EPA/625/R-96/010b
Compendium of Methods
for the Determination of
Toxic Organic Compounds
in Ambient Air
Second Edition
Compendium Method TO-10A
Determination Of Pesticides And
Polychlorinated Biphenyls In Ambient
Air Using Low Volume Polyurethane
Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector
Detection (GC/MD)
Center for Environmental Research Information
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
January 1999
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Method TO-10A
Acknowledgements
This Method was prepared for publication in the Compendium of Methods for the Determination of Toxic
Organic Compounds in Ambient Air, Second Edition (EPA/625/R-96/010b), which was prepared under Contract
No. 68-C3-0315, WA No. 3-10, by Midwest Research Institute (MRI), as a subcontractor to Eastern Research
Group, Inc. (ERG), and under the sponsorship of the U.S. Environmental Protection Agency (EPA). Justice A.
Manning, John Burckle, and Scott R Hedges, Center for Environmental Research Information (CERI), and Frank
F. McElroy, National Exposure Research Laboratory (NERL), all in the EPA Office of Research and
Development (ORD), were responsible for overseeing the preparation of this method. Additional support was
provided by other members of the Compendia Workgroup, which include:
John Burckle, U.S. EPA, ORD, Cincinnati, OH
• James L. Cheney, Corps of Engineers, Omaha, NB
Michael Davis, U.S. EPA, Region 7, KC, KS
Joseph B. Elkins Jr., U.S. EPA, OAQPS, RTP, NC
Robert G Lewis, U.S. EPA, NERL, RTP, NC
Justice A. Manning, U.S. EPA, ORD, Cincinnati, OH
• William A. McClenny, U.S. EPA, NERL, RTP, NC
Frank F. McElroy, U.S. EPA, NERL, RTP, NC
Heidi Schultz, ERG, Lexington, MA
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
Method TO-10 was originally published in March of 1989 as one of a series of peer reviewed methods in the
second supplement to "Compendium of Methods for the Determination of Toxic Organic Compounds in
Ambient Air, " EPA 600/4-89-018. In an effort to keep these methods consistent with current technology,
Method TO-10 has been revised and updated as Method TO-10A in this Compendium to incorporate new or
improved sampling and analytical technologies. In addition, this method incorporates ASTM Method D 4861-94,
Standard Practice for Sampling and Analysis of Pesticides and Poly chlorinate dBiphenyls in Air.
This Method is the result of the efforts of many individuals. Gratitude goes to each person involved in the
preparation and review of this methodology.
Author(s)
Robert G. Lewis, U.S. EPA, NERL, RTP, NC
Peer Reviewers
• William T. "Jerry" Winberry, Jr., EnviroTech Solutions, Gary, NC
• Irene D. DeGraff, Supelco, Bellefonte, PA
Lauren Drees, U. S. EPA, NRMRL, Cincinnati, OH
Finally, recognition is given to Frances Beyer, Lynn Kaufman, Debbie Bond, Cathy Whitaker, and Kathy Johnson
of Midwest Research Institute's Administrative Services staff whose dedication and persistence during the
development of this manuscript has enabled it's production.
DISCLAIMER
This Compendium has been subjected to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or
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METHOD TO-10A
Determination Of Pesticides And Polychlorinated Biphenyls In Ambient
Air Using Low Volume Polyurethane Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector Detection (GC/MD)
TABLE OF CONTENTS
Page
1. Scope 10A-1
2. Summary of Method 10A-1
3. Significance 10A-2
4. Applicable Documents 10A-2
4.1 ASTM Standards 10A-2
4.2 EPA Documents 10A-2
4.3 Other Documents 10A-3
5. Definitions 10A-3
6. Interferences 10A-3
7. Equipment and Materials 10A-4
7.1 Materials for Sample Collection 10A-4
7.2 Equipment for Analysis 10A-5
7.3 Reagents and Other Materials 10A-5
8. Assembly and Calibration of Sampling System 10A-6
8.1 Description of Sampling Apparatus 10A-6
8.2 Calibration of Sampling System 10A-6
9. Preparation of PUF Sampling Cartridges 10A-6
10. Sampling 10A-7
11. Sample Extraction Procedure 10A-8
11.1 Sample Extraction 10A-8
11.2 Sample Cleanup 10A-9
in
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TABLE OF CONTENTS (continued)
Page
12. Analytical Procedure 10A-10
12.1 Analysis of Organochlorine Pesticides by Capillary Gas Chromatography with
Electron Capture Detector (GC/ECD) 10A-10
12.2 Analysis of Organophosphorus Pesticides by Capillary Gas Chromatography
with Flame Photometric or Nitrogen-Phosphorus Detectors (GC/FPD/NPD) 10A-11
12.3 Analysis of Carbamate and Urea Pesticides by Capillary Gas Chromatography
with Nitrogen-Phosphorus Detector 10A-11
12.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by High
Performance Liquid Chromatography (HPLC) 10A-11
12.5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass
Spectrometry Detection (GC/MS) 10A-12
12.6 Sample Concentration 10A-12
13. Calculations 10A-13
13.1 Determination of Concentration 10A-13
14. Sampling and Retention Efficiencies 10A-15
14.1 General 10A-15
14.2 Determining SE 10A-15
15. Performance Criteria and Quality Assurance 10A-17
15.1 Standard Operating Procedures (SOPs) 10A-17
15.2 Process, Field, and Solvent Blanks 10A-17
15.3 Sampling Efficiency and Spike Recovery 10A-17
15.4 Method Precision and Bias 10A-18
15.5 Method Safety 10A-18
16. References 10A-18
IV
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METHOD TO-10A
Determination Of Pesticides And Polychlorinated Biphenyls In Ambient
Air Using Low Volume Polyurethane Foam (PUF) Sampling Followed By
Gas Chromatographic/Multi-Detector (GC/MD) Detection
1. Scope
1.1 This document describes a method for sampling and analysis of a variety of common pesticides and for
polychlorinated biphenyls (PCBs) in ambient air. The procedure is based on the adsorption of chemicals from
ambient air on polyurethane foam (PUF) or a combination of PUF and granular sorbent using a low volume
sampler.
1.2 The low volume PUF sampling procedure is applicable to multicomponent atmospheres containing common
pesticide concentrations from 0.001 to 50 ,ug/m3 over 4- to 24-hour sampling periods. The limits of detection
will depend on the nature of the analyte and the length of the sampling period.
1.3 Specific compounds for which the method has been employed are listed in Table 1. The analytical
methodology described in Compendium Method TO-10A is currently employed by laboratories throughout the
U.S. The sampling methodology has been formulated to meet the needs of common pesticide and PCB sampling
in ambient air.
1.4 Compendium Method TO-10 was originally published in 1989. The method was further modified for indoor
air application in 1990. In an effort to keep the method consistent with current technology, Compendium
Method TO-10 has incorporated ASTM Method D4861-94 (1) and is published here as Compendium
Method TO-10A.
2. Summary of Method
2.1 A low-volume (1 to 5 L/minute) sample is used to collect vapors on a sorbent cartridge containing PUF or
PUF in combination with another solid sorbent. Airborne particles may also be collected, but the sampling
efficiency is not known (2).
2.2 Pesticides and other chemicals are extracted from the sorbent cartridge with 5 percent diethyl ether in hexane
and determined by gas chromatography coupled with an electron capture detector (BCD), nitrogen-phosphorus
detector (NPD), flame photometric detector (FPD), Hall electrolytic conductivity detector (HECD), or a mass
spectrometer (MS). For common pesticides, high performance liquid chromatography (HPLC) coupled with an
ultraviolet (UV) detector or electrochemical detector may be preferable. This method describes the use of an
electron capture detector.
2.3 Interferences resulting from analytes having similar retention times during GC analysis are resolved by
improving the resolution or separation, such as by changing the chromatographic column or operating parameters,
or by fractionating the sample by column chromatography.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-1
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Method TO-10A Pesticides/PCBs
3. Significance
3.1 Pesticide usage and environmental distribution are common to rural and urban areas of the United States.
The application of pesticides can cause potential adverse health effects to humans by contaminating soil, water,
air, plants, and animal life. However, human exposure to PCBs continues to be a problem because of their
presence in the environment.
3.2 Many pesticides and PCBs exhibit bioaccumulative, chronic health effects; therefore, monitoring the presence
of these compounds in ambient air is of great importance.
3.3 Use of a portable, low volume PUF sampling system allows the user flexibility in locating the apparatus.
The user can place the apparatus in a stationary or mobile location. The portable sampling apparatus may be
positioned in a vertical or horizontal stationary location (if necessary, accompanied with supporting structure).
Mobile positioning of the system can be accomplished by attaching the apparatus to a person to test air in the
individual's breathing zone.
3.4 Moreover, this method has been successfully applied to measurement of common pesticides in outdoor air,
indoor air and for personal respiratory exposure monitoring (3).
4. Applicable Documents
4.1 ASTM Standards
• D1356 Definition of Terms Relating to Atmospheric Sampling and Analysis
• D4861-94 Standard Practice for Sampling and Analysis of Pesticides and Poly chlorinate dBiphenyls
in Air
• E260 Recommended Practice for General Gas Chromatography Procedures
• E355 Practice for Gas Chromatography Terms and Relationships
• D3686 Practice for Sampling Atmospheres to Collect Organic Compound Vapors (Activated Charcoal
Tube Adsorption Method
• D3687 Practice for Analysis of Organic Compound Vapors Collected by the Activated Charcoal Tube
Adsorption
• D4185 Practice for Measurement of Metals in Workplace Atmosphere by Atomic Absorption
Spectrophotometry
4.2 EPA Documents
• Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air: Method
TO-10, Second Supplement, U. S. Environmental Protection Agency, EPA 600/4-89-018, March 1989.
• Manual of Analytical Methods for Determination of Pesticides in Humans and Environmental
Standards, U. S. Environmental Protection Agency, EPA 600/8-80-038, June 1980.
• Compendium of Methods for the Determination of Air Pollutants in Indoor Air: Method IP-8, U. S.
Environmental Protection Agency, EPA 600/4-90-010, May 1990.
Page 10A-2 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
4.3 Other Documents
• Code of Federal Regulations, Title 40, Part 136, Method 604
5. Definitions
[Note: Definitions used in this document and in any user-prepared Standard operating procedures (SOPs)
should be consistent with ASTMD1356, E260, andE355. All abbreviations and symbols are defined within
this document at point of use.]
5.1 Sampling efficiency (SE)-ability of the sampling medium to trap analytes of interest. The percentage of
the analyte of interest collected and retained by the sampling medium when it is introduced as a vapor in air or
nitrogen into the air sampler and the sampler is operated under normal conditions for a period of time equal to
or greater than that required for the intended use is indicated by %SE.
5.2 Retention efficiency (RE)-ability of sampling medium to retain a compound added (spiked) to it in liquid
solution.
5.3 Static retention efficiency-ability of the sampling medium to retain the solution spike when the sample
cartridge is stored under clean, quiescent conditions for the duration of the test period.
5.4 Dynamic retention efficiency (REd)-ability of the sampling medium to retain the solution spike when air
or nitrogen is drawn through the sampling cartridge under normal operating conditions for the duration of the test
period. The dynamic RE is normally equal to or less than the SE.
5.5 Retention time (RT)-time to elute a specific chemical from a chromatographic column, for a specific carrier
gas flow rate, measured from the time the chemical is injected into the gas stream until it appears at the detector.
5.6 Relative retention time (RRT)-a rate of RTs for two chemicals for the same chromatographic column and
carrier gas flow rate, where the denominator represents a reference chemical.
5.7 Surrogate standard-a chemically inert compound (not expected to occur in the environmental sample) that
is added to each sample, blank, and matrix-spiked sample before extraction and analysis. The recovery of the
surrogate standard is used to monitor unusual matrix effects, gross sample processing errors, etc. Surrogate
recovery is evaluated for acceptance by determining whether the measured concentration falls within acceptable
limits.
6. Interferences
6.1 Any gas or liquid chromatographic separation of complex mixtures of organic chemicals is subject to serious
interference problems due to coelution of two or more compounds. The use of capillary or microbore columns
with superior resolution or two or more columns of different polarity will frequently eliminate these problems.
In addition, selectivity may be further enhanced by use of a MS operated in the selected ion monitoring (SIM)
mode as the GC detector. In this mode, co-eluting compounds can often be determined.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-3
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Method TO-10A Pesticides/PCBs
6.2 The BCD responds to a wide variety of organic compounds. It is likely that such compounds will be
encountered as interferences during GC/ECD analysis. The NPD, FPD, and HECD detectors are element specific,
but are still subject to interferences. UV detectors for HPLC are nearly universal, and the electrochemical
detector may also respond to a variety of chemicals. Mass spectrometric analyses will generally provide positive
identification of specific compounds.
6.3 PCBs and certain organochlorine pesticides (e.g., chlordane) are complex mixtures of individual compounds
which can cause difficulty in accurately quantifying a particular formulation in a multiple component mixture.
PCBs may interfere with the determination of pesticides.
6.4 Contamination of glassware and sampling apparatus with traces of pesticides or PCBs can be a major source
of error, particularly at lower analyte concentrations. Careful attention to cleaning and handling procedures is
required during all steps of sampling and analysis to minimize this source of error.
6.5 The general approaches listed below should be followed to minimize interferences.
6.5.1 Polar compounds, including certain pesticides (e.g., organophosphorus and carbamate classes) can be
removed by column chromatography on alumina. Alumina clean-up will permit analysis of most organochlorine
pesticides and PCBs (4).
6.5.2 PCBs may be separated from other organochlorine pesticides by column chromatography on silicic acid
(5,6).
6.5.3 Many pesticides can be fractionated into groups by column chromatography on Florisil (6).
7. Equipment and Materials
7.1 Materials for Sample Collection
7.1.1 Continuous-Flow Sampling Pump (see Figure 1). The pump should provide a constant air flow
(
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Pesticides/PCBs Method TO-10A
7.1.4 Particle Filter. The collection efficiency of PUF for small-diameter (0.1 to 1 ,um) airborne particles
is only about 20% (7). However, most pesticides and PCBs exist in air under steady-state conditions primarily
as vapors (8). Most particulate-associated pesticides or PCBs, if any, will also tend to be vaporized from filters
after collection (9). Collocated sampling with and without a quartz-fiber pre-filter has yielded indistinguishable
results for a broad spectrum of pesticides and PCBs found in indoor air (10).
7.1.4.1 An open-face filter may be attached to the sampling cartridge by means of a union for 1-in.
(25.4-mm) tubing.
7.1.4.2 A 32-mm diameter quartz microfiber filter (e.g., Palifelex® type 2500 QAT-UP) is placed in the
open end of the union and supported by means of a screen or perforated metal plate [e.g., a 304-stainless steel
disk, 0.0312-in. (0.8-mm) thick with 1/16-in. (1.6-mm) diameter round perforations at 132 holes per in.2
(20 holes/cm2), 41% open area.]. A 32-mm Viton® O-ring is placed between the filter and outer nut to effect
a seal (see Figure 3). This filter holder is available from Supelco Park, Bellefonte, PA; SKC, 334 Forty Eight,
PA; and other manufacturers.
7.1.5 Size-Selective Impactor Inlet. A size-selective impactor inlet with an average particle-size cut-point
of 2.5 /jm or 10 /jm mean diameter at a sampling rate of 4 L/min may be used to exclude nonrespirable airborne
particulate matter (11). This inlet, particle filter support, sampling cartridge holders are available commercially
from Supelco, Supelco Park, Bellefonte, PA; SKC, 334 Forty Eight, PA and University Research Glassware
(URG), Chapel Hill, NC.
7.1.6 Tenax-TA. 60/80 mesh, 2,6-diphenylphenylene oxide polymer. Commercially available from
Supelco, Supelco Park, Bellefonte, PA and SKC, 334 Forty Eight, PA.
7.2 Equipment for Analysis
7.2.1 Gas Chromatograph (GC). The GC system should be equipped with appropriate detector(s) and
either an isothermally controlled or temperature programmed heating oven. Improved detection limits may be
obtained with a GC equipped with a cool on-column or splitless injector.
7.2.2 Gas Chromatographic Column. As an example, a 0.32 mm (I.D.) x 30 m DB-5, DB-17, DB-608,
and DB-1701 are available. Other columns may also provide acceptable results.
7.2.3 HPLC Column. As an example, a 4.6-mm x 25-cm Zorbax SIL or ^Bondpak C-18. Other columns
may also provide acceptable results.
7.2.4 Microsyringes. 5 /jL volume or other appropriate sizes.
7.3 Reagents and Other Materials
7.3.1 Round Bottom Flasks. 500 mL, I 24/40 joints, best source.
7.3.2 Capacity Soxhlet Extractors. 300 mL, with reflux condensers, best source.
7.3.3 Kuderna-Danish Concentrator. 500 mL, with Snyder columns, best source.
7.3.4 Graduated Concentrator Tubes. 10 mL, with 19/22 stoppers, best source.
7.3.5 Graduated Concentrator Tubes. 1 mL, with 14/20 stoppers, best source.
7.3.6 TFE Fluorocarbon Tape. 1/2 in., best source.
7.3.7 Filter Tubes. Size 40 mm (I.D.) x 80 mm.
7.3.8 Serum Vials. 1 mL and 5 mL, fitted with caps lined with TFE fluorocarbon.
7.3.9 Pasteur Pipettes. 9 in., best source.
7.3.10 Glass Wool. Fired at 500°C, best source.
7.3.11 Boiling Chips. Fired at 500°C, best source..
7.3.12 Forceps. Stainless steel, 12 in., best source.
7.3.13 Gloves. Latex or precleaned (5% ether/hexane Soxhlet extracted) cotton.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-5
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Method TO-10A Pesticides/PCBs
7.3.14 Steam Bath.
7.3.15 Heating Mantles. 500 mL.
7.3.16 Analytical Evaporator. Nitrogen blow-down.
7.3.17 Acetone. Pesticide quality.
7.3.18 n-Hexane. Pesticide quality.
7.3.19 Diethyl Ether. Preserved with 2% ethanol.
7.3.20 Sodium Sulfate. Anhydrous analytical grade.
7.3.21 Alumina. Activity Grade IV, 100/200 mesh.
7.3.22 Glass Chromatographic Column. 2-mm I.D. x 15-cm long.
7.3.23 Soxhlet Extraction System. Including Soxhlet extractors (500 and 300 mL), variable voltage
transformers, and cooling water source.
7.3.24 Vacuum Oven. Connected to water aspirator.
7.3.25 Die.
7.3.26 Ice Chest.
7.3.27 Silicic Acid. Pesticide grade.
7.3.28 Octachloronaphthalene (OCN). Research grade.
7.3.29 Florisil. Pesticide grade.
8. Assembly and Calibration of Sampling System
8.1 Description of Sampling Apparatus
8.1.1 A typical sampling arrangement utilizing a personal air pump is shown in Figure 1. This method is
designed to use air sampling pumps capable of pulling air through the sampling cartridge at flow rates of 1 to
5 L/min. The method writeup presents the use of this device.
8.1.2 The sampling cartridge (see Figure 2) consists of a glass sampling cartridge in which the PUF plug or
PUF/Tenax® TA "sandwich" is retained.
8.2 Calibration of Sampling System
8.2.1 Air flow through the sampling system is calibrated by the assembly shown in Figure 4. All air sampler
must be calibrated in the laboratory before and after each sample collection period, using the procedure described
below.
8.2.2 For accurate calibration, attach the sampling cartridge in-line during calibration. Vinyl bubble tubing
or other means (e.g., rubber stopper or glass joint) may be used to connect the large end of the cartridge to the
calibration system. Refer to ASTM Practice D3686 or D4185, for procedures to calibrate small volume air
pumps.
9. Preparation of PUF Sampling Cartridges
9.1 The PUF adsorbent is white and yellows upon exposure to light. The "yellowing" of PUF will not affect its
ability to collected pesticides or PCBs.
9.2 For initial cleanup and quality assurance purposes, the PUF plug is placed in a Soxhlet extractor and
extracted with acetone for 14 to 24 hours at 4 to 6 cycles per hour.
Page 10A-6 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
[Note: If 'commerciallypre-extractedPUFplugs are used, extraction with acetone is not required.]
Follow with a 16-hour Soxhlet extraction with 5% diethyl ether in n-hexane. When cartridges are reused, 5%
diethyl ether in n-hexane can be used as the cleanup solvent.
9.3 Place the extracted PUF in a vacuum oven connected to a water aspirator and dry at room temperature for
2 to 4 hours (until no solvent odor is detected). Alternatively, they may be dried at room temperature in an air-
tight container with circulating nitrogen (zero grade). Place the clean PUF plug into a labeled glass sampling
cartridges using gloves and forceps. Wrap the cartridges with hexane-rinsed aluminum foil and placed in jars
fitted with TFE fluorocarbon-lined caps. The foil wrapping may also be marked for identification using a blunt
probe.
9.4 Granular sorbents may be combined with PUF to extend the range of use to compounds with saturation vapor
pressures greater than 10~4 kPa (6). A useful combination trap can be assembled by "sandwiching" 0.6 g of
Tenax-TA between two 22-mm ID. x 3.8-cm pre-cleaned PUF plugs, as shown in Figure 2, Cartridge b. The
Tenax-TA should be pre-extracted as described in Section 9.2. This trap may be extracted, vacuum dried, and
removed without unloading it.
9.5 Analyze at least one assembled cartridge from each batch as a laboratory blank before the batch is
acceptable. A blank level of <10 ng/plug for single component compounds is considered to be acceptable. For
multiple component mixtures (e.g., PCBs), the blank level should be <100 ng/plug.
9.6 After cleaning, cartridges are considered clean up to 30 days when stored in sealed containers. Certified clean
cartridges do not need to be chilled when shipping to the field.
10. Sampling
[Note: After the sampling system has been assembled and calibrated as per Section 8, it can be used to collect
air samples as described below. The prepared sample cartridges should be used within 30 days of
certification and should be handled only with latex or precleaned cotton gloves.]
10.1 Carefully remove the clean sample cartridge from the aluminum foil wrapping (the foil is returned to jars
for later use) and attached to the pump with flexible tubing. The sampling assembly is positioned with the intake
downward or in horizontal position. Locate the sampler in an unobstructed area at least 30 meters from any
obstacle to air flow. The PUF or PUF/XAD-2 cartridge intake is positioned 1 to 2 m above ground level.
Cartridge height above ground is recorded on the Compendium Method TO-10A field test data sheet (FTDS),
as illustrated in Figure 5.
10.2 After the PUF cartridge is correctly inserted and positioned, the power switch is turned on and the sampling
begins. The elapsed time meter is activated and the start time is recorded. The pumps are checked during the
sampling process and any abnormal conditions discovered are recorded on the FTDS. Ambient temperatures and
barometric pressures are measured and recorded periodically during the sampling procedure on the FTDS.
10.3 At the end of the desired sampling period, the power is turned off, the PUF cartridge removed from the
sampler and wrapped with the original aluminum foil and placed in a sealed, labeled container for transport, under
blue ice (<4°C), back to the laboratory. At least one field blank is returned to the laboratory with each group of
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-7
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Method TO-10A Pesticides/PCBs
samples. A field blank is treated exactly like a sample except that no air is drawn through the cartridge. Samples
are stored at <4°C or below until analyzed in the laboratory. Extraction must occur within 7 days of sampling
and analysis within 40 days of extraction. Refer to ASTM D4861-94 (1), Appendix X3 for storage stability for
various common pesticides and other compounds on PUF or PUF/Tenax TA sandwich.
11. Sample Extraction Procedure
[Note: Sample extraction should be performed under a properly ventilated hood.]
11.1 Sample Extraction
11.1.1 All samples should be extracted within 1 week after collection. All samples should be stored at <4°C
until extracted.
11.1.2 All glassware should be washed with a suitable detergent; rinsed with deionized water, acetone, and
hexane; rinsed again with deionized water; and fired in an oven (500°C).
11.1.3 Prepare a spiking solution for determination of extraction efficiency. The spiking solution should
contain one or more surrogate compounds that have chemical structures and properties similar to those of the
analytes of interest. Octachloronaphthalene (OCN) and dibutylchlorendate have been used as surrogates for
determination of organochlorine pesticides by GC with an BCD. Tetrachloro-m-xylene and decachlorobiphenyl
can also be used together to insure recovery of early and late eluting compounds. For organophosphate pesticides,
tributylphosphate or triphenylphosphate may be employed as surrogates. The surrogate solution should be
prepared so that addition of 100 /jL into the PUF plug results in an extract containing the surrogate compound
at the high end of the instrument's calibration range. As an example, the spiking solution for OCN is prepared
by dissolving 10 mg of OCN in 10 mL of 10% acetone in n-hexane, followed by serial dilution n-hexane to
achieve a final spiking solution of OCN of 1 ,ug/mL.
[Note: Use the recoveries of the surrogate compounds to monitor for unusual matrix effects and gross sample
processing errors. Evaluate surrogate recovery for acceptance by determining whether the measured
concentration falls within the acceptance limits of 60-120 percent.]
11.1.4 The extracting solution (5% diethyl ether/hexane) is prepared by mixing 1900 mL of freshly opened
hexane and 100 mL of freshly opened diethyl ether (preserved with ethanol) to a flask.
11.1.5 All clean glassware, forceps, and other equipment to be used should be rinsed with 5% diethyl ether/
hexane and placed on rinsed (5% diethyl ether/hexane) aluminum foil until use. The condensing towers should
also be rinsed with 5% diethyl ether/hexane. Then add 300 mL or 5% diethyl ether/hexane to the 500 mL round
bottom boiling flask and add up to three boiling granules.
11.1.6 Using precleaned (i.e., 5% diethyl ether/hexane Soxhlet extracted) cotton gloves, the glass PUF
cartridges are removed from the sealed container, the PUF removed from the glass container and is placed into
the 300 mL Soxhlet extractor using prerinsed forceps.
[Note: If "sandwich" trap is used, carefully clean outside walls of cartridge with hexane-soaked cotton swabs
or laboratory tissues (discard) and place cartridge into extractor with intake (large end) downward.]
11.1.7 Before extraction begins, add 100 uL of the OCN solution directly to the top of the PUF plug.
Page 10A-8 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
[Note: Incorporating a known concentration of the solution onto the sample provides a quality assurance
check to determine recovery efficiency of the extraction and analytical processes.]
11.1.8 Connect the Soxhlet extractor to the 500 mL boiling flask and condenser. Wet the glass joints with
5% diethyl ether/hexane to ensure a tight seal between the fittings. If necessary, the PUF plug can be adjusted
using forceps to wedge it midway along the length of the siphon. The above procedure should be followed for
all samples, with the inclusion of a blank control sample.
11.1.9 The water flow to the condenser towers of the Soxhlet extraction assembly should be checked and the
heating unit turned on. As the samples boil, the Soxhlet extractors should be inspected to ensure that they are
filling and siphoning properly (4 to 6 cycles/hour). Samples should cycle for a minimum of 16 hours.
11.1.10 At the end of the extracting process (minimum of 16 hours), the heating unit is turned off and the
sample cooled to room temperature.
11.1.11 The extracts are then concentrated to 5 mL using a Kuderna-Danish (K-D) apparatus. The K-D is
set up, assembled with concentrator tubes, and rinsed. The lower end of the filter tube is packed with glass wool
and filled with sodium sulfate to a depth of 40 mm. The filter tube is then placed in the neck of the K-D. The
Soxhlet extractors and boiling flasks are carefully removed from the condenser towers and the remaining solvent
is drained into each boiling flask. Sample extract is carefully poured through the filter tube into the K-D. Each
boiling flask is rinsed three times by swirling hexane along the sides. Once the sample has drained, the filter tube
is rinsed down with hexane. Each Synder column is attached to the K-D and rinsed to wet the joint for a tight
seal. The complete K-D apparatus is placed on a steam bath and the sample is evaporated to approximately 5
mL.
[Note: Do not allow samples to evaporate to dryness.]
Remove sample from the steam bath, rinse Synder column with minimum of hexane, and allow to cool. Adjust
sample volume to 10 mL in a concentrator tube, close with glass stopper and seal with TFE fluorocarbon tape.
Alternatively, the sample may be quantitatively transferred (with concentrator tube rinsing) to prescored vials
and brought up to final volume. Concentrated extracts are stored at <4 ° C until analyzed. Analysis should occur
no later than 40 days after sample extraction.
11.2 Sample Cleanup
11.2.1 If polar compounds (from example, organophosphorus and carbamate classes) that interfere with
GC/ECD analysis are present, use column chromatographic cleanup or alumina. The sample cleanup will permit
the analysis of most organochlorine pesticides or PCBs.
11.2.2 Before cleanup, the sample extract is carefully reduced to 1 mL using a gentle stream of clean
nitrogen.
11.2.3 A glass chromatographic column (2-mm ID. x 15-cm long) is packed with alumina, activity grade
IV, and rinsed with approximately 20 mL of n-hexane. The concentrated sample extract is placed on the column
and eluted with 10 mL of n-hexane at a rate of 0.5 mL/minute. The eluate volume is adjusted to exactly 10 mL
and analyzed as per Section 12.
11.2.4 If both PCBs and organochlorine pesticides are sought, alternate cleanup procedures (5,6) may be
required (i.e., silicic acid).
11.2.5 Finally, class separation and improved specificity can be achieved by column clean-up and separation
on Florisil (6).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-9
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Method TO-10A Pesticides/PCBs
12. Analytical Procedure
12.1 Analysis of Organochlorine Pesticides by Capillary Gas Chromatography with Electron Capture
Detector (GC/ECD)
[Note: Organochlorine pesticides, PCBs and many nonchlorinatedpesticides are responsive to electron
capture detection (see Table 1). Most of these compounds can be analyzed at concentration of I to 50 ng/mL
by GC/ECD. The following procedure is appropriate. Analytical methods that have been used to determine
pesticides and PCBs collected from air by this procedure have been published (12).]
12.1.1 Select GC column (e.g., 0.3-mm by 30-m DB-5 column) and appropriate GC conditions to separate
the target analytes. Typical operating parameters for this column with splitless injection are: Carrier gas-
chromatography grade helium at a flow rate of 1 to 2 mL/min and a column head pressure of 7 to 9 psi (48 to
60kPa); injector temperature of 250°C; detector temperature of 350°C; initial oven temperature of 50°C held
for 2.Omin., ramped at 15°C/minto 150°Cfor 8min, ramped at 10°C/min to 295 °C then held for 5 min; purge
time of 1.0 min. A typical injection volume is 2 to 3 ,uL.
12.1.2 Remove sample extract from the refrigerator and allow to warm to room temperature.
12.1.3 Prepare standard solution from reference materials of known purity. Analytically pure standards of
Organochlorine pesticides and PCBs are available from several commercial sources.
12.1.4 Use the standard solutions of the various compounds of interest to determine relative retention times
(RRTs) to an internal standard such as p,p'-DDE, aldrin or octachloronaphthalene. Use 1 to 3-juL injections or
other appropriate volumes.
12.1.5 Determine detector linearity by injecting standard solutions of three different concentrations (amounts)
that bracket the range of analyses. The calibration is considered linear if the relative standard deviation (RSD)
of the response factors for the three standards is 20 percent or less.
12.1.6 Calibrate the system with a minimum of three levels of calibration standards in the linear range. The
low standard should be near the analytical method detection limit. The calibration is considered linear if the
relative standard deviation (RSD) of the response factors for the three standards is 20 percent or less. The initial
calibration should be verified by the analysis of a standard from an independent source. Recovery of 85 to 115
percent is acceptable. The initial calibration curve should be verified at the begining of each day and after every
ten samples by the analysis of the mid point standard; an RPD of 15% or less is acceptable for continuing use
of the initial calibration curve.
12.1.7 Inject 1 to 3 /jL of the sample extract. Record volume injected to the nearest 0.05 /jL.
12.1.8 A typical BCD response for a mixture of single component pesticides using a capillary column is
illustrated in Figure 6. If the response (peak height or area) exceeds the calibration range, dilute the extract and
reanalyze.
12.1.9 Quantify PCB mixtures by comparison of the total heights or areas of GC peaks (minimum of 5) with
the corresponding peaks in the best-matching standard. Use Aroclor 1242 for early-eluting PCBs and either
Aroclor 1254 or Aroclor 1260 as appropriate for late-eluting PCBs.
12.1.10 If both PCBs and Organochlorine pesticides are present in the same sample, use column
chromatographic separation on silicic acid (5,6) prior to GC analysis.
12.1.11 If polar compounds are present that interfere with GC/ECD analysis, use column chromatographic
cleanup or alumina, activity grade IV, in accordance with Section 11.2.
12.1.12 For confirmation use a second GC column such as DB-608. All GC procedures except GC/MS
require second column confirmation.
Page 10A-10 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
12.1.13 For improved resolution use a capillary column such as an 0.25-mm I.D. x 30-m DB-5 with 0.25 ,um
film thickness. The following conditions are appropriate.
• Helium carrier gas at 1 mL/min.
• Column temperature program, 90°C (4 min)/16°C/min to 154°C/4°C/min to 270°C.
• Detector, 63Ni BCD at 350°C.
• Make up gas, nitrogen, or 5% methane/95% argon at 60 mL/min.
• Splitless injection, 2 /J.L maximum.
• Inj ector temperature, 220 ° C.
12.1.14 Class separation and improved specificity can be achieved by column chromatographic separation
on Florisil (6).
12.2 Analysis of Organophosphorus Pesticides by Capillary Gas Chromatography with Flame
Photometric or Nitrogen-Phosphorus Detectors (GC/FPD/NPD)
[Note: Organophosphorus pesticides are responsive to flame photometric and nitrogen-phosphorus (alkali
flame ionization) detection. Most of these compounds can be analyzed at concentrations of 50 to 500 ng/mL
using either of these detectors.]
12.2.1 Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12.1.14 apply, except
for the selection of surrogates.
12.2.2 Use tributylphosphate, triphenylphosphate, or other suitable compound(s) as surrogates to verify
extraction efficiency and to determine RRTs.
12.3 Analysis of Carbamate and Urea Pesticides by Capillary Gas Chromatography with Nitrogen-
Phosphorus Detector
12.3.1 Trazine, carbamate, and urea pesticides may be determined by capillary GC (DB-5, DB-17, or
DB-1701 stationary phase) using nitrogen-phosphorus detection or MS-SIM with detection limits in the 0.05 to
0.2 /jL/mL range. Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12.1.14 apply,
except for the selection of surrogates, detector, and make up gas.
12.3.2 Thermal degradation may be minimized by reducing the injector temperature to 200°C. HPLC may
also be used, but detection limits will be higher (1 to 5 ,ug/mL).
12.3.3 N-methyl carbamates may be determined using reverse-phase high performance liquid
Chromatography (HPLC) (C-18) (Section 12.4) and post-column derivatization with o-phthaldehyde and
fluorescence detection (EPA Method 531). Detection limits of 0.01 to 0.1 ,ug/mL can be achieved.
12.4 Analysis of Carbamate, Urea, Pyrethroid, and Phenolic Pesticides by High Performance Liquid
Chromatography (HPLC)
[Note: Many carbamate pesticides, urea pesticides, pyrethrins, phenols, and other polar pesticides may be
analyzed by high HPLC with fixed or variable wavelength UV detection. Either reversed-phase or normal
phase Chromatography may be used. Detection limits are 0.2 to 10 iJ,g/mL of extract.]
12.4.1 Select HPLC column (i.e., Zorbax-SIL, 46-mm I.D. x 25-cm, or //-Bondapak CIS, 3.9-mm x 30-cm,
or equivalent).
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-11
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Method TO-10A Pesticides/PCBs
12.4.2 Select solvent system (i.e., mixtures of methanol or acetonitrile with water or mixtures of heptane or
hexane with isopropanol).
12.4.3 Follow analytical procedures given in Sections 12.1.2 through 12.1.9.
12.4.4 If interferences are present, adjust the HPLC solvent system composition or use column
chromatographic clean-up with silica gel, alumina, or Florisil (6).
12.4.5 An electrochemical detector may be used to improve sensitivity for some ureas, carbamates, and
phenolics. Much more care is required in using this detector, particularly in removing dissolved oxygen from the
mobile phase and sample extracts.
12.4.6 Chlorophenol (di- through penta-) may be analyzed by GC/ECD or GC/MS after derivatization with
pentafluorobenzylbromide (EPA Method 604).
12.4.7 Chlorinated phenoxyacetic acid herbicides and pentachlorophenol can be analyzed by GC/ECD or
GC/MS after derivatization with diazomethane (EPA Method 515). DB-5 and DB-1701 columns (0.25-mm I.D.
x 30-m) at 60 to 300°C/4°C per min have been found to perform well.
12.5 Analysis of Pesticides and PCBs by Gas Chromatography with Mass Spectrometry Detection
(GC/MS)
[Note: A mass spectrometer operating in the selected ion monitoring mode is useful for confirmation and
identification of pesticides.]
12.5.1 A mass spectrometer operating in the select ion monitoring (SIM) mode can be used as a sensitive
detector for multi-residue determination of a wide variety of pesticides. Mass spectrometers are now available
that provide detection limits comparable to nitrogen-phosphorus and electron capture detectors.
12.5.2 Most of the pesticides shown in Table 1 have been successfully determined by GC/MS/SIM. Typical
GC operating parameters are as described in Section 12.1.1.
12.5.3 The mass spectrometer is typically operated using positive ion electron impact ionization (70 eV).
Other instrumental parameters are instrument specific.
12.5.4 p-Terphenyl-d14 is commonly used as a surrogate for GC/MS analysis.
12.5.5 Quantification is typically performed using an internal standard method. 1,4-Dichlorobenzene,
naphthalene-d8, acenaphthene-d10, phenanthrene-d10, chrysene-d12 and perylene-d12 are commonly used as internal
standards. Procedures given in Section 12.1.1 through 12.1.9 and Section 12.1.13 through 12.1.14 apply, except
for the selection of surrogates, detector, and make up gas.
12.5.6 See ASTM Practice D 3687 for injection technique, determination of relative retention times, and
other procedures pertinent to GC and HPLC analyses.
12.6 Sample Concentration
12.6.1 If concentrations are too low to detect by the analytical procedure of choice, the extract may be
concentrated to 1 mL or 0.5 mL by carefully controlled evaporation under an inert atmosphere. The following
procedure is appropriate.
12.6.2 Place K-D concentrator tube in a water bath and analytical evaporator (nitrogen blow-down)
apparatus. The water bath temperature should be from 25 °C to 50 °C.
12.6.3 Adjust nitrogen flow through hypodermic needle to provide a gentle stream.
12.6.4 Carefully lower hypodermic needle into the concentrator tube to a distance of about 1 cm above the
liquid level.
12.6.5 Continue to adjust needle placement as liquid level decreases.
12.6.6 Reduce volume to slightly below desired level.
Page 10A-12 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
12.6.7 Adjust to final volume by carefully rinsing needle tip and concentrator tube well with solvent (usually
n-hexane).
13. Calculations
13.1 Determination of Concentration
13.1.1 The concentration of the analyte in the extract solution can be taken from a standard curve where peak
height or area is plotted linearly against concentration in nanograms per milliliter (ng/mL). If the detector
response is known to be linear, a single point is used as a calculation constant.
13.1.2 From the standard curve, determine the nanograms of analyte standard equivalent to the peak height
or area for a particular compound.
13.1.3 Ascertain whether the field blank is contaminated. Blank levels should not exceed 10 ng/sample for
organochlorine pesticides or 100 ng/sample for PCBs and other pesticides. If the blank has been contaminated,
the sampling series must be held suspect.
13.1.4 Quantity of the compound in the sample (A) is calculated using the following equation:
A = 1000
A x V
s • e
v.
i
where:
A = total amount of analyte in the sample, ng.
As = calculated amount of material injected onto the chromatograph based on calibration
curve for injected standards, ng.
Ve= final volume of extract, mL.
V; = volume of extract injected, /j,L.
1000 = factor for converting microliters to milliliters.
13.1.5 The extraction efficiency (EE) is determined from the recovery of surrogate spike as follows:
EE(%) = — [100]
where:
EE = extraction efficiency, %.
S = amount of spike recovered, ng.
Sa = amount of spike added to plug, ng.
The extraction efficiency (surrogate recovery) must fall between 60-120% to be acceptable.
13.1.6 The total volume of air sampled under ambient conditions is determined using the following equation:
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-13
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Method TO-10A
Pesticides/PCBs
V. =
11
£
i = 1
1000 L/m3
where:
Va = total volume of air sampled, m3.
T; = length of sampling segment between flow checks, min.
F; = average flow during sampling segment, L/min.
13.1.7 The air volume is corrected to EPA standard temperature (25 °C) and standard pressure (760 mm Hg)
as follows:
=v
P - P
rb w
760 mm Hg,
298K]
where:
Vs = volume of air at standard conditions (25 °C and 760 mm Hg), std. m3.
Va = total volume of air sampled, m3.
Pb = average ambient barometric pressure, mm Hg.
Pw = vapor pressure of water at calibration temperature, mm Hg.
tA = average ambient temperature, °C + 273.
13.1.8 If the proper criteria for a sample have been met, concentration of the compound in a standard cubic
meter of air sampled is calculated as follows:
Ca(ng/std.
(A)
(Vs)
(100)
where:
SE = sampling efficiency as determined by the procedure outlined in Section 14.
If it is desired to convert the air concentration value to parts per trillion (ppt) in dry air at standard
temperature and pressure (STP), the following conversion is used:
ppt=0.844(Ca)
The air concentration can be converted to parts per trillion (v/v) in air at STP as follows:
(24.45) (C)"
pptv =
(MW)
where:
MW = molecular weight of the compound of interest, g/g-mole.
Page 10A-14
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
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Pesticides/PCBs
Method TO-10A
13.1.9 If quantification is performed using an internal standard, a relative response factor (RRF) is calculated
by the equation:
RRF =
where:
Is = integrated area of the target analyte peak, counts.
I1S = integrated area of the internal standard peak, counts.
C1S = concentration of the internal standard, ng/juL.
Cs = concentration of the analyte, ng/uL.
13.1.10 The concentration of the analyte (Ca) in the sample is then calculated as follows:
c
where:
Ca = concentration of analyte, ng/m3
Is = integrated area of the target analyte peak, counts.
RRF = relative response factor (see Section 13.1.10).
14. Sampling and Retention Efficiencies
14.1 General
14.1.1 Before using Compendium Method TO-10A, the user should determine the sampling efficiency for
the compound of interest. The sampling efficiencies shown in Tables 2, 3, 4, and 5 were determined for
approximately 1 m3 of air at about 25 °C, sampled at 3.8 L/min. The SE values in these tables may be used for
similar sampling conditions; for other compounds or conditions, SE values must be determined.
14.1.2 Sampling efficiencies for the pesticides shown in Table 6 are for aflowrate of 3.8 L/min and at25°C.
For compounds not listed, longer sampling times, different flow rates, or other air temperatures, the following
procedure may be used to determine sampling efficiencies.
14.2 Determining SE
14.2.1 SE is determined by a modified impinger assembly attached to the sampler pump, as illustrated in
Figure 7. A clean PUF is placed in the pre-filter location and the inlet is attached to a nitrogen line.
[Note: Nitrogen should be used instead of air to prevent oxidation of the compounds under test. The
oxidation would not necessarily reflect what may be encountered during actual sampling and may give
misleading sampling efficiencies.]
Two PUF plugs (22-mm x 7.6-cm) are placed in the primary and secondary traps and are attached to the pump.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-15
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Method TO-10A Pesticides/PCBs
14.2.2 A standard solution of the compound of interest is prepared in a volatile solvent (i.e., hexane, pentane,
or benzene). A small, accurately measured volume (i.e., 1 mL) of the standard solution is placed into the modified
midget impinger. The sampler pump is set at the rate to be used 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.
14.2.3 The impinger is rinsed with hexane or another suitable solvent and quantitatively transferred to a
volumetric flask or concentrator tube for analysis.
14.2.4 The sampling efficiency (SE) is determined using the following equation:
W,
o/o SE = 1 x 100
W0 -Wr
where:
Wj = amount of compound extracted from the primary trap, ng.
W0 = original amount of compound added to the impinger, ng.
Wr = residue left in the impinger at the end of the test, ng.
14.2.5 If material is found in the secondary trap, it is an indication that breakthrough has occurred. The
addition of the amount found in the secondary trap, W2, to W1; will provide an indication for the overall sampling
efficiency of a tandem-trap sampling system. The sum of W1; W2 (if any), and Wr must equal (approximately
±10%) W0 or the test is invalid.
14.2.6 If the compound of interest is not sufficiently volatile to vaporize at room temperature, the impinger
may be heated in a water bath or other suitable heater to a maximum of 50°C to aid volatilization. If the
compound of interest cannot be vaporized at 50°C without thermal degradation, dynamic retention efficiency
(REd) may be used to estimate sampling efficiency. Dynamic retention efficiency is determined in the manner
described in Section 14.2.7. Table 7 lists those organochlorine pesticides which dynamic retention efficiencies
have been determined.
14.2.7 A pair of PUF plugs is spiked by slow, dropwise addition of the standard solution to one end of each
plug. No more than 0.5 to 1 mL of solution should be used. Amounts added to each plug should be as nearly
the same as possible. The plugs are allowed to dry for 2 hours in a clean, protected place (i.e., desiccator). One
spiked plug is placed in the primary trap so that the spiked end is at the intake and one clean unspiked plug is
placed in the secondary trap. The other spiked plug is wrapped in hexane-rinsed aluminum foil and stored in a
clean place for the duration of the test (this is the static control plug, Section 14.2.8). Prefiltered nitrogen or
ambient air is drawn through the assembly as per Section 14.2.2.
[Note: Impinger may be discarded.]
Each PUF plug (spiked and static control) is analyzed separately as per Section 12.
14.2.8 This dynamic retention efficiency (% REd) is calculated as follows:
W,
% RE, = _L x 100
d
where:
Wj = amount of compound recovered from primary plug, ng.
Page 10A-16 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
W0 = amount of compound added to primary plug, ng.
If a residue, W2, is found on the secondary plug, breakthrough has occurred. The sum of Wj + W2 must equal
W0, within 25% or the test is invalid. For most compounds tested by this procedure, % REd values are generally
less than % SE values determined per Section 14.2. The purpose of the static REd determination is to establish
any loss or gain of analyte unrelated to the flow of nitrogen or air through the PUF plug.
15. Performance Criteria and Quality Assurance
[Note: This section summarizes required quality assurance (QA) measures and provides guidance concerning
performance criteria that should be achieved within each laboratory.]
15.1 Standard Operating Procedures (SOPs)
15.1.1 Users should generate SOPs describing the following activities accomplished in their laboratory: (1)
assembly, calibration, and operation of the sampling system, with make and model of equipment used; (2)
preparation, purification, storage, and handling of sampling cartridges; (3) assembly, calibration, and operation
of the analytical system, with make and model of equipment used; and (4) all aspects of data recording and
processing, including lists of computer hardware and software used.
15.1.2 SOPs should provide specific stepwise instructions and should be readily available to, and understood
by, the laboratory personnel conducting the work.
15.2 Process, Field, and Solvent Blanks
15.2.1 One PUF cartridge from each batch of approximately twenty should be analyzed, without shipment
to the field, for the compounds of interest to serve as a process blank.
15.2.2 During each sampling episode, at least one PUF cartridge should be shipped to the field and returned,
without drawing air through the sampler, to serve as a field blank.
15.2.3 Before each sampling episode, one PUF plug from each batch of approximately twenty should be
spiked with a known amount of the standard solution. The spiked plug will remain in a sealed container and will
not be used during the sampling period. The spiked plug is extracted and analyzed with the other samples. This
field spike acts as a quality assurance check to determine matrix spike recoveries and to indicate sample
degradation.
15.2.4 During the analysis of each batch of samples, at least one solvent process blank (all steps conducted
but no PUF cartridge included) should be carried through the procedure and analyzed.
15.2.5 All blank levels should not exceed 10 ng/sample for single components or 100 ng/sample for multiple
component mixtures (i.e., for organochlorine pesticides and PCBs).
15.3 Sampling Efficiency and Spike Recovery
15.3.1 Before using the method for sample analysis, each laboratory must determine its sampling efficiency
for the component of interest as per Section 14.
15.3.2 The PUF in the sampler is replaced with a hexane-extracted PUF. The PUF is spiked with a
microgram level of compounds of interest by dropwise addition of hexane solutions of the compounds. The
solvent is allowed to evaporate.
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-17
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Method TO-10A Pesticides/PCBs
15.3.3 The sampling system is activated and set at the desired sampling flow rate. The sample flow is
monitored for 24 hours.
15.3.4 The PUF cartridge is then removed and analyzed as per Section 12.
15.3.5 A second sampler, unspiked, is collected over the same time period to account for any background
levels of components in the ambient air matrix.
15.3.6 In general, analytical recoveries and collection efficiencies of 75% are considered to be acceptable
method performance.
15.3.7 Replicate (at least triplicate) determinations of collection efficiency should be made. Relative
standard deviations for these replicate determinations of ±15% or less are considered acceptable performance.
15.3.8 Blind spiked samples should be included with sample sets periodically as a check on analytical
performance.
15.4 Method Precision and Bias
15.4.1 Precision and bias in this type of analytical procedure are dependent upon the precision and bias of
the analytical procedure for each compound of concern, and the precision and bias of the sampling process.
15.4.2 Several different parameters involved in both the sampling and analysis steps of this method
collectively determine the precision and bias with which each compound is detected. As the volume of air
sampled is increased, the sensitivity of detection increases proportionately within limits set by: (a) the retention
efficiency for each specific component trapped on the polyurethane foam plug, and (b) the background
interference associated with the analysis of each specific component at a given site sampled. The sensitivity of
detection of samples recovered by extraction depends on: (a) the inherent response of the particular GC detector
used in the determinative step, and (b) the extent to which the sample is concentrated for analysis. It is the
responsibility of the analyst(s) performing the sampling and analysis steps to adjust parameters so that the
required detection limits can be obtained.
15.4.3 The reproducibility of this method for most compounds for which it has been evaluated has been
determined to range from ±5 to ±30% (measured as the relative standard deviation) when replicate sampling
cartridges are used (N>5). Sample recoveries for individual compounds generally fall within the range of 90 to
110%, but recoveries ranging from 65 to 125% are considered acceptable. PUF alone may give lower recoveries
for more volatile compounds (i.e., those with saturation vapor pressures >10"3 mm Hg). In those cases, another
sorbent or a combination of PUF and Tenax TA (see Figure 2) should be employed.
15.5 Method Safety
15.5.1 This procedure may involve hazardous materials, operations, and equipment. This method does not
purport to address all of the safety problems associated with its use.
15.5.2 It is the user's responsibility to consult and establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to the implementation of this procedure. This should
be part of the user's SOP manual.
16. References
1. "Standard Practice for Sampling and Analysis of Pesticides and Polychlorinated Biphenyls in Air," Annual
Book of ASTMStandards, Method D4861-94, ASTM, Philadelphia, PA.
Page 10A-18 Compendium of Methods for Toxic Organic Air Pollutants January 1999
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Pesticides/PCBs Method TO-10A
2. Lewis, R, and MacLeod, K., "Portable Sampler for Pesticides and Semi-volatile Industrial Organic Chemicals
in Air," Analytical Chemistry, Vol. 54, 1982, pp. 310-315.
3. Whitmore R.W., Immerman, F.W., Camann, D.E., Bond, A.E., Lewis, R.G., and Schaum, J.L., "Non-
occupational Exposure to Pesticides for Residents of Two U.S. Cities," Arch. Environ. Contain. Toxicol, 26,
47-59 (1994).
4. Lewis, R., and Brown, A., and Jackson, M., "Evaluation of Polyurethane Foam for Sampling of Pesticides,
Polychlorinated Biphenyls and Polychlorinated Napththalenes in Ambient Air," Analytical Chemistry, Vol. 49,
1977, pp. 1668-1672.
5. Armour, J., and Burke, J., "Method for Separating Polychlorinated Biphenyls from DDT and Its Analogs,"
Journal of the Association of Official Analytical Chemists,Vol. 53, No. 4, 1970, pp. 761-768.
6. Manual of Analytical Methods for the Analysis of Pesticides in Human and Environmental Samples, U. S.
Environmental Protection Agency, Research Triangle Park, NC 27711, Report No. EPA-600/8-80-038,
June 1980 (NTIS No. PB82-208752).
7. Kogan, V., Kuhlman, M., Coutant, R, and Lewis, R, "Aerosol Filtration in Sorbent Beds," Journal of the Air
and Waste Management Association,Vol. 43, 1993, p. 1367-1373.
8. Lewis, R, and Lee, R, "Air Pollution from Pesticide Sources, Occurrences and Dispersion," In: Air Pollution
from Pesticides and Agricultural Processes, Lee, R., Editor, CRC Press, Boca Raton, FL, 1976, pp. 51-94.
9. Lewis, R, "Problem Associated with Sampling for Semi-volatile Organic Chemicals in Air," Proceedings of
the 1986 EPA/APCA Symposium on Measurement of Toxic Air Pollutants, Air and Waste Management
Association, Pittsburgh, PA, 1986, pp. 134-145.
10. Camann, D., Harding, J., and Lewis, R., "Trapping of Particle-Associated Pesticides in Indoor Air by
Polyurethane Foam and Evaporation of Soil Track-In as a Pesticide Source," In: Indoor Air '90, Vol. 2,
Walkinshaw, D., editor, Canada Mortgage and Housing Corp., Ottawa, 1990, pp. 621-626.
11. Marple, V., Rubow, K., Turner, W., and Spengler, J., "Low Flow Rate Sharp Cut Impactors for Indoor Air
Sampling Design and Calibration," Journal of the Air Pollution Control Association. Vol. 37, 1987, pp. 1303-
1307.
12. Hsu, J., Wheeler, H., Camann, D., Shatterberg, H., Lewis, R., and Bond, A., "Analytical Methods for
Detection of Nonoccupational Exposure to Pesticides," Journal ofChromatographic Science, Vol. 26, 1988,
pp. 181-189.
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Method TO-10A
Pesticides/PCBs
TABLE 1. COMPOUNDS FOR WHICH PROCEDURE HAS BEEN TESTED1
Compound
Alachlor
Aldrin
Allethrin
Aroclor 1242
Aroclor 1254
Aroclor 1260
Atrazine
Bendiocarb
BHC (a- and (3-Hexachlorocyclohexanes)
Captan
Carbaryl
Carbofuran
Chlordane, technical
Chlorothalonil
Chlorotoluron
Chlorpyritos
2,4-D esters and salts
Dacthal
p,p-'DDT
p,p-'DDE
Diazinon
Dicloran
Dieldrin
Dichlorovos (DDVP)
Dicofol
Dicrotophos
Diuron
Ethyl parathion
Fenvalerate
Fluometuron
Folpet
Recommended
Analysis2
GC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/NPD
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/ECD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/NPD or FPD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
HPLC/UV
HPLC/UV
GC/ECD
Compound
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Hexachlorocyclopentadiene3'4
Lindane (y-BHC)
Linuron
Malathion
Methyl parathion
Methoxychlor
Metolachlor
Mexacarbate
Mirex
Monuron
Trans-nonachlor
Oxychlordane
Pentachlorobenzene
Pentachlophenol
Permethrin (cis and trans)
o-Phenylphenol
Phorate
Propazine
Propoxur (Baygon)
Pyrethrin
Resmethrin
Ronnel
Simazine
Terbuthiuron
1 ,2,3,4-tetrachlorobenzene3
1 ,2,3-trichlorobenzene3
2,3,5-trichlorophenol
Trifluralin
Recommended
Analyses
GC/ECD
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
GC/NPD or FPD
GC/NPD or FPD
GC/FCD
GC/ECD
GC/FCD
GC/ECD
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
HPLC/UV
HPLC/UV
GC/NPD or FPD
GC/NPD
HPLC/UV
HPLC/UV
HPLC/UV
GC/ECD
HPLC/UV
HPLC/UV
GC/ECD
GC/ECD
GC/ECD
GC/ECD
'The following recommendations are specific for that analyte for maximum sensitivity.
2GC = gas chromatography; ECD = electron capture detector, FPD = flame photometric detector; HPLC = high performance
liquid chromatography; NPD = nitrogen-phosphorus detector; UV = ultraviolet absorption detector, (GC/MS (gas chromatography/mass
spectrometry) may also be used).
3Using PUF/Tenax-TA "sandwich" trap.
tompound is very unstable in solution.
Page 10A-20
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
TABLE 2. SAMPLING EFFICIENCIES FOR SOME ORGANOCHLORINE PESTICIDES
Compound
a-Hexachlorocyclohexane (a-BHC)
Y-Hexachlorocyclohexane (Lindane)
Chlordane, technical
n,n'-DDT
n,n'-DDE
Mirex
2,4-D Esters:
Isopropyl
Butyl
Isobutyl
Isoctyl
Quantity
Introduced,
Mg2
0.005
0.05-1.0
0.2
0.6,1.2
0.2,0.4
0.6,1.2
0.5
0.5
0.5
0.5
Air
Volume, m3
0.9
0.9
0.9
0.9
0.9
0.9
3.6
3.6
3.6
3.6
Sam]
mean
115
91.5
84.0
97.5
102
85.9
92.0
82.0
79.0
>802
sling efficiency, %
RSD
8
8
11
21
11
22
5
10
20
--
n
6
5
8
12
12
7
12
11
12
--
'Air volume = 0.9 m3.
2Not vaporized. Value base on %RE = 81.0 (RSD = 10%, n = 6).
TABLE 3. SAMPLING EFFICIENCIES FOR ORGANOPHOSPHORUS PESTICIDES
Compound
Dichlorvos (DDVP)
Ronnel
Chlorpyrifos
Diazinon1
Methyl parathion1
Ethyl parathion1
Malathion1
Quantity
Introduced, ,ug2
0.2
0.2
0.2
1.0
0.6
0.3
0.3
Sampling efficiency, %
mean
72.0
106
108
84.0
80.0
75.9
1003
RSD
13
8
9
18
19
15
-
n
2
12
12
18
18
18
-
Analyzed by gas chromatography with nitrogen phosphorus detector or flame photometric detector.
2Air volume = 0.9 m3.
3Decomposed in generator; value based on %RE =101 (RDS = 7, n = 4).
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-21
-------
Method TO-10A
Pesticides/PCBs
TABLE 4. SAMPLING EFFICIENCIES FOR SOME SEMI-VOLATILE
ORGANOCHLORINE COMPOUNDS AND PCBs
Compound
1,2,3-Trichlorobenzene
1,2,3,4-Tetrachlorobenzene
Pentachlorobenzene
Hexachlorobenzene
Hexachlorocyclopentadiene
2,4,5-Trichlorophenol
Pentachlorophenol
Aroclor 1242
Aroclor 1254
Aroclor 1260
Quantity
Introduced, /^g1
1.0
1.0
1.0
0.5, 1.0
1.0
1.0
1.0
0.1
0.1
0.1
Sampling efficiency, %
mean
6.62
62.32
94.0
94.5
8.32
108
107
96.0
95.0
109
RSD
22
33
12
8
12
3
16
15
7
5
n
8
5
5
5
5
5
5
6
6
11
JAir volume = 0.9 m3.
2% SEs were 98, and 97% (n = 2), respectively, for these three compounds by the PUF/Tenax® TA
"sandwich" trap.
Page 10A-22
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
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-------
Method TO-10A
Pesticides/PCBs
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Method TO-10A
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-------
Method TO-10A
Pesticides/PCBs
PUF or PUF/TENAX-TA
SAMPLING CARTRIDGE
115V ADAPTER/
CHARGER PLUG
Figure 1. Low volume air sampler.
Page 10A-26
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
PUF
Adsorbent
Tenax® TA
Adsorbent
PUF Adsorbent
Figure 2. Polyurethane foam (PUF) sampling cartridge (a) and PUF-Tenax® TA
"sandwich" sampling cartridge (b).
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-27
-------
Method TO-10A
Pesticides/PCBs
Air
Filter Cartridge Assembly
L
Flow
Figure 3. Open-face filter assembly attached to a PUF cartridge:
(a) Inner Viton® o-ring, (b) filter cartridge, (c) stainless steel screen, (d) quartz filter,
(e) filter ring, and (f) cartridge screw cap.
Page 10A-28
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
FLOW RATE
METER (0-1 in. H20)
(
FLOW RATE
VALVE
1,OOOmL
BUBBLE TUBE
AIR IN
DISH WITH
BUBBLE SOLUTION
PRESSURE DROP
METER (0-50 in. H2O)
PRESSURE DROP
VALVE
Figure 4. Calibration assembly for air sampler pump.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-29
-------
Method TO-10A
Pesticides/PCBs
COMPENDIUM METHOD TO-10A
FIELD TEST DATA SHEET (FTDS)
I. GENERAL INFORMATION
PROJECT:.
SITE:
DATE(S) SAMPLED:.
LOCATION:
INSTRUMENT MODEL NO.:.
PUMP SERIAL NO.:
TIME PERIOD SAMPLED:.
OPERATOR:
CALIBRATED BY:
RAIN: YES NO
ADSORBENT CARTRIDGE INFORMATION:
Cartridge 1 Cartridge 2 Cartridge 3 Cartridge 4
Type:
Adsorbent:
Serial No.:
Sample No.:
II. SAMPLING DATA
Cartridge
Identifi-
cation
Sampling
Location
Ambient
Temp., °F
Ambient
Pressure, in
Hg
Flow Rate (Q), mL/min
Cartridge 1
Cartridge 2
Sampling Period
Start
Stop
Total
Sampling
Time, min.
Total
Sample
Volume,
L
III. FIELD AUDIT
Cartridge 1 Cartridge 2
Audit Flow Check Within
10% of Set Point (Y/N)? pre-
post-
pre-
post-
Cartridge 3 Cartridge 4
pre-
post-
pre-
post-
CHECKED BY:.
DATE:
Figure 5. Compendium Method TO-10A field test data sheet.
Page 10A-30
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs
Method TO-10A
OPERATING CONDITIONS
Column Type:
DB-5 0.32 copillory,
0.25 um film thickness
Dibutylchlorendate
Column Temperature Program: 90°C(4min)/16*C per min to
154'C/44C 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.
Methoxychlor
Heptachlor
Lindane
Endrin
p,p'DDT
Dieldrin
TIME
Figure 6. Chromatogram showing a mixture of single component pesticides determined
by GC/ECD using a capillary column.
January 1999
Compendium of Methods for Toxic Organic Air Pollutants
Page 10A-31
-------
Method TO-10A
Pesticides/PCBs
Page 10A-32
Compendium of Methods for Toxic Organic Air Pollutants
January 1999
-------
Pesticides/PCBs Method TO-10A
January 1999 Compendium of Methods for Toxic Organic Air Pollutants Page 10A-33
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