1、Designation: D 2650 04An American National StandardStandard Test Method forChemical Composition of Gases By Mass Spectrometry1This standard is issued under the fixed designation D 2650; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 quantitative analysis ofgases containing specific combinations of the fol
3、lowing com-ponents: hydrogen; hydrocarbons 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 prese
4、nt inamounts less than 0.1 mole %. 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 m
5、ixturecomposition; minimum error 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 pro
6、ceduresrecommended for stated applications 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 This stand
7、ard 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 Documents2.1 AS
8、TM Standards:2D 1137 Method for Analysis of Natural Gases and RelatedTypes of Gaseous Mixtures by the Mass Spectrometer3D 1145 Test Method for Sampling Natural Gas3D 1247 Method of Sampling Manufactured Gas3D 1265 Practice for Sampling Liquefied Petroleum (LP)Gases (Manual Method)D 1302 Method for A
9、nalysis of Carbureted Water Gas bythe Mass Spectrometer33. 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 a
10、t anym/e relative to its 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
11、 value of an ionthe quotient 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
12、100 % in comput-ing the cracking pattern coefficients.3.1.8 partial pressurethe pressure of any component inthe inlet system before opening the expansion bottle to leak.3.1.9 sensitivitythe height of any peak in the spectrum ofthe pure compound divided by the pressure prevailing in theinlet system o
13、f 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 gaseous mix-ture are dissociated and ionized by electron bombardment. Thepositiv
14、e ions of the different masses thus formed are acceler-ated in an electrostatic field and separated in a magnetic field.The abundance of each mass present is recorded. The mixturespectrum obtained is resolved into individual constituents by1This test method is under the jurisdiction of ASTM Committe
15、e D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04 on Hydrocarbon Analysis.Current edition approved Nov. 1, 2004. Published November 2004. Originallyapproved in 1967. Last previous edition approved in 1999 as D 265099.2For referenced ASTM standards, visi
16、t 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.3Withdrawn.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Inte
17、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, 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 t
18、otal number of components.P=m/e of peak used and prefix, M, if monoisotopic.M = 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 indep
19、endent check on the method.SerialNo. 123456Name or ApplicationD 1137ANatural GasD 1302BCarburetedWater 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 1
20、5 26 M 0 . . . . .Ethane 12 30 M2 8 30 M 12 30 U 13 30 M 0 . . . . .Propene 10 42 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
21、 M2 8 56 M 4 56 M . . MIsobutene 8 56 M2 5 56 U 11 56 M2 8 56 M 5 39 M . . MIsobutane 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
22、 72 U 7 72 M2 5 72 M . . . . . .Benzene . . . 2 . . 7 . . 4 78 M . . . . . .Hexanes . . . 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 .
23、. 21 34 M . . . . . .Carbon dioxide 11 44 M2 10 44 M 1 . C 20 44 M . . . . . .Carbon 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 13N
24、ame or ApplicationCommercialPropaneCommercialButaneBB Stream(CrackedButanes)Dry 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 1
25、6 M 15 16 MEthyleneE7 26 M . . . . . . 12 26 M . . . . . . 13 26 MEthane 6 30 M . . . . . . 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
26、 1 56 M 7 41 M 1 . . . . . . . . 9 41 MButene-2 1 56 M 1 56 M 8 56 M 1 56 M . . . . . . 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 258M 258M 258M 458M. . . 258M 358MPentenes . . . 6 70 MG70 U 9 70 M . . . 3 57 M . 70 UIsope
27、ntane . . . 3 57 M 3 57 M 5 57 M 2 57 M 4 72 M 4 57 Mn-Pentane . . . . . . . . . 6 72 M . . . . . . 5 72 MBenzene . . . . . . . . . . . . . . . . . .HHDHexanes . . . . . . . . . . . . . . . . . .HHDC6cyclic paraffins . . . . . . . . . . . . . . . . . .HHDHexanes . . . . . . . . . . . . . . . . . .HH
28、DToluene . . . . . . . . . . . . . . . . . .HHDHydrogen sulfide . . . . . . . . .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
29、 32 MD2650042means of simultaneous equations derived from the massspectra 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 asfe
30、edstocks for polymerization and alkylation, and for monitor-ing 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,TABLE 1
31、 ContinuedSerialNo. 7 8 9 10 11 12 13Name or ApplicationCommercialPropaneCommercialButaneBB Stream(CrackedButanes)Dry GasCrackedFuel GasMixed Isoand NormalButanesReformerMake-UpGasUnstabi-lized FuelGasAcid Gases . . . . . . . . .I. C . . .IICIICResidualE827M 827M1027M1614M 527M1 14M1714MResidualE929
32、M 929M1 29M1715M 629M1215M1815MResidualE. . . . . . . . . 18 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
33、2 16 M 2 16 M 17 16 MEthylene 4 26 M . . . 14 26 MEthane 7 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 5
34、8 M 8 58 MPentenes 21 70 M . . . 15 70 MIsopentane 17 57 M 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 di
35、oxide 13 44 M 10 44 M 16 44 UCarbon monoxide . . . . . . 18 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
36、. . .Ethylmercaptan 19 62 M 15 62 M . . .Residual 41 10 41 M 8 41 M . . .Residual 14 24 14 M 22 14 M . . .AMethod D 1137.BMethod D 1302.CThe mass spectrometer analysis for isomeric butenes is far less accurate than for the other hydrocarbon components. The inaccuracies involved in the isomeric buten
37、eanalysis by mass spectrometer range from 1.0 to 4.0 mole %, 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.
38、991; Ibid, Vol 21, 1949, p. 547; and Ibid,Vol 21, 1949, p. 572.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
39、: m/e 56, 42, 30, 29, 14. All Group A residual shall be 0.2 division 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 ar
40、e less than 5 %.GIf pentenes exceed 1 %, they are determined by other means and the spectrum removed from the poly spectrum.HRemoved from sample by distillation.IChemically removed.D2650043therefore, be compared with the observed spectrum of themixture at masses independent of the original calculati
41、on.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 reduce interferences and in-crease accur
42、acy 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 described herein.8. Reference Standards8.1 The
43、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 spectrometer is capable ofdetecting impuritie
44、s 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 combined spectra are as follows:(1) Repres
45、entative 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 combined mixtures is given. Atthe level reco
46、mmended, 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 material to be analyzed.Samples can be c
47、ollected in accordance with Test MethodD 1145 or Method D 1247 or Practice D 1265.10. Calibration and Standardization10.1 ApparatusDetermine whether operating conditionsremain normal by making certain tests periodically, followinginstructions furnished by the manufacturer of the apparatus.Include in
48、 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 spectrometerswith conventional temperature control and for laboratories thatvary t
49、he temperature of the ionization chamber to obtainconstant patterns:Run Number Compound1 n-butane2 n-butane3 hydrogen4 n-butane5 hydrogen10.1.2 If the 43/58 and 43/29 ratios of the first two runs donot agree with 0.8 %, further runs must be made until agree-ment is attained, either by adjusting the temperature of theionization chamber or by other techniques commonly used bythe laboratory. In any case, the three 43/58 and 43/29 ratiosmust agree within 0.8 % and the three butane sensitivitieswithin 1 %. The two hydrogen sensitivities must agree within1.5 %. A standard
