1、Designation: D5059 13D5059 14Standard Test Methods forLead in Gasoline by X-Ray Spectroscopy1This standard is issued under the fixed designation D5059; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber 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 U.S. Department of Defense.1. Scope*1.1 These test methods cover the determination of the
3、total lead content of a gasoline within the following concentration ranges: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 5.0 g 5.0 g Pb/US gal. Test Method C covers the range of 0.010 to 0.50g 0.50 g Pb/US gal.1.1.2 These t
4、est methods compensate for normal variation in gasoline composition and are independent of lead alkyl type.1.2 Test Method A (formerly in withdrawn Test Method D2599)Sections 5 9.Test Method B (formerly in withdrawn Test Method D2599)Sections 10 14.Test Method C (formerly in withdrawn Test Method D3
5、229)Sections 15 19.1.3 The values stated in SI are to be regarded as the standard. For reporting purposes the values stated in grams per U.S. gallonare the preferred units in the United States. Note that in other countries, other units can be preferred.1.4 This standard does not purport to address a
6、ll of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For specific hazard statements, see Sections 5, 6, 11, and 18.2
7、. Referenced Documents2.1 ASTM Standards:2D3341 Test Method for Lead in GasolineIodine Monochloride MethodD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-men
8、t System PerformanceD6792 Practice for Quality System in Petroleum Products and 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 Method High Concentration)One volume of sample is mixed thor
9、oughly withan equal volume of bismuth internal standard solution. The mixture is placed in the X-ray beam and the intensities of the lead L-1radiation at 1.175 and the bismuth L-1 radiation at 1.144 1.144 are determined. The lead concentration of the sample ismeasured by comparing the ratio of gross
10、 counting rate at 1.175 with the gross counting rate at 1.144 1.144 to a previousprepared calibration curve of concentration versus the same ratios.3.1.2 Test Method B (Scattered Tungsten Radiation Method)The ratio of the net X-ray intensity of the lead L-1 radiation tothe net intensity of the incoh
11、erently scattered tungsten L-1 radiation is obtained on a portion of the sample. The lead content isdetermined by multiplying this ratio by a calibration factor obtained with a standard lead solution of known concentration.1 These test methods are under the jurisdiction of Committee D02 on Petroleum
12、 Products Products, Liquid Fuels, and Lubricants and are the direct responsibility ofSubcommittee D02.03 on Elemental Analysis.Current edition approved June 15, 2013June 1, 2014. Published August 2013July 2014. Originally approved in 1990. Last previous edition approved in 20072013 asD5059 07.D5059
13、13. DOI: 10.1520/D5059-13.10.1520/D5059-14.Initially published as D2599 67T and D3229 73, now withdrawn.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards
14、 Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, A
15、STM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, P
16、O Box C700, West Conshohocken, PA 19428-2959. United States13.1.3 Test Method C (Bismuth Internal Standard Method, Low Concentration)Twenty millilitres of sample is mixedthoroughly with two milliliters of bismuth internal standard solution. The mixture is placed in the X-ray beam of a spectrometeran
17、d the intensities of the lead L-1 radiation at 1.175 , the bismuth L-1 radiation at 1.144 , and a background at 1.194 aredetermined.Ablank, made with iso-octane and bismuth internal standard, is run using the same procedure. The lead concentrationis measured by determining the ratio of the net count
18、ing rate at 1.175 to the gross counting rate at 1.144 for the sample,subtracting the comparable ratio found for the blank, and comparing to a previously prepared calibration curve of concentrationversus the same ratios.4. Significance and Use4.1 These test methods determine the concentration of lead
19、 (from alkyl addition) in gasoline. These alkyl additives improve theantiknock properties.4.2 Test Method C is used to ensure compliance of trace lead as required by federal regulations for lead-free gasoline (40 CFRpart 80).TEST METHOD A (BISMUTH INTERNAL STANDARD)5. Apparatus5.1 X-ray Spectrometer
20、, capable of measuring radiations mentioned 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 Fluoride (LiF)Optical Path Air, Helium(WarningCompressed gas underpressure)Dete
21、ctor Proportional or ScintillationNOTE 1The X-ray spectrometer and manner of use should comply with the regulations governing the use of ionizing radiation or recommendationsof the International Commission of Radiological Protection, or both.6. Reagents and Materials6.1 Purity of ReagentsReagent gra
22、de chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allreagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where suchspecifications are available.3 Other grades may be used, provided it is first ascertai
23、ned that the reagent is of sufficiently high purityto permit its use without lessening the accuracy of the determinations.6.2 Hydrocarbon-Soluble Bismuth.NOTE 2Bismuth 2-Ethylhexoate has been found suitable to use. Other bismuth containing materials that are hydrocarbon-soluble may also be usedwhen
24、they are certified to conform to 6.1.6.3 Bismuth Internal Standard Solution Dilute the hydrocarbon-soluble bismuth with a suitable solvent. If bismuth2-ethylhexoate is used, add 2-ethylhexanoic acid as a stabilizer (see Note 3) to obtain a solution containing the following:3.00 g Bi/US gal at 15.5C
25、(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 bismuth 2-ethylhexoate internal standard solution. If the standard is blended to contain5 % 2-ethylhexanoic acid, the standard has been found to last almost indefinitely. The 2-e
26、thylhexanoic acid stabilizes iso-octane, toluene, and benzenesolutions of the bismuth 2-ethylhexoate which are otherwise stable for only a day or two. Normal octanoic acid does not stabilize solution.6.4 Iso-octane. (WarningExtremely flammable.)6.5 Solvent, capable of dissolving the bismuth internal
27、 standard. Mixed xylenes and dodecane have been found suitable to use.6.6 Hydrocarbon-Soluble LeadEither tetraethyllead (TEL) or a lead-containing compound (for example, lead naphthenate)with a certifiable lead concentration.6.7 Lead (Pb) Standard Solution Dissolve tetraethyllead (TEL) (WarningTEL i
28、s toxic by ingestion), lead naphthenate (seeNote 4), or other suitable lead containing compound in iso-octane (WarningExtremely flammable), toluene, or a mixture ofthese two solvents. This standard solution shall contain an accurately known lead concentration of approximately the followingmagnitude:
29、3 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmac
30、opeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D5059 1425 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 in use.NOTE 4A lead naphthenate solution of same lead concentration
31、has also proven satisfactory as a calibration material. Concentrated TEL is not usedto make up standard solutions. The concentrated solution is too acutely toxic to be handled safely under normal laboratory conditions.NOTE 5When this lead standard solution is prepared with TEL, the lead concentratio
32、n can be determined with Test Method D3341.6.8 Toluene. (WarningFlammable. Vapor harmful.)7. Calibration7.1 Make dilutions of the lead (Pb) standard solution to give 0.10, 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 at 15.5C (60F) o
33、r 0.025, 0.264, 0.529, 0.793, 1.057, 1.322 g Pb/L at 15Cin toluene, iso-octane, or a mixture of these solvents.7.2 Allow the lead standards and bismuth internal standard solutions to come to room temperature.7.3 Pipet accurately 10 mL of each standard into separate glass-stoppered bottles or flasks
34、and add an equal, accuratelymeasured volume of the bismuth internal standard solution to each one. Mix thoroughly.7.4 Place one of these solutions in the sample cell using techniques consistent with good operating practice for the spectrometeremployed. Place the cell in the instrument, allow the spe
35、ctrometer atmosphere to reach equilibrium (if appropriate), and determinethe counting rate at the lead L-1 line (1.175 ) and at the bismuth L-1 line (1.144 ).NOTE 6When possible, collect at least 100 000 counts at each line. When sensitivity or concentration, or both, makes it impractical to collect
36、 thismany counts, the technique that allows the greatest statistical precision in the time allotted for each analysis should be used. Sample stability should alsobe considered in determining counting rate. Variation in counting rates should be observed and if the counting rate tends to go in one dir
37、ection only, thesample is probably decomposing. If this occurs, shorter counting times should be used consistent with acceptable statistical precision.7.5 Determine the ratio, R, for each standard as follows:R 5A/B (1)where:A = counting rate at 1.175 , andB = counting rate at 1.144 .7.6 Plot a calib
38、ration curve relating R to the grams of lead per gallon.NOTE 7Many modern X-ray spectrometer instruments will plot and store the calibration curve, slope, and related information in the instrumentcomputer system, as an alternative to hand-plotting this information.8. Quality Control Checks8.1 Confir
39、m the calibration of the instrument each day it is in use by analyzing a quality control (QC) sample containing aquantifiable concentration of lead, that is, independent of the calibration curve. It is advisable to analyze additional QC samplesas appropriate, such as at the beginning and end of a ba
40、tch of samples or after a fixed number of samples, to ensure the qualityof the results.Analysis of result(s) from these QC samples can be carried out using control chart techniques.4 When the QC sampleresult causes the laboratory to be in an out-of-control situation, such as exceeding the laboratory
41、s control limits, instrumentre-calibration may be required.An ample supply of QC sample material shall be available for the intended period of use, and shallbe homogeneous and stable under the anticipated storage conditions. If possible, the QC sample shall be representative of samplestypically anal
42、yzed and the average and control limits of the QC sample shall be determined prior to monitoring the measurementprocess. The QC sample precision shall be checked against the ASTM method precision to ensure data quality. Further guidanceon quality control can be found in Practices D6299 and D6792.9.
43、Procedure9.1 Obtain sample in accordance with Practice D4057.9.2 Prepare the samples to be analyzed as described in 7.3 and 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 relating the R values obtained to the previo
44、usly determined calibration curve.10. Report10.1 Report the lead content obtained as g Pb/US gal at 15.5C (60F) or g Pb/UK gal at 15.5C (60F) to the nearest 0.01 g,or g Pb/L at 15.5C to the nearest 0.003 g, as appropriate.4 ASTM MNL 7, Manual on Presentation of Data Control Chart Analysis, “Section
45、3, Control Charts for Individuals,” 6th ed., ASTM International, W. Conshohocken,PA.D5059 143NOTE 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) grams per litreat 15.5C, multiply by 0.2201.0.2642.TEST METHOD B (SCATTERED TUNGSTEN R
46、ADIATION)11. Apparatus11.1 X-ray Spectrometer, capable of measuring radiations mentioned 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 (LiF
47、)Optical Path Air, Helium(WarningCompressed gas underpressure)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 Two
48、 restrictions are imposed upon the period of the fixed time: namely, that it is 30 s or greater, and that it is such thatthe count on the position of minimum intensity (background at A = 1.211 ) should exceed 200 000.NOTE 9The X-ray spectrometer and manner of use should comply with the regulations g
49、overning the use of ionizing radiation or recommendationsof the International Commission of Radiological Protection, or both.12. Reagents and Materials12.1 Iso-octane. (WarningExtremely flammable.)12.2 Lead (Pb) Standard SolutionDissolve tetraethyllead (TEL) (WarningTEL is toxic by ingestion), lead naphthenate(see Note 4), or other suitable lead containing compound in iso-octane (WarningExtremely flammable), toluene, or a mixtureof these two solvents. When TEL is used, refer to Note
