EPA METHOD 9038 Sulfate (Turbidimetric)

《EPA METHOD 9038 Sulfate (Turbidimetric)》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、METHOD9038SULFATE(TURBIDIMETRIC)1.0SCOPEANDAPPLICATION1.1Thismethodisapplicabletogroundwater,drinkingandsurfacewaters,anddomesticandindustrialwastes.1.2Thismethodissuitableforallconcentrationrangesofsulfate-2(SO4);however,inordertoobtainreliablereadings,useasamplealiquot-2containingnotmoreth

2、an40mg/LofSO4.-21.3Theminimumdetectablelimitisapproximately1mg/LofSO4.2.0SUMMARYOFMETHOD2.1Sulfateionisconvertedtoabariumsulfatesuspensionundercontrolledconditions.Theresultingturbidityisdeterminedbyanephelometer,filterphotometer,orspectrophotometerandcomparedwithacurvepreparedfromstandardsu

3、lfatesolution.3.0INTERFERENCES3.1Colorandturbidityduetothesamplematrixcancausepositiveinterferenceswhichmustbeaccountedforbyuseofblanks.3.2Silicainconcentrationsover500mg/Lwillinterfere.4.0APPARATUSANDMATERIALS4.1Magneticstirrer:Variablespeedsothatitcanbeheldconstantjustbelowsplashing.Useide

4、nticalshapesandsizesofmagneticstirringbars.4.2Photometer(oneofthefollowing,giveninorderofpreference):4.2.1Nephelometer.4.2.2Spectrophotometer:Foruseat420nmwithlightpathof4to5cm.4.2.3Filterphotometer:Withavioletfilterhavingamaximumnear420nmandalightpathof4to5cm.4.3Stopwatch:Ifthemagneticstirr

5、erisnotequippedwithanaccuratetimer.90381CD-ROMRevision0DateSeptember19864.4Measuringspoon:Capacity0.2to0.3mL.5.0REAGENTS5.1ASTMTypeIIwater(ASTMD1193):Watershouldbemonitoredforimpurities.5.2Conditioningreagent:Slowlyadd30mLconcentratedHClto300mLTypeIIwater,100mL95%ethanolorisopropanol,and75gN

6、aClinsolutioninacontainer.Add50mLglycerolandmix.b5.3Bariumchloride(BaCl2):Crystals,20to30mesh.5.4Sodiumcarbonatesolution:(approximately0.05N):Dry3to5gprimarystandardNa2CO3at250ECfor4hrandcoolinadesiccator.Weigh2.5+0.2g(tothenearestmg),transfertoa1-litervolumetricflask,andfilltothemarkwithTyp

7、eIIwater.5.5Proprietaryreagents:SuchasHachSulfaverorequivalent,areacceptable.-25.6Standardsulfatesolution(1.00mL=100ugSO4):PreparebyParagraph5.6.1or5.6.2.5.6.1StandardsulfatesolutionfromH2SO4:5.6.1.1Standardsulfuricacid,0.1N:Dilute3.0mLconcentrated