ASTM_D_3340_-_98_2003.pdf

Designation:D 3340 98(Reapproved 2003)An American National StandardStandard Test Method forLithium and Sodium in Lubricating Greases by FlamePhotometer1This standard is issued under the fixed designation D 3340;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers determination of the lithium andsodium content of lubricating greases by means of a flamephotometer.1.2 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.3 The preferred units are mass%and accepted SI units.The values given in parentheses are for information only.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water23.Summary of Test Method3.1 The sulfated ash of the grease is extracted with waterand the lithium and sodium content of the resulting solution isdetermined by means of a suitable flame photometer.4.Significance and Use4.1 Lubricating greases can contain the lithium soap ofhydroxy stearic acid or the sodium soap of various fatty acidsas thickeners.The determination of total lithium or totalsodium is a measure of the amount of thickener in the grease.5.Apparatus5.1 Flame Photometer,suitably equipped to determinelithium and sodium over a range from 0 to 15 mg/Llithium andfrom 0 to 5 mg/L sodium.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type II of Specification D 1193.6.3 Lithium Sulfate,Stock Solution1.188 g of lithiumsulfate dried to constant weight at 180C(356F),is dissolvedin water and made up to 1 L.This will contain 150 mg/Llithium.6.4 Sodium Sulfate,Stock Solution0.1544 g of sodiumsulfate,dried to constant weight at 105C(221F),is dissolvedin water and made up to 1 L.This will contain 50 mg/Lsodium.6.5 Sulfuric Acid(rel.den.1.84)Concentrated sulfuricacid(H2SO4).7.Sampling7.1 A homogeneous sample shall be obtained to ensurequantitative analytical results.8.Procedure8.1 Weigh to the nearest 1 mg approximately 1 g of thegrease into a platinum dish or crucible.Heat the dish until thesample can be ignited with a flame.Maintain at such atemperature that the sample burns at a uniform and moderaterate,leaving only ash and carbon when the burning ceases.8.2 Cool the dish and completely moisten the residue by thedropwise addition of concentrated sulfuric acid.Heat the dishat a low temperature,taking care to avoid spattering of thecontents,and continue heating until fumes are no longerevolved.Place the dish in a furnace at 550 6 25C(1022 645F)and continue heating until the oxidation of the carbon ispractically complete.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved May 10,2003.Published July 2003.Originallyapproved in 1974.Last previous edition approved in 1998 as D 334098.2Annual Book of ASTM Standards,Vol 11.01.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.8.3 Cool and repeat 8.2 to complete the sulfation.8.4 Extract the sulfated ash with hot distilled water andtransfer the aqueous extract,filtering if necessary,to a 100-mLvolumetric flask.Allow to cool and make up to the mark withdistilled water.8.5 Prepare the following fresh calibration standards byappropriate dilution of the stock solutions:8.5.1 Lithium SulfateSolutions containing 0,3,6,9,12and 15 mg/L lithium.8.5.2 Sodium SulfateSolutions containing 0,1,2,3,4,and5 mg/L sodium.8.6 Obtain the flame photometer readings for each calibra-tion standard and prepare curves relating concentration tophotometer reading.8.7 Obtain readings for the extract derived from