1、Designation: D2650 10Standard Test Method forChemical Composition of Gases by Mass Spectrometry1This standard is issued under the fixed designation D2650; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the quantitative analysis ofgases containing specific combinations of the following com-ponents: hydrogen; hy
3、drocarbons with up to six carbon atomsper molecule; carbon monoxide; carbon dioxide; mercaptanswith one or two carbon atoms per molecule; hydrogen sulfide;and air (nitrogen, oxygen, and argon). This test method cannotbe used for the determination of constituents present inamounts less than 0.1 mole
4、%. Dimethylbutanes are assumedabsent unless specifically sought.NOTE 1Although experimental procedures described herein are uni-form, calculation procedures vary with application. The following influ-ences guide the selection of a particular calculation: qualitative mixturecomposition; minimum error
5、 due to components presumed absent; mini-mum cross interference between known components; maximum sensitiv-ity to known components; low frequency and complexity of calibration;and type of computing machinery.Because of these influences, a tabulation of calculation proceduresrecommended for stated ap
6、plications is presented in Section 12 (Table 1).NOTE 2This test method was developed on Consolidated Electrody-namics Corporation Type 103 Mass Spectrometers. Users of otherinstruments may have to modify operating parameters and the calibrationprocedure.1.2 The values stated in SI units are to be re
7、garded asstandard. No other units of measurement are included in thisstandard.1.3 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 deter
8、mine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1137 Method for Analysis of Natural Gases and RelatedTypes of Gaseous Mixtures by the Mass Spectrometer3D1247 Method of Sampling Manufactured Gas3D1265 Practice for Sampling Liquefied Petroleum
9、 (LP)Gases, Manual MethodD1302 Method forAnalysis of Carbureted Water Gas by theMass Spectrometer32.2 American Petroleum Institute Standards:4MPMS 14.1 Collecting and Handling of Natural GasSamples for Custody Transfer2.3 Gas Producers Association Standards:5GPA 2166 Obtaining Natural Gas Samples fo
10、r Analysis byGas Chromatography3. Terminology3.1 Definitions:3.1.1 base peak of a compoundthe peak used as 100 % incomputing the cracking pattern coefficient.3.1.2 cracked gaseshydrocarbon gases that contain unsat-urates.3.1.3 cracking pattern coeffcientthe ratio of a peak at anym/e relative to its
11、parent peak (or in some cases its base peak).3.1.4 GLCa gas-liquid chromatographic column that iscapable of separating the isomers of butenes, pentenes, hex-anes, and hexenes.3.1.5 IRinfrared equipment capable of analyzing gasesfor the butene isomers.3.1.6 mass number or m/e value of an ionthe quoti
12、ent ofthe mass of that ion (given in atomic mass units) and itspositive charge (number of electrons lost during ionization).3.1.7 parent peak of a compoundthe peak at which them/e is equal to the sum of the atomic mass values for thatcompound. This peak is sometimes used as 100 % in comput-ing the c
13、racking pattern coefficients.3.1.8 partial pressurethe pressure of any component inthe inlet system before opening the expansion bottle to leak.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04
14、.0M on Mass Spectroscopy.Current edition approved May 1, 2010. Published July 2010. Originally approvedin 1967. Last previous edition approved in 2004 as D265004. DOI: 10.1520/D2650-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
15、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from American Petroleum Institute (API), 1220 L. St., NW, Wash-ington,
16、 DC 20005-4070, http:/www.api.org.5Available from Gas Processors Association (GPA), 6526 E. 60th St., Tulsa, OK74145, www.gpaglobal.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-295
17、9, United States.TABLE 1 Calculation Procedures for Mass Spectrometer Gas AnalysisNOTECoding of calculation procedures is as follows:O = Order peaks are used in the calculation expressed serially from 1 to n, n being the total number of components.P=m/e of peak used and prefix, M, if monoisotopic.M
18、= Method of computationU = Unicomponent Peak MethodMa= Simultaneous equations where “a” identifies the particular set of equations if more than one is used.C = Chemically removed.Residual = m/e of peak suitable as an independent check on the method.SerialNo. 123456Name or ApplicationD1137ANatural Ga
19、sD1302BCarburetedWater GasH2-C6ReformerGasC3,C4iC4Component O P M O P M OCPCMOPMOCPCMOPMHydrogen . . . 6 2 M 16 2 U 17 2 M 0 . . . . .Methane 15 16 U 71516 M 15 16 U 16 16 M 0 . . . . .Ethylene 13 27 M2 12 27 M 13 26 U 15 26 M 0 . . . . .Ethane 12 30 M2 8 30 M 12 30 U 13 30 M 0 . . . . .Propene 10 4
20、2 M2 11 42 M 8 42 M2 12 42 M 6 42 M . . MPropane 9 29 M2 9 29 M 3 44 M1 14 29 M 9 29 M 3 29 MButadiene . . . 9 . . 3 . . 10 54 M 9 . M . . MButene-1 8 56 M2 5 56 U 9 41 M2 8 56 M 8 41 M . . MButene-2 8 56 M2 5 56 U 10 55 M2 8 56 M 4 56 M . . MIsobutene 8 56 M2 5 56 U 11 56 M2 8 56 M 5 39 M . . MIsob
21、utane 7 43 M2 5 . . 4 M43 M1 11 43 M 7 43 M 2 43 Mn-Butane 6 58 M2 4 58 U 5 58 M1 6 58 M 2 58 M 1 58 MPentenes . . . 3 70 U 2 70 U 9 55 M 3 70 M . . MIsopentane . . . 3 . . 6 M57 M1 7 57 M 1 72 M . . .n-Pentane 4 72 M2 2 72 U 7 72 M2 5 72 M . . . . . .Benzene . . . 2 . . 7 . . 4 78 M . . . . . .Hexa
22、nes . . . 2 . . 7 . . . . M . . . . . .C6cyclic paraffins . . . 2 . . 7 . . 3 84 M . . . . . .Hexanes 5 57 M2 2 . . 1 71 U 2 86 M . . . . . .Toluene . . . 2 . . 1 . . 1 92 M . . . . . .Hydrogen sulfide 2 34 M1 2 . . 1 . . 21 34 M . . . . . .Carbon dioxide 11 44 M2 10 44 M 1 . C 20 44 M . . . . . .Ca
23、rbon monoxide . . . 13 12 M 1 . C 18 28 M . . . . . .Nitrogen 14 28 M2 14 14 M 14 28 U 19 14 M . . . . . .Air 3 32 M1 1 32 U 14 . . 22 32 M 1 32 U . . .Helium 1 4 U 1 . . 14 . .DD. . . . . . .SerialNo. 7 8 9 10 11 12 13Name or ApplicationCommercialPropaneCommercialButaneBB Stream(CrackedButanes)Dry
24、GasCrackedFuel GasMixed Isoand NormalButanesReformerMake-UpGasUnstabi-lized FuelGasComponent O P M O P M OCPCMOPMOPMOPMOCPCMHydrogen . . . . . . . . . 15 2 M . . . 10 2 M 16 2 MMethane . . . . . . . . . 14 16 M . . . 9 16 M 15 16 MEthyleneE7 26 M . . . . . . 12 26 M . . . . . . 13 26 MEthane 6 30 M
25、. . . . . . 11 30 M . . . 7 30 M 12 30 MPropene 5 42 M 7 42 M 6 42 M 10 42 M . . . . . . 8 42 MPropane 3 44 M 4 44 M 4 44 M 7 44 M 3 44 M 5 44 M 6 44 MButadiene . . . . . . 1 54 M 3 54 M . . . . . . 2 54 MButene-1 1 56 M 1 56 M 7 41 M 1 . . . . . . . . 9 41 MButene-2 1 56 M 1 56 M 8 56 M 1 56 M . .
26、. . . . 10 56 MIsobutene 1FFM1FF939M 1F. 4 43 M . . . 11 39 MIsobutane 4 43 M 5 43 M 5 43 M 8 43 M 1 58 M 6 43 M 7 43 Mn-Butane 2 58 M 2 58 M 2 58 M 4 58 M . . . 2 58 M 3 58 MPentenes . . . 6 70 MG70 U 9 70 M . . . 3 57 M . 70 UIsopentane . . . 3 57 M 3 57 M 5 57 M 2 57 M 4 72 M 4 57 Mn-Pentane . .
27、. . . . . . . 6 72 M . . . . . . 5 72 MBenzene . . . . . . . . . . . . . . . . . .HHDHexanes . . . . . . . . . . . . . . . . . .HHDC6cyclic paraffins . . . . . . . . . . . . . . . . . .HHDHexanes . . . . . . . . . . . . . . . . . .HHDToluene . . . . . . . . . . . . . . . . . .HHDHydrogen sulfide . .
28、 . . . . . . .I. C . . .IICIICCarbon dioxide . . . . . . . . .I. C . . .IICIICCarbon monoxide . . . . . . . . . 13 28 M . . . 8 28 M 14 28 MNitrogen . . . . . . . . . . . . . . . . . . . . .Air . . . . . . . . . 2 32 M . . . 1 32 M 1 32 MD2650 1023.1.9 sensitivitythe height of any peak in the spectr
29、um ofthe pure compound divided by the pressure prevailing in theinlet system of the mass spectrometer immediately beforeopening the expansion bottle to leak.3.1.10 straight-run gaseshydrocarbon gases that do notcontain unsaturates.4. Summary of Test Method4.1 The molecular species which make up a ga
30、seous mix-ture are dissociated and ionized by electron bombardment. Thepositive ions of the different masses thus formed are acceler-ated in an electrostatic field and separated in a magnetic field.TABLE 1 ContinuedSerialNo. 7 8 9 10 11 12 13Name or ApplicationCommercialPropaneCommercialButaneBB Str
31、eam(CrackedButanes)Dry GasCrackedFuel GasMixed Isoand NormalButanesReformerMake-UpGasUnstabi-lized FuelGasAcid Gases . . . . . . . . .I. C . . .IICIICResidualE8 27 M 8 27 M 10 27 M 16 14 M 5 27 M 11 14 M 17 14 MResidualE9 29 M 9 29 M 11 29 M 17 15 M 6 29 M 12 15 M 18 15 MResidualE. . . . . . . . . 1
32、8 27 M . . . 13 27 M 19 27 MResidualE. . . . . . . . . 19 29 M . . . 14 29 M 20 29 MSerialNo. 14 15 16Name or Application H2-C6Cracked Gas H2-C6Straight Run Gas Light Refinery GasComponent O P M O P M O P MHydrogen 1 2 M 1 2 M 20 2 UMethane 2 16 M 2 16 M 17 16 MEthylene 4 26 M . . . 14 26 MEthane 7
33、30 M 5 30 M 13 30 MPropene 11 42 M . . . 12 42 MPropane 6 29 M 4 29 M 10 29 MButadiene 15 54 M . . . . . .Butane-1 . . . . . . 11 56 MButene-2 16 56 M . . . . . .Isobutene . . . . . . . . .Isobutane 12 43 M 9 43 M 9 43 Mn-Butane 18 58 M 14 58 M 8 58 MPentenes 21 70 M . . . 15 70 MIsopentane 17 57 M
34、13 57 M 7 57 Mn-Pentane 22 72 M 18 72 M 6 72 MBenzene . . . 19 78 M 5 78 UHexanes 23 84 M . . . 4 84 UC6cyclic paraffins . . . 20 84 M . . .Hexanes . . . 17 71 M 3 86 UToluene . . . 21 92 M . . .Hydrogen sulfide 9 34 M 7 34 M 1 34 UCarbon dioxide 13 44 M 10 44 M 16 44 UCarbon monoxide . . . . . . 18
35、 12 UNitrogen 5 28 M . . . 19 28 UAir 8 32 M 6 32 M 2 32 UWater 3 18 M 3 18 M . . .Cyclobutane . . . 12 56 M . . .Cyclopentene 20 67 M . . . . . .Pentadienes 20 67 M . . . . . .Cyclopentane . . . 16 70 M . . .Methylmercaptan 14 48 M 11 48 M . . .Ethylmercaptan 19 62 M 15 62 M . . .Residual 41 10 41
36、M 8 41 M . . .Residual 14 24 14 M 22 14 M . . .AMethod D1137.BMethod D1302.CThe mass spectrometer analysis for isomeric butenes is far less accurate than for the other hydrocarbon components. The inaccuracies involved in the isomeric buteneanalysis by mass spectrometer range from 1.0 to 4.0 mole %,
37、depending upon the concentration, ranges, and extent of drifts in instrument calibrations. These inaccuracieswill range still higher when pentenes are present in larger than 0.5 % concentrations. See Analytical Chemistry, Vol 22, 1950, p. 991; Ibid, Vol 21, 1949, p. 547; and Ibid,Vol 21, 1949, p. 57
38、2.DIn Method 4, butylenes and pentenes spectra are composites based on typical GLC analyses. Hexene and hexane spectra are from appropriately corrected spectraof representative fractions.EResiduals Groups A: m/e 72, 58, 57, 44, 43; Group B: m/e 56, 42, 30, 29, 14. All Group A residual shall be 0.2 d
39、ivision or less with the residual of the largest peakalso being less than 0.3 % of its total peak height. All Group B residuals shall be less than 1 % of the peak height or 0.2 division, whichever is greater.FButenes are grouped if they are less than 5 %.GIf pentenes exceed 1 %, they are determined
40、by other means and the spectrum removed from the poly spectrum.HRemoved from sample by distillation.IChemically removed.D2650 103The abundance of each mass present is recorded. The mixturespectrum obtained is resolved into individual constituents bymeans of simultaneous equations derived from the ma
41、ssspectra of the pure compounds.5. Significance and Use5.1 A knowledge of the composition of refinery gases isuseful in diagnosing the source of plant upsets, in determiningthe suitability of certain gas streams for use as fuel, or asfeedstocks for polymerization and alkylation, and for monitor-ing
42、the quality of commercial gases.6. Interferences6.1 In setting up an analysis, it is possible that a constituentwas ignored. Also, an impure calibration may have been used.The spectrum calculated from the composition found is to,therefore, be compared with the observed spectrum of themixture at mass
43、es independent of the original calculation.Differences so computed, called residuals, should as a generalrule be less than 1 % of the original mixture peak for anacceptable analysis. Masses suitable for this calculation aretabulated with each calculation procedure.NOTE 3Another strategy employed to
44、reduce interferences and in-crease accuracy consists of using spectra which have been corrected forcontributions caused by the rare isotopes of carbon and hydrogen.7. Apparatus7.1 Mass SpectrometerAny mass spectrometer can beused with this test method that shall be proven by performancetests describ
45、ed herein.8. Reference Standards8.1 The mass spectrometer must be calibrated with each ofthe components constituting the unknown mixture to beanalyzed. The calibrating compounds must be of high purity.Research grade calibrants are readily available from a numberof sources. In general, the mass spect
46、rometer is capable ofdetecting impurities in calibrants and the contribution of suchimpurities to the calibration spectrum can be removed.NOTE 4Some of the calculation procedures require the use of com-bined spectra, for example, air and butylenes. Three frequently usedpossibilities for producing co
47、mbined spectra are as follows:(1) Representative fraction from a specific source,(2) Multiplication factors to convert the spectrum of a pure constituentto a simulated spectrum of the mixture, and(3) Proportionality factors for combining actual calibrations.A recommended concentration limit for comb
48、ined mixtures is given. Atthe level recommended, the residual spectrum contribute less than 0.1 %error in any one result when the concentration of any constituent in thecombined mixture is doubled.9. Sampling9.1 Samples shall be collected by methods known to pro-vide a representative mixture of the
49、material to be analyzed.Samples can be collected in accordance with Test MethodD1247, Practice D1265, API MPMS 14.1,orGPA 2166.10. Calibration and Standardization10.1 ApparatusDetermine whether operating conditionsremain normal by making certain tests periodically, followinginstructions furnished by the manufacturer of the apparatus.Include in these tests rate of leak, ion-beam control settings,pattern reproducibility, and galvanometer calibrations.10.1.1 To ascertain pattern stability, the following scheduleis provided both for laboratories that have mass spect
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