1、Designation:D334812Standard 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 revision,the year o
2、f 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.Scope*1.1 This test method covers and is intended for use in thefield by nontechnical people for the quantitative measurementof le
3、ad in unleaded gasoline in the range from 0.01 to 0.10 gPb/U.S.gal(2.64 to 26.4 mg Pb/L).This method applies to allcommercial gasolines and responds to all types of lead alkylsas well as to other organic and inorganic forms of lead.NOTE1This test method is based on the use of the Mobil Lead TestKit(
4、Fig.1).NOTE2This test method is a screening test and is not to be used as areplacement for withdrawn Test Method D3116,withdrawn Test MethodD3229,Test Method D3237,Test Method D3341,or Test Method D5059.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are
5、 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 regulatory limitations prior
6、 to use.For specificwarning statements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D3116 Test Method for Trace Amounts of Lead in Gasoline(Withdrawn 1994)3D3229 Test Method for Low Levels of Lead in Gasoline byX-Ray Spectrometry(Withdrawn 1992)3D3237 Test Method for Lead in Gasoline byAt
7、omicAbsorp-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 AnalyticalMeasurement System PerformanceD679
8、2 Practice for Quality System in Petroleum Productsand Lubricants Testing Laboratories3.Summary of Test Method3.1 The gasoline is treated with iodine and tetraethyl am-monium chloride in chloroform and subjected to ultravioletlight.The lead alkyls form water-soluble lead alkyl iodides,which are remo
9、ved 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 PAR complex colorimetrically at 490 nmusing a previously prepared
10、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 catalytic mufflers.5.Interferences5.1 PAR also reacts with many other meta
11、ls 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 mayinterfere 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 th
12、e rareearths.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved Dec.1,2012.Published January 2013.Originallyapproved in 1974.Last prev
13、ious edition approved in 2007 as D334807.DOI:10.1520/D3348-12.2For 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
14、 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.Apparatus6.1 Ultraviolet Lamp,long waveleng
15、th,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 by150-mm test tube,with a mark at a level equal to 5.0 mL ofliquid in the test tube.6.3 Colorimeter,Portable,capable of
16、 operating at 490 mm.Any equivalent instrument capable of measurement near 514nm(the optimum Pb-PAR complex wavelength)may be used.6.4 Test Tubes,5,6borosilicate,18 by 150 mm.6.5 Pipets,glass,dropping,capable of delivering 2.0 mLwith a 2-mL bulb.(WarningGasoline or any of the reagentsmust not come in contact with rubber.If this happens,discardthe bulb and pipet and start again.)6.6 Funnel,plastic,2 in.in inside diameter.6.7 Filter Paper,ashless,hardened,smooth,very fast,11.0cm in diameter.NOTE4C
