EPA METHOD 3541 Automated Soxhlet Extraction

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1、METHOD3541AUTOMATEDSOXHLETEXTRACTION1.0SCOPEANDAPPLICATION1.1Method3541describestheextractionoforganicanalytesfromsoil,sediment,sludges,andwastesolids.Themethodusesacommerciallyavailable,unique,threestageextractionsystemtoachieveanalyterecoverycomparabletoMethod3540,butinamuchshorte

2、rtime.TherearetwodifferencesbetweenthisextractionmethodandMethod3540.IntheinitialextractionstageofMethod3541,thesample-loadedextractionthimbleisimmersedintotheboilingsolvent.Thisensuresveryrapidintimatecontactbetweenthespecimenandsolventandrapidextractionoftheorganicanalytes.Inthese

3、condstagethethimbleiselevatedabovethesolvent,andisrinse-extractedasinMethod3540.Inthethirdstage,thesolventisevaporated,aswouldoccurintheKuderna-Danish(K-D)concentrationstepinMethod3540.Theconcentratedextractisthenreadyforcleanup(Method3600)followedbymeasurementoftheorganicanalytes.1

4、.2Themethodisapplicabletotheextractionandconcentrationofwaterinsolubleorslightlywatersolublepolychlorinatedbiphenyls(PCBs)inpreparationforgaschromatographicdeterminationusingeitherMethod8080or8081.Thismethodisapplicabletosoils,clays,solidwastesandsedimentscontainingfrom1to50µgofPCBs

5、(measuredasArochlors)pergramofsample.Ithasbeenstatisticallyevaluatedat5and50µg/gofArochlors1254and1260,andfoundtobeequivalenttoMethod3540(SoxhletExtraction).HigherconcentrationsofPCBsaremeasuredfollowingvolumetricdilutionwithhexane.1.3Themethodisalsoapplicabletheextractionandconcent

6、rationofsemivolatileorganicsinpreparationforGC/MSanalysisbyMethod8270orbyanalysisusingspecificGCorHPLCmethods.2.0SUMMARYOFMETHOD2.1PCBs:Moistsolidsamples(e.g.,soil/sedimentsamples)maybeair-driedandgroundpriortoextractionorchemicallydriedwithanhydroussodiumsulfate.Thepreparedsampleis

7、extractedusing1:1(v/v)acetone:hexaneintheautomatedSoxhletfollowingthesameprocedureasoutlinedforsemivolatileorganicsinSec.2.1.TheextractisthenconcentratedandexchangedintopurehexanepriortofinalgaschromatographicPCBmeasurement.2.2Othersemivolatileorganics:A10-gsolidsample(thesampleispr

8、e-mixedwithanhydrou