ASTM_D_3237_-_12.pdf

Designation:D323712Standard Test Method forLead in Gasoline by Atomic Absorption Spectroscopy1This standard is issued under the fixed designation D3237;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.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1 This test method covers the determination of the totallead content of gasoline within the concentration range of0.010 to 0.10 g of lead/U.S.gal(2.5 to 25 mg/L).This testmethod compensates for variations in gasoline compositionand is independent of lead alkyl type.1.2 The values given in grams per U.S.gallon are to beregarded as the standard in the United States.Note that in othercountries,other units can be preferred.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 6.6 and 6.8.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1368 Test Method for Trace Concentrations of Lead inPrimary Reference Fuels(Withdrawn 1994)3D2550 Method of Test for Water Separation Characteristicsof Aviation Turbine Fuels(Withdrawn 1989)3D3116 Test Method for Trace Amounts of Lead in Gasoline(Withdrawn 1994)3D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6792 Practice for Quality System in Petroleum Productsand Lubricants Testing LaboratoriesD7740 Practice for Optimization,Calibration,and Valida-tion of Atomic Absorption Spectrometry for Metal Analy-sis of Petroleum Products and Lubricants3.Summary of Test Method3.1 The gasoline sample is diluted with methyl isobutylketone and the alkyl lead components are stabilized by reactionwith iodine and a quaternary ammonium salt.The lead contentof the sample is determined by atomic absorption flamespectrometry at 283.3 nm,using standards prepared fromreagent grade lead chloride.By the use of this treatment,allalkyl lead compounds give identical response.3.2 Protocols for using atomic absorption spectrometry aregiven in Practice D7740.4.Significance and Use4.1 This test method is used to ensure compliance of tracelead as required by federal regulation for lead-free gasoline(40CFR part 80).5.Apparatus5.1 Atomic Absorption Spectrometer,capable of scale ex-pansion and nebulizer adjustment,and equipped with a slotburner and premix chamber for use with an air-acetylene flame.5.2 Volumetric Flasks,50-mL,100-mL,250-mL,and 1-Lsizes.5.3 Pipets,2-mL,5-mL,10-mL,20-mL,and 50-mL sizes.5.4 Micropipet,100-L,Eppendorf type or equivalent.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 June 1,2012.Published August 2012.Originallyapproved in 1973.Last previous edition approved in 2006 as D3237 061.DOI:10.1520/D323712.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 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.46.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water as definedby Types II or III of Specification D1193.6.3 Aliquat 336(tricapryl methyl ammonium chloride).6.4 Aliquat336/MIBKSolution(10%volumepervolume)Dissolve and dilute 100 mL(88.0 g)of Aliquat 336with MIBK to 1 L.6.5 Aliquat 336/MIBK Solution(1%volume per volume)Dissolve and dilute 10 mL(8.8 g)of Aliquat 336 with MIBKto 1 L.6.6 Iodine SolutionDissolve and dilute 3.0 g of iodinecrystals with toluene to 100 mL.(WarningFlammable.Vapor harmful.)6.7 Lead Chloride(PbCl2).6.8 Lead-Sterile GasolineGasoline containing less than0.005 g Pb/gal(1.32 mg Pb/L).(WarningExtremely flam-mable.Harmful if inhaled.Vapors may cause flash fire.)NOTE1One way to confirm lead concentrations of less than 0.005 gPb