EPA METHOD 3630C Silica Gel Cleanup

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1、METHOD3630CSILICAGELCLEANUP1.0SCOPEANDAPPLICATION1.1Silicagel(silicicacid)isaregenerativeadsorbentofsilicawithweaklyacidicproperties.Itisproducedfromsodiumsilicateandsulfuricacid.Silicagelcanbeusedincolumnchromatographyfortheseparationofanalytesfrominterferingcompoundsofadifferentc

2、hemicalpolarity.Itmaybeusedactivated,afterheatingto150-160EC,ordeactivatedwithupto10%water.1.2Thismethodincludesguidanceforstandardcolumncleanupofsampleextractscontainingpolynucleararomatichydrocarbons,derivatizedphenoliccompounds,organochlorinepesticides,andPCBsasAroclors.1.3Thism

3、ethodalsoprovidescleanupproceduresusingsolid-phaseextractioncartridgesforpentafluorobenzylbromide-derivatizedphenols,organochlorinepesticides,andPCBs.ThistechniquealsoprovidesthebestseparationofPCBsfrommostsinglecomponentorganochlorinepesticides.WhenonlyPCBsaretobemeasured,thismeth

4、odcanbeusedinconjunctionwithsulfuricacid/permanganatecleanup(Method3665).1.4OtheranalytesmaybecleanedupusingthismethodiftheanalyterecoverymeetsthecriteriaspecifiedinSec.8.0.1.5Thismethodisrestrictedtousebyorunderthesupervisionoftrainedanalysts.Eachanalystmustdemonstratetheabilityto

5、generateacceptableresultswiththismethod.2.0SUMMARYOFMETHOD2.1Thismethodprovidestheoptionofusingeitherstandardcolumnchromatographytechniquesorsolid-phaseextractioncartridges.Generally,thestandardcolumnchromatographytechniquesuselargeramountsofadsorbentand,therefore,haveagreaterclean

6、upcapacity.2.2Inthestandardcolumncleanupprotocol,thecolumnispackedwiththerequiredamountofadsorbent,toppedwithawateradsorbent,andthenloadedwiththesampletobeanalyzed.Elutionoftheanalytesisaccomplishedwithasuitablesolvent(s)thatleavestheinterferingcompoundsonthecolumn.Theeluateisthenc

7、oncentrated(ifnecessary).2.3Thecartridgecleanupprotocolusessolid-phaseextractioncartridgespackedwith1gor2gofsilicagel(silicicacid)adsorbent.Eachcartridgeissolventwashedimmediatelypriortouse.Aliquotsofsampleextractsareloadedontothecartridges,whicharethenelutedwithsuitablesolvent(s).

8、Avacuummanifoldisrequiredt