EPA METHOD 3660B Sulfur Cleanup

《EPA METHOD 3660B Sulfur Cleanup》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、METHOD3660BSULFURCLEANUP1.0SCOPEANDAPPLICATION1.1Elementalsulfurisencounteredinmanysedimentsamples(generallyspecifictodifferentareasinthecountry),marinealgae,andsomeindustrialwastes.Thesolubilityofsulfurinvarioussolventsisverysimilartotheorganochlorineandorganophosphoruspesticid

2、es.Therefore,thesulfurinterferencefollowsalongwiththepesticidesthroughthenormalextractionandcleanuptechniques.Ingeneral,sulfurwillusuallyeluteentirelyinFraction1oftheFlorisilcleanup(Method3620).1.2Sulfurwillbequiteevidentingaschromatogramsobtainedfromelectroncapturedetectors,fla

3、mephotometricdetectorsoperatedinthesulfurorphosphorousmode,andCoulsonelectrolyticconductivitydetectorsinthesulfurmode.Ifthegaschromatographisoperatedatthenormalconditionsforpesticideanalysis,thesulfurinterferencecancompletelymasktheregionfromthesolventpeakthroughAldrin.1.3Twotec

4、hniquesfortheeliminationofsulfuraredetailedwithinthismethod:(1)theuseofcopperpowder;and(2)theuseoftetrabutylammoniumsulfite.Tetrabutylammoniumsulfitecausestheleastamountofdegradationofabroadrangeofpesticidesandorganiccompounds,whilecoppermaydegradeorganophosphorusandsomeorganoch

5、lorinepesticides.1.4Thismethodisrestrictedtousebyorunderthesupervisionoftrainedanalysts.Eachanalystmustdemonstratetheabilitytogenerateacceptableresultswiththismethod.2.0SUMMARYOFMETHOD2.1Thesampletoundergocleanupismixedwitheithercopperortetrabutylammonium(TBA)sulfite.Themixturei

6、sshakenandtheextractisremovedfromthesulfurcleanupreagent.3.0INTERFERENCESThecoppertechniquerequiresthatthecopperpowderbeveryreactive,asevidencedbyabrightshinyappearance(seeSec.5.5forthepreparationofthisreagent).However,caremustbetakentoremovealltracesoftheacidusedtopreparethecop

7、per,inordertoavoiddegradationofsomeanalytes.4.0APPARATUSANDMATERIALS4.1Mechanicalshakerormixer-VortexGenieorequivalent.4.2Pipets,disposable-Pasteurtype.4.3Centrifugetubes,calibrated-12mL.4.4Glassbottlesorvials-10mLand50mL,withpolytetrafluoroethylene(PTFE)-linedscrewcapsorcrimpto

8、ps.CD-ROM3660B-1Revision2December19965.0REAGENT