1、Designation: D 5059 98 (Reapproved 2003)e1Designation: 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 adoptio
2、n or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOT
3、EWarning notes were editorially moved into the standard text in August 2003.1. Scope1.1 These test methods 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
4、 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/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 Test Method D 2599)Sections 5-9.Test Meth
5、od B (formerly in Test Method D 2599)Sections10-14.Test Method C (formerly in Test Method D 3229)Sections15-19.1.3 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 oth
6、er countries, other units can be preferred.1.4 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 regulato
7、ry limitations prior to use. For specific hazardstatements, see Sections 5, 6, 11, and 18.2. Referenced Documents2.1 ASTM Standards:D 2599 Test Method for Lead in Gasoline by X-Ray Spec-trometry2D 3229 Test Method for Low Levels of Lead in Gasoline byWavelength Dispersive X-Ray Spectrometry3D 3341 T
8、est Method for Lead in Gasoline-IodineMonochloride Method4D 4057 Practice for Manual Sampling of Petroleum andPetroleum Products43. 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 sam
9、ple 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 r
10、atio 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)Tw
12、enty millilitres of sample is mixedthoroughly with two milliliters of bismuth internal standard1These 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 Ma
13、y 10, 2003. Published August 2003. (Originallypublished as D 2599 67T and D 3229 73.) Originally approved in 1990. Lastprevious edition approved in 1998 as D 5059 98.These test methods have been approved by the sponsoring committees andaccepted by the cooperating organizations in accordance with est
14、ablished proce-dures.2Discontinued. See 1991 Annual Book of ASTM Standards , Vol 05.02.3Discontinued. See 1991 Annual Book of ASTM Standards , Vol 05.03.4Annual Book of ASTM Standards, Vol 05.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unit
15、ed States.solution. The mixture is placed in the X-ray beam of aspectrometer and the intensities of the lead L-a1radiation at1.175 , the bismuth L-a1radiation 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 sameproced
16、ure. 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, subtracting thecomparable ratio found for the blank, and comparing to apreviously prepared calibration curve of concentration versusthe same ratios.4.
17、Significance and Use4.1 These test methods determine the concentration of lead(from alkyl addition) in gasoline. These alkyl additives im-prove the antiknock 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 8
18、0).TEST METHOD A (BISMUTH INTERNALSTANDARD)5. Apparatus5.1 X-ray Spectrometer, capable of measuring radiationsmentioned in 3.1.1 and of being operated under the followinginstrumental conditions or other giving equivalent results:Tube Voltage 50 kVTube Current 20 to 45 mAAnalyzing Crystal Lithium Flu
19、oride (LiF)Optical Path Air, Helium(WarningCompressed gas under pressure)Detector Proportional or ScintillationNOTE 1The X-ray spectrometer and manner of use should complywith the regulations governing the use of ionizing radiation or recommen-dations of the International Commission of Radiological
20、Protection, orboth.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specificati
21、ons are available.5Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determinations.6.2 Hydrocarbon-Soluble Bismuth.NOTE 2Bismuth 2-Ethylhexoate has been found suitable to use. Otherbismuth
22、containing materials that are hydrocarbon-soluble may also beused when they are certified to conform to 6.1.6.3 Bismuth Internal Standard SolutionDilute thehydrocarbon-soluble bismuth with a suitable solvent. If bis-muth 2-ethylhexoate is used, add 2-ethylhexanoic acid as astabilizer (see Note 3) to
23、 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 difficulties have been experienced with bis-muth 2-ethylhexoate internal standard solution. If the standard is blendedto contain 5 % 2-ethylhexanoic
24、acid, the standard has been found to lastalmost indefinitely. The 2-ethylhexanoic acid stabilizes iso-octane, tolu-ene, and benzene solutions of the bismuth 2-ethylhexoate which areotherwise stable for only a day or two. Normal octanoic acid does notstabilize solution.6.4 Iso-octane.(WarningExtremel
25、y flammable.)6.5 Solvent, capable of dissolving the bismuth internalstandard. Mixed xylenes and dodecane have been foundsuitable to use.6.6 Hydrocarbon-Soluble LeadEither tetraethyllead(TEL) or a lead-containing compound (for example, leadnaphthenate) with a certifiable lead concentration.6.7 Lead (
26、Pb) Standard SolutionDissolve tetraethyllead(TEL) (WarningTEL is toxic by ingestion), lead naphthen-ate (see Note 4), or other suitable lead containing compound iniso-octane (WarningExtremely flammable), toluene, or amixture of these two solvents. This standard solution shallcontain an accurately kn
27、own 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 Keep the standard solution refrigerated when not inuse.NOTE 4A lead naphthenate solution of same lead concentration hasalso proven satisfactory as a
28、 calibration material. Concentrated TEL is notused to make up standard solutions. The concentrated solution is tooacutely toxic to be handled safely under normal laboratory conditions.NOTE 5When this lead standard solution is prepared with TEL, thelead concentration can be determined with Test Metho
29、d 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, 3.00, 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,
30、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 room temperature.7.3 Pipet accurately 10 mL of each standard into separateglass-stoppered bottles or flasks and add an equal, accuratelymeasured vol
31、ume of the bismuth internal standard solution toeach one. Mix thoroughly.7.4 Place one of these solutions in the sample cell usingtechniques consistent with good operating practice for thespectrometer employed. Place the cell in the instrument, allowthe spectrometer atmosphere to reach equilibrium (
32、if appropri-ate), and determine the counting rate at the lead L-a1line(1.175 ) and at the bismuth L-a1line (1.144 ).5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical So
33、ciety, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 5059 98 (2003)e12NOTE 6When possible, collect at least 100 000 counts at each line.When sensitivity
34、 or concentration, or both, makes it impractical to collectthis many counts, the technique that allows the greatest statisticalprecision in the time allotted for each analysis should be used. Samplestability should also be considered in determining counting rate. Variationin counting rates should be
35、 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 consistent with acceptable statisticalprecision.7.5 Determine the ratio, R, for each standard as follows:R 5 A/B (1)where:A = counting rate at
36、 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 will plot andstore the calibration curve, slope, and related information in the instrumentcomputer system, as an alternative to hand-plottin
37、g 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 containing aquantifiable concentration of lead, that is, independent of thecalibration curve. It is advisable to analyze additional QCsamples as a
38、ppropriate, 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) from these QCsamples can be carried out using control chart techniques.6When the QC sample result causes the laboratory to be in anout-of-c
39、ontrol situation, such as exceeding the laboratoryscontrol limits, instrument re-calibration may be required. Anample supply of QC sample material shall be available for theintended period of use, and shall be homogeneous and stableunder the anticipated storage conditions. If possible, the QCsample
40、shall be representative of samples typically analyzedand the average and control limits of the QC sample shall bedetermined prior to monitoring the measurement process. TheQC sample precision shall be checked against the ASTMmethod precision to ensure data quality.9. Procedure9.1 Obtain sample in ac
41、cordance with Practice D 4057.9.2 Prepare the samples to be analyzed as described 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.
42、10. Report10.1 Report the lead content obtained as g Pb/US gal at15.5C (60F) or g 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 an
43、d (b) gramsper litre at 15.5C, multiply by 0.2201.TEST METHOD B (SCATTERED TUNGSTENRADIATION)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 kV
44、Tube Current 20 to 45 mATube Target TungstenAnalyzing Crystal Lithium Fluoride (LiF)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 em
45、ployed.Detector Proportional or ScintillationCounting Technique Fixed Time11.1.1 Two 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
46、.NOTE 9The X-ray spectrometer and manner of use should complywith the regulations 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) Stand
47、ard SolutionDissolve tetraethyllead(TEL) (WarningTEL is toxic by ingestion), lead 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 shal
48、l contain an accurately knownlead concentration of approximately the following magnitude: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 cellusi
49、ng 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 of the follow-ing wavelength settings, then replace the standard solution witha fresh portion and repeat the readings. Repeat this procedurewith iso-octane.Analytical line, lead L-a1l = 1.175 WL-a1(incoherent) l = 1.500
