Designation:D5085−21StandardTestMethodforDeterminationofChloride,Nitrate,andSulfateinAtmosphericWetDepositionbySuppressedIonChromatography1ThisstandardisissuedunderthefixeddesignationD5085;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodisapplicabletothedeterminationofchloride,nitrate,andsulfateinatmosphericwetdepositionsamples(rain,snow,sleet,andhail)bysuppressedionchro-matography.Foradditionalapplications,seetoTestMethodD4327.1.2Theconcentrationrangesforthistestmethodareaslistedbelow.Therangetestedwasconfirmedusingtheinterlaboratorycollaborativetest(seeTable1forstatisticalsummaryofthecollaborativetest).MethodDetectionL(mg/L)(1)RangeofMethod(mg/L)RangeTested(mg/L)Chloride0.030.09–2.00.15–1.36Nitrate0.030.09–5.00.15–4.92Sulfate0.030.09–8.00.15–6.521.3Themethoddetectionlimit(MDL)isbasedonsingleoperatorprecision(1)2andmaybehigherorlowerforotheroperatorsandlaboratories.Theprecisionandbiasdatapre-sentedareinsufficienttojustifyuseatthislowlevel;however,ithasbeenreportedthatthistestmethodisreliableatlowerlevelsthanthosethatweretested.TheMDLslistedaboveweredeterminedfollowingtheguidancein40CFRPart136AppendixB.OtherapproachestothedeterminationofMDLsmayyielddifferentMDLs.1.4MethodDetectionLimitswillvarydependingonthetypeandlengthofcolumn(s)used,thecompositionandstrengthofeluentused,theboresizeoftheinstrumentation(thatis,microboreorstandardbore),eluentflowrateandothervariablesbetweeninstruments.ThemethoddetectionlimitslistedabovearethoseusedindeterminingthePrecisionandBiasofthismethodasgiveninTable1.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitat...
