1、Designation: D 5059 07Designation: 228/79An American National StandardStandard Test Methods forLead in Gasoline by X-Ray Spectroscopy1This standard is issued under the fixed designation D 5059; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 These test me
3、thods cover the determination of the totallead content of a gasoline within the following concentrationranges:0.010 to 5.0 g Pb/US gal0.012 to 6.0 g Pb/UK gal0.0026 to 1.32 g Pb/L1.1.1 Test Methods A and B cover the range of 0.10 to 5.0g Pb/US gal. Test Method C covers the range of 0.010 to 0.50g Pb
4、/US gal.1.1.2 These test methods compensate for normal variationin gasoline composition and are independent of lead alkyl type.1.2 Test Method A (formerly in withdrawn Test MethodD 2599)Sections 5-9.Test Method B (formerly in withdrawn Test MethodD 2599)Sections 10-14.Test Method C (formerly in with
5、drawn Test MethodD 3229)Sections 15-19.1.3 The values stated in SI are to be regarded as thestandard. For reporting purposes the values stated in grams perU.S. gallon are the preferred units in the United States. Notethat in other countries, other units can be preferred.1.4 This standard does not pu
6、rport 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
7、 5, 6, 11, and 18.2. Referenced Documents2.1 ASTM Standards:2D 3341 Test Method for Lead in GasolineIodineMonochloride MethodD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate Ana
8、lyticalMeasurement System PerformanceD 6792 Practice for Quality System in Petroleum Productsand Lubricants Testing Laboratories3. Summary of Test Method3.1 There are three alternative test methods, as follows.3.1.1 Test Method A (Bismuth Internal Standard MethodHigh Concentration)One volume of samp
9、le is mixed thor-oughly with an equal volume of bismuth internal standardsolution. The mixture is placed in the X-ray beam and theintensities of the lead L-a1radiation at 1.175 and the bismuthL-a1radiation at 1.144 are determined. The lead concentra-tion of the sample is measured by comparing the ra
10、tio of grosscounting rate at 1.175 with the gross counting rate at 1.144 to a previous prepared calibration curve of concentrationversus the same ratios.3.1.2 Test Method B (Scattered Tungsten RadiationMethod)The ratio of the net X-ray intensity of the lead L-a1radiation to the net intensity of the
11、incoherently scatteredtungsten L-a1radiation is obtained on a portion of the sample.The lead content is determined by multiplying this ratio by acalibration factor obtained with a standard lead solution ofknown concentration.3.1.3 Test Method C (Bismuth Internal Standard Method,Low Concentration)Twe
12、nty millilitres of sample is mixed1These test methods are under the jurisdiction of Committee D02 on PetroleumProducts and Lubricants and are the direct responsibility of Subcommittee D02.03on Elemental Analysis.Current edition approved Dec. 1, 2007. Published January 2008. Originallyapproved in 199
13、0. Last previous edition approved in 2003 as D 505998(2003)1.Initially published as D 2599 67T and D 3229 73, now withdrawn.These test methods have been approved by the sponsoring committees andaccepted by the cooperating organizations in accordance with established proce-dures.2For referenced ASTM
14、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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM
15、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.thoroughly with two milliliters of bismuth internal standardsolution. The mixture is placed in the X-ray beam of aspectrometer and the intensities of the lead L-a1radiation at1.175 , the bismuth L-a1ra
16、diation at 1.144 , and a back-ground at 1.194 are determined. A blank, made withiso-octane and bismuth internal standard, is run using the sameprocedure. The lead concentration is measured by determiningthe ratio of the net counting rate at 1.175 to the grosscounting rate at 1.144 for the sample, su
17、btracting thecomparable ratio found for the blank, and comparing to apreviously prepared calibration curve of concentration versusthe same ratios.4. Significance and Use4.1 These test methods determine the concentration of lead(from alkyl addition) in gasoline. These alkyl additives im-prove the ant
18、iknock properties.4.2 Test Method C is used to ensure compliance of tracelead as required by federal regulations for lead-free gasoline(40 CFR part 80).TEST METHOD A (BISMUTH INTERNALSTANDARD)5. Apparatus5.1 X-ray Spectrometer, capable of measuring radiationsmentioned in 3.1.1 and of being operated
19、under the followinginstrumental conditions or other giving equivalent results:Tube Voltage 50 kVTube Current 20 to 45 mAAnalyzing Crystal Lithium Fluoride (LiF)Optical Path Air, Helium(WarningCompressed gas under pressure)Detector Proportional or ScintillationNOTE 1The X-ray spectrometer and manner
20、of use should complywith the regulations governing the use of ionizing radiation or recommen-dations of the International Commission of Radiological Protection, orboth.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is
21、intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without l
22、essening the accuracy ofthe determinations.6.2 Hydrocarbon-Soluble Bismuth.NOTE 2Bismuth 2-Ethylhexoate has been found suitable to use. Otherbismuth containing materials that are hydrocarbon-soluble may also beused when they are certified to conform to 6.1.6.3 Bismuth Internal Standard SolutionDilut
23、e thehydrocarbon-soluble bismuth with a suitable solvent. If bis-muth 2-ethylhexoate is used, add 2-ethylhexanoic acid as astabilizer (see Note 3) to obtain a solution containing thefollowing:3.00 g Bi/US gal at 15.5C (60F) or3.60 g Bi/UK gal at 15.5C (60F) or0.793 g Bi/L at 15CNOTE 3Some stability
24、difficulties have been experienced with bis-muth 2-ethylhexoate internal standard solution. If the standard is blendedto contain 5 % 2-ethylhexanoic acid, the standard has been found to lastalmost indefinitely. The 2-ethylhexanoic acid stabilizes iso-octane, tolu-ene, and benzene solutions of the bi
25、smuth 2-ethylhexoate which areotherwise stable for only a day or two. Normal octanoic acid does notstabilize solution.6.4 Iso-octane.(WarningExtremely flammable.)6.5 Solvent, capable of dissolving the bismuth internalstandard. Mixed xylenes and dodecane have been foundsuitable to use.6.6 Hydrocarbon
26、-Soluble LeadEither tetraethyllead(TEL) or a lead-containing compound (for example, leadnaphthenate) with a certifiable lead concentration.6.7 Lead (Pb) Standard SolutionDissolve tetraethyllead(TEL) (WarningTEL is toxic by ingestion), lead naphthen-ate (see Note 4), or other suitable lead containing
27、 compound iniso-octane (WarningExtremely flammable), toluene, or amixture of these two solvents. This standard solution shallcontain an accurately known lead concentration of approxi-mately the following magnitude:5 g Pb/US gal at 15.5C (60F) or6 g Pb/UK gal at 15.5C (60F) or1.3 g Pb/L at 15.5C6.7.1
28、 Keep the standard solution refrigerated when not inuse.NOTE 4A lead naphthenate solution of same lead concentration hasalso proven satisfactory as a calibration material. Concentrated TEL is notused to make up standard solutions. The concentrated solution is tooacutely toxic to be handled safely un
29、der normal laboratory conditions.NOTE 5When this lead standard solution is prepared with TEL, thelead concentration can be determined with Test Method D 3341.6.8 Toluene.(WarningFlammable. Vapor harmful.)7. Calibration7.1 Make dilutions of the lead (Pb) standard solution to give0.10, 1.00, 2.00, 3.0
30、0, 4.00 and 5.00 g Pb/US gal at 15.5C(60F) or 0.10, 1.00, 2.50, 3.50, 5.00, and 6.00 g Pb/UK gal at15.5C (60F) or 0.025, 0.264, 0.529, 0.793, 1.057, 1.322 gPb/L at 15C in toluene, iso-octane, or a mixture of thesesolvents.7.2 Allow the lead standards and bismuth internal standardsolutions to come to
31、 room temperature.7.3 Pipet accurately 10 mL of each standard into separateglass-stoppered bottles or flasks and add an equal, accuratelymeasured volume of the bismuth internal standard solution toeach one. Mix thoroughly.7.4 Place one of these solutions in the sample cell usingtechniques consistent
32、 with good operating practice for thespectrometer employed. Place the cell in the instrument, allow3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual
33、 Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D5059072the spectrometer atmosphere to reach equilibrium (if appropri-ate), and determine the counting rate at the lea
34、d L-a1line(1.175 ) and at the bismuth L-a1line (1.144 ).NOTE 6When possible, collect at least 100 000 counts at each line.When sensitivity or concentration, or both, makes it impractical to collectthis many counts, the technique that allows the greatest statisticalprecision in the time allotted for
35、each analysis should be used. Samplestability should also be considered in determining counting rate. Variationin counting rates should be observed and if the counting rate tends to goin one direction only, the sample is probably decomposing. If this occurs,shorter counting times should be used cons
36、istent with acceptable statisticalprecision.7.5 Determine the ratio, R, for each standard as follows:R 5 A/B (1)where:A = counting rate at 1.175 , andB = counting rate at 1.144 .7.6 Plot a calibration curve relating R to the grams of leadper gallon.NOTE 7Many modern X-ray spectrometer instruments wi
37、ll plot andstore the calibration curve, slope, and related information in the instrumentcomputer system, as an alternative to hand-plotting this information.8. Quality Control Checks8.1 Confirm the calibration of the instrument each day it isin use by analyzing a quality control (QC) sample containi
38、ng aquantifiable concentration of lead, that is, independent of thecalibration curve. It is advisable to analyze additional QCsamples as appropriate, such as at the beginning and end of abatch of samples or after a fixed number of samples, to ensurethe quality of the results. Analysis of result(s) f
39、rom these QCsamples can be carried out using control chart techniques.4When the QC sample result causes the laboratory to be in anout-of-control situation, such as exceeding the laboratoryscontrol limits, instrument re-calibration may be required. Anample supply of QC sample material shall be availa
40、ble for theintended period of use, and shall be homogeneous and stableunder the anticipated storage conditions. If possible, the QCsample shall be representative of samples typically analyzedand the average and control limits of the QC sample shall bedetermined prior to monitoring the measurement pr
41、ocess. TheQC sample precision shall be checked against the ASTMmethod precision to ensure data quality. Further guidance onquality control can be found in Practices D 6299 and D 6792.9. Procedure9.1 Obtain sample in accordance with Practice D 4057.9.2 Prepare the samples to be analyzed as described
42、in 7.3and 7.4 for the standard lead solutions and determine the ratio,R, as described in 7.5.9.3 Determine the lead content of the samples by relatingthe R values obtained to the previously determined calibrationcurve.10. Report10.1 Report the lead content obtained as g Pb/US gal at15.5C (60F) or g
43、Pb/UK gal at 15.5C (60F) to the nearest0.01 g, or g Pb/L at 15.5C to the nearest 0.003 g, asappropriate.NOTE 8To convert grams per US gallon at 15.5C (60F) to: (a)grams per UK gallon at 15.5C (60F) multiply by 1.200 and (b) gramsper litre at 15.5C, multiply by 0.2201.TEST METHOD B (SCATTERED TUNGSTE
44、NRADIATION)11. Apparatus11.1 X-ray Spectrometer, capable of measuring radiationsmentioned in 3.1.2 and of being operated under the followinginstrumental conditions or others giving equivalent results:Tube Voltage 50 kVTube Current 20 to 45 mATube Target TungstenAnalyzing Crystal Lithium Fluoride (Li
45、F)Optical Path Air, Helium(WarningCompressed gas under pressure)Collimation FinePulse Height Analyzer Threshold discrimination set as low as pos-sible consistent with the removal of noise withrespect to the detector employed.Detector Proportional or ScintillationCounting Technique Fixed Time11.1.1 T
46、wo restrictions are imposed upon the period of thefixed time: namely, that it is 30 s or greater, and that it is suchthat the count on the position of minimum intensity (back-ground at A = 1.211 ) should exceed 200 000.NOTE 9The X-ray spectrometer and manner of use should complywith the regulations
47、governing the use of ionizing radiation or recommen-dations of the International Commission of Radiological Protection, orboth.12. Reagents and Materials12.1 Iso-octane.(WarningExtremely flammable.)12.2 Lead (Pb) Standard SolutionDissolve tetraethyllead(TEL) (WarningTEL is toxic by ingestion), lead
48、naphthen-ate (see Note 4), or other suitable lead containing compound iniso-octane (WarningExtremely flammable), toluene, or amixture of these two solvents. When TEL is used, refer to Note5. This standard solution shall contain an accurately knownlead concentration of approximately the following mag
49、nitude:5 g Pb/US gal at 15.5C (60F)6 g Pb/UK gal at 15.5C (60F)1.3 g Pb/L at 15.5C12.2.1 Keep the standard solution refrigerated when not inuse.13. Calibration13.1 Place the standard lead solution in the sample cellusing techniques consistent with good operating practice forthe spectrometer employed. Insert the cell in the X-ray beamusing the instrumental conditions described in Section 10 andallow the spectrometer atmosphere to reach equilibrium (whenappropriate). Take one intensity reading at each
