1、Designation: D 3831 01 (Reapproved 2006)An American National StandardStandard Test Method forManganese in Gasoline By Atomic AbsorptionSpectroscopy1This standard is issued under the fixed designation D 3831; the number immediately following the designation indicates the year oforiginal adoption or,
2、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.1. Scope*1.1 This test method covers the determination of the totalmanganese content, presen
3、t as methylcyclopentadienyl manga-nese tricarbonyl (MMT),2of gasoline within the concentrationrange from 0.25 to 40 mg/L of manganese.1.2 This test method is applicable to reformulated gasolinecontaining up to 12 % volume methyl tertiary butylether or upto 10 % volume ethanol. This test method may n
4、ot be appli-cable to highly cracked materials containing greater than 18volume % olefins as determined by Test Method D 1319(nondepentanized).1.3 This test method has been developed and tested specifi-cally for the determination of MMT in gasoline over therecommended concentration range. Application
5、 of the methodto other concentration ranges, to the determination of MMT inother materials, or to the determination of other manganesecompounds in gasoline have not been tested1.4 The values stated in SI units are to be regarded as thestandard. The preferred concentration units are mg/L manga-nese.1
6、.5 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 to use. For specificwar
7、ning statements, see Sections 5 and 6.2. Referenced Documents2.1 ASTM Standards:3D 1319 Test Method for Hydrocarbon Types in LiquidPetroleum Products by Fluorescent Indicator AdsorptionD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Pet
8、roleum andPetroleum ProductsD 6299 Practice for Applying Statistical Quality AssuranceTechniques to Evaluate Analytical Measurement SystemPerformanceD 6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricants3. Summary of Test Method3.1 Th
9、e gasoline sample is treated with bromine solutionand diluted with methyl isobutyl ketone. The manganesecontent of the sample is determined by atomic absorptionspectrometry using an air-acetylene flame at 279.5 nm andstandards prepared from an organo-manganese standard mate-rial.4. Significance and
10、Use4.1 Certain organo-manganese compounds act as antiknockagents when added to gasoline. This test method provides ameans for determining the concentration of such a material ina gasoline sample.5. Apparatus5.1 Atomic Absorption Spectrometer, capable of scale ex-pansion and equipped with a manganese
11、 hollow-cathode lampfor monitoring manganese absorption at 279.5 nm, a premixslot-type burner with rotatable burner head, and an adjustablenebulizer. (WarningHazardous. Potentially toxic and explo-sive. Refer to the manufacturers instrument manual for asso-ciated safety hazards.)5.2 Vials, up to 40-
12、mL size with polyethylene or TFE-fluorocarbon-lined caps or glass stoppers.5.3 Pipet, Delivery, 1-mL size.5.4 Micropipet, 100-L size, Eppendorf type or equivalent.5.5 Automatic Pipet, or equivalent delivery pipet, capable ofdelivering 9.0-mL quantities.6. Reagents6.1 Purity of ReagentsReagent grade
13、chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lu
14、bricants and is the direct responsibility of SubcommitteeD02.03 on Elemental Analysis.Current edition approved May 1, 2006. Published June 2006. Originallyapproved in 1979. Last previous edition approved in 2001 as D 3831 01.2MMT is a registered trademark of Ethyl Corp.3For referenced ASTM standards
15、, 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 Internati
16、onal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determina
17、tion.6.2 Bromine SolutionAdd reagent grade bromine to anequal volume of cyclohexane. (WarningBromine can causesevere and painful burns when it contacts the skin. In additionto other precautions, wear protective gloves in preparing thesolution and prepare, store, and use it in a well-ventilatedhood.)
18、6.3 Manganese Standard Solution 400 mg Mn/LDissolvethe appropriate amount of organometallic manganese standardin methyl isobutyl ketone to give a standard solution of 400 mgMn/L.6.4 Manganese, Standard Solution 4.0, 10.0, 20.0, and 40.0mg Mn/LDilute the 400 mg/L standard manganese solutionwith methy
19、l isobutyl ketone using volumetric glassware to givethe desired lower concentration manganese standard solutions.6.5 Organometallic Manganese StandardPre-preparedcommercially available organometallic stock solutions havebeen found to be satisfactory.6.6 Methyl Isobutyl Ketone, reagent grade. (Warnin
20、gFlammable. Vapor harmful.) (WarningSolutions of MMT ingasoline are chemically unstable when exposed to light. Lowand erratic results may be obtained if the gasoline sample isexposed to light prior to stabilization during analysis.)6.7 Quality Control (QC) Sample(s), preferably are a por-tion of one
21、 or more gasoline materials that are stable andrepresentative of the samples of interest.7. Sampling7.1 Take samples of gasoline in compliance with the in-structions in Practice D 4057 or D 4177 where appropriate.Analyze as soon as possible after sampling.8. Calibration8.1 Preparation of Working Sta
22、ndardsPrepare four work-ing standards using the 4.0, 10.0, 20.0, and 40.0 mg Mn/Lstandard manganese solutions described in 6.3.8.1.1 Using a micropipet, add 100 L of bromine solution toeach of four separate vials.8.1.2 Pipet 1 mL of each of the four low-manganesestandards into each of the vials. Mix
23、 with the bromine solutionby swirling the vials.8.1.3 Deliver 9.0 mL of methyl isobutyl ketone to each ofthe vials. Mix well. This tenfold dilution of the low-manganesestandards is the same as the final dilution of the sample.8.2 Preparation of InstrumentSet the atomic absorptionspectrometer operati
24、ng conditions to those recommended bythe manufacturer for monitoring manganese absorption at279.5 nm using an air-acetylene flame. This test methodassumes that good operating procedures are followed. Designdifferences between spectrometers make it impractical toexactly specify required instrument se
25、ttings.8.2.1 Nebulize methyl isobutyl ketone into the flame.Adjustthe nebulizer (sample flow rate), acetylene, and air flow rates togive a lean, nonluminous flame.8.2.2 With methyl isobutyl ketone as a blank, nebulize, inturn, the four working standards.NOTE 1Record the absorbances and check these d
26、ata for linearity. Ifnonlinear, readjust the sample or acetylene flow rates, or both, slightly toleaner conditions and repeat the calibrations until absorbances are linear.Rotation of the burner head to decrease the absorbance may aid inachieving linearity.NOTE 2Three working standards may be used t
27、o cover the expectedconcentration range of the samples. Fuel specification limits should beconsidered. For example, the use of the high 40 mg/L standard may not benecessary.9. Procedure9.1 Deliver 100 L of bromine solution into a vial.9.2 Add 1.0 mL of the gasoline sample. Mix well.9.3 Add 9.0 mL of
28、 methyl isobutyl ketone. Mix well.9.4 Aspirate the working standards and the sample into theflame and record the absorbances of each.NOTE 3Measure absorbances of the working standards and thesamples promptly as the sample absorbances may change with time.10. Calculations10.1 The direct concentration
29、 read out of the instrument isthe preferred mode of quantification. Alternatively, plot theabsorbance values that were obtained by aspirating the workingstandard solutions versus manganese concentration and drawthe best straight line through the points. From the plot read themanganese concentration
30、corresponding to the absorbance ofthe gasoline sample. Report the manganese content of thegasoline to the nearest 0.1 mg/L Mn.11. Quality Control11.1 Confirm the performance of the test procedure byanalyzing a quality control (QC) sample that is stable andrepresentative of the sample of interest.11.
31、2 When the quality control/quality assurance protocolsare already established in the testing facility, these may be usedto confirm the reliability of the test result.11.3 When there is no quality control/quality assuranceprotocol established in the testing facility, Appendix X1 can beused to perform
32、 this function.12. Precision and Bias12.1 Precision5The precision of this test method as ob-tained by statistical examination of interlaboratory test resultsfrom eleven samples of motor gasoline, covering concentrationrange of 0.25 to 40 mg/L manganese, run in duplicate byeleven laboratories is as f
33、ollows:12.1.1 RepeatabilityThe difference between successivetest results, obtained by the same operator with the same4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical S
34、ociety, 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.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting
35、 Research Report RR: D021500.D 3831 01 (2006)2apparatus under constant operating conditions on identical testmaterial, would in the long run, in the normal and correctoperation of the test method, exceed the following values onlyin one case in twenty:0.3308=x 1 0.1062! mg Mn/L (1)where x = average o
36、f the two results.12.1.2 ReproducibilityThe difference between two singleand independent results, obtained by different operators work-ing in different laboratories on identical test material, would inthe long run, in the normal and correct operation of the testmethod, exceed the following values on
37、ly in one case intwenty:1.650=x 1 0.1062! mg Mn/L (2)where x = average of the two results.12.2 BiasThe bias for the procedure in this test methodcannot be determined, since a suitable reference material is notavailable.13. Keywords13.1 AAS; atomic absorption spectroscopy; gasoline; man-ganese; methy
38、lcyclopentadienyl manganese tricarbonyl; MMTAPPENDIX(Nonmandatory Information)X1. QUALITY CONTROLX1.1 Confirm the performance of the instrument or the testprocedure by analyzing a quality control (QC) sample that is,if possible, representative of the samples typically analyzed.X1.2 Prior to monitori
39、ng the measurement process, the userof the method needs to determine the average value and controllimits of the QC sample. See Practices D 6299, D 6300, andMNL 7.6X1.3 Record the QC results and analyze by control chartsor other statistically equivalent techniques to ascertain thestatistical control
40、status of the total testing process. SeePractices D 6299, D 6300, and MNL 7.6Any out-of-controldata should trigger investigation for root cause(s). The resultsof this investigation may, but not necessarily, result in instru-ment recalibration.X1.4 In the absence of explicit requirements given in the
41、test method, the frequency of QC testing is dependent on thecriticality of the quality being measured, the demonstratedstability of the testing process, and customer requirements.Generally, a QC sample is analyzed each testing day withroutine samples. The QC frequency should be increased if alarge n
42、umber of samples are routinely analyzed. However,when it is demonstrated that the testing is under statisticalcontrol, the QC testing frequency may be reduced. The QCsample precision should be periodically checked against theASTM method precision to ensure data quality. See PracticeD 6300.X1.5 It is
43、 recommended that, if possible, the type of QCsample that is regularly tested be representative of the samplesroutinely analyzed. An ample supply of QC material should beavailable for the intended period of use, and must be homoge-neous and stable under the anticipated storage conditions.X1.6 See Pr
44、actices D 6299, D 6300, or MNL 76for furtherguidance on QC and Control Charting techniques.SUMMARY OF CHANGESCommittee D02.03 has identified the location of selected changes to this standard since the last issue(D 383198) that may impact the use of this standard.(1) Cyclohexane replaced the use of c
45、arbon tetrachloride as abromine reagent solvent.(2) The scopes upper range of quantitation was extended from30 mg/L to 40 mg/L.(3) The test method was modernized with regards to currentASTM Blue Book guidelines, preferred units (SI units only),and Subcommittee D02.03 Quality Control requirements.(4)
46、 A round robin study using cyclohexane as the replacementbromine reagent solvent for carbon tetrachloride was con-ducted and found to have similar precision to the previousrevision.6ASTM MNL 7 “Manual on Presentation of Data Control Chart Analysis,” 6thed., Section 3: Control Chart for Individuals,
47、available from ASTM Headquarters.D 3831 01 (2006)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent right
48、s, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for r
49、evision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or
