Designation:D6174–01(Reapproved2006)StandardTestMethodforInorganicSulfateinSurfactantsbyPotentiometricLeadTitration1ThisstandardisissuedunderthefixeddesignationD6174;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethoddescribesapotentiometrictitrationprocedurefordeterminingtheinorganicsulfatecontentofsurfactants.Itisintendedfortheanalysisofa-olefinsul-fonates,alkanesulfonates,alcoholsulfates,alcoholethersulfates,alkylbenzenesulfonates,andthelike.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.MaterialSafetyDataSheetsareavailableforreagentsandmaterials.Reviewthemforhazardspriortousage.2.ReferencedDocuments2.1ASTMStandards:D1193SpecificationforReagentWater3.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1inorganicsulfate,n—sulfatespeciespresentassulfu-ricacid,ionicsaltsofthisacid,ormixturesofthese.4.SummaryofTestMethod4.1Asurfactantsamplecontaininginorganicsulfateistitratedinethanolicmediumwithastandardleadsolution.Leadsulfateprecipitateisformedduringthetitration.Ethanolandsodiumperchloratearepresenttodecreasethesolubilityofleadsulfate,thussharpeningtheendpoint.Aceticacidisaddedtoremovepossibleinterferencefromcarbonate.Theendpointissignaledbyanincreaseinleadionactivity,asmeasuredbyalead-selectiveelectrode.5.SignificanceandUse5.1Anionicsurfactants,suchasthoselistedin1.1,com-monlyareusedindetergentformulations.Theiracceptabilityforusedependsontheirpurity.Sulfatecontent,asmeasuredbythistestmethod,canbeusedtoestimatethepurityofananionicsurfactantundertest.6.Apparatus6.1PotentiometricTitrationAssembly,consistingofanautomatictitratorfittedwith...
