Designation:D6129−97(Reapproved2015)StandardTestMethodforSiliconinEngineCoolantConcentratesbyAtomicAbsorptionSpectroscopy1ThisstandardisissuedunderthefixeddesignationD6129;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofsiliconintherangefrom200to500ppminenginecoolantconcentratesbyatomicabsorption.Thismethodisasaccurateandpreciseasphotometricmethods,whilerequiringconsiderablylessopera-tortimeandavoidingproblemswithreagentinstability.1.1.1Coolantswithsiliconcontentoutsideofthisrangemaybeanalyzedbythismethodbysuitablyadjustingthesamplesize.Careshouldbetakentoensurethattheglycolcontentoftheworkingstandardscorrespondstothatofthesamplesolutionbeinganalyzed.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1176PracticeforSamplingandPreparingAqueousSolu-tionsofEngineCoolantsorAntirustsforTestingPurposes3.SummaryofTestMethod3.1Thesampleisdissolvedinwaterandthesiliconcontentisdeterminedfromastandardcurveestablishedatthetimethesampleisrun.Anatomicabsorptionspectrometerwithanitrousoxide-acetyleneflameisused.4.Apparatus4.1AtomicAbsorptionSpectrometer,withnitrousoxide-acetyleneflame.4.2Hollow-CathodeLamp,forsilicon.5.Reagents5.1Reagentgradechemicalsshallbeusedinalltests.35.2Referencestowatershallbeunderstoodtomeandis-tilledwaterorwaterofequalquality.5.3StandardSiliconSolution,1000mg/L(seeNote1).5.4EthyleneGlycol(propyleneglycolshouldbeusedwhenanalyzingPG-basedcoolants).5.5SodiumHydroxide,5%inwa...
