EPA METHOD 3200 MERCURY SPECIES FRACTIONATION AND

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1、METHOD3200MERCURYSPECIESFRACTIONATIONANDQUANTIFICATIONBYMICROWAVEASSISTEDEXTRACTION,SELECTIVESOLVENTEXTRACTIONAND/ORSOLIDPHASEEXTRACTIONSW-846isnotintendedtobeananalyticaltrainingmanual.Therefore,methodproceduresarewrittenbasedontheassumptionthattheywillbeperformedbyanalystswhoarefo

2、rmallytrainedinatleastthebasicprinciplesofchemicalanalysisandintheuseofthesubjecttechnology.Inaddition,SW-846methods,withtheexceptionofrequiredmethodusefortheanalysisofmethod-definedparameters,areintendedtobeguidancemethodswhichcontaingeneralinformationonhowtoperformananalyticalproc

3、edureortechniquewhichalaboratorycanuseasabasicstartingpointforgeneratingitsowndetailedStandardOperatingProcedure(SOP),eitherforitsowngeneraluseorforaspecificprojectapplication.1.0SCOPEANDAPPLICATION1.1Thismethodcontainsasequentialextractionandseparationprocedurethatmaybeusedinconjun

4、ctionwithadeterminativemethodtodifferentiatemercuryspeciesthatarepresentinsoilsandsediments.Thismethodprovidesinformationonbothtotalmercuryandvariousmercuryspecies.1.2Thespeciationofametal,inthiscasemercury,involvesdeterminingtheactualformofthemoleculesorionsthatarepresentinthesampl

5、e.Whencombinedwithanappropriatedeterminativemethod,thisprocedureisdesignedtoprovidevaryingdegreesofmercuryspeciesinformation.Allmetalspeciationmethodsareoperationallydefinedbythelevelofpost-extractionprocessingandthechosenmethodofanalysis.Examplesoftheoperationally-definedmercuryfra

6、ctionsandindividualspeciesthatmaybedeterminedusingthisprocedurearepresentedinthetablebelow.Theenvironmentalmobilityandtoxicityofmercuryinasoilprofiledependonitsspeciation.Alkylmercuryspeciessuchasmethylmercuryareatleastanorderofmagnitudemoremobilethaninorganicmercuryspecies,andthusa

7、remoretoxicandmorereadilybioaccumulated.Solubleinorganicmercuryspeciessuchasmercurychloridearemoreeasilytransportedbynaturalprocessthantheotherinorganicmercuryspeciesandserveasthesubstrateformercurymethylationprocess(Ref.1).Theseextractableorganomercuryspeciesandextractableinorganic

8、speciescontributeth