1、Designation:D334812(Reapproved 2017)Standard Test Method forRapid Field Test for Trace Lead in Unleaded Gasoline(Colorimetric Method)1This standard is issued under the fixed designation D3348;the number immediately following the designation indicates the year oforiginal adoption or,in the case of re
2、vision,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 covers and is intended for use in thefield by nontechnical people for the quantitative
3、measurementof lead in unleaded gasoline in the range from 0.01 g to 0.10 gPb/U.S.gal(2.64 mg to 26.4 mg Pb/L).This method applies toall commercial gasolines and responds to all types of leadalkyls as well as to other organic and inorganic forms of lead.NOTE1This test method is based on the use of th
4、e Mobil Lead TestKit(Fig.1).NOTE2This test method is a screening test and is not to be used as areplacement for withdrawn Test Method D3116,withdrawn Test MethodD3229,Test Method D3237,Test Method D3341,or Test Method D5059.1.2 The values stated in SI units are to be regarded asstandard.No other uni
5、ts of measurement are included in thisstandard.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 regulat
6、ory limitations prior to use.For specificwarning statements,see Section 7.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Rec
7、om-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D3116 Test Method for Trace Amounts of Lead in Gasoline(Withdrawn 1994)3D3229 Test Method for Low Levels of Lead in Gasoline byX-Ray Spectrometry(Withdrawn 1992)3D3
8、237 Test Method for Lead in Gasoline byAtomicAbsorp-tion SpectroscopyD3341 Test Method for Lead in GasolineIodine Mono-chloride MethodD5059 Test Methods for Lead in Gasoline by X-Ray Spec-troscopyD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate Ana
9、lyticalMeasurement System PerformanceD6792 Practice for Quality Management Systems in Petro-leum Products,Liquid Fuels,and Lubricants TestingLaboratories3.Summary of Test Method3.1 The gasoline is treated with iodine and tetraethyl am-monium chloride in chloroform and subjected to ultravioletlight.T
10、he lead alkyls form water-soluble lead alkyl iodides,which are removed from the gasoline by shaking it with anaqueous ammonium nitrate solution.The aqueous extract isfiltered into a solution of 4-(2-pyridylazo)-resorcinol disodiumsalt(PAR)and ammonium hydroxide.The lead is determinedby measuring its
11、 PAR complex colorimetrically at 490 nmusing a previously prepared calibration curve.4.Significance and Use4.1 This test is used to determine trace quantities of lead inunleaded gasoline.Unwarranted amounts of lead may causedeposits in automotive pollution control equipment and poi-soning of catalyt
12、ic mufflers.5.Interferences5.1 PAR also reacts with many other metals forming highlycolored complexes.However,none of these are normally foundpresent in a soluble form in gasoline.The following metalswere found to form colors with PAR and if present may1This test method is under the jurisdiction of
13、ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved May 1,2017.Published June 2017.Originallyapproved in 1974.Last previous edition approved in 2012 as D3348 12.DOI:10.1520/D3348-12R
14、17.2For 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 refer
15、enced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDeve
16、lopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 interfere to give high results:Fe II,Fe III,Co II,Ni II,Cu II,Zn II,Cd II,Mn II,Sn II,V IV,Pb II,U VI,Ti IV,and the rareearths.6.Apparatus6.1 Ultraviolet Lamp,long wavelength,3660,placed in astandard 4 W fluorescent fixture.NOTE3A 3 min electric timer4,5is connected to the fixture in theprototype kit.6.2 Measuring Block,aluminum,drilled to hold an 18 mm