EPA METHOD 3810 Headspace

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1、METHOD3810HEADSPACE1.0SCOPEANDAPPLICATION1.1Method3810wasformerlyMethod5020inthesecondeditionofthismanual.1.2Method3810isastaticheadspacetechniqueforextractingvolatileorganiccompoundsfromsamples.Itisasimplemethodthatallowslargenumbersofsamplestobescreenedinarelativelyshortpe

2、riodoftime.Itisidealforscreeningsamplespriortousingthepurge-and-trapmethod.Detectionlimitsforthismethodmayvarywidelyamongsamplesbecauseofthelargevariabilityandcomplicatedmatricesofwastesamples.Themethodworksbestforcompoundswithboilingpointsoflessthan125EC.Thesensitivityofthi

3、smethodwilldependontheequilibriaofthevariouscompoundsbetweenthevaporanddissolvedphases.1.3Duetothevariabilityofthismethod,thisprocedureisrecommendedforuseonlyasascreeningprocedureforother,moreaccuratedeterminativemethods(Methods8010,8015,8020,8030,and8240).2.0SUMMARYOFMETHOD

4、2.1Thesampleiscollectedinsealedglasscontainersandallowedtoequilibrateat90EC.Asampleoftheheadspacegasiswithdrawnwithagas-tightsyringeforscreeninganalysisusingtheconditionsspecifiedinoneoftheGCorGC/MSdeterminativemethods(8010,8015,8020,8030,or8240).3.0INTERFERENCES3.1Samplesca

5、nbecontaminatedbydiffusionofvolatileorganics(particularlychlorofluorocarbonsandmethylenechloride)throughthesamplecontainerseptumduringshipmentandstorage.Afieldsampleblankpreparedfromreagentwaterandcarriedthroughsamplingandsubsequentstorageandhandlingcanserveasacheckonsuchcon

6、tamination.3.2Contaminationbycarryovercanoccurwheneverhigh-levelandlow-levelsamplesaresequentiallyanalyzed.Toreducecarryover,thesamplesyringemustberinsedoutbetweensampleswithreagentwater.Wheneveranunusuallyconcentratedsampleisencountered,itshouldbefollowedbyananalysisofreage

7、ntwater.Itmaybenecessarytowashoutthesyringewithdetergent,rinsewithdistilledwater,anddryina105ECovenbetweenanalyses.3.3Beforeprocessinganysamples,theanalystshoulddemonstratedailythroughtheanalysisofanorganic-freewaterorsolventblankthattheentireanalyticalsystemisinterference-f

8、ree.3810-1CD-ROMRevision0DateSeptember19864.0APPARATUSANDMATERIALS4.1Refert