A Risk-Management Strategy for PCB-Contaminated Sediments (2001) / Chapter Skim
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Appendix F: Methods of Analysis of PCBs in Sediments, Water, and Biota
Appendix F: Methods of Analysis of PCBs in Sediments, Water, and Biota
Pages 334-362
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From page 334... ...
Gas-Chromatography-Based Methods The gas chromatography schemes that are used in the quantification of PCBs can generally be divided into two types: PCB quantification based on analogy to Aroclor technical mixtures is referred to as the Aroclor method and that based on quantification of individual PCB congeners present in samples is referred to as the congener-specific method. The typical Aroclor analysis is based on estimating residue PCB concentrations by measuring a subset of PCB congeners or by approximating the profile as an appropriate set of technical mixtures (Newman et al.
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From page 335... ...
The capillary GC columns offer improved resolution, better selectivity, and increased sensitivity compared with packed GC columns. For that reason, many standard EPA methods have been rewritten to allow the use of capillary GC columns for the analysis of environmental samples.
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From page 336... ...
However, due to biological processes, such as biodegradation and metabolism, or environmental processes, such as volatilization, congener profiles of PCBs in environmental samples are different from technical Aroclor standards. The alteration ofthe congenerpattem in environmental samples can tee influenced by several factors, including source and type of PCBs, type of environmental media (air, water, soil, sediment, and biota)
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From page 337... ...
The discrepancies in the congener composition between the commercial mixture and real-worId environmental exposures imply that the predictive value of studies based on commercial mixtures might be limited with respect to estimating risks from environmental exposure. Determination of all PCB isomers and congeners present in environmental matrices using a mixture of technical PCB preparations (such as an equivalent mixture of Aroclors 1016,1242,1254 and 1260)
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From page 338... ...
Therefore, the development of scientifically based regulations for the risk assessment of PCBs requires analytical and toxicological data on the individual PCB congeners present in any technical mixture and information regarding interactive effects. Although developments in highresolution isomer-specific PCB analysis have enabled identification and quantification of individual PCB congeners present in commercial mixtures and environmental samples, there are important challenges associated with risk assessment of PCBs due to their different mechanisms of biological activity and toxicity.
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From page 339... ...
In most studies, the PCDF and PCN contents were not quantified, and their contribution to technical PCBs-induced toxicity is unknown. Accepted Methods for Aroclor-Based Analysis The recent EPA method 8082 is a performance-based procedure that describes a dual capillary -column gas-chromatographic analysis of PCBs as Aroclors or as individual PCB congeners in extracts from solid or aqueous matrices ~ EPA ~ 996a)
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From page 340... ...
Instrumentation: High-resolution gas chromatography with electron capture detection (HRGC-ECD) or electrolytic conductivity detection (ELCD)
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From page 341... ...
The method recommends the analysis of reference material and samples spiked with compounds of interest following SW 846 guidance. The method warns users that acceptable qualitative and quantitative analysis of Aroclor in environmental samples using this method or other methods is difficult to obtain because of weathering.
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From page 342... ...
Typical approaches for handling PCB congener data include Reporting and using only individual congener data. Summing the identified congeners to arrive at a total observed PCB concentration.
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From page 343... ...
1998~. Total PCB concentrations can also be measured by summing concentrations of all the individual PCB congeners identified in samples.
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From page 344... ...
The EPA method 1668 measures 13 toxic or suspected toxic congeners that usually constitute a small fraction ( |
From page 346... ...
Thus, the recovcry and GC response of PCB 209 might not be representative, and its use as an internal standard might lead to a higher degree of imprecision compared with the NOAA method. Otherwise, method 8082 is acceptable for measuring the 19 PCB congeners in environmental samples.
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From page 347... ...
1993~. Method: EPA Method 166S, Toxic PCBs byisotopeDilution High-Resolution Gas Chromatography-High-Resolution Mass Spectrometry (EPA 19979 Analytes Measured: The 13 congeners tested by the method include PCB 77, PCB 105, PCB 1 14, PCB 1 18, PCB 123, PCB 126, PCB 156, PCB 157, PCB 167, PCB 169, PCB 170, PCB 180, and PCB 189.
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From page 348... ...
Discussion: The method is based on previously written EPA methods for the analysis of chlorinated dioxins and furans in environmental samples (EPA 1994~. The labeled compounds are spiked into the sample, the sample is then extracted by an appropriate method, and the extract is concentrated.
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From page 349... ...
MAIL: The MDEs for the target congeners range from 0.1,ug/kg of sediment, 0.4 ,ug/kg of biological tissue dry weight. Discussion: The Battelle PCB congener method by low-resolution mass spectrometry is a performance-based method based on EPA method 8270b (EPA 1996b)
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From page 350... ...
Method: Extraction and Analysis of PCB and Non-ortho-Coplanar PCBs in Biological Matrices (Cannan and Giesy 19989 Analytes Measured: The PCB congeners tested by the method include 69 individual PCB congeners, plus 14 co-eluting groups of two to three congeners, and all major non-ortho and mono-ortho PCB congeners as listed: PCB 4,PCBs5/8,PCB6,PCB9,PCBlO,PCB15,PCB16,PCB17,PCB18,PCB 19,PCBs53/33/20,PCB22,PCB25,PCB26,PCB27,PCBs31/28,PCB32, PCB37,PCB40,PCB41,PCB42,PCB44,PCB45,PCBs75/47,PCB49, PCB 52,PCB56,PCBs95/66,PCB 70,PCB74,PCB 77,PCB 81,PCBs 151/82,PCB83,PCB84,PCB85,PCB87, PCB 90, PCB91,PCB92,PCB 97,PCB99,PCBlOl,PCB105,PCB107,PCBllO,PCB113,PCB117, PCB118,PCBll9,PCBs120/136,PCB126,PCB128,PCBs178/129,PCBs 153/132,PCB133,PCB134,PCBs135/144, PCB 137,PCBs138/158, PCBs 179/141,PCB156,PCB157, PCBs 167/185,PCB169, PCB 170,PCB171, PCB 174,PCB176,PCB177,PCB180,PCB183,PCB187,PCB194, PCBs 195/208,PCB199,PCB200,PCB201,PCB202,PCB205,PCB206,PCB 207, and PCB209. (PCB congeners presented as PCB/PCB represent coeTuting PCB peaks under most analytical conditions.
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From page 351... ...
The congener list has been developed to include most PCB congeners found in environmental samples and recovers between 95°/0 and 99% oftotal PCBs in all samples analyzed. The analyte list includes most of the toxic PCBs measured with EPA method 1668.
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From page 352... ...
. The H4TIE rat hepatoma cell bioassay (Tillitt et al.
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From page 353... ...
Fortunately, environmental samples have been extracted for PCBs for over 25 years. During this time, sample extraction and cleanup procedures have been refined, and procedures delivering MDEs in the low parts per billion are well recognized.
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From page 354... ...
Cleanup Procedures Cleanup methods—that is, laboratory techniques that remove interfering materials from extracts of environmental samples before analysis are also presented. Table F-7 presents and compares several cleanup procedures suitable for the isolation of PCB from other classes of organic compounds in extracts of environmental samples.
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From page 355... ...
Sample is soxhlet sediment mixed thoroughly and blended with equal amounts drying extraction agent (sodium sulfate)
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From page 356... ...
This method is similar to the FDA method, from which it was originally taken. Wet tissue is placed in a Teflon extraction container along with equal amounts of anhydrous sodium sulfate and extracted with methylene dichloride using a commercial highspeed homogenizer.
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From page 357... ...
Others include silica gel and florisil, and ac cepted methods for using these also can be found in the litera ture. The method for extracts from water, waste water, soil, sed iments, biological tissue, and other environmental samples upon method validation.
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From page 358... ...
1994a. Method 8080A, Organochlorine Pesticides and Polychlorinated biphenyls by Gas Chromatography, Revision 1,Test Methods for Evaluating Solid Waste: Physical/ Chemical Methods, SW-846.
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From page 359... ...
1996a. Method 8082, Polychlorinated Biphenyls by Gas Chromatography, Revision 0, Test Methods for Evaluating Solid Wastes, Physical/ Chemical Methods, SW-846.
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From page 360... ...
and estrogen receptor (ER) mediated activity in environmental samples.
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From page 361... ...
1991. Characterization of the H4IIE rat hepatoma cell bioassay as a tool for assessing toxic potency of planar halogenatedhydrocarbonsinenvironmentalsamples.
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From page 362... ...
362 A Risk-Management Strategy for PCB-Cor~tam inated Sediments Williams, L.L., J.P. Giesy, N
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