ASTM_D_3341_-_05_2011.pdf

Designation:D334105(Reapproved 2011)Standard Test Method forLead in GasolineIodine Monochloride Method1This standard is issued under the fixed designation D3341;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method determines total lead in gasolinescontaining lead alkyls at concentrations between 0.026 and 1.3g Pb/L,and 0.12 and 6.0 g Pb/UK gal,0.1 and 5.0 g Pb/US gal.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.2.1 The preferred units are grams per litre although bothgram per US gallon and grams per UK gallon are acceptabledue to their widespread use in the industry.1.2.2 Temperature is given in degrees Fahrenheit and de-grees Celsius in this test method.1.3 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.For specific hazardstatements,see Sections 6 and 8.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance3.Summary of Test Method3.1 A known volume of the sample is diluted with heavydistillate and shaken with aqueous iodine monochloride re-agent.Any tetraalkyl lead compounds present react with theiodine monochloride and are extracted into the aqueous phaseas the dialkyl lead compounds.The aqueous extract is sepa-rated from the gasoline and evaporated to low bulk to decom-pose free iodine monochloride.Any organic matter present isremoved by oxidation with nitric acid,which also serves toconvert the dialkyl lead compounds into inorganic lead com-pounds.The residue is dissolved in distilled water and bufferedto pH 5 using sodium acetate-acetic acid buffer.The leadcontent of the buffered solution is determined by titration withEDTA using xylenol orange as indicator.4.Significance and Use4.1 This test method determines the concentration of leadalkyl additives in gasoline.These additives improve the anti-knock properties.5.Apparatus5.1 Separatory Funnel,borosilicate glass,capacity 250 mL,glass-stoppered with preferably an iodine flask type of neck.5.2 Erlenmeyer Flask,borosilicate glass,capacity 500 mL.6.Reagents and Materials6.1 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.6.1.1 Commercially available reagents may be used in placeof laboratory preparations when they conform to the specifi-cations in 6.1.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Type III or Type IV of Specification D1193.1This 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 1,2011.Published August 2011.Originallyapproved in 1974.Last previous edition approved in 2005 as D334105.DOI:10.1520/D3341-05R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For Suggestions on the testing of reagents notlisted by the American Chemical Society,see Annual Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.3 Ammonia Solution(1+1)Mix 1 volume of concen-trated ammonia solution(rel dens 0.90)with 1 volume ofdistilled water.6.4 Bromthymol Blue Indicator Solution Dissolve 0.1 g ofbromthymol blue in 50 mL of ethanol and dilute to 100 mLwith distilled water.6.5 EDTA,Standard Solution(0.005 M)Dissolve approxi-mately 3.75 g of diaminoethanetetra-acetic acid,disodium salt,in 2-L of distilled water.Determine the molarity of the solutionby