EPA METHOD 9066 Phenolics (Colorimetric, Automated 4-AAP with Distillation)

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1、METHOD9066PHENOLICS(COLORIMETRIC,AUTOMATED4-AAPWITHDISTILLATION)1.0SCOPEANDAPPLICATION1.1Thismethodisapplicabletotheanalysisofgroundwaterandofdrinking,surface,andsalinewaters.1.2Themethodiscapableofmeasuringphenolicmaterialsfrom2to500ug/Lintheaqueousphaseusingph

2、enolasastandard.2.0SUMMARYOFMETHOD2.1Thisautomatedmethodisbasedonthedistillationofphenolandsubsequentreactionofthedistillatewithalkalineferricyanide(K3Fe(CN)6)and4-amino-antipyrine(4-AAP)toformaredcomplexwhichismeasuredat505or520nm.3.0INTERFERENCES3.1Interferenc

3、esfromsulfurcompoundsareeliminatedbyacidifyingthesampletoapHof<4.0withH2SO4andaeratingbrieflybystirring.3.2Oxidizingagentssuchaschlorine,detectedbytheliberationofiodineuponacidificationinthepresenceofpotassiumiodide,areremovedimmediatelyaftersamplingbytheadditio

4、nofanexcessofferrousammoniumsulfate(5.5).Ifchlorineisnotremoved,thephenoliccompoundsmaybepartiallyoxidizedandtheresultsmaybelow.3.3Backgroundcontaminationfromplastictubingandsamplecontainersiseliminatedbyfillingthewashreceptaclebysiphon(usingKel-Ftubing)andusing

5、glasstubesforthesamplesandstandards.4.0APPARATUSANDMATERIALS4.1Automatedcontinuous-flowanalyticalinstrument:4.1.1Sampler:Equippedwithcontinuousmixer.4.1.2Manifold.4.1.3ProportioningpumpIIorIII.4.1.4Heatingbathwithdistillationcoil.4.1.5Distillationhead.90661CD-RO

6、MRevision0DateSeptember19864.1.6Colorimeter:Equippedwitha50mmflowcelland505or520nmfilter.4.1.7Recorder.5.0REAGENTS5.1ASTMTypeIIwater(ASTMD1193):Watershouldbemonitoredforimpurities.5.2Distillationreagent:Add100mLofconcentratedphosphoricacid(85%H3PO4)to800mLofType

7、IIwater,coolanddiluteto1liter.5.3Bufferedpotassiumferricyanide:Dissolve2.0gpotassiumferricyanide,3.1gboricacid,and3.75gpotassiumchloridein800mLofTypeIIwater.AdjusttopHof10.3with1Nsodiumhydroxide(5.3)anddiluteto1liter.Add0.5mLofBrij-35(availablefromTechnicon).(Br

8、ij-35isawettingagentandisaproprietaryTechniconproduct.)Preparefreshweekly.5.4Sodiumhydroxide(1N):Dissolve40gNaOHin500mLofTypeIIwater,coolanddiluteto1liter.5.54-Aminoa