Designation:D4608−89(Reapproved2009)StandardTestMethodforCitrateinDetergents1ThisstandardisissuedunderthefixeddesignationD4608;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversapotentiometrictitrationpro-cedureforthedeterminationofcitrateinliquidandpowderdetergents.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.MaterialSafetyDataSheetsareavailableforreagentsandmaterials.Reviewthemforhazardspriortousage.SpecificsafetyprecautionsaregiveninSection8.2.ReferencedDocuments2.1ASTMStandards:2E70TestMethodforpHofAqueousSolutionsWiththeGlassElectrodeE180PracticeforDeterminingthePrecisionofASTMMethodsforAnalysisandTestingofIndustrialandSpe-cialtyChemicals(Withdrawn2009)33.SummaryofTestMethod3.1ThesampleistitratedinanaqueoussolutionbufferedatpH8.5,withstandardcoppersulfatesolution.Theendpointisdetectedpotentiometricallyusingacopperionselectiveelec-trode.Thecitratecontentiscalculatedfromtheamountofstandardcoppersulfatesolutionconsumed.4.SignificanceandUse4.1Thistestmethodissuitableinresearch,development,andmanufacturingcontroltomonitorthelevelofcitrate,asequesteringagent,inpowderandliquiddetergents.4.2Accuratedeterminationofsequesteringagentisimpor-tantinevaluatingcostandperformanceofdetergentproducts.5.Interferences5.1Othercomplexingagentssuchasnitrilotriaceticacid(NTA),ethylenedinitrilotetraaceticacid(EDTA),phosphates,etc.willtitrateascitrateinthismethod.Foraccuratecitratedeterminations,suchcomplexingagentsmustbeabsent.6.Apparatus6.1pHMeter,withm...
