資源描述：
《EPA 9078 SCREENING TEST METHOD FOR POLYCHLORINATED BIPHENYLS IN SOIL》由會員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、METHOD9078SCREENINGTESTMETHODFORPOLYCHLORINATEDBIPHENYLSINSOIL1.0SCOPEANDAPPLICATION1.1ThemethodmaybeusedtodeterminetheamountofPCB(polychlorinatedbiphenyl)contaminationinsoilssuchassand,gravel,loam,sediment,andclay,assumingthatPCBsarethesolesourceoforga
2、nichalogensinthesample.1.2Thiselectrochemicalmethodisdesignedtoprovidequantitativefieldresultsoverarangeof2to2000μg/gPCBs,significantlycuttingdownonthenumberofsamplesrequiringlaboratorytesting.1.3ChlorinesareremovedfromthePCBmoleculeusinganorgano-sodium
3、reagent.Theresultingchlorideionsaremeasuredusingachloridespecificelectrode.AnalystsmustidentifythetypeofAroclorcontaminationinordertousethisasaquantitativemethod.1.4Thismethodisrestrictedtousebyorunderthesupervisionoftrainedanalysts.Eachanalystmustdemon
4、stratetheabilitytogenerateacceptableresultswiththismethod.2.0SUMMARYOFMETHODAsampleofthesoiltobetestedisextractedwithahydrocarbonbasedsolvent.Theresultingextractisfilteredtoremovemoistureandinorganicsalts.Thedriedextractisreactedwithmetallicsodiumandaca
5、talysttostripchloridefromanyPCBthatmaybepresent.Theresultingchlorideionsareextractedintoanaqueousbuffersolutionwheretheyaredetectedusingachlorideionspecificelectrode.CAUTION:Someofthereagentsusedwiththistestingprocedurecontainflammablesolvents,diluteaci
6、ds,andmetallicsodium.Wearglovesandsafetyglasseswhileperformingtests.ReadallMSDSandwarningsincludedwiththeinstrumentbeforestartingtestingprocedure.3.0INTERFERENCES3.1Thisprocedureissensitivetoanychlorinatedcompoundthatispreferentiallysolubleinanon-polars
7、olvent.WhenanalyzingforPCBs,thepresenceofotherchlorinatedorganicswillresultinahighbias.Iodineandbrominecontainingcompoundswillaffectresultsifpresentinsignificantquantities.Wetordrysamplesmayberun,butresultsforallsamplesarecalculatedonawet-weightbasis.In
8、oneevaluationstudy(Table1),1.4%ofthemeasurementswerefalsenegatives.3.2Inorganicchloridesshouldnotinterfereusingthismethodifthesampleisextractedwithorganicsolvent.CD-ROM9078-1Revision0December19964.0APPARATUSANDMATERIALSElectroche
