EPA METHOD 3550B Ultrasonic Extraction

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1、METHOD3550BULTRASONICEXTRACTIONSeeDisclaimer.Seemanufacturer'sspecificationsforoperationalsettings.1.0SCOPEANDAPPLICATION1.1Method3550isaprocedureforextractingnonvolatileandsemivolatileorganiccompoundsfromsolidssuchassoils,sludges,andwastes.Theultrasonicprocessensuresintimatecontactofthesampl

2、ematrixwiththeextractionsolvent.1.2Themethodisdividedintotwosections,basedontheexpectedconcentrationoforganicsinthesample.Thelowconcentrationmethod(individualorganiccomponentsoflessthanorequalto20mg/kg)usesalargersamplesizeandamorerigorousextractionprocedure(lowerconcentrationsaremoredifficul

3、ttoextract).Themedium/highconcentrationmethod(individualorganiccomponentsofgreaterthan20mg/kg)ismuchsimplerandthereforefaster.1.3Itishighlyrecommendedthattheextractsbecleaneduppriortoanalysis.SeeChapterFour(Cleanup),Sec.4.2.2,forapplicablemethods.1.4Ultrasonicextractionisnotasrigorousasothere

4、xtractionmethodsforsoils/solids.Therefore,itiscriticalthatthemethod(includingthemanufacturer'sinstructions)befollowedexplicitlyinordertoachievethemaximumextractionefficiency.SeeSec.7.0forthecriticalaspectsoftheextractionprocedure.1.5EPAhasnotvalidatedMethod3550fortheextractionoforganophosphor

5、ouscompoundsfromsolidmatrices.Inaddition,thereareconcernsthattheultrasonicenergymayleadtobreakdownofsomeorganophosphorouscompounds(seeReference3).Asaresult,thisextractiontechniqueshouldnotbeusedfororganophosphorouscompoundswithoutextensivevalidationonreal-worldsamples.Suchstudiesshouldassesst

6、heprecision,accuracy,ruggedness,andsensitivityofthetechniquerelativetotheappropriateregulatorylimitsorproject-specificconcentrationsofinterest.1.6Thismethodisrestrictedtousebyorunderthesupervisionoftrainedanalysts.Eachanalystmustdemonstratetheabilitytogenerateacceptableresultswiththismethod.1

7、.7Thismethodisnotappropriateforapplicationswherehighextractionefficienciesofanalytesatverylowconcentrationsisnecessary(e.g.,demonstrationofeffectivenessofcorrectiveaction).2.0SUMMARYOFMETHOD2.1Lowconcentrationmethod-A30-gsampleismixedwithanhy