1、Designation: D 5622 95 (Reapproved 2005)An American National StandardStandard Test Methods forDetermination of Total Oxygen in Gasoline and MethanolFuels by Reductive Pyrolysis1This standard is issued under the fixed designation D 5622; the number immediately following the designation indicates the
2、year oforiginal adoption 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.1. Scope1.1 These test methods cover the quantitative determina
3、tionof total oxygen in gasoline and methanol fuels by reductivepyrolysis.1.2 Precision data are provided for 1.0 to 5.0 mass %oxygen in gasoline and for 40 to 50 mass % oxygen inmethanol fuels.1.3 Several types of instruments can be satisfactory forthese test methods. Instruments can differ in the w
4、ay that theoxygen-containing species is detected and quantitated. How-ever, these test methods are similar in that the fuel is pyrolyzedin a carbon-rich environment.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.5 This s
5、tandard 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.2. Referenced Documents2.
6、1 ASTM Standards:2D 1298 Test Method for Density, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD 4052 Test Method for Density and Relative Density ofLiquids by Digital Density MeterD 4057 Practice for Manual Sampling of Petrol
7、eum andPetroleum ProductsD 4815 Test Method for Determination of MTBE, ETBE,TAME, DIPE, tertiary-Amyl Alcohol and C1to C4Alco-hols in Gasoline by Gas Chromatography2.2 Other Standards:Clean Air Act (1992)33. Summary of Test Method3.1 Afuel specimen of 1 to 10 L is injected by syringe intoa 950 to 13
8、00C high-temperature tube furnace that containsmetallized carbon. Oxygen-containing compounds are pyro-lyzed, and the oxygen is quantitatively converted into carbonmonoxide.3.2 A carrier gas, such as nitrogen, helium, or a helium/hydrogen mixture, sweeps the pyrolysis gases into any of fourdownstrea
9、m systems of reactors, scrubbers, separators, anddetectors for the determination of the carbon monoxide con-tent, hence of the oxygen in the original fuel sample. The resultis reported as mass % oxygen in the fuel.4. Significance and Use4.1 These test methods cover the determination of totaloxygen i
10、n gasoline and methanol fuels, and they complementTest Method D 4815, which covers the determination ofseveral specific oxygen-containing compounds in gasoline.4.2 The presence of oxygen-containing compounds in gaso-line can promote more complete combustion, which reducescarbon monoxide emissions. T
11、he CleanAirAct (1992) requiresthat gasoline sold within certain, specified geographical areascontain a minimum percent of oxygen by mass (presently 2.7mass %) during certain portions of the year. The requirementcan be met by blending compounds such as methyl tertiarybutyl ether, ethyl tertiary butyl
12、 ether, and ethanol into the1These 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 May 1, 2005. Published June 2005. Originallyapproved in 1994. Last pr
13、evious edition approved in 2000 as D 562295(2000).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.3Federal Re
14、gister, Vol 57, No. 24, Feb. 5, 1992, p. 4408.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.gasoline. These test methods cover the quantitative determina-tion of total oxygen which is the regulated parameter.5. Apparatus5.1 Oxygen
15、Elemental Analyzer4,5,6,7,8A variety of instru-mentation can be satisfactory. However, the instrument mustreductively pyrolize the specimen and convert oxygen tocarbon monoxide.5.1.1 Test Method A4,8Helium carrier gas transports thepyrolysis products through a combination scrubber to removeacidic ga
16、ses and water vapor. The products are then transportedto a molecular sieve gas chromatographic column where thecarbon monoxide is separated from the other pyrolysis prod-ucts. A thermal conductivity detector generates a response thatis proportional to the amount of carbon monoxide.5.1.2 Test Method
17、B5,8Nitrogen carrier gas transports thepyrolysis products through a scrubber to remove water vapor.The pyrolysis products then flow through tandem infrareddetectors that measure carbon monoxide and carbon dioxide,respectively.5.1.3 Test Method C6,8A mixture of helium and hydrogen(95:5 %), helium, or
18、 argon transports the pyrolysis productsthrough two reactors in series. The first reactor contains heatedcopper which removes sulfur-containing products. The secondreactor contains a scrubber which removes acidic gases and areactant which oxidizes carbon monoxide to carbon dioxide(optional). The pro
19、duct gases are then homogenized in amixing chamber, which maintains the reaction products atabsolute conditions of temperature, pressure, and volume. Themixing chamber is subsequently depressurized through acolumn that separates carbon monoxide (or carbon dioxide, ifoperating in the oxidation mode)
20、from interfering compounds.A thermal conductivity detector measures a response propor-tional to the amount of carbon monoxide or carbon dioxide.5.1.4 Test Method D7,8Nitrogen carrier gas transports thepyrolysis products through scrubbers to remove acidic gasesand water vapor. A reactor containing cu
21、pric oxide at 325Coxidizes the carbon monoxide to carbon dioxide, which in turnis transported into a coulometric carbon dioxide detector.Coulometrically generated base titrates the acid formed byreacting carbon dioxide with monoethanolamine.5.2 A technique must be established to make a quantitativei
22、ntroduction of the test specimen into the analyzer. Specimenvials and transfer labware must be clean and dry.5.3 For instruments that measure carbon monoxide only,pyrolysis conditions must be established to quantitativelyconvert oxygen to carbon monoxide.5.4 A system of scrubbers and separators must
23、 be estab-lished to effectively remove pyrolysis products that interferewith the detection of carbon monoxide or carbon dioxide, orboth.5.5 The detector responses must be linear with respect toconcentration, or nonlinear responses must be detectable andaccurately related to concentration.5.6 Selecte
24、d items are available from the instrument manu-facturer.5.6.1 Pyrolysis Tubes,5.6.2 Scrubber Tubes, and5.6.3 Absorber Tubes.6. Reagents6.1 Purity of Reagents9Reagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications o
25、f the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available. Other 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 determination.6.2 Calibration
26、 Standards:6.2.1 NIST SRM 1837,10which contains certified concen-trations of methanol and t-butanol in reference fuel, can beused to calibrate the instrument for the analysis of oxygenatesin gasoline.6.2.2 Anhydrous methanol, 99.8 % minimum assay, can beused to calibrate the instrument for the analy
27、sis of methanolfuels.6.2.3 Isooctane, or other hydrocarbons, can be used as theblank provided the purity is satisfactory.6.3 Quality Control StandardNIST SRM 183810can beused to check the accuracy of the calibration.6.4 The instrument manufacturers require additional re-agents.6.4.1 Test Method A:4,
28、86.4.1.1 Anhydrone (anhydrous magnesium perchlorate),6.4.1.2 Ascarite II (sodium hydroxide on silica),6.4.1.3 Helium carrier gas, 99.995 % pure,6.4.1.4 Molecular sieve, 5, 60 to 80 mesh,6.4.1.5 Nickel wool,6.4.1.6 Nickelized carbon, 20 % loading,6.4.1.7 Quartz chips, and6.4.1.8 Quartz wool.6.4.2 Tes
29、t Method B:5,86.4.2.1 Anhydrone (anhydrous magnesium perchlorate),4The sole source of supply of the apparatus (Carlo Erba Models 1106 and 1108)known to the committee at this time is CE Elantech, Inc., 170 Oberlin Ave. N., Ste5, Lakewood, NJ 08701.5The sole source of supply of the apparatus (Leco Mod
30、el RO-478) known to thecommittee at this time is Leco Corp., 3000 Lakeview Ave., St. Joseph, MI 49085.6The sole source of supply of the apparatus (Perkin-Elmer Series 2400) knownto the committee at this time is Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT06859.7The sole source of supply of the app
31、aratus (UIC, Inc./Coulometrics Model 5012CO2coulometer and Model 5220 autosampler-furnace) known to the committee atthis time is UIC Inc., Box 863, Joliet, IL 60434.8If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will recei
32、ve careful consider-ation at a meeting of the responsible technical committee,1which you may attend.9Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Anala
33、r Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.10Available from the National Institute of Standards and Technology, Gaithers-burg, MD 20899.D 5622 95 (2005)26.4.2.2
34、 Carbon pyrolysis pellets, and6.4.2.3 Nitrogen carrier gas, 99.99 % pure.6.4.3 Test Method C:6,86.4.3.1 Anhydrone (anhydrous magnesium perchlorate),6.4.3.2 Ascarite II (sodium hydroxide on silica),6.4.3.3 Carrier gas, either helium (95 %)/hydrogen (5 %),mixture, 99.99 % pure; helium, 99.995 % pure;
35、or argon,99.98 % pure,6.4.3.4 Copper plus, wire form, and6.4.3.5 Platinized carbon.6.4.4 Test Method D:7,86.4.4.1 Anhydrone (anhydrous magnesium perchlorate),6.4.4.2 Ascarite II (sodium hydroxide on silica),6.4.4.3 Copper (II) oxide,6.4.4.4 Coulometric cell solutions, including a cathode so-lution o
36、f monoethanolamine in dimethyl sulfoxide and ananode solution of water and potassium iodide in dimethylsulfoxide,6.4.4.5 Nickelized carbon, 20 % loading, and6.4.4.6 Nitrogen carrier gas, 99.99 % pure.7. Sampling7.1 Take samples in accordance with the instructions inPractice D 4057.7.2 Visually inspe
37、ct the samples, and when there is evidenceof nonuniformity, take fresh samples.7.3 Store the samples in a cold room or a laboratoryrefrigerator designed for storage of chemicals.8. Preparation of Apparatus8.1 Prepare the instrument in accordance with the manufac-turers recommendations. These test me
38、thods require thatcorrect operating procedures are followed for the model used.Instrument design differences make it impractical to specify allof the required operating conditions.8.2 The carrier gas can be scrubbed to remove traces ofoxygen and oxygen-containing compounds.9. Calibration and Standar
39、dization9.1 Calibration for Test Methods A, B, and C, Oxygenates inGasoline:9.1.1 Use a syringe to introduce 1 to 10 L, or 1 to 10 mg,of the blank. The amount of specimen must be preciselyknown. Measure the response. Repeat the introduction andmeasurement until stable readings are observed.9.1.2 In
40、similar fashion, introduce 1 to 10 L, or 1 to 10 mg,of SRM 183710and measure the response. Repeat two timeswith the same quantity of the SRM. If the blank correctedresponses do not agree within 2 % relative, take correctiveaction and repeat the calibration.9.1.3 Calculate the K-factor as follows:K 5
41、Cstd3 MstdRavg(1)where:Cstd= mass % oxygen in the SRM,Mstd= mass of the SRM, mg,= volume of the SRM (L) 3 density of the SRM(g/mL), andRavg= average of the blank corrected responses.NOTE 1Density can be determined by Test Method D 1298 or TestMethod D 4052.9.2 Calibration for Test Methods A, B, and
42、C, MethanolFuelsRepeat procedure 9.1; however, substitute anhydrousmethanol for the SRM. For methanol fuels, a unique K-factorcan be necessary.9.3 Calibration for Test Method DThis test method doesnot require calibration; however, a quality control standardmust be analyzed to ensure proper operation
43、 of the instrument.Ablank must also be analyzed periodically to ensure consistentresponses.9.4 Quality Control (QC):9.4.1 Introduce the QC standard SRM 183810in the samemanner as the calibration standards. Calculate the percentoxygen (m/m) as described in Section 10.9.4.2 When results obtained on th
44、e QC standard do notagree with the certified values within 2 % relative, takecorrective action and repeat the calibration and quality control.9.4.3 For Test Method D, when the recovery of oxygen fromthe QC SRM is less than 0.85 (that is, 85 %), take correctiveaction and repeat the quality control. R
45、ecoveries that aregreater than 0.85 but less than unity can be used to correct thecalculated result (refer to the r parameter in Section 10).9.5 Procedure:9.5.1 Introduce the samples, and record the instrumentresponse. Calculate the results as described in Section 10. Usethe appropriate K-factor for
46、 oxygenates in gasoline and metha-nol fuels.9.5.2 Recalibrate the instrument with the appropriate cali-bration standard after each set of ten samples.10. Calculation and Report10.1 Calculate the mass % oxygen for the QC standard andsamples as follows:Mass % Oxygen 5R 3 KM3 r(2)where:R = blank correc
47、ted instrument response,K = K-factor, refer to Eq 1, assume unity for Test MethodD,M = mass of sample, mg,= volume (L) 3 density (g/mL), andr = recovery, refer to 9.4.3, assume unity for Test Meth-ods A, B, and C.10.2 For instruments with computer data systems, the cal-culation of the K-factor (Eq 1
48、) and the calculation of mass %oxygen (Eq 2) can be automatic with a digital readoutprovided.10.3 Report mass % oxygen to the nearest 0.01 %.D 5622 95 (2005)311. Precision and Bias1111.1 PrecisionThe precision of these test methods wasdetermined by statistical analysis of interlaboratory test result
49、s.Twelve laboratories analyzed in duplicate eight differentsamples, providing a total of thirteen data sets. One laboratoryused two different test methods. The breakdown on data sets bytest method is: Test Method A, three; Test Method B, two; TestMethod C, three; Test Method D, five. The statistical analysiswas performed on the set of 13 data sets because the reductivepyrolysis technique is common to all four test methods.Separate statistics were not determined for individual testmethods. The sample set included anhydrous methanol andgasoline stocks that were spi
