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57?6191 F GEOQNALYTIi'AL I ^RP4^ <br /> GE n3 <br /> FChromatography <br /> Method 508A (EPA 500-Series, Revision 1.0, 1989) page 1 <br /> rE. <br /> Screening For Polychlorinated Biphenyls By Perchlorination/Gas <br /> MMUOD#:508A (EPA-500 Series,Revision 1.0, 1989) <br /> TITLE: Screening For Polychlorinated Biphenyls By Perchlorination/Gas <br /> Chromatography <br /> 1.0 SCOPE AND APPLICATION <br /> This procedure may be used for screening finished drinking water, raw <br /> source water, or drinking water in any treatment stage for poly- chlorinated <br /> biphenyls(PCBs). This procedure <br /> as single congeners or as is applicable to samples containing PCBs <br /> is <br /> mixtures such as weathered, intact,or <br /> mixtures of commercial Aroclors The procedure is incapable of identifying <br /> the Parent PCBs because the original PCBs are chemically converted to a <br /> common Product, decachlorobiphenyl(DCB). The Procedure has only been <br /> evaluated using Aroelors and 2-chlorobiphenyl as a source of PCBs. <br /> nNILLYTs s <br /> cas a <br /> 2-chlorobiphenyi <br /> Aroclor 1221 <br /> Aroclor 1232 1104-28-2 <br /> Aroclor 1242 11141-16-5 <br /> Aroclor 1016 53469-21-9 <br /> Aroclor 1248 12674-11-2 <br /> Aroclor 1254 12672-29-6 <br /> Aroclor 1260 11097-69-1 <br /> Dachlorobiphenyl 11096-82_5 <br /> INSTRUMENTATION: GC <br /> 1.2. This procedure is primarily designed to function as a pass/fail test, for DCB <br /> at 0.5 ug/L. However,it will accurately measure DCB from the method <br /> detection limit(MDL)to 5.0 ug/L. It is prone to false positive interferences <br /> and can result in a calculated weight of PCBs significantly greater than that <br /> of PCB originally present in the sample. If DCB is detected at 0.5 ug/L or <br /> above, then an approved method for the analysis of PCBs should be used to <br /> accurately identify the source and measure the concentration of the PCBs. <br /> 1.3. This procedure can be used to help confirm the presence of PCBs for other <br /> methods using electron capture or halogen specific detectors whenever <br /> chromatographic patterns are not representative of those described in the <br /> method. <br /> 2.0 SUMMARY OF PROCEDURE <br /> 2.1. A 1-L water sample is placed into a separatory funnel and extracted with <br /> methylene chloride or one of several optional solvents.The extract is dried, <br /> concentrated, and the solvent is exchanged to chloroform.The PCBs are <br /> then reacted with antimony pentachloride(SbC]s) (in the presence of an iron <br /> catalyst and heat)to form DCB. The DCB is extracted with hexane from the <br /> reaction mixture;after the extract is purified, an aliquot is injected into a gas <br /> 0 Genium PublLihitt Corporation 1996,Schenectady,NY 12304 <br /> CP <br />