands, contains a Deuterium lamp with
wavelength selection between 150 and 600 nanometers. It
is set at 254 nanometers with the time constant (detector
response) at 1.0 seconds.
15.7.5 The LS-4 Fluorescence Spectrometer contains separate exci-
tation and emission monochromators which are positioned
by separate microprocessor-controlled stepper motors. It
contains a Xenon discharge. la,mp, side-on photomultiplier
and a 3-microliter illuminated volume flow cell. It is
equipped with a wavelength programming facility to set
the monochromators automatically to a given wavelength
position. This greatly enhances selectivity by changing
-------
T013-60
the fluorescence excitation and emission detection wave- ,
lengths during the chromatographic separation in order to
optimize the detection of each PAH. The excitation wave-
lengths range from 230 to 720 nanometers; the emission
wavelengths range from 250 to 800 nanometes. The excita-
tion and emission slits are both set at 10 nanometers
nominal bandpass.
15.7.6 The UV detector is used for determining naphthalene, acenap-
thylene and acenapthene, and the fluorescence detector is
used for the remaining PAHs. Table 9 outlines the detec-
tion techniques and minimum detection limit (MDL) employing
this HPLC system. A Dual Channel Spectra Physics (SP) 4200
computing integrator, with a Labnet power supply, provides
data analysis and a chromatogram. An IBM PC XT with a
10-megabyte hard disk provides data storage and reporting.
Both the SP4200 and the IBM PC XT can control all functions
of the instruments in the series through the Labnet system
except for the LS-4, whose wavelength program is started
with a signal from the High Performance Liquid Chromatograph
autosampler when it injects. All data are transmitted to
the XT and stored on the hard disk. Data files can .later
be transmitted to floppy disk storage.
16.0 Quality Assurance/Quality Control
16.1 General System QA/QC
16.1.1 Each laboratory that uses these methods is required to oper-
ate a formal quality control program. The minimum require-
ments 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 labora-
tory 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 stand-
ard must.be analyzed to confirm that the measurements were
performed in an in-control mode of operation.
-------
T013-61
16.1.2 Before processing any samples, the analyst should demon-
strate, 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.
16.1.3 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.
16.1.4 The experience of the analyst performing gas chromatography
and high performance liquid chromatography is invaluable
to the success of the methods. Each day that analysis is
performed9 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?; Is 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.
16.2 Process, Field, and Solvent Blanks
16.2.1 One cartridge (XAD-2 or PUT) and filter from each batch of
approximately twenty should be analyzed, without shipment
to the field, for the compounds of interest per to serve as
a process blank. A blank level of less than 10 ng per
cartridge/filter assembly for single PAH component is
considered to be acceptable.
-------
T013-62
16.2.2 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.
16.2.3 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 less than 10 ng/sample
for single components to be acceptable.
16.2.4 Because the sampling configuration (filter and backup
adsorbent) has been tested for targeted PAHs in the
laboratory in relationship to collection efficiency and
has been demonstrated to be greater than 95% for targeted
PAHs, no field recovery evaluation will occur as part of
the QA/QC program outlined in this section.
16.3 Gas Chromatography with Flame lonization Detection
16.3.1 Under the calibration procedures (internal and external), the
% RSD of the calibration factor should be <20% over the
linear working range of a five point calibration curve
(Sections 13.4.1.6 and 13.4.2.6).
16.3.2 Under the calibration procedures (internal and external),
the daily working calibration curve for each analyte should
not vary from the predicted response by more than +20%
(Sections 13.4.1.7 and 13.4.2.8).
16.3.3 For each analyte, the retention time window must be
established (Section 13.5.1), verified on a daily basis
(Section 13.6.3.2) and established for each analyte
throughout the course of a 72-hour period (Section 13.5.3).
16.3.4 For each analyte, the mid-level standard must fall within the
retention time window on a,(dc|ily basis as a qualitative
performance evaluation of the GC system (Section 13.6.3.4).
16.3.5 The surrogate standard recovery must not deviate from 100%
by no more than 20% (Section 13.6.3.5).
-------
T013-63
16.4 Gas Chromatography with Mass Spectroscopy Detection
16.4.1 Section 14.5.1 requires the mass spectrometer be tuned
daily with DFTPP and meet relative ion abundance require-
ments outlined in Table 3.
16.4.2 Section 14.3.1.1 requires a minimum of five concentration
levels of each analyte (plus deuterated internal standards)
be prepared to establish a calibration factor to illustrate
<20% variance over the linear working range of the
calibration curve.
16.4.3 Section 14.3.1.13 requires the verification of the working
curve each working day (if using the external standard tech-
nique) by the measurement of one or more calibration stand-
ards. The predicted response must not vary by more than
+2036.
16.4.4 Section 14.3.2.6 requires the initial calibration curve
be verified each working day (if using the internal standard
technique) by the measurement of one or more calibration
standards. If the response varies by more than +20% of
predicted response, a fresh calibration curve (five point)
must be established.
16.4.5 Section 14.4.5 requires that for sample analysis, the com-
parison between the sample and reference spectrum illustrate:
(1) Relative intensities of major ions in the reference
spectrum (ions >10% of the most abundant ion) should be
present in the sample spectrum.
(2) The relative intensities of the major ions should
agree within +20%. (Example: For an ion with an abundance
of 50% in the standard spectrum, the corresponding sample
ion abundance must be between 30 and 70%).
(3) Molecular ions present in the reference spectrum
should be present in sample the spectrum.
(4) Ions present in the sample spectrum but not in the
reference spectrum should be reviewed for possible back-
ground contaminatiuon or presence of coeluting compounds.
(5) Ions present in the reference spectrum but not in
the sample spectrum should be reviewed for possible sub-
traction from the sample spectrum because of background
contamination or coeluting peaks. Data system library re-
duction programs can sometimes create these discrepancies.
-------
T013-66
17.2.2 6C/MS Detection
17.2.2.1 When an analyte has been identified, the quanti-
fication of that analyte will be based on the
integrated abundance from the monitoring of the
primary characteristic ion. Quantification will
take place using the internal standard technique.
The internal standard used shall be the one
nearest the retention time of that of a given
analyte (see Section 14.3.2.1).
17.2.2.2 Calculate the concentration of each identified
analyte in the sample as follows:
Concentration, ng/m3 = [(Aj(Ig)(Vt)(D)]
C(A-{s)(RF)(y1)(Vs)]
Where
Ax = area of characteristic ion(s)
for analyte being measured.
Is = amount of internal standard ^^
injected, ng. ••
V"t = volume of total sample, uL.
D = dilution factor, if dilution was
made on the sample prior to analysis.
If no dilution was made, D = 1,
dimensionless.
Ajs = area of characteristic ion(s) for
internal standard.
RF = Response factor for analyte being
measured, Section 14.3.2.5.
V-j = volume of analyte injected, uL.
Vs = total sample volume (m ) at standard
temperature and pressure (25°C and
760 mm Hg), Section 17.1.3.
17.2.3 HPLC Detection
17.2.3.1 The concentration of each analyte in the
sample may be determined from the external
standard technique by calculating response
factor and peak response using the calibration
curve.
-------
T013-67
17.2.3.2 The concentration of a specific analyte is
calculated as follows:
Concentration, ng/m3 = C(RFJ(AY)(Vt)(D)]
UVi)(vs)J
Where
RFC = response factor (nanograms injected
per area counts) calculated in
Section 15.4.7.
Ax = response for the analyte in the sample,
area counts or peak height.
Vt = volume of total sample, uL.
D = dilution factor, if dilution was
made on the sample prior to analysis.
If no dilution was made, D = 1,
dimensionless.
Vj = volume of sample injected, uL.
^
Vs = total sample volume (m ) at standard
temperature and pressure (25°C and
760 mm Hg), Section 17.1.3.
17.3 Sample Concentration Conversion From ng/m3 to ppbv
. 17.3.1 The concentrations calculated in Section 17.2 can be
converted to ppbv for general reference.
17.3.2 The analyte concentration can be converted to ppbv using
the following equation:
CA (ppbv) = CA (ng/m3) x 24.4
MWA
Where
CA = concentration of analyte, ng/m3, calculated
according to Sections 17.2.1 through 17.2.3.
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), I/mole.
-------
T013-68
18.0 BIBLIOGRAPHY
1. Dubois, L., Zdrojgwski, A., Baker, C., and Monknao J.L., "Some Improve-
ment in the Determination of Benzo[a]Pyrene in Air Samples," Air Pol-
lution Control Association J., 17:818-821, 1967.
2. Intersociety Committee "Tentative Method of Analysis for Polynuclear
Aromantic Hydrocarbon of Atmospheric Particulate Matter, Health Labora-
tory Science, Vol. 7, No. 1, pp. 31-40, January, 1970.
3. Cautreels, W., and Van Cauwenberghe, K., "Experiments on the Distribu-
tion of Organic Pollutants Between Airborne Particulate Matter and
Corresponding Gas Phase", Atmos. Environ., 12:1133-1141 (1978).
4. "Tentative Method of Microanalysis for Benzo[a]Pyrene in Airborne
Particules and Source Effluents," American Public Health Association,
Health Laboratory Science, Vol 7, No. 1, pp. 56-59, January, 1970.
5. "Tentative Method of Chromatographic Analysis for Benzo[a]Pyrene and
Benzo[k]Fluoranthene in Atmospheric Particulate Matter," American
Public Health Association, Health Laboratory Science, Vol. 7, No. 1,
pp. 60-67, January, 1970.
6. "Tentative Method of Spectrophotometric Analysis for Benzo[a]Pyrene
in Atmospheric Particulate Matter," American Public Health Association,
Health Laboratory Science, Vol. 7, No. 1, pp. 68-71, January, 1970.
7. Jones, P.W., Wilkinson, J.E., and Strup, P.E., "Measurement of Poly-
cyclic Organic Materials and Other Hazardous Organic Compounds in
Stack Gases: State-of-art," U.S. EPA-600/2-77-202, 1977.
8. "Standard Operating Procedure for Ultrasonic Extraction and Analysis
of Residual Benzo[a]Pyrene from Hi-Vol Filters via Thin-Layer Chroma-
tography", J.F. Walling, U.S. Environmental Protection Agency, Environ-
mental Monitoring Systems Laboratory, Methods Development and Analysis
Division, Research Triangle Park, N.C., EMSL/RTP-SOP-MDAD-015, December,
1986.
9. "Standard Operating Procedure for Polynuclear Aromantic Hydrocarbon
Analysis by High Performance Liquid Chromatography Methods," Susan Rasor,,
Acurex Corporation, Research Triangle Park, N.C., 1978.
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. Technol., 14:1505-1509,
1980.
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T013-69
11. Konlg, J., Balfanz, E., Funcke, W., and Romanowski, T., "Determination
of Oxygenated Polycyclic Aromantic Hydorcarbons in Airborne Particu-
late Matter by Capillary Gas Chromatography and Gas Chromatography/Mass
Spectrometry", Anal. Chem., Vol. 55, pp. 599-603, 1983.
12. Chuang, J. C., Bresler,W. E. and Hannan, S. W.,"Evaluation of Polyurethane
Foam Cartridges for Measurement of Polynuclear Aromantic Hydrocarbons
in Air," U.S. Environmental Protection Agency, Environmental Monitoring
Systems Laboratory, Methods Development and Analysis Division, Research
Triangle Park, N.C., EPA-600/4-85-055, September, 1985.
13. Chuang, J.C., Hannan, S.W., and Kogtz, J. R., "Stability of Polynuclear
Aromantic Compounds Collected from Air on Quartz Fiber Filters and XAD-2
Resin," U.S. Environmental Protection Agency, Environmental Monitoring
Systems Laboratory, Methods Development and Analysis Division, Research
Triangle Park, N.C., EPA-600/4-86-029, September, 1986.
14. Feng, Y. and Bidleman, T.F., "Influence of Volatility on the Collection
of Polynuclear Aromantic Hydrocarbon Vapors with Polyurethane Foam",
Envir. Sci. Technol., 18:330-333, 1984.
15. Yamasaki, H., Kuwata, K., and Miyamoto, H., "Effects of Ambient Tempera-
ture on Aspects of Airborne Polycyclic Aromantic Hydrocarbons", Envir.
Sci. Techno!., Vol. 16, pp. 189-194, 1982.
16. Chuang, J.C., Hannan, S.W. and Kogtz, J. R., "Comparison of Polyurethane
Foam and XAD-2 Resin as Collection Media for Polynuclear Aromantic
Hydrocarbons in Air," U.S. Environmental Protection Agency, Environmental
Monitoring Systems Laboratory, Methods Development and Analysis Division,
Research Triangle Park, N.C., EPA-600/4-86-034, December, 1986.
17. Chuang, J. C., Mack, G. A., Mondron., P. J. and Peterson, B. A., "Evalua-
ation of Sampling and Analyjtical Methodology for Polynuclear Aromatic
Compounds in Indoor Air," Environmental Protection Agency, Environmental,
Monitoring Systems Laboratory, Methods Development and Analysis Division,
Research Triangle Park, N.C., EPA-600/4-85-065, January, 1986.
18. Methods for Organic Chemical Analysis of Municipal and Industrial Waste-
water, U.S. Environmental Protection Agency, Environmental Monitoring
and Support Laboratory, Cincinnati, OH, EPA-600/4-82-057, July 1982.
19. 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.
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20. Burke, J.A., "Gas Chromatography for Pesticle Residue Analysis; Some
Practical Aspects," Journal of the Association of Official Analytical
Chemists, Vol. 48, p. 1037, 1965.
21. Cole, T., Riggins, R., and Glaser, J., "Evaculation of Method Detection
Limits an Analytical Curve for EPA Merhod 610 - PNAs," International
Symposium on Polynuclear Aromantic Hydrocarbons, 5th, Battelle Columbus
Laboratory, Columbus, Ohio, 1980.
22. "Handbook of Analytical Quality Control in Water and Wastewater Labora-
tories, "U.S. Environmental Protection Agency, Environmental Monitoring
and Support Laboratory, Cincinnati, Ohio 45268, EPA-600/4-79-019, March,
1979.
23. ASTM Annual Book of Standards, Part 31, D 3370, "Standard Practice for
Sampling Water," American Society for Testing and Materials, Philadelphia
PA, p. 76, 1980.
24. Protocol for the Collection and Analysis of Volatile POHC's (Principal
Organic Hazardous Constituents) using VOST (Volatile Organic Sampling
Train)", PB84-170042, EPA-600/8-84-007, March, 1984.
25. Sampling and Analysis Methods for Hazardous Waste Combustion - Methods
3500, 3540, 3610, 3630, 8100, 8270, and 8310; Test Methods For Evaluating
Solid Waste (SW-846), U.S. EPA, Office of Solid Waste, Washington, D.C.
26. Chuang, C.C. and Peterson, B.A., "Review of Sampling and Analysis Method-
ology for Polunuclear Aromantic Compounds in Air from Mobile Sources",
Final Report, EPA-600/S4-85-045, August, 1985.
27. "Measurement of Polycyclic Organic Matter for Environmental Assessment,"
U.S. Environmental Protection Agency, Industrial Environmental Research
Laboratory, Research Triangle Park, N.C., EPA-600/7-79-191, August, 1979.
28. "Standard Operating Procedure No. FA 113C: Monitoring For Particulate
and Vapor Phase Pollutants Using the Portable Particulate/Vapor Air
Sampler," J.L. Hudson, U.S. Environmental Protection Agency, Region VII,
Environmental Monitoring and Compliance Branch, Environmental Services
Division, Kansas City, Kansas, March, 1987.
29. Technical Assistance Document for Sampling and Analysis of Toxic Organic
Compounds in Ambient Air, U.S. Environmental Protection Agency, Environ-
mental Monitoring Systems Laboratory, Quality Assurance Division,
Research Triangle Park, N.C., EPA-600/4-83-027, June, 1983.
-------
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30. Winberry, W. T., 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, N.C.,
EPA-600/4-87-006, September, 1986.
31. Riggins, 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, N.C., EPA-600/4-84-041, April, 1984.
32. Quality Assurance Handbook for Air Pollution Measurement Systems, Vo-
lume II - "Ambient Air Specific Methods," Section 2.2 - "Reference
Method for the Determination of Suspended Particulates in the Atmos-
phere," Revision 1, July, 1979, EPA-600/4-77-027A.
33. 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.
34. "HPLC Troubleshooting Guide - How to Identify, Isolate, and Correct
Many, HPLC Problems," Supelco, Inc., Supelco Park, Bellefonte, PA,
16823-0048, Guide 826, 1986.
35. "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.
36. "OSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Administration, OSHA 2206, Revised,
January, 1976.
37. "Safety in Academic Chemistry Laboratories," American Chemical Society
Publication, Committee on Chemical Safety, 3rd Edition, 1979.
38. Hudson, J., "Monitoring for Particulate And Vapor Phase Pollutants
Using A Portable Particulate/Vapor Air Sampler - Standard Operating
Procedure No. SA-113-C"9 U.S. Environmental Protection Agency, Region
VII, Environmental Services Division, 25 Funston Road, Kansas City,
Kansas, 66115.
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TABLE 1.0 FORMULAE AND PHYSICAL PROPERTIES OF SELECTIVE PAHs
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b) f 1 uoranthene
Benzo(e)pyrene
Benzo(g.h,i)perlene
Benzo(k)fl uoranthene
Chrysene
Dibenzo(a,h)anthracene
FT uoranthene
Fluorene
Indeno(l,2,3-cd)pyrene
^Naphthalene
Phenanthrene
Pyrene
FORMULA
C].2Hio
C12H8
Ci4Hio
C18H12
CEO HI 2
C20H12
C2QH12
C22H12
C20H12
C18H12
C22H14
CieHio
CisHiO
C22»12
ClQHs
C14H10
CieHio
MOLECULAR
WEIGHT
154.21
152.20
178.22
228.29
252.32
252.32
252.32
276.34
252.32
228.29
278.35
202.26
166.22
276.34
128.16
178.22
202.26
MELTING POINT
°C
96.2°
92-93
218°
158-159
177°
168
178-179
273
217
255-256
262
110
116-117
161.5-163
80.2
100°
156
BOILING POINT
°C
279
265-275
342
-
310-312
-
-
-
480
-
-
293-295
-
217.9
340
399
CASE
#
83-32-9
208-96-8
120-12-7
56-55-3
50-32-8
205-99-2
192-92-2
191-24-2
207-08-9
218-01-9
53-70-3
206-44-0
86-73-7
193-39-5
.91-20-3
85-01-8
129-00-0
*Hany of these compounds sublime.
-------
T013-73
TABLE 2.0 RETENTION TIMES FOR SELECTIVE PAHs FOR PACKED
AND CAPILLARY COLUMNS
Packed1 Capillary2
Acenaphthene
Acenaphthylene
Anthracene
Benzo( a) anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Chrysene
Dibenzo( a, h) anthracene
Fluoranthene
Fluorene
Indeno(l,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
10.8
10.4
15.9
20.6
29.4
28.0
38.6
28.0
24.7
36.2
19.8
12.6
36.2
4.5
15.9
20.6
16.8
15.9
20.7
29.1
36.2
34.2
48.4
34.4
29.3
46.1
24.3
18.1
45 .6
11.0.
20.6
25.0
conditions: Chromosorb W-AW-DMCS (100/120 mesh) coated with 3%
OV-17, packed in a 1.8-m long x 2 mm ID glass column, with nitrogen
carrier gas at a flow rate of 40 mL/min. Column temperature was held
at 100°C for 4 min. then programmed at 8°/minute to a final hold at 280°C,
2capillary GC conditions: 30 meter fused silica SPB-5 capillary column;
flame ionization detector, splitless injection; oven temperature held at
80 degrees C for 2 minutes, increased at 8 degrees/min. to 280 degrees C.
-------
T013-74
TABLE 3.0 DFTPP KEY IONS. AND ION ABUNDANCE CRITERIA
Mass
Ion Abundance Criteria
51
68
70
127
197
198
199
275
365
441
442
443
30-60% of mass 198
Less than 2% of mass 69
Less than 2% of mass 69
40-60% of mass 198
Less than 1% of mass 198
Base peak, 100% relative abundance
5-9% of mass 198
10-30% of mass 198
Greater than 1% of mass 198
Present but less than mass 443
Greater than 40% of mass 198
17-23% of mass 442
-------
T013r75
TABLE 4.0 GC AND MS OPERATING CONDITIONS
Chromatography
Column Hewlett-Packard Ultra #2 cross!inked 5% phenyl
methyl silicone (50 m x 0.25 mm, 0.25 urn film
thickness) or equivalent
Carrier.Gas He!iurn velocity 20 cm3/sec at 250°C
Injection Volume Constant (1-3 uL)
Injection Mode Splitless
Temperature Program
Initial Column Temperature 45°C
Initial Hold Time 1 min
Program 45°C to 100°C in 5 min, then 100°C to 320°C at
8°C/min
Final Hold Time 15 min
Mass Spectrometer
Detection Mode Multiple ion detection, SIM mode
-------
T013-76
TABLE 5.0 CHARACTERISTIC IONS FROM 6C/MS DETECTION
FOR DEUTERATED INTERNAL STANDARDS AND SELECTED PAHs
. Compound
M/Z
Dg-naphthalene
Dig-phenanthrene
Phenathrene
Anthracene
Fluoranthene
DiQ-pyrene
Pyrene
Cyclopenta[c,d]pyrene
Benz[a]anthracene
Benzo[e]pyrene
Di2-benzo[a]pyrene
Benzo[a]pyrene
136
188
178
178
202
212
202
226
228
240
252
264
252
-------
T013-77
TABLE 6.0 CHARACTERISTIC IONS FROM GC/MS DETECTION
FOR SELECTED PAHs
Compound
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)f 1 uoranthene
Benzo(ghi)perylene
Benzo(k)fl uoranthene
Chrysene
Dibenzo(a,h)anthracene
Fl uoranthene
Fluorene
Indeno(l,2,3-cd)pyrene
Naphthalene
Phenanthrene
Pyrene
154
152
178
228
252
252
276
252
228
278
202
166
276
128
178
202
Primary
153
151
179
229
253
253
138
253
226
139
101
165
138
129
179
200
Secondary - ••
152
153
176
226
125
125
277
125
229
279
203
167
227
127
176
203
-------
T013-80
TABLE 9.0.
Ultraviolet Detector
RT MDL
Naphthalene j
Acenaphthylene ,
Acenaphthene >
Fluorene
Phenanthrene j
Anthracene /
Fluoranthene
Pyrene /
Benzo(a)anthracene
Chrysene '
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenzo(a,h)anthracene
Benzo(ghi)perylene
jyidejipii.ili^dleyj
RT = Retention time in minutes
MDL f Minimum detection limit
14.0
15.85
18.0
18.5
19.9
21.0,
22.5
23.4
26.3
26.7
29.3
30.2
31.1
32.7
33.9
34.6
250pg/uL
250pg/uL
250pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
50pg/uL
_. -N* / *
50pq/uL ..._
. 18.5
19.9
21.0
22.5
23.4
26.3
26.7 .
29.3
30.2
31.1
32.7
33.9
•34. 6
O't . w
•
5pg/uL
10pg/uL
50pg/uL
lOpg/uL
5pg/uL
5pg/uL
5pg/uL
lOpg/uL
5pg/uL
5pg/uL
5pg/uL
5pg/uL
50pg/uL
-------
T013-81
Acenaphthene
Benzo(a)anthracene
Benzo(g,h,i)perylene
Chrysene
Fluorene
Acenaphthylene
Benzo(b)fluoranthene
Benzo{a)pyrene
Dibenz(a,h)anthracene
Anthracene
Benzo(k)fluoranthene
Fluoranthene
Naphthalene
Phenanthrene Pyrene
FIGURE 1.0 RING STRUCTURE OF SELECTIVE PAHs.
-------
TO 13- 82
c:
Air Flow
4" Diameter
Pallflex Filter
Particulate
Filter
Support
Adsorbent
Cartridge and
Support
Air Flow
Exhaust
Filter Retaining Ring
Silicone Gasket
4" Diameter
Pallflex
Filter
TX40H120WW
Filter Support Screen
Filter Support Base
Silicone Gasket
Glass Cartridge
Adsorbent
(XAD-2 or PUF)
Retaining Screen
Silicone Gasket
Adsorbent
Support
FIGURE 2.0 GENERAL METAL WORKS SAMPLING HEAD
-------
T013-83
Water In
Soxhlet
Extraction.
Tube and
Thimble
&>-** Water Out
.Allihn
Condenser
-Flask
(a) Soxhlet Extraction Apparatus
with Allihn Condenser
3 Ball Macro
Synder Column
500 mL
Evaporator
Flask
10 mL
Concentrator
Tube
(b) Kuderna-Danish (K-D) Evaporator
with Macro Synder Column
Disposable 6 inch
Pasteur Pipette
1 Gram Sodium Sulfate
10 Gram Silica
Gel Slurry
ilass Wool Plug
(c) Silica Gel Clean-up Column
FIGURE 3. APPARATUS USES IN SAMPLING ANALYSIS.
-------
T013-84
Sampling
Head
(See Figure 2)
Magnehellc
Gauge
0-100 In.
Exhaust
Duct
(6 In. x 10 ft)
Voltage
Variator
Elapsed Time
Meter
7-Day
Timer
Base Plate
FIGURE 4. MODIFIED HIGH VOLUME AIR SAMPLER
GENERAL METAL WORKS MODEL PS-1 SAMPLER
-------
TO13-85
Venturl
Exhaust Hose
ft
4" Diameter Pullf lex
Filter And Support
XAD-2 or PUF Adsorbent
Cartridge And Support
Quick Release Connections
For Module
Quick Release Connections
For Magnahelic Gage
- Flow Control Valve
Elapsed Time Indicator
FIGURE 5. PORTABLE HIGH VOLUME AIR SAMPLER
-------
T013-86
Mercury
Manometer
Barometer
Thermometer
Filter Adapter
Rootsmeter
High Volume Motor
Resistance Plates
FIGURE 6. LABORATORY ORIFICE CALIBRATION SETUP
-------
T013-87
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TO13-90
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-------
T013-91
Filter
Surrogate Standard
Addition for GC/FID
and GC/MS Analysis
(Section 12.2.1)
fc.
Soxhlet Extraction In Methylene Chloride
18 Hours/3 Cycles/Hr) or
Ether/Hexane Solvent
(Section 12.2.1)
i
^
•^-
Surrogate Standard
Addition for
HPLC Analysis
(Section 12.2.1)
Drying with Anhydrous Sodium Sulfate
(Section 12.2.2)
Kuderna-Danish (K-D) Evaporator
Attached with Macro Synder Column
(Section 12.2.3)
Water Bath
at60°C
Solvent Exchange to Cyclohexane by
K-D Apparatus with Macro Snyder Column
(Section 12.3.2)
-^
Add 5 mL of
Cyclohexane
(No Extract Clean-up Required) Concentrate
toLOmL
^
^
i (Extract Clean-Up
Required) , —
Silica Gel Column Topped w'ri
Sodium Sulfate
(Section 12.4.1)
or Lobar Column
(Section (12.4.2)
f
h
^
Add 0.5 mL
Cyclohexane
Pentane
Elution
Methylene
Chloride/Pentane
Elution
Methanol
Elution
Pentane
Fraction
(Optional)
Methylene Chloride/Pentane Fraction
Concentrated by K-D Apparatus to 1 mL
(Section 12.4.1.3)
Methanol
Fraction
(Optional)
Analysis by
GCorHPLC
I
Gas Chromatography
Analysis
(Section 13.0)
Flame lonlzation
(Fl) Detection
(Section 13.3)
Solvent Exchange to Acetonitrile
by K-D Apparatus
(Section 15.2)
Mass
Spectroscopy
(MS) Detection
(Section 14.0)
HPLC Analysis
(Section 15.4)
Ultraviolet
(UV) Detection
Fluorescence
(FL) Detection
FIGURE 11.0. SAMPLE CLEAN-UP, CONCENTRATION,
SEPARATION AND ANALYSIS SEQUENCE.
-------
T013-92
Injection
Port
Flow
Controller
Canier
Gas
Bottle
, ::" ^••^"X ^-J^
^Detector -
Flame
lonization
(Fl)
Detector
Mass
Spectroscopy
(MS)
In
SCAN Mode
FIGURE 12.0 GC SEPARATION WITH SUBSEQUENT
FLAME IONIZATION (Fl) OR MASS
SPECTROSCOPY (MS) DETECTION.
-------
TO13-93
Establish Gas Chromatograph
Operating Parameters:
(Section 13.3)
Prepare Calibration Standards
(Section 13.4)
Select Internal Standards
Having Similar Behavior to
Compounds of Interest
(Section 13.4.2)
I
Prepare Calibration/
Internal Standards
(Section 13.4.2.1)
Inject Calibration Standards:
Calculate Response Factor (RF)
(Section 13.4.2.2)
Verify Working Calibration
Curve or RF Each Day
(Section 13.4.2.6)
Internal Standard
•4—
External Standard
Calibration Technique
(Section 13.4)
Prepare Calibration Standards
for EachAnalyte
of Interest
(Section 13.4.1)
Inject Calibration Standard:
Prepare Calibration Curve
or Calibration Factor (CF)
(Section 13.4.1.5)
Verify Working Calibration
Curve Each Day
(Section 13.4.1.7)
Calculate Retention
Time Windows
(Section 13.5)
Introduce Extract Into
Gas Chromatograph by
Direct Injection
(Section 13.6.1)
Does Response Exceed
Linear Range ,
of System?
(Section 13.6.3.1)
Yes
•Dilute Extract
and Reanalyze
(Section 13.6.3.1)
Determine Identity and
Quantity of Each Analyte,
Using Appropriate Formulas
and Curves
(Section 13.6.3 and 17.2.1)
FIGURE 13.0 GC CALIBRATION AND RETENTION
TIME WINDOW DETERMINATION.
-------
TO 13-94
t
CD
8
Retention Time, minutes
Column: 3% OV-17 on Chromosorb W-AW-DCMS
Program: 100 °C. 4 min., 8 ° per min. to 280 °C.
Detector: Flame lonization
FIGURE 14.0
TYPICAL CHROMATOGRAM OF SELECTIVE PNAs
BY GC EQUIPPED WITH Fl DETECTOR.
-------
TO13-95
Establish Gas Chromatograph/
Mass Spectroscopy Operating Parameters:
Prepare Calibration Standards
(Section 14.2)
Select Internal Standards
Having Similar Behavior to
Compounds of Interest
Normally Deuterated PAHs
(Section 14.3.2 and 14.3.2.1)
Tune GC/MS with DFTPP
(Section 14.2)
Internal Standard y External Standard
Calibration Technique
(Section 14.3)
Prepare Calibration Standards
for Each Analysis
of Interest
(Section 14.3.1)
Prepare Calibration
Standards
(Section 14.3.2.4.1)
Add Internal
Standards
(Section 14.3.1.10)
Inject Calibration Standard:
Prepare Calibration Curve
or Calibration Factor (CF)
(Section 14.3.1.12)
Inject Calibration Standards:
Calculate Response Factor (RD)
(Section 14.3.2.5)
Verify Working Calibration
Curve or RF Each Day
(Section 14.3.2.6)
Verify Working Calibration
Curve Each Day
(Section 14.3.1.13)
Introduce Extract into
GC/MS by Direct Injection
(Section 14.4)
Does Response Exceed
Linear Range of System?
(Section 14.4.3)
Yes
Dilute Extract and
Reanalyze
(Section 14.4.3)
Calculate Concentration of
Each Analyte, Using
Appropriate Formulas
(Section 14.4.4 and 17.2.2)
Daily GC/MS Tuning
With DFTPP
(Section 14.5.1)
fe
GC/MS Performance Test
(Section 14.5)
-^
^i
12-Hr Calibration Verification
(Section 14.5.3)
Daily 1-Point
Calibration Verification
(Section 14.5.2)
FIGURE 15.0 GC/MS CALIBRATION AND ANALYSIS.
-------
T013-96
D>
m
ULJ
g
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-------
T013-97
f
i
4
8
12
16 20 24 28
Retention Time, minutes
32
40
FIGURE 17.0
TYPICAL CHROMATOGRAM OF SELECTIVE PAHs
ASSOCIATES WITH HPLC ANALYSIS WITH
FLUORESCENCE DETECTION.
-------
-------
Limitations
Sample Collection
7*1*? p"batmosPheric
7.2 samni. ,Pre?surized
Analysis
7.3
8.
9.
10.
10
"'
Revision
-32 "outle Ca'l /j?™4 ' »"
-------
11.
OUTLINE
Program
12.
Ac ««' •
13
a
-------
METHOD T014
DETERMINATION OF VOLATILE ORGANIC COMPOUNDS (VOCs) IN AMBIENT AIR
USING SUMMA® PASSIVATED CANISTER SAMPLING AND GAS
CHROMATOGRAPHIC ANALYSIS
Scope
1.1 This document describes a procedure for sampling and analysis
of volatile organic compounds (VOCs) in ambient air. The method
is based on collection of whole air samples in SUMMA® passivated
stainless steel canisters. The VOCs are subsequently separated
by gas chromatography and measured by mass-selective detector or
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 (1,2). However,
minimal documentation is currently available demonstrating
stability of VOCs in subatmospheric pressure canisters.
1.3 The organic compounds that have been successfully collected in
pressurized canisters by this method are listed in Table 1.
These compounds have been successfully measured at the parts per
billion by volume (ppbv) level.
Applicable Documents
2.1 ASTM Standards
D1356 - Definition of Terms Related to Atmospheric Sampling and
Analysis
E260 - Recommended Practice for General Gas Chromatography
Procedures
E355 - Practice for Gas Chromatography Terms and Relationships
2.2 Other Documents
U.S. Environmental Protection Agency Technical Assistance Document (3)
Laboratory and Ambient Air Studies (4-17)
-------
T014-2
Summary of Method
3.1 Both subatmospheric pressure and pressurized sampling modes use
an initially evacuated canister and a pump-ventilated sample line
during sample collection. Pressurized sampling requires an addi-
tional 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 SUMMA® passivated canister.
3.2 After the air sample is collected, the canister valve is closed,
an identification tag is attached to the canister, and the canis-
ter is transported to a predetermined laboratory for analysis.
3.3 Upon receipt at the laboratory, the canister tag data is recorded
and the canister is attached to the analytical system. During analy-
sis, water vapor is reduced in the gas stream by a Nafion® dryer
(if applicable), and the VOCs are then concentrated by collection
in 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 revolatilized, separated on a GC column, then de-
tected by one or more detectors for identification and quantisation.
3.4 The analytical strategy for Method T014 involves using a high-
resolution gas chromatograph (GC) coupled to one or more appro-
priate 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 (FID), the electron capture detector (ECD) and the photo-
ionization detector (PID). The specific detectors include the
mass spectrometer (MS) operating in either the selected ion moni-
toring (SIM) mode or the SCAN mode, or the ion trap detector.
The use of these detectors or a combination of these detectors
as part of an 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 more sensitive than the specific detector, they vary in
specificity and sensitivity for a specific class of compounds.
For instance, if multiple halogenated compounds are targeted,
-------
T014-3
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 are sought, the broad response .of the
FID or PID is appropriate. In each of these cases, however, the
specific identification of the compound within the class is deter-
mined only by its retention time, which can be subject to shifts
or to interference from other nontargeted compounds. When misiden-
tification occurs, the error is generally a result of a cluttered
chromatogram, making peak assignment difficult. In particular,
the more volatile organics (chloroethanes, ethyltoluenes, dichloro-
benzenes, and various freons) exhibit less well defined chromato-
graphic peaks, leading to misidentification using non-specific
detectors. Quantitative comparisons indicate that the FID is more
subject to error than the ECD because the ECD is a much more selec-
tive detector for a smaller class of compounds which 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 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 nonspecific detector system can provide a "snapshot"
of the constituents in the sample, allowing determination of:
- Extent of misidentification due to overlapping peaks,
- Position of the VOCs within or not within the concentration
range of anticipated further analysis by specific detectors
(GC-MS-SCAN-SIM) (if not, the sample is further diluted), and
- Existence of unexpected peaks which need further identification
by specific detectors.
On the other hand, the use of specific detectors (MS coupled to a
GC) allows positive compound identification, thus lending itself
to more specificity than the multidetector GC.- Operating in the
SIM mode, the MS can readily approach the same sensitivity as the
-------
T014-6
combination of retention time and multiple general detector veri-
fication to identify compounds. However, interference due to
nearly identical retention times can affect system quantitation
when using this option.
'Due to the low concentrations of VOCs encountered in urban air
(typically less than 4 ppbv and the majority below 1 ppbv) along
with their complicated chromatograms, Method TO-14 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.
For the experienced analyst whose analytical system is limited to the
non-specific detectors, Section 10.3 does provide guidelines and
example chromatograms showing typical retention times and calibra-
tion response factors, and utilizing the non-specific detectors
(GC-FID-ECD-PID) analytical system as the primary quantitative
technique.
4. Significance
4.1 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.
4.2 Conventional methods for VOC determination use solid sorbent sampl-
ing techniques. The most widely used solid sorbent is Tenax®. An
air sample is drawn through a Te,nax®-filled cartridge where certain
VOCs are trapped on the polymer. The sample cartridge is transferred
to a laboratory and analyzed by GC-MS.
4.3 VOCs can also be successfully collected in stainless steel canisters.
Collection of ambient air samples in canisters provides (1) conven-
ient 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 col-
lection; (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
-------
T014-7
samples by several analytical systems. However, care must be exer-
cised in selecting, cleaning, and handling sample canisters and
sampling apparatus to avoid losses or contamination of the samples.
Contamination is a critical issue with canister-based sampling be-
cause the canister is the last element in the sampling train.
4.4 Interior surfaces of the canisters are treated by the SUMMA®
passivation process, in which a pure chrome-nickel oxide is
formed on the surface. This type of vessel has been used in the
past for sample collection and has demonstrated sample storage
stability of many specific organic compounds.
4.5 This method can be applied to sampling and analysis of not only
VOCs, but also some selected semivolatile organic compounds
(SVOCs). The term "semivolatile organic compounds" is used to
broadly describe organic compounds that are too volatile to be
collected by filtration air sampling but not volatile enough for
thermal desorption from solid sorbents. SVOCs can generally be
classified as those with saturation vapor pressures at 25°C be-
tween 10-1 and 10-7 mm Hg. VOCs are generally classified as
those organics having saturated vapor pressures at 25°C greater
than 10'1 mm Hg.
Definitions
Note: Definitions used in this document and in any user-prepared
Standard Operating Procedures (SOPs) should be consistent with ASTM
Methods D1356, E260, and E355. All abbreviations and symbols within
this method are defined at point of use.
5.1 Absolute canister pressure = Pg+Pa, where Pg = gauge pressure in
the canister (kPa, psi) and Pa = barometric pressure (see 5.2).
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.
5.3 Cryogen - A refrigerant used to obtain very low temperatures in
the cryogenic trap of the analytical system. A typical cryogen
is liquid oxygen (bp -183.0°C) or liquid argon-(bp -185.7°C).
-------
T014-8
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 in a manner very similar to the normal sampling or
analytical process.
5.5 Gauge pressure - Pressure measured above ambient atmospheric
pressure (as opposed to absolute pressure). Zero gauge pressure
is equal to ambient atmospheric (barometric) pressure.
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 identi-
fication 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.
5.8 Megabore® column - Chromatographic column having an internal di-
ameter (I.D.) 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 I.D.
5.9 Pressurized sampling - Collection of an air sample in a canister
with a (final) canister pressure above atmospheric pressure,
using a sample pump.
5.10 Qualitative accuracy - The ability of an analytical system to
correctly identify compounds.
5.11 Quantitative accuracy - The ability of an analytical system to
correctly measure the concentration of an identified compound.
5.12 Static calibration - Calibration of an analytical system using
standards in a form different than 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.
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T014-9
5.13 Subatmospheric sampling - Collection of an air sample in an
evacuated canister at a (final) canister pressure below atmos-
pheric 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 accumu-
lates 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 pro-
cedure does not degrade sample integrity.
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 12.1 and 12.2,
respectively.
6.3 Because the 6C-MS analytical system employs a Nafion® permeable
membrane dryer to remove water vapor selectively from the sample
stream, polar organic compounds may permeate concurrent with the
moisture molecule. Consequently, the analyst should quantitate
his or her system with the specific organic constituents under
examination.
7. Apparatus
/.I 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 Toxics Air Monitoring
Stations (TAMS), Urban Air Toxic Pollutant Program (UATP), and
the non-methane organic compound (NMOC) sampling and analysis
program.]
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TO14-10
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.
7.1.1.2 Sample canister - leak-free stainless steel pressure
vessels of desired volume (e.g., 6 L), with valve
and SUMMA® passivated interior surfaces (Scientific
Instrumentation Specialists, Inc., P.O. Box 8941,
Moscow, ID 83843, or Anderson Samplers, Inc., 4215-C
Wendell Dr., Atlanta, 6A, 30336, or equivalent).
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 kPa or 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 main-
taining a constant flow rate (_+ 10%) over a sampl-
ing period of up to 24 hours and under conditions
of changing temperature (20-40°C) and humidity
(Tylan Corp., 19220 S. Normandie Ave., Torrance,
CA 90502, Model FC-260, or equivalent).
7.1.1.5 Particulate matter filter - 2-um sintered stainless
steel in-line filter (Nupro Co., 4800 E. 345tn St.,
Willoughby, OH 44094, Model SS-2F-K4-2, or equiva-
lent).
7.1.1.6 Electronic timer - for unattended sample collection
(Paragon Elect. Co., 606 Parkway Blvd., P.O. Box 28,
Twin Rivers, WI 54201, 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, or equivalent) with
Viton® seat and o-rings.
7.1.1.8 Chromatographic grade stainless steel tubing and
fittings - for interconnections (Alltech Associates,
2051 Waukegan Rd., Deerfield, IL 60015, Cat. #8125,
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T014-11
or equivalent). All such materials in contact with
sample, analyte, and support gases prior to analy-
sis should be chromatographic grade stainless steel.
7.1.1.9 Thermostatically controlled heater - to maintain
temperature inside insulated sampler enclosure above
ambient temperature (Watlow Co., Pfafftown, NC,
Part 04010080, or equivalent).
7.1.1.10 Heater thermostat - automatically regulates heater
temperature (Elmwood Sensors, Inc., 500 Narragansett
Park Dr., Pawtucket RI 02861, Model 3455-RC-0100-
0222, or equivalent).
7.1.1.11 Fan - for cooling sampling system (EG&G Rotron,
Woodstock, NY, Model SUZAI, or equivalent).
7.1.1.12 Fan thermostat - automatically regulates fan opera-
tion (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 Nupro stainless steel shut-off valve - leak free,
for vacuum/pressure gauge.
7.1.1.15 Auxiliary vacuum pump - continuously draws ambient
air to be sampled 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. [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 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 appropri-
ate only in situations where screening samples are
taken to assess future sampling activity.
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T014-12
7.1.2 Pressurized (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 sampl-
ing system has been developed by Dr. R. Rasmussen,
The Oregon Graduate Center (18,19) and is illustrated
in Figure 3. This flow system uses, in order, a
pump, a mechanical flow regulator, and a mechanical
compensating flow restrictive device. In this con-
figuration the pump is purged with a large sample
flow, thereby eliminating the need for an auxiliary
vacuum pump 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 (Figure 2 with metal
bellows type pump and Figure 3) are similar to compo-
nents 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 The GC-MS-SCAN analytical system must be capable of
acquiring and processing data in the MS-SCAN mode.
7.2.1.2 Gas chromatograph - capable of sub-ambient tempera-
ture programming for the oven, with other generally
standard features such as gas flow regulators, auto-
matic 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.)
7.2.1.3 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,
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T014-13
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 quantisation of VOC species.
7.2.1.4 Cryogenic trap with temperature control assembly -
refer to Section 10.1.1.3 for complete description
of trap and temperature control assembly (Nutech
Corporation, 2142 Geer St., Durham, NC, 27704,
Model 320-01, or equivalent).
7.2.1.5 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 cm3/min, or equivalent).
7.2.1.6 Vacuum pump - general purpose laboratory pump,
capable of drawing the desired sample volume through
the cryogenic trap (Thomas Industries, Inc., Sheboygan,
WI, Model 107BA20, or equivalent).
7.2.1.7 Chromatographic grade stainless steel tubing and
stainless steel plumbing fittings - refer to Section
7.1.1.8 for description.
7.2.1.8 Chromatographic column - to provide compound separation
such as shown in Table 5 (Hewlett Packard, Rt. 41,
Avondale, PA 19311, OV-1 capillary column, 0.32 mm x
50 m with 0.88 urn crosslinked methyl silicone coating,
or equivalent).
7.2.1.9 Stainless steel vacuum/pressure gauge (optional) -
capable of measuring vacuum (-101.3 to 0 kPa) and pres-
sure (0-206 kPa) in the sampling system (Matheson, P.O.
Box 136, Morrow, GA 30200, (Model 63-3704, or equiva-
lent). Gauges should be tested clean and leak tight.
7.2.1.10 Stainless steel cylinder pressure regulators - standard,
two-stage cylinder regulators with pressure gauges for
helium, zero air and hydrogen gas cylinders.
7.2.1.11 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).
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T014-14
7.2.1.12 Low dead-volume tee (optional) - used to split the
exit flow from the GC column (Alltech Associates,
2051 Waukegan Rd., Deerfield, IL 60015, Cat. #5839,
or equivalent).
7.2.1.13 Nafion® dryer - consisting of Nafion tubing co-
axial ly 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.
7.2.1.14 Six-port gas chromatographic valve - (Seismograph
Service Corp., Tulsa, OK, Seiscor Model VIII, or
equivalent).
7.2.1.15 Chart recorder (optional) - compatible with the
detector output signals to record optional FID
detector response to the sample.
7.2.1.16 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 cor-
rected for baseline drift.
7.2.2 6C-MS-SIM Analytical System (See Figure 4)
7.2.2.1 The GC-MS-SIM analytical system must be capable of
acquiring and processing data in the MS-SIM mode.
7.2.2.2 All components of the GC-MS-SIM system are identi-
cal to Sections 7.2.1.2 through 7.2.1.16.
7.2.3 GC-Multidetector Analytical System (See Figure 5 and Figure 6)
7.2.3.1 Gas chromatograph with flame ionization and elec-
tron capture detectors (photoionization detector
optional) - capable of sub-ambient temperature
programming for the oven and simultaneous opera-
tion 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 5880A, with oven temperature control and
Level 4 BASIC programming, or equivalent).
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T014-15
7.2.3.2 Chart recorders - compatible with the detector output
signals to record detector response to the sample.
7.2.3.3 Electronic integrator - compatible with the detec-
tor 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 - (Seismograph Ser-
vice Corp, Tulsa, OK, Seiscor Model VIII, or equivalent).
7.2.3.5 Cryogenic trap with temperature control assembly -
refer to Section 10.1.1.3 for complete description of
trap and temperature control assembly (Nutech Corpora-
tion, 2142 Geer St., Durham, NC 27704, Model 320-01,
or equivalent).
7.2.3.6 Electronic mass flow controllers (3) - maintain con-
stant flow (for carrier gas, nitrogen make-up gas and
sample gas) and to provide analog output to monitor
flow anomalies (Tylan Model 260, 0-100 cm3/min, or
equivalent).
7.2.3.7 Vacuum pump - general purpose laboratory pump, capable
of drawing the desired sample volume through the cry-
ogenic trap (see 7.2.1.6 for source and description).
7.2.3.8 Chromatographic grade stainless steel tubing and stain-
less steel plumbing fittings - refer to Section 7.1.1.8
for description.
7.2.3.9 Chromatographic column - to provide compound separation
such as shown in Table 7. (Hewlett Packard, Rt. 41,
Avondale, PA 19311, OV-1 capillary column, 0.32
mm x 50 m with 0.88 urn crosslinked methyl silicone
coating, or equivalent). [Note: Other columns
(e.g., DB-624) can be used as long as the system
meets user needs. The wider Megabore® column (i.e.,
0.53 mm I.D.) is less susceptible to plugging as
a result of trapped water, thus eliminating the
need for a Nafion® dryer in the analytical system.
The Megabore® column has sample capacity approaching
that of a packed column, while retaining much of
the peak resolution traits of narrower columns
(i.e., 0.32 mm I.D.).
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T014-16
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.
7.2.3.12 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)
7.3.1 Vacuum pump - capable of evacuating sample canister(s) to
an absolute pressure of <0.05 mm Hg.
7.3.2 Manifold - stainless steel manifold with connections for
simultaneously cleaning several canisters.
7.3.3 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.
7.3.5 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).
7.3.6 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).
7.3.-S 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.
7.3.9 Isothermal oven (optional) for heating canisters (Fisher
Scientific, Pittsburgh, PA, Model 349, or equivalent).
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TO14-17
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.
7.4.3 Electronic mass flow controllers - one 0 to 5 L/min and
one 0 to 50 cm3/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.
8.2 Gas calibration standards - cylinder(s) 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-dichloroethane
benzene
toluene
Freon 12
methyl chloride
1,2-di chloro-1,1,2,2-tetrafluoroethane
methyl bromide
ethyl chloride
Freon 11
dichloromethane
1,1-dichloroethane
cis-1,2-dichloroethylene
1,2-dichloropropane
1,1,2-trichloroethane
1,2-dibromoethane
tetrachloroet.hylene
chlorobenzene
benzyl chloride
hexachloro-1,3-butadiene
methyl chloroform
carbon tetrachloride
trichloroethylene
ci s-1,3-di chloropropene
trans-1,3-di chloropropene
ethyl benzene
o-xylene
m-xylene
p-xylene
styrene
1,1,2,2-tetrachloroethane
1,3,5-trimethyl benzene
1,2,4-trimethylbenzene
m-dichlorobenzene
o-dichlorobenzene
p-dichlorobenzene
1,2,4-trichlorobenzene
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T014-18
The cylinder(s) should be traceable to a National Bureau of
Standards (NBS) Standard Reference Material (SRM) or to a NBS/EPA
approved Certified Reference Material (CRM). 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 target list.
8.3 Cryogen - liquid oxygen (bp -183.0°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 Road, Deerfield, IL, 60015, or equivalent).
8.5 Deionized water - high performance liquid chromatography (HPLC)
grade, ultrahigh purity (for humidifier), best source.
8.6 4-bromofluorobenzene - used for tuning GC-MS, best source.
8.7 Hexane - for cleaning sampling system components, reagent grade,
best, source. .
8.8 Methanbl - for cleaning sampling system components, reagent grade,
best source.
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 collec-
tion in a canister, the canister is evacuated to
0.05 mm Hg. When opened to the atmosphere con-
taining the VOCs to be sampled, the differential
pressure causes the sample to flow into the can-
ister. This technique may be used to collect grab
samples (duration of 10 to 30 seconds) or time-
integrated samples (duration of 12 to 24 hours)
taken through a flow-restrictive inlet (e.g.,
mass flow controller, critical orifice).
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1014- 19
9.1.1.2 With a critical orifice flow restrictor, there will
be a decrease in the flow rate as the pressure
approaches atmospheric. However, with amass flow
controller, the subatmospheric sampling system can
maintain a constant flow rate from full vacuum to
within about 7 kPa (1.0 psi) 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 inte-
grated 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 cm3/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 sampl-
ing or to about one atmosphere above ambient pressure
for pressurized sampling) over the desired sample
period. The flow rate can be calculated by
F = P x V
T x 60
where:
*
F = flow rate (em3/min).
P = final canister pressure, atmospheres
absolute. P is approximately equal to
101.2
-------
T014-20
V = volume of the canister (cm3).
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 x 6000 = 8.3 cm3/min
24 x 60
9.1.3.2 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 sole-
noid valve, to open the valve when starting the pump
and close the valve when stopping the pump.
9.1.3.3 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 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 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 in-
corporating a time-delay relay to provide more re-
liable valve operation is shown in Figure 9(b).
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T014-21
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 Sec-
tion 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 12.2.2).
All plumbing should be checked carefully for leaks.
The canisters must also pass a humid zero air certi-
fication before use (see Section 12.1).
9.2 Sampling Procedure
9.2.1 The sample canister should be cleaned and tested according
to the procedure in Section 12.1.
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 12.2.3. [Note: 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 canister sampling field data sheet (Figure 10).
[Note: The following discussion is related to Figure 2.]
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T014-22
9.2.5 To verify correct sample flow, a "practice" (evacuated)
canister is used in the sampling system. [Note: For a
subatmospheric sampler, the flow meter and practice can-
ister 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 flow meter needs to be recalibrated or there is a
leak in the system. This should be investigated and
corrected. [Note: 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 the proper
value (as indicated by the certified mass flow meter) by
the sampler flow control unit controller (e.g., 3.5
cm3/min for 24 hr, 7.0 cm3/min for 12 hr). Record final
flow under "CANISTER FLOW RATE," Figure 10.
9.2.6 The sampler is turned off and the elapsed time meter is
reset to 000.0. Note: 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 12.1)
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 (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 meter readings are recorded on the
canister sampling field data sheet.
9.2.11 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.
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10.
T014-23
9.2.12 After the desired sampling period, the maximum, minimum,
current interior temperature and current ambient temper-
ature 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 field
data sheet. 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 sampl-
ing field data sheet.] Time of day and elapsed time
meter readings are also recorded.
9.2.14 The canister valve is closed. The sampling line is dis-
connected from the canister and the canister is removed
from the system. For a subatmospheric system, a certi-
fied mass flow meter is once again connected to the in-
let manifold in front of the in-line filter and a "prac-
tice" 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). [Note: For a pressurized system, the final flow
may be measured directly.] The sampler is turned off.
9.2.15 An identification tag is attached to the canister. Can-
ister serial number, sample number, location, and date
are recorded on the tag.
Analytical System (See Figures 4, 5 and 6)
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
-------
T014-24
GC run. The system includes a computer and
appropriate software for data acquisition,
data reduction, and data reporting. A 400
cm3 air sample 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. [Note: 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. Mois-
ture can adversely affect detector precision.
The Nafion® dryer also prevents freezing of
moisture on the 0.32 mm I.D. column, which may
cause column blockage and possible breakage.]
The trap is heated (-160°C to 120°C in 60 sec)
and the analyte is injected onto the OV-1 cap-
illary column (0.32 mm x 50 m). [Note: Rapid
heating of the trap provides efficient transfer
of the sample components onto the gas chromato-
graphic column.] Upon sample injection onto
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 detec-
tion of compounds in Table 1, the range should
be 18 to 250 amu, resulting in a 1.5 Hz repeti-
tion rate. Six (6) scans per eluting chromato-
graphic 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 sub-
traction is performed. A library search is then
performed and the top ten best matches for each
peak are listed. A qualitative characterization
-------
T014-25
of the sample is provided by this procedure. A
typical chromatogram of VOCs determined by GC-MS-
SCAN is illustrated in Figure ll(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 fluorosulfonyl 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 a
dry air purge stream flowing through the annular
space between the Nafion® and outer tubing.
[Note: To prevent excessive moisture build-up
and any memory effects in the dryer, a clean-
up procedure involving periodic heating of the
dryer (100°C for 20 minutes) while purging with
dry zero air (500 cm3/min) should be .implemented
as part of the user's SOP manual. The clean-up
procedure is repeated during each analysis (see
Section 14, reference 7). Recent studies have
indicated no substantial loss of targeted
VOCs utilizing the above clean-up procedure
(7). This cleanup procedure is particularly
useful 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.]
-------
T014-26
10.1.1.3 The packed metal tubing used for reduced tem-
perature trapping of VOCs is shown in Figure 12.
The cooling unit is comprised of a 0.32 cm out-
side 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 cylindrical ly 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 addi-
tional 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 when used
with the Hewlett-Packard 5880 GC. [Note:
Alternative trap assembly and connection to
the GC "may be used depending upon user's
requirements.] The carrier gas line is con-
nected to the injection end of the analytical
column with a zero-dead-volume fitting that is
usually held in the heated zone above the GC
oven. A 15 cm x 15 cm x 24 cm aluminum box
is fitted over the sample handling elements
to complete the package. Vaporized cryogen
is vented through the top of the box.
-------
T014-27
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 a flame
ionization detector, 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. In
particular, the FID provides the user:
o Semi-real time picture of the progress
of the analytical scheme;
o Confirmation by the concurrent MS
analysis of other labs that can provide
only FID results; and
o Ability to compare 6C-FID with other
analytical laboratories with only GC-
FID capability.
10.1.2 6C-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 cm3 air sample with analytical precision
of about 5% relative standard deviation. Con-
centration of compounds based upon a previously
installed calibration table is reported by an
automated data reduction program. A Nafion®
dryer is also employed by this analytical sys-
tem prior to cryogenic preconcentration; there-
fore, many polar compounds are not identified
by this procedure.
-------
T014-28
10.1.2.2 SIM analysis is based on a combination of reten-
tion 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 chromato-
graphic 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 mea-
sured 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. While 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 6C-MS-SIM mode is
illustrated in Figure ll(b).
10.1.3 GC-Multidetector (GC-FID-ECD) System with Optional PID
10.1.3.1 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 pressur-
ized canisters is vented past the inlet to
the analytical system from the canister at a
flow rate of 75 cm^/min. For analysis, only
35 cm-Vmin of sample gas is used, while excess
-------
T014-29
is vented to the atmosphere. Sub-ambient
pressure canisters are connected directly to
the inlet. The sample gas stream is routed
through a six port chromatographic valve and
into the cryogenic trap for a total sample
volume of 490 cm^. [Note: This represents a
14 minute sampling period at a rate of 35
cm^/min.] The trap (see Section 10.1.1.3)
is cooled to -150°C by controlled release of
a cryogen. VOCs and SVOCs are condensed on
the trap surface while N2, 02, 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 revola-
tilized compounds are transported by helium
carrier gas at a rate of 4 cm-Vmin 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 and SVOCs
are cryofocussed on the head of the column.
Then, the oven temperature is programmed to
increase and the VOCs/SVOCs in the carrier gas
are chromatographically separated. The carrier
gas containing the separated VOCs/SVOCs is then
directed to two parallel detectors at a flow
rate of 2 cnrVmin each. The detectors sense
the presence of the speciated VOCs/SVOCs, and
the response is recorded by either a strip
chart recorder or a data processing unit.
10.1.3.2 Typical, chromatograms of VOGs determined by
the GC-FID-ECD analytical system are illus-
trated in Figures ll(c) and ll(d), respectively,
10.1.3.3 Helium is used as the carrier gas (4 cm^/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
-------
T014-30
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
cnvVmin 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. [Note:
Purity of gas purifiers is checked prior to use
by passing humid zero-air through the gas purifier
and analyzing according to Section 12.2.2.]
10.1.3.5 All lines should be kept as short as practical.
All tubing used for the system should be chro-
matographic grade stainless steel connected
with stainless steel fittings. After assembly,
the system should be checked for leaks accord-
ing to manufacturer's specifications.
10.1.3.6 The FID burner air, hydrogen, nitrogen (make-
up), and helium (carrier) flow rates should
be set according to the manufacturer's instruc-
tions to obtain an optimal FID response while
maintaining a stable flame throughout the analy-
sis. Typical flow rates are: burner air, 450
cm^/min; hydrogen, 30 cm^/min; nitrogen, 30
cnvVmin; helium, 2 cm^/min.
10.1.3.7 The ECD nitrogen make-up gas and helium carrier
flow rates should be set according to manufac-
turer's instructions to obtain an optimal ECD
response. Typical flow rates are: nitrogen,
76 cm^/min and helium, 2 cm-Vmin.
10.1.3.8 The GC-FID-ECD could be modified to include a
PID (see Figure 6) for increased sensitivity
(20). In the photoionization process, a mole-
cule 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
-------
T014-31
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 (02, N£, CO, C02, and HaO) 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 adja-
cent to the sensor. When a positive potential
is applied to the electrodes, any ions formed
by the absorption of UV light are driven by
the created electronic field to the cathode,
and the current (proportional to the organic
vapor concentration) is measured. The PID
is generally used for compounds having ioni-
zation 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 lamp 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.
This system is currently being used in EPA's
FY-88 Urban Air Toxics Monitoring Program.
-------
T014-32
10.2 GC-MS-SCAN-SIM System Performance Criteria
10.2.1 6C-MS System Operation
10.2.1.1 Prior to analysis, the 6C-MS system is assembled
and checked according to manufacturer's instruc-
tions.
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 FID 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 is introduced via a
sample loop valve injection system. [Note:
Some systems allow auto-tuning to facilitate
this process.] 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 (chromatographic
check) and as an internal standard. Obtain a
background correction mass spectra of 4-bromo-
fluorobenzene and check that all key ions cri-
teria 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
-------
T014-33
any key ion abundance observed for the daily 4-
bromofluorobenzene mass tuning check differs by
more than 10% absolute abundance from that observed
during the previous daily tuning, the instrument
must be retuned or the sample and/or calibration
gases reanalyzed until the above condition is met.
10.2.3 GC-MS Calibration (See Figure 13)
[Note: Initial and routine calibration procedures are
illustrated in Figure 13.3
10.2.3.1 Initial Calibration - Initially, a multipoint Dy-
namic calibration (three levels plus humid zero
air) is performed on the GC-MS system, before
sample analysis, with the assistance of a calibra-
tion system (see Figure 8). The calibration sys-
tem uses NBS traceable standards or NBS/EPA CRMs
in pressurized cylinders [containing a mixture
of the targeted VOCs at nominal concentrations of
10 ppmv in nitrogen (Section 8.2)] as working
standards to be diluted with humid zero air. The
contents of the working standard cylinder(s) are
metered (2 cm3/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 min-
utes. ' After the equilibration period, the gas
standard mixture is sampled and analyzed by the
real-time GC-MS system [see Figure 8(a) and Sec-
tion 7.2.1]. The results of the analyses are
averaged, flow audits are performed on the mass
flow meters and the calculated concentration com-
pared 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 (less than 0.2 ppbv of target compounds).
-------
T014-34
10.2.3.2 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) SUMMA® passivated 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. The expected
retention time and ion abundance (see Table
2 and Table 5) are used to verify proper opera-
tion of the GC-MS system. A calibration re-
sponse factor is determined for each analyte,
as illustrated in Table 5, and the computer
calibration table is updated with this infor-
mation, as illustrated in Table 6.
10.2.3.3 Routine Calibration - The GC-MS system is cal-
ibrated 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 SUMMA®
passivated canister filled with humid calibration
standards from the calibration manifold (see
Section 10.2.3.2). After the single point cali-
bration, the GC-MS analytical system is challenged
with a humidified zero gas stream to insure the
analytical system returns to specification (less
than 0.2 ppbv of selective organics).
10.3 GC-FID-ECD System Performance Criteria (With Optional PID System)
(See Figure 14)
10.3.1 Humid Zero Air Certification
10.3.1.1 Before system calibration and sample analysis,
the GC-FID-ECD analytical system is assembled and
checked according to manufacturer's instructions.
-------
T014-35
10.3.1.2 The 6C-FID-ECD system Is first challenged with
humid zero air (see Section 12.2.2) and moni-
to red.
10.3.1.3 Analytical systems contaminated with less than
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 contain-
ing 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 com-
ponent standard. The retention window is
defined as the mean plus or minus three times
the standard deviation of the individual reten-
tion times for each standard. In those cases
where the standard deviation for a particular
standard is zero, the laboratory must substi-
tute 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 re-
tained in a notebook by the laboratory as
part of the user SOP and as a quality assurance
check of the analytical system.
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T014-36
10.3.3 GC Calibration
[Note: Initial and routine calibration procedures are
illustrated in Figure 14.]
10.3.3.1 Initial Calibration - Initially, a multipoint
dynamic calibration (three levels plus humid
zero air) is performed on the GC-FID-ECD sys-
tem, before sample analysis, with the assist-
ance of a calibration system (see Figure 8).
The calibration system uses NBS traceable
standards or NBS/EPA CRMs in pressurized
cylinders [containing a mixture of the
targeted VOCs at nominal concentrations of
10 ppmv in nitrogen (Section 8.2)] as working
standards to be diluted with humid zero air.
The contents of the working standard cylinders
are metered (2 cm3/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 control-
lers used to generate the standards and the
appropriate response factors (concentration/
area counts) are calculated for each compound,
as illustrated in Table 5. [Note: GC-FIDs
are linear in the 1-20 ppbv range and may
not require repeated multipoint calibra-
tions; whereas, the GC-ECD will require
frequent linearity evaluation.] Table 5 out-
lines typical calibration response factors
-------
T014-37
and retention times for 40 VOCs. After the
6C-FID-ECD is calibrated at the three concen-
tration 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
(less than 0.2 ppbv of target compounds).
10.3.3.2 Routine Calibration - A one point calibration
is performed daily on the analytical system to
verify 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.
10.3.4 GC-FID-ECD-PID System Performance Criteria
10.3.4.1 As an option, the user may wish to include a
photoionization detector (PID) to assist in
peak identification and increase sensitivity.
10.3.4.2 This analytical system is presently being used
in U.S. Environmental Protection Agency's Urban
Air Toxic Pollutant Program (UATP).
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).
10.3.4.4 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.
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T014-38
10.4.1.2 Each canister is recorded in the dedicated
laboratory logbook. Also noted on the identi-
fication 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 addi-
tional 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 can-
ister sampling field data sheet (see Figure 10),
10.4.1.4 If the canister pressure is increased, a di-
lution factor (DF) is calculated and recorded
on the sampling data sheet.
DF = Ya
Xa
where:
Xa = canister pressure (kPa, psia) abso-
lute before dilution.
Ya = canister pressure (kPa, psia) abso-
lute after dilution.
After sample analysis, detected VOC concentra-
tions are multiplied by the dilution factor
to determine concentration in the sampled air.
-------
TO14-39
10.4.2 GC-MS-SCAN Analysis (With Optional FID System)
10.4.2.1 The analytical system should be properly assem-
bled, humid zero air certified (see Section
12.3), 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.
10.4.2.3 The sample canister is connected to the inlet
of the GC-MS-SCAN (with optional FID) 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 cm3/min so that 40
cm3/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
-160°C, respectively.
10.4.2.5 As soon as the cryogenic trap reaches its lower
set point of -160°C, the six-port chromatographic
valve is turned to its fill position to initiate
sample collection.
10.4.2.6 A ten minute collection period of canister sample
is utilized. [Note: 40 cm3/min x 10 min = 400
, ,-, ,em3t sampled canister contents.]
10.4.2.7 After the sample is preconcentrated in the cry-
::•••;• ogenic 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 I.D. 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.
-------
T014-40
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 (Section 10.4.1.4).]
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 contin-
uously between two mass limits.
10.4.3.2 As a result, increased sensitivity and improved
quantitative analysis can be achieved.
10.4.3.3 Similar to the GC-MS-SCAN configuration, the
GC^-MS-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 identi-
fication of each chromatographic peak. Once
the GC-MS-SIM has identified the peak, a calibra-
tion response factor is used to determine the
analyte's concentration.
-------
T014-41
10.4.3.4 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 pro-
gram 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 com-
pletion of the macro program, the data reporting
software is accessed. The appropriate calibra-
tion 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 refer-
ence to certain pre-set acceptance criteria,
peaks are automatically identified and quanti-
fied and a final summary report is prepared,
as illustrated in Table 10.
10.4.4 GC-FID-ECD Analysis (With Optional PID System)
10.4.4.1 The analytical system should be properly assem-
bled, humid zero air certified (see Section 12.2)
•'•:•• and calibrated through a dynamic standard cali-
bration procedure (see Section 10.3.2). The
FID detector is lit and allowed to stabilize.
10.4.4.2 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.]
-------
T014-42
10.4.4.3 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 FID-ECD. The hydrogen, burner air, and ni-
trogen 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
cm3/min using a 0-500 cm3/min Tylan mass flow
controller. During analysis, 40 cm3/min of sample
gas is pulled through the six-port chromatographic
valve and routed through the trap at the appro-
priate time while the extra sample is vented.
The VOCs are condensed in the trap while the
excess flow is exhausted through an exhaust
vent, which assures that the sample air flow-
ing 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 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 cryo-
focussed on the column. Then, the oven tempera-
ture (programmed) increases and the VOCs elute
from the column to the parallel FID-ECD assembly.
10.4.4.8 The peaks eluting from the detectors are iden-
tified by retention time (see Table 7 and
Table 8), while peak areas are recorded in area
-------
T014-43
counts. Figures 15 and 16 illustrate typical
response of the FID and ECD, respectively,
for the forty (40) targeted VOCs. [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 dilu-
tion of the canister (see Section 10.4.1.4).
10.4.4.10 Depending on the number of canisters to be
analyzed, 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 6C-FID-ECD analytical system
discovers unexpected peaks which need further
identification and attention or overlapping
peaks are discovered, eliminating possible quan-
titation, 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 valve 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 illus-
trated in Figure 7. Cryogen is added to both the
vacuum pump and zero air supply traps. The canister(s)
-------
T014-44
are connected to the manifold. The vent shut-off valve
and the canister valve(s) are opened to release any re-
maining 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 gener-
ator 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. Steps 11.1.3 through 11.1.5 are repeated two
additional times for a total of three (3) evacuation/
pressurization cycles for each set of canisters.
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 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 targets VOCs). The check can then be
reduced to a lower percentage of canisters.
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 can-
ister connection is capped with a stainless steel fitting.
-------
T014-45
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 Section 11.1.3 to ensure that lower mole-
cular weight compounds (02-63) are not retained on the
walls of the canister. [Note: For sampling heavier, more
complex VOC mixtures, the canisters should be heated to
250°C during Section 11.1.3.7.] 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 (less than 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
11.2.1.1 Sample components are disassembled and cleaned
before the 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
-------
T014-46
zero air and humid calibration gases that pass through
all active components of the sampling system. The sys-
tem is "certified" if no significant additions or dele-
tions (less than 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 deter-
mined by testing the sampler with humid zero air
without an evacuated gas cylinder, as follows.
11.2.2.2 The calibration system and manifold are assem-
bled, as illustrated in Figure 8. The sampler
(without an evacuated gas cylinder) is con-
nected 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)].
11.2.2.3 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 cm3/min
so that 40 cm3/min is pulled 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 col-
umn. 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
-------
T014-47
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 concen-
tration levels expected in field sampling (e.g.,
0.5 to 2 ppbv) as outlined in Section 11.2.3.
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).
11.2.3.3 The assembled dynamic calibration system is
certified clean if less than 0.2 ppbv of
targeted compounds are found.
11.2.3.4 For generating the humidified calibration
standards, the calibration gas cylinder(s)
(see Section 8.2) containing nominal concen-
trations, 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 cm3/min certified mass flow
controllers to generate ppb 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 illus-
trated in Figure 8(a).
-------
T014-48
11.2.3.6 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 calibra-
tion gas stream at the inlet of the in-line
filter of the sampling system so the flow
will be less than 500 cm^/min.]
11.2.3.7 Concurrent with the sampling system operation,
realtime monitoring of the calibration gas
stream is accomplished by the on-line GC-MS
or GC-multidetector analytical system
[Figure 8(b)] to provide reference concentra-
tions of generated VOCs.
11.2.3.8 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-multi-
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 110% is expected
for all targeted VOCs.
12. Performance Criteria and Quality Assurance
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 the analytical
system,, addressing the specific equipment used; (4) can-
ister storage and cleaning; and (5) all aspects of data
recording and processing, including lists of computer
hardware and software used.
-------
T014-49
12.1.2 Specific stepwise instructions should be provided in
the SOPs and should be readily available to and under-
stood by the laboratory personnel conducting the work.
12.2 Method Relative Accuracy and Linearity
12.2.1 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 con-
tained in the audit canister. Percent relative accuracy
is calculated:
% Relative Accuracy = Y - X x -^QQ
X
Where: Y = Concentration of the targeted
compound recovered from sampler.
X = Concentration of VOC targeted
compound in the NBS-SRM or
EPA-CRM audit cylinders.
12.2.2 If the relative accuracy does not fal1 between 90 and
and 110 percent, the field sampler should be removed
from use, cleaned, and recertified according to initial
certification procedures outlined in Section 11.2.2
and Section 11.2.3. Historically, concentrations of
carbon tetrachloride, tetrachloroethylene,'and hexachlo-
robutadiene have sometimes been detected at lower con-
centrations when using parallel ECD and FID 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 illus-
trated in Figures 18(a) through 18(c). Other targeted
ECD and FID compounds scaled linearly for the range 0 to
8 ppbv9 as shown for chloroform in Figure 18(d). For
compounds that are not linear over the calibration
-------
T014-50
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 at 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. The software for the Hewlett-Packard
5880 level 4 GC is designed to accommodate multilevel
calibration entries, so the correct response factors
are automatically calculated for concentrations in this
range.
12.3 Method Modification
12.3.1 Sampling
12.3.1.1 The sampling system for pressurized canister
sampling could be modified to use a lighter,
more compact pump. The pump currently being
used weighs about 16 kilograms (35 Ibs). Com-
mercially available pumps that could be used
as alternatives to the prescribed sampler pump
are described below. Metal Bellows MB-41 pump;
These pumps are cleaned at the factory; however,
some precaution should be taken with the circu-
lar (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 are also cleaned with
swabs and allowed to air dry. These pumps have
-------
T014-51
proven to be very reliable; however, they are
only useful up to an outlet pressure of about
137 kPa (20 psig). Neuberger Pump: Viton gas-
kets 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 stain-
less 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 pres-
sure. This pump is utilized in the sampling sys-
tem illustrated in Figure 3.
12.3.1.2 Urban Air Toxics Sampler
The sampling system described in this method can
be modified like the sampler in EPA's FY-88 Urban
Air Toxics Pollutant Program. This particular
sampler is described in Appendix C (see Figure 19).
12.3.2 Analysis
12.3.2.1 Inlet tubing from the calibration manifold could
be heated to 50°C (same temperature as the cali-
bration manifold) to prevent condensation on the
internal walls of the system.
12.3.2.2 The analytical strategy for Method TO-14 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 detec-
tor system (GC-MS-SCAN-SIM) is more complicated
and expensive than the use of non-specific detectors
-------
T014-52
(GC-FID-ECD-PID), 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
quantitation. The GC-FID-ECD-PID provides a "snap--
shot" of the constituents in the sample, allow-
ing the analyst to determine:
- Extent of misidentification due to over-
lapping peaks,
- Whether the constituents are within the
calibration range of the anticipated
GC-MS-SCAN-SIM analysis or does the
sample require further dilution, and
- 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 identi-
fied and only a select number of VOCs are of con-
cern, 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 com-
pounds along with the water. The analyst often
has to make this decision incorporating project
objectives, detection limits, equipment availa-
bility, cost and personnel capability in develop-
ing an analytical strategy. Figure 20 outlines
the use of the GC-FID-ECD-PID as a "screening"
approach, with the GC-MS-SCAN-SIM for final
identification and quantitation.
-------
T014-53
12.4 Method Safety
This procedure may involve hazardous materials, operations, and
equipment. This method does not purport to address all of the
safety problems associated with its use. It is the user's respon-
sibility to 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.
12.5 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 meas-
urements with a certified mass flow controller
for flow verification of sampling system.
12.5.1.3 Section 11.1 requires all canisters to be pres-
sure tested to 207 kPa _+ 14 kPa (30 psig _+ 2 psig)
over a period of 24 hours.
12.5.1..4 Section 11.1 requires that all canisters be
certified clean (containing less than 0.2 ppbv
of targeted VOCs) through a humid zero air certi-
fication program.
12.5.1.5 Section 11.2.2 requires all field sampling systems
to be-certified initially clean (containing less
than 0.2 ppbv of targeted VOCs) through a humid
zero air certification program.
12.5.1.6 Section 11.2.3 requires all field sampling sys-
tems to pass an initial humidified calibration
gas certification [at VOC concentration levels
expected in the field (e.g., 0.5 to 2 ppbv)]
with a percent recovery of greater than 90.
12.5.2 GC-MS-SCAN-SIM System Performance Criteria
12.5.2.1 .Section 10.2.1 requires the GC-MS analytical
system to be certified clean (less than 0.2
-------
T014-54
ppbv of targeted VOCs) prior to sample analy-
sis, through a humid zero air certification.
12.5.2.2 Section 10.2.2 requires the daily tuning of
the GC-MS with 4-bromofluorobenzene (4-BFB)
and that it meet the key ions and ion abun-
dance critera (10%) outlined in Table 5.
12.5.2.3 Section 10.2.3 requires both an initial multi-
point humid static calibration (three levels
plus humid zero air) and a daily calibration
(one point) of the GC-MS analytical system.
12.5.3 GC-Multidetector System Performance Criteria
12.5.3.1 Section 10.3.1 requires the GC-FID-ECD analyti-
cal system, prior to analysis, to be certified
clean (less than 0.2 ppbv of targeted VOCs)
through a humid zero air certification.
12.5.3.2 Section 10.3.2 requires that the GC-FID-ECD
analytical system establish retention time
windows for each analyte prior to sample analy-
sis, when a new GC column is installed, or
major components of the GC system altered
since the previous determination.
12.5.3.3 Section 8.2 requires that all calibration
gases be traceable to a National Bureau of
Standards (NBS) Standard Reference Material
(SRM) or to a NBS/EPA approved Certified
Reference Material (CRM).
12.5.3.4 Section 10.3.2 requires that the retention
time window be established throughout the
course of a 72-hr analytical period.
12.5.3.5 Section 10.3.3 requires both an initial multi-
point 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 NBS traceable or NBS/EPA CRMs
gases. [Note: Gas cylinders of VOCs at the
ppm and ppb level are available for audits
from the USEPA, Environmental Monitoring Systems
-------
T014-55
Laboratory, Quality Assurance Division, MD-77B,
Research Triangle Park, NC 27711, (919)541-4531.
Appendix A outlines five groups of audit gas
cylinders available from USEPA.]
13. Acknowledgements
The determination of volatile and some semi-volatile organic compounds
in 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/SVOCs in ambient air, this method draws upon the
best aspects of each one and combines them into a standardized method-
ology. To that end, the following individuals contributed to the
research, documentation and peer review of this manuscript.
-------
T014-56
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T014-58
14. REFERENCES
1. K. D. Oliver, J. D. Pleil, and W. A. McClenny, "Sample Integrity of
Trace Level Volatile Organic Compounds in Ambient Air Stored in
SUMMA® Polished Canisters," Atmospheric Environ. 20:1403, 1986.
2. M. W. Holdren and D. L. Smith, "Stability of Volatile Organic Compounds
While Stored in SUMMA® Polished Stainless Steel Canisters," Final
Report, EPA Contract No. 68-02-4127, Research Triangle Park, NC,
Battelle Columbus Laboratories, January, 1986.
3. Ralph M. Riggin, Technical Assistance Document for Sampling and
Analysis of Toxic Organic Compounds in Ambient Air, EPA-600/4-83-027,
U.S. Environmental Protection Agency, Research Triangle Park, NC, 1983.
4. Ralph M. Riggin, Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, EPA-600/4-84-041, U.S. Environmental
Protection Agency, Research Triangle Park, NC, 1986.
5. W. T. Winberry and N. V. Til ley, Supplement to EPA-600/4-84-041;
Compendium of Methods for the Determination of Toxic Organic Compounds
TnAmbient Air, EPA-600/4-87-006, U.S. Environmental Protection Agency,
Research Triangle Park, NC, 1986.
6. W. A. McClenny, J. D Pleil, J. W. Holdren, and R. N. Smith, "Automated
Cryogenic Preconcentration and Gas Chromatographic Determination of
Volatile Organic Compounds," Anal. Chem. 56:2947, 1984.
7. J. D. Pleil and K. D. Oliver, "Evaluation of Various Configurations of
Nafion Dryers: Water Removal from Air Samples Prior to Gas Chromatographic
Analysis," EPA Contract No. 68-02-4035, Research Triangle Park, NC,
Northrop Services, Inc.- Environmental Sciences, 1985.
8. K. D. Oliver and J. D. Pleil, "Automated Cryogenic Sampling and Gas
Chromatographic Analysis of Ambient Vapor-Phase Organic Compounds:
Procedures and Comparison Tests," EPA Contract No. 68-02-4035, Research
Triangle Park, NC, Northrop Services, Inc.- Environmental Sciences, 1985.
9. W. A. McClenny and J. D. Pleil, "Automated Calibration and Analysis of
VOCs with a Capillary Column Gas Chromatograph Equipped for Reduced Temper-
ature Trapping," Proceedings of the 1984 Air Pollution Control
Association Annual Meeting, San Francisco, CA, June 24-29, 1984.
10. W. A. McClenny, J. D. Pleil, T. A, Lumpkin, and K. D. Oliver, "Update
on Canister-Based Samplers for VOCs," Proceedings of the 1987 EPA/APCA
Symposium on Measurement of Toxic and Related Air Pollutants, May, 1987
APCA Publication VlP-8, EPA 600/9-87-010.
11. J. D. Pleil, "Automated Cryogenic Sampling and Gas Chromatographic
Analysis of Ambient Vapor-Phase Organic Compounds: System Design,"
EPA Contract No. 68-02-2566, Research Triangle Park, NC, Northrop
Services, Inc.- Environmental Sciences, 1982.
-------
T014-59
12. K. D. Oliver and J. D. Pleil, "Analysis of Canister Samples Collected
During the CARB Study in August 1986," EPA Contract No. 68-02-4035,
Research Triangle Park, NC, Northrop Services, Inc,- Environmental
Sciences, 1987.
13. J. D. Pleil and K. D. Oliver, "Measurement of Concentration Variability
of Volatile Organic Compounds in Indoor Air: Automated Operation of a
Sequential Syringe Sampler and Subsequent GC/MS Analysis," EPA Contract
No. 68-02-4444, Research Triangle Park, NC, Northrop Services, Inc. -
Environmental Sciences, 1987.
14. J. F. Walling, "The Utility of Distributed Air Volume Sets When
Sampling Ambient Air Using Solid Adsorbents," Atmospheric Environ.,
18:855-859, 1984.
15. J. F. Walling, J. E. Bumgarner, J, D. Driscoll, C. M. Morris, A. E. Riley,
and L. H. Wright, "Apparent Reaction Products Desorbed From Tenax Used
to Sample Ambient Air," Atmospheric Environ., 20: 51-57, 1986.
16. Portable Instruments User's Manual for Monitoring VOC Sources, EPA-
340/1-88-015, U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards, Washington, DC, June, 1986.
17. F. F. McElroy, V. L. Thompson, H. 6. Richter, A Cryogenic Preconcentra-
tion - Direct FID (PDFID) Method for Measurement of NMOC in the Ambient
Air. EPA-600/4-85-063, U.S. Environmental Protection Agency, Research
Triangle Park, NC, August 1985.
18. R. A. Rasmussen and J. E. Lovelock, "Atmospheric Measurements Using
Canister Technology," J. Geophys. Res.. 83: 8369-8378, 1983.
19. R. A. Rasmussen and M.A.K. Khalil, "Atmospheric Halocarbons: Measure-
ments and Analysis of Selected Trace Gases," Proc. NATO ASI on Atmos-
pheric Ozone, BO: 209-231.
20. Dave-Paul Dayton-and JoAnn Rice, "Development and Evaluation of a
Prototype Analytical System for Measuring Air Toxics," Final Report,
Radian Corporation for the U.S. Environmental Protection Agency,
Environmental Monitoring Systems Laboratory, Research Triangle Park,
NC 27711, EPA Contract No. 68-02-3889, WA No. 120, November, 1987.
-------
TO14-60
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-------
TO 14- 62
TABLE 2. ION/ABUNDANCE AND
FOR SELECTED VOCs
Compound
Freon 12 (Dichlorodifluoromethane)
Methyl chloride (Chloromethane)
Freon 114 (1, 2-Dichloro-l, 1,2,2-
tetrafluoroethane)
Vinyl chloride (Chloroethene)
*
Methyl bromide (Bromomethane)
Ethyl chloride (Chloroethane)
Freon 11 (Trichlorofluoromethane)
Vinylidene chloride (1,1-Dichloroethylene)
Dichloromethane (Methylene chloride)
Freon 113 (l,l,2-Trichloro-l,2,2-
trifluoroethane)
1,1-Dichloroethane (Ethylidene dichloride)
cis-l,2-Dichloroethylene
Chloroform (Trichloromethane)
1,2-Dichloroethane (Ethylene dichloride)
Methyl chloroform (1,1,1-Trichloroethane)
Benzene (Cyclohexatrierie)
Carbon tetrachloride (Tetrachloromethane)
EXPECTED RETENTION
TIME
ANALYZED BY 6C-MS-SIM
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
' rt f I r" r*
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
6 1/ 61
78/100
~r ~7 / or*
77/ 25
50/ 35
117/100
119/ 97
Expected Retention
Time (min)
5.01
5.69
6.55
6.71
7.83
8.43
9.97
10.93
11.21
•
^1^
11.60
12.50
13.40
13.75
14.39
14.62
15.04
15.18
A
(continued)
-------
T014-63
TABLE 2. ION/ABUNDANCE AND EXPECTED RETENTION TIME
SELECTED VOCs ANALYZED BY GC-MS-SIM (cont
FOR
§)
Ion/Abundance Estimated Retention
Compound (amu/% base peak) Time (min)
1,2-Dichloropropane (Propylene dichlon'de) 63/100
41/ 90
62/ 70
Trichloroethylene (Trichloroethene) 130/100
132/ 92
95/ 87
cis-l,3-Dichloropropene 75/100
39/ 70
77/ 30
trans-l,3-Dichloropropene (1,3 75/100
dichloro-1-propene) 39/ 70
77/ 30
1,1,2-Trichloroethane (Vinyl trichloride) 97/100
83/ 90
61/ 82
Toluene (Methyl benzene) 91/100
92/ 57
1,2-Dibromoethane (Ethylene dibromide) 107/100
109/ 96
•27/115
Tetrachloroethylene (Perchloroethylene) 166/100
164/ 74
131/ 60
Chlorobenzene (Benzene chloride) 112/100
77/ 62
114/ 32
Ethyl benzene 91/100
106/ 28
m,p-Xylene(l,3/l,4-dimethylbenzene) 91/100
106/ 40
Styrene (Vinyl benzene) 104/100
78/ 60
103/ 49
1,1,2,2-Tetrachloroethane (Tetrachloroethane) 83/100
85/ 64
o-Xylene (1,2-Dimethylbenzene) 91/100
106/ 40
4-Ethyltoluene 105/100
120/ 29
1,3,5-Trimethylbenzene (Mesitylene) 105/100
120/ 42
1, 2, 4-Tri methyl benzene (Pseudocumene) 105/100
120/ 42
m-Dichlorobenzene (1,3-Dichlorobenzene) 146/100
148/ 65
A 111/ 40
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
22.65
23.18
23.31
1
(continued)
-------
TOM-64
TABLE 2. ION/ABUNDANCE AND EXPECTED RETENTION TIME FOR
SELECTED VOCs ANALYZED BY GC-MS-SIM (cont.)
Ion/Abundance
Compound (amu/% base peak)
Benzyl chloride (a-Chlorotoluene)
p-Dichlorobenzene (1,4-Dichlorobenzene)
o-Dichl orobenzene (1 ,2-Dichl orobenzene)
1,2,4-Trichlorobenzene
Hexachlorobutadiene (1,1,2,3,4,4
Hexachloro-l,3-butadiene)
91/100
126/ 26
146/100
148/ 65
111/ 40
146/100
148/ 65
111/ 40
180/100
182/ 98
184/ 30
225/100
227 / 66
223/ 60
Expected Retention
Time (min)
23.32
23.41
23.88
26.71
27.68
-------
T014-65
TABLE 3. GENERAL GC AND MS OPERATING CONDITIONS
Chromatography
Col umn
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 Flow
Carrier Flow
Burner Air
Hewlett-Packard OV-1 cross!inked
methyl silicone (50 m x 0.31-mm I.D.,
17 urn film thickness), or equivalent
Helium (2.0 cm3/min at 250°C)
Constant (1-3 uL)
Splitless
-50°C
2 min
8°C/min to 150°C
15 min
18 to 250 amu
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 cm3/minute
30 cm3/minute
400 cm3/minute
-------
T014-66
TABLE 4. 4-BROMOFLUOROBENZENE KEY IONS AND ION ABUNDANCE CRITERIA
Mass
Ion Abundance Criteria
50
75
95
96
173
174
175
176
177
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% of mass 95
5 to 9% of mass 174
>95% but< 101% of mass 174
5 to 9% of mass 176
-------
T014-67
TABLE 5. RESPONSE FACTORS (ppbv/area count) AND
EXPECTED RETENTION TIME FOR GC-MS-SIM
ANALYTICAL CONFIGURATION
Compounds
Freon 12
Methyl chloride
Freon 114
Vinyl chloride
Methyl bromide
Ethyl chloride
Freon 11
Vinylidene chloride
Dichloromethane
Trichlorotrifluoroethane
lsl-Dichloroethane
cis-l,2-Dichloroethylene
Chloroform
1,2-Dichloroethane
Methyl chloroform
Benzene
Carbon tetrachloride
1,2-Dichloropropane
Trichloroethylene
ci s-l,3-Dichloropropene
trans-l,3-Dichloropropene
1 ,1 ,2-Trichl oroethane
Tol uene
1,2-Dibromoethane (EDB)
Tetrachloroethylene
Chlorobenzene
Ethyl benzene
m,p-Xylene
Styrene
1 ,1 ,2,2-Tetrachl oroethane
o-Xylene
4-Ethyltoluene
1, 3, 5-Trimethyl benzene
1 ,2 ,4-Tri methyl benzene
m-Di chlorobenzene
Benzyl chloride
p-Di chlorobenzene
o-Dichlorobenzene
1 ,2 ,4-Tri chl orobenzene
Hexachl orobut adi ene
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
-------
T014-68
TABLE 6. GC-MS-SIM CALIBRATION TABLE
*** External Standard ***
Operator: JDP
Sample In-fo : SYR 1
Misc In-fo:
Integration File Name : DATA:SYR2AO2A.I
Sequence Index: 1
9 Jan 87 10:02 am
Bottle Number : 2
Last Update: 8 Jan 87 8:13 am
Re-ference Peak Window: 5.OO Absolute Minutes
Non-Reference Peak Window: O.4O Absolute Minutes
Sample Amount: 0.000 Uncalibrated Peak RF: O.OOO Multiplier: 1.667
Compound
Name
FREDN, 12
METHYLCHLORI
FREON 114
VINYLCHLORID
METHYLBROMID
ETHYLCHLORID
FREON 11
VINDENECHLOR
DICHLOROMETH
ALLYLCHLORID
3CHL3FLUETHA
1,1DICHLOETH
c-1,2DICHLET
CHLOROFORM
1,2DICHLETHA
METHCHLOROFD
BENZENE
CARBONTETRAC
1,2DICHLPROP
TRICHLETHENE
c-1,3DICHLPR
t-1,3DICHLPR
1,1,2CHLETHA
TOLUENE
EDB
TETRACHLETHE
CHLOROBENZEN
ETHYLBENZENE
m,p-XYLENE
STYRENE
TETRACHLETHA
o-XYLENE
4-ETHYLTOLUE
1,3,5METHBEN
1,2,4METHBEN
m-DICHLBENZE
BENZYLCHLORI
p-DICHLBENZE
o-DICHLBENZE
1,2,4CHLBENZ
HEXACHLBUTAD
Peak
Int
Num Type Type
1
2
3
4
5
6
7
8
9
10
ii
12
13
14
15
16
17
ia
19
20
21
22
23
24
25
26
27
25
2?
30
31
32
33
34
35
36
37
38
39
40
41
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
1
pp.
PP
BP
PB
BP
BB
BV
BP
BP
PP
BP
BP
VP
PH
BP
PB
VP
VP
BB
BB
PB
BP
BB
BV
PB
PH
PB
BP
PB
BV
BH
BP
VV
VB
BB
BV
VV
VB
BP
BB
BB
Ret
Time
. er
5.
6.
6.
7.
8.
9.
10.
11.
11.
11.
12.
13.
13.
14.
14.
15.
15.
15.
16.
16.
17.
17.
17.
13.
18.
19.
20.
20.
20.
20.
20.
22.
22.
23.
23.
23.
23.
23.
26.
27.
020
654
525
650
818
421
94O
369
187
225
578
492
394
713
378
594
OO9
154
821
O67
941
475
594
844
463
989
7O5
168
372
778
887
892
488
609
144
273
279
378
850
673
637
Signal
Description
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
85.
5O.
85.
62.
94.
64.
1O1.
61.
49.
41.
151.
63.
61.
•83.
62.
97.
78.
117.
63.
130.
75.
75.
97.
91.
107.
166.
112.
91.
91.
1 04 .
83.
91.
1O5.
105.
1O5.
146.
91.
146.
146.
180.
225.
,00
,OO
,OO
. OO
i OO
, oo
, oo
. oo
, 00
. oo
, oo
, oo
,00
. oo
, 00
, oo
,00
,00
, 00
,00
, oo
, oo
,00
,00
, 00
, oo
oo •
,00
oo
,00
oo
, do
oo
, oo
oo
oo
00
, oo
oo
oo
00
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
•amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
• amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
Area
12893
4445
7067
2892
2401
2134
25069
5034
48O3
761
'5477
5052
4761
,5327
5O09
6656
8352
5888
3283
4386
2228
1626
2721
14417
4070
6874
5648
11O84
17989
3145
4531
9798
7694
6731
7892
3046
388O
609O
2896
562
63O9
Amount
4O11
2586
1215
1929
1729
2769
6460
17OO
2348
8247
1672
1738
1970
1678
2263
2334
2167
1915
1799
21O9
987.
689.
1772
2733
1365
2065
1524
1842
3790
1695
1376
20 10
1481
1705
2O95
1119
1 006
2164
1249
767.
1789
pptv
pptv
pptv
pptv *
pptv
pptv *
pptv
pptv
pptv
pptv *
pptv
pptv *'
pptv
PPtv
pptv
pptv
pptv
pptv
pptv *•
pptv
3 pptv
2 pptv
pptv
pptv
pptv *
pptv
pptv
pptv
PPtv
pptv
PPtv
PPtv
pptv
pptv
PPtv
pptv
PPtv
pptv
pptv
1 pptv
pptv
-------
T014-69
TABLE 7. TYPICAL RETENTION TIME (MIN) AND
CALIBRATION RESPONSE FACTORS (ppbv/area count)
FOR TARGETED VOCs ASSOCIATED WITH FID
AND ECD ANALYTICAL SYSTEM
Peak
Number*
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 x
29
30
31
32
33
34
35
36
37
38
39
40
Compound
rreon 12
viethyl chloride
Freon 114
Vinyl chloride
Methyl bromide
Ethyl chloride
Freon 11
Vinylidene chloride
Dichloromethane
Trichlorotrifluoroethane
1,1-Dichl oroethane
cis-l,2-Dichloroethylene
Chloroform
1,2-Dichl oroethane
Methyl chloroform
Benzene
Carbon tetrachloride
1,2-Dichloropropane
Trichl oroethy lene
cis-l,3-Dichloropropene
trans-l,3-Dichloropropene
1 ,1 ,2-Trichl oroethane
Toluene
1,2-Dibromoethane (EDB)
Tetrachl oroethylene
Chlorobenzene
Ethyl benzene
m,p-Xylene
Styrene
1 ,1 ,2 ,2-Tetr achl oroethane
o-Xylene
4-Ethyltoluene
1, 3, 5-Tri methyl benzene
1 ,2 ,4-Tri methyl benzene
m-Dichlorobenzene
Benzyl chloride
p-Dichl orobenzene
o-Dichl orobenzene
1 ,2 ,4-Trichl orobenzene
Hexachl orobutadi ene
Retention
Time (RT)S
minutes
3.65
4.30
5.13
5.28
6.44
7.06
8.60
9.51
9.84
10.22
11.10
11.99
12.30
12.92
13.12
13.51
13.64
14.26
14.50
15.31
15.83
15.93
16.17
16.78
17.31
18.03
18.51
18.72
19.12
19.20
19.23
20.82
20.94
21.46
21.50
21.56
21.67
22.12
24.88
25.82
FID
Response
Factor (RF)
(ppbv/area
count)
3.465
0.693
0.578
0.406
0.413
6.367
0.347
0.903
0.374
0.359
0.368
1.059
0.409
0.325
0.117
1.451
0.214
0.327
0.336
0.092
0.366
0.324
0.120
0.092
0.095
0.143
0.100
0.109
0.111
0.188
0.188
0.667
0.305
ECD
Response
Factor
(ppbv/area
count x 10"5)
13.89
22.32
»
26.34
1.367
3.955
11.14
3.258
1.077
8.910
5.137
1.449
9.856
1.055
1 Refer to Figures 15 and 16 for peak location
-------
T014-70
TABLE 8. TYPICAL RETENTION TIME (minutes) FOR
SELECTED OR6ANICS USING GC-FID-ECD-PID*
ANALYTICAL SYSTEM
—
Compound
Acetylene
1,3-Butadiene
Vinyl chloride
Chloromethane
Chloroethane
Bromoethane
Methylene Chloride
trans -1,2-Dichloroethylene
1 ,1-Dichl oroethane
Chloroprene
Perfluorobenzene
Bromochloromethane
Chloroform
1 ,1 ,1-Trichl oroethane
Carbon Tetrachloride
Benzene/1 ,2-Dichl oroethane
Perfluorotoluene
Trichloroethylene
1 ,2-Dichl oropropene
Bromodi chloromethane
trans-l,3-Dichloropropylene
Toluene
ci s-1 ,3-Dichl oropropylene
1,1 ,2-Trichl oroethane
Tetrachl oroethylene
Dibromochloromethane
Chlorobenzene
m/p-Xylene
Sty rene/o-Xy le ne
Bromof 1 uorobenzene
1,1,2 ,2-Tetrachl oroethane
m-Dichlorobenzene
p-Dichl orobenzene
o-Di chlorobenzene
Retention Time (minutes)
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
ECD
•» M
--
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
PID
_-
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 I.D. mm) using helium carrier gas.
-------
T014-71
TABLE 9. GC-MS-SIM CALIBRATION TABLE
Last Update: 18 Dec 86 7s54 am
Reference Peak Window: 5.OO Absolute Minutes
Non-Re-ference Peak Window: O.40 Absolute Minutes
Sample Amount: O.OOO Uncalibrated Peak RF: O.OOO Multiplier: l.OOO
Ret Time Pk#
5.
5.
6.
6.
7.
8.
9.
10.
11.
11.
11.
12.
13.
13.
14.
14.
.J5.
•15.
15.
16.
16.
17.
17.
17.
18.
19.
19.
20.
20.
2O.
2O.
2O.
22.
22.
23.
23.
23 »
23.
23.
26.
27.
ooa
69O
552
7O9
331
431'
97O
927
2O9
331
595
5O2
4O3
747
387
623
038
183
829
096
956
492
610
862
485
012
729
195
407
SO6
916
921
528
648
179
3O7
317
413
885
714
680
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IS
19
2O
21
22
23
24
25
26
27
23
29
3O
31
32
33
34
35
36 .
37
33
39
40
41
Signal Descr
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
Mass
• Mass
Mass
Mass
Mass
Mass
Mass
Mass .
Mass
Mass
Mass
85.
50.
85.
62.
94.
64.
101.
61.
49.
41.
151.
63.
61.
83.
62.
97.
73.
117.
63.
130.
75.
OO
OO
oo
oo
oo
00
oo
oo
oo
oo
oo
oo
oo
00
00
oo
oo
oo
00
oo
oo
75.OO
97.
91.
1O7.
166.
112.
91.
. 91.
1O4.
83.
91.
1O5.
1O5.
105.
146.
91.
146.
146.
ISO.
225.
00
00
00
oo
oo
oo
00
oo
00
00
oo
oo
oo
oo
oo
oo
00
oo
00
Amt pptv
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
amu
136 2O
1272O
333O
3O5O
1221O
12574
12330
789O
12760
1265O
7420
1271O
12630
767O
9040
8100
10760
834O
1278O
. 875O
454O
3380
1269O •
1OO1O
6710
783O
716O
1274O
254OO
12390
11690
11085
12560
1262O
1271O
12650 •
7900
1239O
135 1O
15520
7470
Lvl
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
1
CArea3
72974
36447
81251
2O118
28265
16149
80038
38954
435O7
1945
4O530
61595
509OO
4O585
33356
385O3
69119
42737
38375
3O33 1
. 17078.
13294
32480
SBO36
33350
43454
44224
127767
200973
38332
64 162
9O096
1O3747
83666
79833
574O9
5O774
58127
52233
18967
4392O
Pk-Type Partial Name
1 FREON 12
1 METKYLCHLORID
1 FREDN 114
1 VINYL-CHLORIDE
1 METHYLBROMIDE
1 ETHYLCHLORIDE
1 FREON 11
1 VINDENECHLQRI
1 DICHLOROMETHA
1 ALLYLCHLORl'DE
1 3CHL3FLUETHAN
1 1,1DICHLC£THM
1 c-l,2DICHLETH
1 CHLOROFORM
.1 1 , 2DICHLETHAM
1 METHCHLOPOFOR
1 BENZENE
1 CARBQNTETRACH
1 1,2DICHLPROPA
1 TRICHLETHENE
1 c-l,3DICHLPRO
1 t-l,3DICHLPRO
11,1,2CHLE7HAN
1 TOLUENE
1 EDB
1 TETRACHLETHEM
1 CHLOROBENZENE
1 ETHYLBENZENE
1 m,p-XYLENE
1 STYRENE
1 TETRACHLETHAN.
1 o-XYLENE
1 4-ETHYLTOLUEM
1 1,3,5METHBENZ
1 1,2,4METHBENZ
1 m-DICHLBEN2EN
1 BENZYLCHLORID
1 p-DICHLBENZSr-4
1 o-DICHLBENZEN
1 1,2,4CHLBENZE
1 HEXACHLBUTADI
-------
T014-72
TABLE 10. EXAMPLE OF HARD-COPY OF GC-MS-SIM ANALYSIS
Data •file
File type
Name In-fo
Misc In-fo
Operator
Date
Instrment
Inlet
DATA:SYR2A02A.D
GC / MS DATA FILE
SYR 1
JDP
S Jan 37 10: O2 am
MS 597O
GC
Sequence index :
Als bottle num :
Replicate num :
TIC af DRTRsEYR3RB2R.D
2BBB-
1BBB'
1BBB
14BB
1BBB
BBB
BBB
SBB
B
p.
5
IB
15
2B
25
3B
*** Integration Parameters *•*•*
FALSE : Shoulder Detection Enabled
0.02O : Expected Peak Width (Min)
11 : Initial Peak Detection Threshold
4. 000 THRESHOLD,
4.000 PEAK_WIDTH
9.8OO PEAK WIDTH
5. 000
0.200
0. O6O
-------
TO14-73
TABLE 10. EXAMPLE OF HARD-COPY OF GC-MS-SIM ANALYSIS (cont.)
Operator: JDP
Sample Ircfc : SYR 1
Misc In-fo:
Integration File Name : DATA:BYR2AO2A.I
Sequence Index: 1
8 Jan 87 10: 0:. *.'
Bottle Number
Last Update: 8 Jan 87 B:13 am
Reference Peak Window: 5.OO Absolute Minutes
Non-Re-ference Peak Window: 0.40 Absolute Minutes
Sample Amount: O.OOO Uncalibrated Peak RF: O.OOO Multiplier: 1.667
Peal:.
Num Type
1
*\
tj
4
cr
6
7
8
e?
•"!
1
1«?
13
14
15
16
17
13
19
20
21
22
23
24
25
26
•27
28
29
3O
31
•32
33
34
35
"s
•17
38
39
40
41
Int
Tvpe
1 PP
1 PP
3 BP
1 PB
1 BP
1 BB
1 BV
1 BP
1 BP
1 PP
1 BP
1 BP
1 VP
1 PH
1 BP
1 PB
1 VP
1. VP
1 BB
1 BB
1 PB
1 BP
1 BB
1 BV
1 PB
1 PH
1 PB
1 BP
1 PB
1 BV
1 BH
1 BP
1 VV
1 VB
1 BB
1 BV
1 VV
1 VB
1 BP
1 BB
1 BB
Ret
Time
• 5.02O
5.654
6.525
6 . 650
7.818
8.421
9.940
10.369
11. 187
1 1 . 225
1 1 . 578
12.492
13.394
13.713
14.378
14.594
1-5. O09
15. 154
15.821
16.067
16.941
17.475
17.594
17.844
18.463
18.989
19.7O5
2O. 168
20.372
2O. 778
2O. 887
2O. 892
22.488
22.609
23. 144
23.273
23.279
23.378
23.850
26 . 673
27.637
Signal
Descripti on
Mass 85.OO amu
Mass 50.00 amu
Mass 85.OO amu
Mass 62.OO amu
Mass 9-4. OO amu
Mass 64.OO amu
Mass 1O1.OO amu
Mass 61.OO amu
Mass 49.OO amu
Mass 41.OO amu
Mass 151.00 amu
Mass 63.OO amu
Mass 61.00 amu
Mass . 83.00 amu
Mass 62. OO .amu
Mass 97.OO amu
Mass 78.00 amu
.Mass 117.OO amu
Mass 63.OO amu
Mass 130.OO amu
Mass 75.OO amu
Mass 75.00 amu
Mass 97.00 amu
Mass 91.OO amu
Mass 1O7.0O amu
Mass 166.OO amu
Mass 112.OO-amu
Mass 91.00 amu
Mass 91.OO amu
Mass 104.0O. amu
Mass 83.OO amu
Mass 91.00 amu
Mass 105.OO amu
Mass 1O5,00 amu
Mass 1O5.00 amu
Mass 146.OO amu
Mass 91.0O amu
Mass 146.0O amu
Mass 146.OO amu
Mass 180.0O amu
Mass 225.00 amu
Compound
Name
FREON 12
METHYLCHLORI
F.REON 114
VINYLCHLORID
METHYLBROMID
ETHYLCHLORID
FREON 11
VINDENECHLOR
DICHLDROMETH
ALLYLCHLORID
3CHL3FLUETHA
1,1DICHLOETH
c-i,2DICHLET
CHLOROFORM
1,2DICHLETHA
METHCHLOROFO
BENZENE
CARBONTETRAC
1,2DICHLPROP
TRICHLETHENE
c-l,3DICHLPR
t-l,3DICHLPR
1,1,2CHLETHA
TOLUENE
EDB
TETRACHLETHE
CHLOROBENZEN
ETHYLBENZENE
m,p-XYLENE
STYRENE
TETRACHLETHA
o-XYLENE
4-ETHYLTOLUE
1,3,5METHBEN
1,2,4METHBEN
m-DICHLBENZE
BENZYLCHLORI
p-DICHLBENZE
o-DICHLBENZE
1,2,4CHLBENZ
HEXACHLBUTAD
Area
12893
4445
7067
2892
24O1
2134
25069
5034
48O3
761
5477
5052
4761
,5327
5OO9
6656
8352
5888
3283
4336
2228
1626
2721
14417
4O70
6874
5648
11084
17989
3145
4531
9798
7694
6781
7892
3046
338O
609O
2896
562
63O9
Amount
4011 pptv
2586 pptv
1215 pptv
1929 pptv *
1729 pptv
2769 pptv *
6460 pptv
1700 pptv
2348 pptv
8247 pptv *
Ifa72 pptv
1738 pptv #
1970 pptv
• 1673 pptv
2263 pptv
2334 pptv
2167 pptv
1915 pptv
1799 pptv •»-
2109 pptv
987.3 pptv
689.2 pptv
1772 pptv
2733 pptv
1365 pptv *
2065 pptv
1524 pptv
1842 ppt\
3790 pptv
1695 pptv
1376 pptv
2010 pptv
1481 pptv
1705 pptv
2O95 pptv
1119 pptv
1OO6 pptv
2164 pptv
1249 pptv
767. 1 pptv
1789 pptv
-------
T014-74
GC-MS-SCAN
(Section 10.4.2)
Receive
Sample
Canister
(Section
9.2.2)
Log Sample In
(Section 10.4.1.2)
Check and Record
Initial Pressure
(Section 10.4.1.3)
Analyze
<83kPa
(12psig)
(Optional)
GC-MS-SIM
(Section 10.4.3)
Pressurize
w'rth N2 To
138 kPa
(20psig)
i
Record Final
Pressure
(Section 10.4.1.3)
Calculate
Dilution Factor
(Section 10.4.1.4)
1
GC-Multidetector
(GC-FID-ECD-PID)
(Section 10.4.4)
Non-Speclfic Detector (FID)
(Optional)
FIGURE 1. ANALYTICAL SYSTEMS AVAILABLE FOR CANISTER
VOC IDENTIFICATION AND QUANTITATION
-------
f f s% ^
-.<.-. v -\-5 ^N •>
Insulated Enclosure
~1.6 Meters
(~5ft)
Inlet
Manifold
Vacuum/Pressure |.
Gauge *:'
\ \
Metal Bellows ' '
Type Pump ^ ''j
For Pressurized , f r —
Sampling ' , , /
s ~ { '
s
Magnelatch
\ /*} fA rfi
Mass Flow Meter
Auxilliary
Vacuum
Pump
\L
Fan
t
sr
5ta
y
t
/
1
v. j
k-
s
-nJlOOO
I Valve
/
Mass Flow
Control Unit
O Q
_OQ^-i M
Heater
Canister
\ ,
To AC
FIGURE 2. SAMPLER CONFIGURATION FOR SUBATMOSPHERIC
PRESSURE OR PRESSURIZED CANISTER SAMPLING
-------
T014-76
Inlet
Vent
Auxilliary
Vacuum
Pump
Vacuum/Pressure
Gauge
Mechanical
Flow
Regulator
To AC
FIGURE 3. ALTERNATIVE SAMPLER CONFIGURATION FOR
PRESSURIZED CANISTER SAMPLING
-------
T014-77
Pressure
Regulator
Vent
Nafion
Dryer
Exhaust
4
Optional
Pressure
Gauge
j Mass Flow
j Controller
Vent
(Excess)
\-Dry
Forced
Air In
1
— \
Uy
6-Port
Chromatographic
Valve
Cryogenic
Trapping
Unit
Tee
Connection
Pressure
Regulators
Gas
Purifiers
OV-1
Capillary
Column
(0.32mm x 50m)
Low Dead-Volume
v ^
• ''r
„ J, ,j_
Flame lonizatiori i |
Detector (FID) \ |
1"
Tee (Optic
Flow
Restrictor
(Optional)
Mass Spectrometer
in SCAN or SIM Mode
FIGURE 4.
CANISTER ANALYSIS UTILIZING GC-MS-SCAN-SIM
ANALYTICAL SYSTEM WITH OPTIONAL FLAME
IONIZATION DETECTOR WITH THE 6-PORT
CHROMATOGRAPHIC VALVE IN THE SAMPLE
DESORPTION MODE
-------
T014-78
S>
-------
T014-79
£
-------
T014-80
Pressure
^Regulator
Exhaust
Exhaust
Zero
Air
Supply
Vacuum Pump
Shut Off Valve
Vent
Valve Check Valve
Vacuum
Pump
Vent Shut
Off Valve
Vent Shut
Off Valve
Pressure
Regulator
Cryogenic
Trap Cooler
(Liquid Argon)
Zero
A5r
Supply
Cryogenic
Trap Cooler
(Liquid Argon)
Vacuum
Shut Off
Valve
Vacuum
Gauge^v
Flow
Control
Valve
Vacuum
Gauge
Shut Off
Valve
Vent
Shut Off
Valve
SampleA /Sample \ /Sample
Canister/ vCanister/ \Canister
Exhaust
Optional
Isothermal
Oven
FIGURE 7. CANISTER CLEANING SYSTEM
-------
T014-81
0
S
a
DCQ
UJCC
111
3o«
u_ 5* DC
I
CO
=
-------
T014-82
100K
TIMER lA/WV "c
SWITCH [^ GI _|
o— — cr^ 40jifd, 450 V DC F"1
115 VAC °1 R21°°K °1
115VAC ^WV\ BLACK
(N 40u.fd, 450 V DC D2
PUMP \^J r- i
1 WHITE
COMPONENTS
MAGNELATCH
SOLENOID
VALVE
Capacitor Ci and Cz • 40 uf, 450 VDC (Sprague Atoms TVA 1712 or equivalent)
Resislcr Rj and R2 - 0.5 watt, 5% tolerance
Diode DI and D2 - 1000 PRV, 2.5 A (RCA, SK 3081 or equivalent)
(a). Simple Circuit For Operating Mag ne latch Valve
TIMER
SWITCH
... ..... , Q
/
115 VAC . ,
AC 12.7K 2.7K /
D1
n W RE°
/ ^
' 0 D2
I l^ BLACK
n
+ rfVW vWV -[/
Q i RI _ Ro /^~\
/^S. BRIDGE . °1 ( )RELAY
(PUMP) nccnncn vX/iiuuuf TnoK
V* y AC - -r 200 volt COIL
^-j-'' (aSma
j
C2
\( WHITE
IV.
COMPONENTS
MAGNELATCH
SOLENOID
VALVE
Brkfge RactiHer - 200 PRV, 1.5 A (RCA. SK 3105 or equivalent) 400 Volt
Diode DI and Da - 1000 PRV, 2.5 A (RCA, SK 3081 or equivalent) NON-POLARIZED
Capacitor Cz - 20 uf. 400 VDC Non-Polarized (Sprague Atom® TVAN 1652 or equivalent)
Rol«y - 10.000 ohm coil, 3,5 ma (AMP Potter and Brumlield, KCP 5; or equivalent)
Resistor R) and R2 - 0.5 watt, 5% tolerance
(b). Improved Circuit Designed To Handle Power Interruptions
FIGURE 9. ELECTRICAL PULSE CIRCUITS FOR DRIVING
SKINNER MAGNELATCH SOLENOID VALVE WITH
A MECHANICAL TIMER
-------
T014-83
CANISTER SAMPLING FIELD DATA SHEET
A. GENERAL INFORMATION
SITE LOCATION:
SITE ADDRESS:
SAMPLING DATE:.
SHIPPING DATE:
CANISTER SERIAL NO.:
SAMPLER ID:
OPERATOR:
CANISTER LEAK
CHECK DATE:
B. SAMPLING INFORMATION
TEMPERATURE
PRESSURE
START
STOP
INTERIOR
AMBIENT
MAXIMUM
^x^
MINIMUM
r^xc
CANISTER PRESSURE
^>
-------
T014-84
CO
111
TIME
(a) SCAN analysis
CO
z
UJ
iiiiJLL
TIME —*-
(b) SIM analysis
co
2
1U
TIME —I
(c) FID analysis
>-
CO
UJ
2
TIME
(d) ECD analysis
*UUi
u
FIGURE 11. TYPICAL CHROMATOGRAMS OF A VOC SAMPLE
ANALYZED BY GC-MS-SCAN-SIM MODE AND
GC-MULTIDETECTOR MODE
-------
T014-85
Cryogen
Exhaust
Trap
Insulated Shell
Cylindrically Wound
Tube Heater (250 watt)
Sample
in
Cryogen in
(Liquid Nitrogen)
Bracket and
Cartridge
Heaters (25 watt)
FIGURE 12. CRYOGENIC TRAPPING UNIT
-------
T014-86
Receive
Sample
Canister
(Section
9.2.2)
Log Sample In
(Section 10.4.1.2)
Check and Record
Initial Pressure
(Section 10.4.1.3)
< 83 kPa
(Optional)
Pressurize with N2
To138kPa
(20pslg)
Record Final Pressure
(Section 10.4.1.3)
Preparation of
GC-MS-SCAN-S3M
(with Optional FID)
Analytical System
Calculate Dilution Factor
(Section 10.4.1.4)
i
Initial Preparation and Tuning
Routine Preparation and Tuning
Humid Zero Air Test
Humid Zero Air Test
Initial Three (3) Point
Static Calibration
Additional Five (5) Point Static
Calibration for Nonlinear Compounds
Daily One (1) Point
Static Calibration
Additional Three (3) Point Static
Calibration for Nonlinear Compounds
J
GC-MS-SCAN-SIM
(with Optional RD)
Analytical System
FIGURE 13.
FLOWCHART OF GC-MS-SCAN-SIM ANALYTICAL
SYSTEM PREPARATION (WITH OPTIONAL FID SYSTEM)
-------
T014-87
Receive
Sample
Canister
(Section
9.2.2)
1
r
Log Sample In
(Section 10.4.1.2)
Check and Record
Initial Pressure
(Section 10.4.1.3)
<83kPa
(Optional)
Pressurize with N2
To138kPa
(20psig)
Record Rnal Pressure
(Section 10.4.1.5)
Analyze
Calculate Dilution Factor
(Section 10.4.1.4)
Preparation of GC-Ffl£EC~D^PID
Analytical System
Initial Preparation
Routine Preparation
Humid Zero Air Test and
Retention Time Window Test
Humid Zero Air Test and
Retention Time Window Test
Initial Three (3) Point
Static Calibration
Additional Five (5) Point Static
Calibration for Nonlinear Compounds
Daily One (1) Point
Static Calibration
Additional Three (3) Point Static
Calibration for Nonlinear Compounds
I
GC-FID-ECD-PID
Analysis for Primary Quantftation
FIGURE 14. FLOWCHART OF GC-FID-ECD-PID
ANALYTICAL SYSTEM PREPARATION
-------
T014-8B
-------
T014-89
00
N.
«0
t
o
<3
o
g
LLJ
LU
W
e
in
o
Q.
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LU
a
a
I
to
T-
LU
CC
1 E
£
s
-------
T014-90
TIME
(a). Certified Sampler
TIME
(b). Contaminated Sampler
FIGURE 17. EXAMPLE OF HUMID ZERO AIR TEST RESULTS FOR A
CLEAN SAMPLER (a) AND A CONTAMINATED SAMPLER (b)
-------
1000
, 900 —
o 800 —
| 700-
OT 600 —
§ 500 H
O
° 400 —
-------
T014-92
a:
LU
Q.
•»*SS
Q-*i
H- <
LUQ
CL^
-10.
o
SCO
0>
T-
LU
DC
i
-------
T014-93
Canister Receipt
I Record Sample Canister In Dedicated Logbook
Initial Preparation
Humid Zero Air Test
Check Canister Pressure
1
<12pslg ^
Pressurize with N2
to 15-20 psig
• *
1 Calculate Dilution Factor I
r
GC-RD-ECDandGC-MS
Sample Analysis
-^ IPrr
*
»rd Initial/Final Pressure I
GC-FID-ECD-PID
Analytical Preparation
»
Initial Three (3) Point
Dynamic Calibration
f
Additional Five (5) Point Dynamic
Calibration for Nonlinear Compounds
Routine Preparation
Humid Zero Air Test
Daily One (1) Point
Dynamic Calibration
Additional Three (3) Point Dynamic
Calibration for Nonlinear Compounds
GC-FID-ECD-PID
Screening Analysis
GC/MS
Analytical Preparation
SCAN Mode
SIM Mode
Initial Preparation
Humid Zero Air Test
Cal
Initial Three (3) Point
Static Calibration
»
Additional Five (5) Point Static
bration for Nonlinear Compoun
ds
Routine Preparation
Humid Zero Air Test
Daily One (1) Point
Static Calibration
t ... ...
Additional Three (3) Point Static
Calibration for Nonlinear Compounds
GC-MSD-SCAN Identification and
Semi-quantitatlon of VOCs
GC-MSD-SIM Selected VOCs for
Identification and Quantitation
FIGURE 20. FLOWCHART OF ANALYTICAL SYSTEMS PREPARATION.
-------
T014-94
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-------
APPENDIX A
AVAILABILITY OF AUDIT CYLINDERS FROM UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY USEPA PROGRAMS/
REGIONAL OFFICES, STATE AND LOCAL. AGENCIES AND
THEIR CONTRACTORS
1* Availability of Audit Cylinders
1.1 The USEPA has available, at no charge, cylinder gas standards
of hazardous organic compounds at the ppb level that may be
used to audit the performance of ambient air source measurement
systems.
1.2 Each audit cylinder contains 5 to 18 hazardous organic com-
pounds in a balance of Nj> gas. Audit cylinders are available
in several concentration ranges. The concentration of each
organic compound in the audit cylinder's within the range
illustrated in Table A-l.
2. Audit Cylinder Certification
2.1 All audit cylinders are periodically analyzed to assure that
cylinder concentrations have remained stable.
2.2 All stability analyses include quality control analyses of
ppb hazardous organic gas standards prepared by the National
Bureau of Standards for USEPA.
3. Audit Cylinder Acquisition
3.1 USEPA program/regional offices, state/local agencies, and their
contractors may obtain audit cylinders (and an audit gas delivery
*
system, if applicable) for performance audits during:
o RCRA Hazardous Waste Trial Burns For PHOC's; and
o Ambient Air Measurement of Toxic Organics.
3.2 The audit cylinders may be acquired by contacting:
Robert L. Lampe
U.S. Environmental Protection Agency
Environmental Monitoring Systems Laboratory
Quality Assurance Division
MD-77B •
Research Triangle Park, NC 27711
919-541-4531
-------
T014-A2
TABLE A-l. AVAILABLE USERA PERFORMANCE
AUDIT CYLINDERS
Group I Compounds
Carbon
tetrachloride
Chloroform
Perchloroethylene
Vinyl chloride
Benzene
Group II Compounds
Trichloroethylene
1,2-dichloroethane
1,2-dibromoethane
Acetonitrile
Trichlorof1uoromethane
(Freon-11)
Dichlorodi f1uoromethane
(Freon-12)
Bromomethane
Methyl ethyl ketone
1,1,1-trichloroethane
Group III Compounds
Pyridine (Pyridine in Group
III cylinders but certified
analysis not available)
Vinylidene chloride
l,l,2-trichloro-l,2,2-
trifluoroethane
(Freon-113)
l,2-dichloro-l,l,2,2-
tetraf1uoroethane
(Freon-114)
Acetone
1-4 Dioxane
Toluene
Chlorobenzene
Group I Ranges
7 to 90 ppb
90 to 430 ppb
430 to 10,000 ppb
Group II Ranges
7 to 90 ppb
90 to 430 ppb
Group III Ranges
7 to 90 ppb
90 to 430 ppb
Group IV
Acrylonitrile
1,3-butadiene
Ethylene oxide
Methylene chloride
Propylene oxide
o-xylene
Group IV Ranges
7 to 90 ppb
430 to 10,000 ppb
Group V
Carbon tetrachloride
Chloroform
Perchloroethylene
Vinyl chloride
Benzene
Trichloroethylene
1,2-dichloroethane
1,2-dibromoethane
1,1,1-trichloroehtane
Group V Ranges
1 to 40 ppb
Methylene chloride
Tri chlorof1uoromethane
(Freon-11)
Bromomethane
Toluene
Chlorobenzene
1,3-Butadiene
o-xylene
Ethyl benzene
1,2-dichloropropane
-------
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 (Photovac Models 10S10, 10S50, or equivalent).
This procedure is not intended to yield quantitative or definite quali-
tative information regarding the substances detected. Rather, it pro-
vides 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 PID, 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,
-------
T014-B2
natural gas processing plants, and automobile exhaust. Many of
these VOC emissions are acutely toxic; therefore, their determi-
nation in ambient air is necessary to assess human health impacts.
4.2 Conventional methods for VOC determination use solid sorbent
• and canister sampling techniques.
4.3 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 analy-
sis; (3) ease of storing and shipping samples, if necessary;
(4) unattended sample collection; (5) analysis of samples from
multiple sites w\th one analytical system; and (6) collection of
sufficient sample volume to allow assessment of measurement pre-
cision 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 tool"
to determine "hot spots," potential interferences, and semi-
quantitation of VOCs/SVOCs, 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
6.1 The most significant interferences result from extreme differ-
ences in limits of detection (LOD) among the target VOCs (Table
B-l). Limitations in resolution associated with ambient tempera-
ture, chromatography and the 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.,
-------
T014-B3
6.2 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 (Table B-2) have pre-
concentrator capabilities for sampling lower concentrations of VOCs,
pre-column detection with back-flush capability for shorter analyti-
cal time, constant column temperature for method precision and ac-
curacy and multidetector (PID, ECD, and FID) capability for ver-
satility. Many of these newer features address the weaknesses and
interferences mentioned above.
7. Apparatus
7.1 Gas chromatograph. A GC (Photovac Inc., 739 B Parks Ave, Hunt-
ington, NY, 11743, Model 10S10 or 10S50, or equivalent) used for
surveying ambient air environments (which could employ a multide-
tector) for sensing numerous VOCs compounds eluting from a packed
column at ambient temperatures. This particular portable GC procedure
is written employing the photoionization detector as its major
sensing device, as part of the Photovac Model 10S10 portable GC
survey tool. Chromatograms 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 cm3/min air.
7.2 GC accessories. In addition to the basic gas chromatograph,
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 connec-
tions for filling the internal carrier gas reservoir, and if
the Model 10S10 is used, a recording integrator (Hewlett Packard,
Avondale, PA, Model 3390A, or equivalent).
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
-------
T014-B4
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)] from Scott
Specialty Gases, or equivalent.
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 1002LT, or equivalent) are used to intro-
duce 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 con-
centrations of volatile compounds, disposable glass syringes
(e.g, Glaspak, or equivalent) with stainless steel/Teflon® hub
needles are used.
8.5 High pressure filler. An adapter (Photovac SA101, or equivalent)
for filling the internal carrier gas reservoir on the portable
GC is used to deliver "zero" air.
9. Procedure , .
9.1 Instrument Setup
9.1.1 The portable gas chromatograph must be prepared prior to
use in the ambient survey sampling. The pre-sampling acti-
vities 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 12V, 6AH lead/acid battery can be recharged
to provide up to eight hours of operation. A battery
-------
T014-B5
which is discharged will automatically cause the power
to the instrument to be shut down and will require an
overnight charge. During AC operation, the batteries
will automatically be trickle-charged or in a standby
mode.
9.1.3 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 pho-
toionzation detector has stabilized. Upon arriving at
the area to be sampled, the unit should be connected
t
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 flows 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 60 cm3/min (5% SE-30) and 30 cm3/min (3% SP2100)
are adjusted by means of a calibrated rotameter. 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.
9.2.2 Prior to analysis of actual samples, an injection of the
performance evaluation mixture must be made to verify
chromatographic and detector performance. This is accom-
plished by withdrawing 1.0 ml samples of this 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,
-------
T014-B6
especially for early eluting components, are reinjected
on the 5% SE-3Q column. [Note: In no i nstance should a
syringe which has been used for the injection of the
calibrant/system performance mixture be used for the
acquisition and collection of samples, or vice versa.]
9.2.4 Samples have generally been collected from the ambient air
at sites which are near suspected sources of yOGs and
SVOCs 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 concen-
trated 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 should be collected throughout the entire location,
but with particular attention given to areas of high or
frequent occupation.
9.3 Sample Analysis
9.3.1 Qualitative analysis. Positive identification of sample
components is not the.objective of this "screening" proce-
dure. Visual comparison of retention times 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, esti-
mates 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.
-------
T014-B7
10. Performance Criteria and Quality Assurance
Required quality assurance measures and guidance concerning perfor-
mance 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 labora-
tory: (1) assembly, calibration, leak check, and oper-
ation of the specific portable GC sampling system and
equipment used; (2) preparation, storage, shipment, and
handling of the portable GC sampler; (3) purchase, cer-
tification, and transport of standard reference mate-
rials; and (4) all aspects of data recording and processing,
including lists of computer hardware and software used.
10.1.2 Specific stepwise instructions should be provided in
the SOPs and should be readily available to and under-
stood 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 from Scott Specialty Gases,
or equivalent.
> "".•.- ' -
10.2.2 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.
10.2.3 Blanks, Duplicates, and System Performance Samples
10.2.3.1 Blanks and Duplicates. Ten percent of all in-
jections made to the portable GC are blanks,
-------
T014-B8
where the blank is reagent grade nitrogen gas.
This is the second injection in each sampling
location. An additional 1Q% of all injections
made are duplicate injections. This will en-
hance the probability that the chromatogram of a
sample reflects only the composition of that sam-
ple and not any previous injection. Blank injec-
tions showing a significant amount of contaminants
will be cause for remedial action.
10.2.3.2 System Performance Mixture. An injection of the
system performance mixture will be made at the be-
ginning of a visit to a particular sampling loca-
tion (i.e., the first injection). The range of
acceptable chromatographic system performance cri-
teria and detector response is shown in Table B-4.
These criteria are selected with regard to the in-
tended application of this protocol and the limited
availability of standard mixtures in this area.
Corrective action should be taken with the column
or PID before sample injections are made if the per-
formance is deemed out-of-range. Under this regimen
of blanks and system performance samples, approxi-
mately eight samples can be collected and analyzed
in a three hour visit to each sampling location.
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 and SVOCs emissions. In this context, precision
and accuracy are to be determined. However, quality assurance
criteria 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 the various
-------
T014-B9
target compounds. Aromatic compounds and olefinic halogenated
compounds will be detected at lower levels than the halomethanes
or aliphatic hydrocarbons. The concentration range of applica-
tion of this method is approximately two ordars of magnitude.
-------
T014-B10
TABLE B-l
ESTIMATED LIMITS OF DETECTION (LOD) FOR SELECTED VOCs
BASED ON 1 uL SAMPLE VOLUME
Compound LOD (ng) LOD (ppb)
Chloroform3
l,l,l-Trichloroethanea
Carbon tetrachloride3
Benzene
l,2-Dichloroethaneb
Trichloroethyleneb
Tetrachloroethyleneb
1,2-Dibromoethane
p-Xylenec
m-Xylenec
o-Xylened
Styrene"
2
2
2
.006
.05
.05
.05
.02
.02
.02
.01
.01
450 '
450
450
2
14
14
14
2
4
4
3
3
aChloroform, 1,1,1-Trichloroethane, and Carbon tetrachloride coelute on
0.66 m 3% SP2100.
bl,2-Dichloroethane, Tricholroethylene, and Tetrachloroethylene coelute on
0.66 m 3% SP2100.
^p-Xylene and m-Xylene coelute on 0.66 m 3% SP2100.
dStyrene and o-Xylene coelute on 0.66 m 3% SP2100. Jttk
-------
T014-B11
TABLE B-2
COMMERCIALLY AVAILABLE
PORTABLE VOC DETECTION INSTRUMENTS
Monitor
550,551
555,580
(AID, Inc.
OVA 108,
128
Century
Systems ,
Inc.
(Foxboro)
PI-101
(HNu Sys-
tems, Inc)
TLV Sniffer
(Bacharach)
Ecolyzer
400
(Energetics
Science)
Hi ran 1A
(Foxboro)
Hi ran IB
(Foxboro)
Scentor
(Sentex)
Photovac
Standard
Automatic
Computer
Auto Comp.
Communica-
tion
Photovac
Tip
Detection
principle
PID,
FID
FID
PID
Catalytic
combus-
tion
Catalytic
combus-
tion
1R
1ft.
GC/EC,
Argon
loniza-
tion PIO
P10
(UV
Light)
P'llT
Range ,
ppm
0-200,
0-2000,
0-10,000
0-10,
0-100,
0-1000,
0-10,000,
0-100,000
I
1-20
1-200
1-2000
0-500
0-5000
0-50,000
0-100% '
LFL
ppm to %
ppm to 1
0
0-200U
ppm
Sensitivity
0.1 ppm at
0-200 ppm
0.2 ppm
(Model 128)
0.5 ppm
(Model 108)
0.1 ppm
Low molecular
weights
aromatics
2.U ppm
li LFL
1 ppm
0.01 ppb Cl
organics
0.1 ppb Ben-
zene with
signal -to-
noi se ratio
4:1,
Good for
aromatics •
O.Ob ppm
Benzene
Response
time, s
<5
2
2
<5
' 5
15
1,4,10
and 40
2
2
3
Accessories
o Thermal
Oesorbers
available
o Optional GC
available
o Three lamps
available
o 9.5
(aromatics)
o 10.2
(2-4 com-
pounds)
o 11. ,7
(halocar-
bons )
Preconcentra-
tor Thermal •
Qesoprtiqn
GC Columns
Auto Cal.
from Integral
G.as Cylinder
o Dual Column
o Manual /Auto
Injection
o Column Cond.
o Pre-flush
o Auto Dial
Modem
o Programmable
Calibration
Techniques
o Bag
Sampling
o Hand
Space
.0 Direct
Injection
o Bag Samp.
o External
Gas Cyl .
o .Sag Samp.
o Bag Samp.
0 Head
Space
o Bag' 'Samp.
o internal
. gas cyl .
o P-recon^
centrator
o GC Column
Weaknesses
o .Umbi 1 i'eal
cord too
short
o Digital
readout
hard to
read
o Flame out
frequently
o Battery
failure
o Sample
line kinks
o Compounds
containing
02/N give
1 ow re-
sponse
o Keg. resp.
to CO/CO?
p Three ' .
lamps T
may miss
something
o Changes in
gas temp/
humidity
affects
response
o Column op-
erates at
ambient
temp.
o STO in lab
then to
field at
di f f . .temp
o Can't in-
ject li-
quid samp.
o Light frac-
tions in-
terfere
Service
'Rate
8 hrs
8 hrs
10: hrs
Lack of
Response
o C.1 hydro
carbons
o CH4
o H20
o 02
Cost.J
4,300
6,300
4,955
900
9,500
12,500
12,950 .
6,995
8,995
10,500
10,955
12,955
Samp
Kate
L/m
1.5
O.b
-------
T014-B12
TABLE B-3
PORTABLE GAS CHROMATOGRAPH
SAMPLING DATA SHEET
DATE:
LOCATION:
TIME:
CHROMATOGRAPH1C CONDITIONS:
COLUMN 1: COLUMN TYPE:
I.D. (mm):
COLUMN 2: COLUMN TYPE:
I.D. (mm):
LENGTH (mm):_
LENGTH (mm):
INJ. NO.
INJ. VOL.
COLUMN NO.
SETTING
FLOW (mL/min):_
FLOW (mL/min):_
LOCATION
SITE PLAN (indicate sampling locations):
DATE
SIGNATURE
-------
T014-B13
TABLE B-4
SYSTEM PERFORMANCE CRITERIA FOR PORTABLE 6Ca
Criteria
Test
Compound
Acceptable
Range
Suggested
Corrective Action
PID Response
Elution Time
Resolution13
Trichloroethylene
Styrene
Benzene/Trichloro-
ethylene
j> 108 uV-sec/ng Re-tune or replace
lamp
2.65 +_ 0.15 min Inspect for leaks,
adjust carrier flow
> 1.4
Replace column
aBased on analysis of a vapor mixture of benzene, styrene, and trichloro-
.ethylene.
Define by: R + = 2d/(W1+W2); where d = distance between the peaks and
W = peak width at base.
-------
T014-B14
TABLE B-5
ESTIMATED LIMITS OF DETECTION (LOD) FOR SELECTED VOCs
LOP (ng) LOD (ppb)
Ch1oroforma
1 ,1 ,1-Trichl oroethane9
Carbon tetrachloridea
Benzene
1 ,2-Di chl oroethane"
Trichloroethyleneb
Tetrachloroethyleneb
1,2-Dibromoethane
p-Xylenec
m-Xylene<-
o-Xylened
Styrene"
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-TM chl oroethane, and Carbon tetrachloride coelute on
0.66 m 3% SP2100.
bl,2-Dichloroethane, Trichloroethylene, and Tetrachloroethylene coelute on
0.66 m 3% SP2100.
Cp-Xylene and m-Xylene coelute on 0.66 m 3% SP2100.
dStyrene and o-Xylene coelute on 0.66 m 3% SP2100.
-------
T014-B15
Peak Assignments For Standard Mixture
Peak No.
Compound{s)a
2
3
4
5
Benzene; Chloroform;
1,1,1 -Trichloroetnane;
Carbon Tetrachloride
1,2-Dich!oroethane;
Trichloroethytene
Tetrachloroethylene;
1,2-Dibromoethane
Ethylbenzene
m&- Xylene
S-XyIene;Styrene
a Toluene (not listed) eiutes between
peaks 1 and 2.
Time-
FIGURE B-1
TYPICAL CHROMATOGRAM OF VOCs DETERMINED
BY A PORTABLE GC
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-------
APPENDIX C
INSTALLATION AND OPERATION PROCEDURES FOR
U.S. ENVIRONMENTAL PROTECTION AGENCY'S
URBAN AIR TOXIC POLLUTANT PROGRAM SAMPLER
1. Scope
1.1 The subatmospheric sampling system described in this method has
been modified and redesigned specifically for use in USEPA's Urban
Air Toxic Pollutant Program (UATP), a joint project of USEPA's
Office of Air Quality Planning and Standards, the Environmental
Monitoring Systems Laboratory, and the participating state air
pollution control agencies. The purpose of UATP is 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. The sampler is described in the paper, "Auto-
matic Sampler for Collection of 24-Hour Integrated Whole-Air
Samples for Organic Analysis," to be presented at the 1988 Annual
Meeting of APCA, Dallas, Texas, June, 1988 (Paper No. 88-150.3).
1.2 The sampler is based on the collection of whole air samples in
6-liter, SUMMA® passivated stainless steel canisters. The sampler
features electronic timer for ease, accuracy and flexibility of
sample period programming, an independently setable 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-l.
1.3 The design of the sampler is pump!ess, using an evacuated canis-
ter to draw the ambient sample air into itself at a fixed flow
rate (3-5 cm3/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 accumu-
late substantial concentrations of organic materials under stag-
nant (zero flow rate) conditions. Therefore such lines and sur-
faces 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 speci-
fied start of the sample period to purge the inlet lines and
-------
T014-C2
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, timer 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 cap-
illary to approximately 100 cm3/min. Timer 1 also energizes the •
heated inlet line to allow it to come up to its controlled temper-
ature 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 into the canister.
2.3 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 line. 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 connections for the canister sample and the two optional
formaldehyde cartridge samples.
3. Sampler 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
-------
T014-C3
on a table, shelf, or other flat surface. Access to a source
s^r- 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 (Figure C-l)
3.2.1 The sampler cover is removed. The sampler is not plugged
into the 115 vac power until all other electrical connec-
tions are completed.
3.2.2 The pump is plugged into its power connector (if not al-
ready 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 ground-
ed 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.
3.3.2 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 Swagelok fitting on the canister must not be cross-
threaded. The connection is tightened snugly with a wrench.
-------
T014-C8
Heated Inlet Line
Pump Activated
PrtorTo
Sample Period
To Purge
Inlet Lines
DNPH-Coated
Sep-PAK
Formaldehydf
Cartridges
H
Duplicate
Filter/Orifice Assembly
H
I Primary
Toggle
Valve
Vent
Vacuum
Relief
n
3-Way
Solenoid
Valve
»»*'*
Capillary
Paniculate
Filter
-100 cm3/min
Flow
Controller
(3-5cm3/min)
Latching
Solenoid
Valve
f
j
t
FIGURE C-1.
U.S. ENVIRONMENTAL PROTECTION AGENCY
UATP SAMPLER SCHEMATIC OF SAMPLE
INLET CONNECTIONS
------- |