EPA300.0离子色谱测定无机阴离子

METHOD300.0DETERMINATIONOFINORGANICANIONSBYIONCHROMATOGRAPHYJohnD.PfaffInorganicChemistryBranchChemistryResearchDivisionRevision2.1August1993ENVIRONMENTALMONITORINGSYSTEMSLABORATORYOFFICEOFRESEARCHANDDEVELOPMENTU.S.ENVIRONMENTALPROTECTIONAGENCYCINCINNATI,OHIO45268METHOD300.0DETERMINATIONOFINORGANICANIONSBYIONCHROMATOGRAPHY1.0SCOPEANDAPPLICATION1.1Thismethodcoversthedeterminationofthefollowinginorganicanions:PARTA.BromideNitriteChlorideOrtho-Phosphate-PFluorideSulfateNitratePARTB.BromateChloriteChlorate1.2Thematricesapplicabletoeachmethodareshownbelow:1.2.1Drinkingwater,surfacewater,mixeddomesticandindustrialwastewaters,groundwater,reagentwaters,solids(afterextraction11.7),leachates(whennoaceticacidisused).1.2.2Drinkingwaterandreagentwaters1.3ThesinglelaboratoryMethodDetectionLimit(MDLdefinedinSection3.2)fortheaboveanalytesislistedinTables1Aand1B.TheMDLforaspecificmatrixmaydifferfromthoselisted,dependinguponthenatureofthesample.1.4MethodAisrecommendedfordrinkingandwastewaters.Themultilaboratoryrangestestedforeachanionareasfollows:Analytemg/LBromide0.63-21.0Chloride0.78-26.0Fluoride0.26-8.49Nitrate-N0.42-14.0Nitrite-N0.36-12.0Otho-Phosphate-P0.69-23.1Sulfate2.85-95.01.5Thismethodisrecommendedforuseonlybyorunderthesupervisionofanalystsexperiencedintheuseofionchromatographyandintheinterpretationoftheresultingionchromatograms.1.6Whenthismethodisusedtoanalyzeunfamiliarsamplesforanyoftheaboveanions,anionidentificationshouldbesupportedbytheuseofafortifiedsamplematrixcoveringtheanionsofinterest.ThefortificationprocedureisdescribedinSection11.6.1.7Usersofthemethoddatashouldstatethedata-qualityobjectivespriortoanalysis.Usersofthemethodmustdemonstratetheabilitytogenerateacceptableresultswiththismethod,usingtheproceduresdescribedinSection9.0.2.0SUMMARYOFMETHOD2.1Asmallvolumeofsample,typically2-3mL,isintroducedintoanionchromatograph.Theanionsofinterestareseparatedandmeasured,usingasystemcomprisedofaguardcolumn,analyticalcolumn,suppressordevice,andconductivitydetector.2.2ThemaindifferencesbetweenPartsAandBaretheseparatorcolumnsandguardcolumns.Sections6.0and7.0willelicitthedifferences.2.3Anextractionproceduremustbeperformedtousethismethodforsolids(SeeSection11.7).2.4Limitedperformance-basedmethodmodificationsmaybeacceptableprovidedtheyarefullydocumentedandmeetorexceedrequirementsexpressedinSection9.0,QualityControl.3.0DEFINITIONS3.1CalibrationBlank(CB)--Avolumeofreagentwaterfortifiedwiththesamematrixasthecalibrationstandards,butwithouttheanalytes,internalstandards,orsurrogateanalytes.3.2CalibrationStandard(CAL)--Asolutionpreparedfromtheprimarydilutionstandardsolutionorstockstandardsolutionsandtheinternalstandardsandsurrogateanalytes.TheCALsolutionsareusedtocalibratetheinstrumentresponsewithrespecttoanalyteconcentration.3.3FieldDuplicates(FD)--Twoseparatesamplescollectedatthesametimeandplacedunderidenticalcircumstancesandtreatedexactlythesamethroughoutfieldandlaboratoryprocedures.Analysesoffieldduplicatesindicatetheprecisionassociatedwithsamplecollection,preservationandstorage,aswellaswithlaboratoryprocedures.3.4InstrumentPerformanceCheckSolution(IPC)--Asolutionofoneormoremethodanalytes,surrogates,internalstandards,orothertestsubstancesusedtoevaluatetheperformanceoftheinstrumentsystemwithrespecttoadefinedsetofcriteria.3.5LaboratoryFortifiedBlank(LFB)--Analiquotofreagentwaterorotherblankmatricestowhichknownquantitiesofthemethodanalytesareaddedinthelaboratory.TheLFBisanalyzedexactlylikeasample,anditspurposeistodeterminewhetherthemethodologyisincontrol,andwhetherthelaboratoryiscapableofmakingaccurateandprecisemeasurements.3.6LaboratoryFortifiedSampleMatrix(LFM)--Analiquotofanenvironmentalsampletowhichknownquantitiesofthemethodanalytesareaddedinthelaboratory.TheLFMisanalyzedexactlylikeasample,anditspurposeistodeterminewhetherthesamplematrixcontributesbiastotheanalyticalresults.ThebackgroundconcentrationsoftheanalytesinthesamplematrixmustbedeterminedinaseparatealiquotandthemeasuredvaluesintheLFMcorrectedforbackgroundconcentrations.3.7LaboratoryReagentBlank(LRB)--Analiquotofreagentwaterorotherblankmatricesthataretreatedexactlyasasampleincludingexposuretoallglassware,equipment,solvents,reagents,internalstandards,andsurrogatesthatareusedwithothersamples.TheLRBisusedtodetermineifmethodanalytesorotherinterferencesarepresentinthelaboratoryenvironment,thereagents,ortheapparatus.3.8LinearCalibrationRange(LCR)--Theconcentrationrangeoverwhichtheinstrumentresponseislinear.3.9MaterialSafetyDataSheet(MSDS)--Writteninformationprovidedbyvendorsconcerningachemical'stoxicity,healthhazards,physicalproperties,fire,andreactivitydataincludingstorage,spill,andhandlingprecautions.3.10MethodDetectionLimit(MDL)--Theminimumconcentrationofananalytethatcanbeidentified,measuredandreportedwith99%confidencethattheanalyteconcentrationisgreaterthanzero.3.11PerformanceEvaluationSample(PE)--AsolutionofmethodanalytesdistributedbytheQualityAssuranceResearchDivision(QARD),EnvironmentalMonitoringSystemsLaboratory(EMSL-Cincinnati),U.S.EnvironmentalProtectionAgency,Cin