Designation:D4191−15StandardTestMethodforSodiuminWaterbyAtomicAbsorptionSpectrophotometry1ThisstandardisissuedunderthefixeddesignationD4191;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationoflowamountsofsodiuminwaters2havinglowsolidscontent.Theapplicablerangeofthistestmethodisfrom0.20to3.0mg/Lwhenusingthe589.6-nmresonanceline.Thisrangemaybeextendedupwardbydilutionofanappropriatealiquotofsampleorbyuseoftheless-sensitive330.2-nmresonanceline(seeTestMethodD3561).Manyworkershavefoundthatthistestmethodisreliableforsodiumlevelsto0.005mg/L,butuseofthistestmethodatthislowlevelisdependentontheconfigurationoftheaspiratorandnebulizersystemavailableintheatomicabsorptionspectrophotometeraswellastheexpe-rienceandskilloftheanalyst.Theprecisionandbiasdatapresentedareinsufficienttojustifyuseofthistestmethodinthe0.005to0.20-mg/Lrange.1.2Thistestmethodhasbeenusedsuccessfullywithspikedreagentwater.Itistheanalyst’sresponsibilitytoassurethevalidityofthetestmethodtootherlowdissolvedsolidsmatrices.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesaremathematicalconversionstoinch-poundunitsthatareprovidedforinforma-tiononlyandarenotconsideredstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:3D1066PracticeforSamplingSteamD1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD2777PracticeforDeterminationofPrecisionandBiasofApplicableTestMethodsofCommitteeD19onWaterD3370PracticesforSamplingWaterfromClosedConduitsD3561TestMethodforLithium,Potassium,andSodiumIonsinBr...
