ASTM_D_2650_-_10_2015.pdf

Designation:D265010(Reapproved 2015)Standard 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 number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the quantitative analysis ofgases containing specific combinations of the following 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 present inamounts less than 0.1 mole%.Dimethylbutanes are assumedabsent unless specifically sought.NOTE1Although experimental procedures described herein areuniform,calculation procedures vary with application.The followinginfluences guide the selection of a particular calculation:qualitativemixture composition;minimum error due to components presumedabsent;minimum cross interference between known components;maxi-mum sensitivity to known components;low frequency and complexity ofcalibration;and type of computing machinery.Because of these influences,a tabulation of calculation proceduresrecommended for stated applications is presented in Section 12(Table 1).NOTE2This 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 regarded 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 determine 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Standards:2D1137 Method for Analysis of Natural Gases and RelatedTypes of Gaseous Mixtures by the Mass Spectrometer(Withdrawn 1981)3D1247 Test Method for Sampling Manufactured Gas(With-drawn 1986)3D1265 Practice for Sampling Liquefied Petroleum(LP)Gases,Manual MethodD1302 Test Method for Analysis of Carbureted Water Gasby the Mass Spectrometer(Withdrawn 1967)32.2 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 for 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 un-saturates.3.1.3 cracking pattern coeffcientthe ratio of a peak at 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,hexanes,and hexenes.3.1.5 IRinfrared equipment capable of analyzing gases forthe butene isomers.3.1.6 mass number or m/e 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 the m/eis equal to the sum of the atomic mass values for thatcompound.This peak is sometimes used as 100%in comput-ing the cracking pattern coefficients.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0M on Mass Spectroscopy.Current edition approved June 1,2015.Published July 2015.Originally approvedin 1967.Last previous edition approved in 2010 as D2650 10.DOI:10.1520/D2650-10R15.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American Petroleum Institute(API),1220 L.St.,NW,Washington,DC 20005-4070,http:/www.api.org.5Available from Gas Processors Association(GPA),6526 E.60th St.,Tulsa,OK74145,www.gpaglobal.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 TABLE 1 Calculation Procedures for Mass Spectrometer Gas AnalysisNOTE1Coding 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=Method of computationU=Unicomponent Peak MethodMa=Simultaneous equations where“a”identifies t