资源描述：
《EPA METHOD 9045D Soil and Waste pH》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、METHOD9045DSOILANDWASTEpH1.0SCOPEANDAPPLICATION1.1ThismethodisanelectrometricprocedureformeasuringpHinsoilsandwastesamples.Wastesmaybesolids,sludges,ornon-aqueousliquids.Ifwaterispresent,itmustconstitutelessthan20%ofthetotalvolumeofthesample.2.0SUMMARYOFMETHOD2.1Thesamplei
2、smixedwithreagentwater,andthepHoftheresultingaqueoussolutionismeasured.3.0INTERFERENCES3.1SampleswithveryloworveryhighpHmaygiveincorrectreadingsonthemeter.ForsampleswithatruepHof>10,themeasuredpHmaybeincorrectlylow.Thiserrorcanbeminimizedbyusingalow-sodium-errorelectrode.S
3、trongacidsolutions,withatruepHof<1,maygiveincorrectlyhighpHmeasurements.3.2Temperaturefluctuationswillcausemeasurementerrors.3.3Errorswilloccurwhentheelectrodesbecomecoated.Ifanelectrodebecomescoatedwithanoilymaterialthatwillnotrinsefree,theelectrodecan(1)becleanedwithanul
4、trasonicbath,or(2)bewashedwithdetergent,rinsedseveraltimeswithwater,placedin1:10HClsothatthelowerthirdoftheelectrodeissubmerged,andthenthoroughlyrinsedwithwater,or(3)becleanedperthemanufacturer'sinstructions.4.0APPARATUSANDMATERIALS4.1pHmeterwithmeansfortemperaturecompensa
5、tion.4.2Glasselectrode.4.3Referenceelectrode--Asilver-silverchlorideorotherreferenceelectrodeofconstantpotentialmaybeused.NOTE:Combinationelectrodesincorporatingbothmeasuringandreferencedfunctionsareconvenienttouseandareavailablewithsolid,gel-typefillingmaterialsthatrequir
6、eminimalmaintenance.4.4Beaker--50-mL.4.5Thermometerand/ortemperaturesensorforautomaticcompensation.4.6Analyticalbalance--capableofweighing0.1g.9045D-1Revision4November20045.0REAGENTS5.1Reagentgradechemicalsshallbeusedinalltests.Unlessotherwiseindicated,itisintendedthatallr
7、eagentsshallconformtothespecificationsoftheCommitteeonAnalyticalReagentsoftheAmericanChemicalSociety,wheresuchspecificationsareavailable.Othergradesmaybeused,provideditisfirstascertainedthatthereagentisofsufficientlyhighpuritytopermititsusewithoutlesseningtheaccuracyofthed
8、etermination.5.2Reagentwater.Allreferencestowaterinthismethodrefertoreagentwater,asdefine
