Designation:D4901−99(Reapproved2009)StandardPracticeforPreparationofSolutionofLiquidVegetableTanninExtracts1ThisstandardisissuedunderthefixeddesignationD4901;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticecoversthepreparationofasolutionofliquidextractthatistobeusedinthetanninanalysisofthatextract.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D4904PracticeforCoolingofAnalyticalSolutionsD6404PracticeforSamplingVegetableMaterialsContain-ingTannin2.2ALCAMethods:A10PreparationofSolutionofLiquidExtracts33.SummaryofPractice3.1Thepracticedescribesatechniquefoundusefulinthepreparationofanalyticalstrengthsolutionsfromsamplesofliquidvegetabletanninextracts.4.SignificanceandUse4.1Theconcentrationoftannininextractsmustbereducedtoanalyticalstrength(4gtanninperL)foranalyses.4.2Vegetabletanninextractsareheterogeneousmixturesofcomponentswithvaryingsolubility.4.3Thesolubilityofsuchextractsisinfluencedbytempera-tureandconcentration,whichaffectthedegreeofdispersionandsizeofthecomponentparticles.4.4Whilethesolubilityisbetterinhotwaterthanincoldwater,itisappropriatetodissolveanddisperseanextractinhotwaterandthenletthesolutioncoolslowlytostandardroomtemperature.5.ApparatusandReagents5.1Formaldehyde—40%solution.5.2Toluene—assay$99.5%.5.3Flask,1Lvolumetric.TheClassAtype,withupperbulbinneck,isespeciallysuitableforthiswork.6.TestSpecimen6.1Thespecimenshallconsistofanaliquotofthesample,preparedasdescribedinPracticeD6404,suffici...
