ASTM_D_2786_-_91_2016.pdf

Designation:D278691(Reapproved 2016)Standard Test Method forHydrocarbon Types Analysis of Gas-Oil Saturates Fractionsby High Ionizing Voltage Mass Spectrometry1This standard is issued under the fixed designation D2786;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 method2covers the determination by highionizing voltage mass spectrometry of seven saturated hydro-carbon types and one aromatic type in saturate petroleumfractions having average carbon numbers 16 through 32.Thesaturatetypesincludealkanes(0-rings),single-ringnaphthenes,and five fused naphthene types with 2,3,4,5,and6 rings.The nonsaturate type is monoaromatic.Noncondensednaphthenes are analyzed as single rings.Samples must benonolefinic and must contain less than 5 volume%monoaro-matic.Composition data are in volume percent.1.2 The values stated in acceptable SI units are to beregarded as the standard.The values given in parentheses areprovided for information purposes only.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:3D2549 Test Method for Separation of Representative Aro-matics and Nonaromatics Fractions of High-Boiling Oilsby Elution ChromatographyD3239 Test Method for Aromatic Types Analysis of Gas-OilAromatic Fractions by High Ionizing Voltage Mass Spec-trometryE137 Practice for Evaluation of Mass Spectrometers forQuantitative Analysis from a Batch Inlet(Withdrawn1992)43.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1Characteristic Mass Groupings:3.1.1.1(715 711851991113alkanes!.(1)3.1.1.2(695 691831971111112511391 2 ring!.(2)3.1.1.3(1095 1091123113711511165117911932 2 ring!.(3)3.1.1.4(1495 14911631177119112051219123312473 2 ring!.(4)3.1.1.5(1895 189120312171231124512591273128713014 2 ring!.(5)3.1.1.6(2295 2291243125712711285129913131327134113555 2 ring!.(6)3.1.1.7(2695 26912831297131113251339135313671381139514096 2 ring!.(7)3.1.1.8(915 91110511171119112911311133114311451147115711591171monoaromatic!.(8)4.Summary of Test Method4.1 The relative abundance of alkanes(0-ring),1-ring,2-ring,3-ring,4-ring,5-ring,and 6-ring naphthenes in petro-leum saturate fractions is determined by mass spectrometry1This 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 Oct.1,2016.Published November 2016.Originallyapproved in 1969.Last previous edition approved in 2011 as D2786 91(2011).DOI:10.1520/D2786-91R16.2Hood,A.,and ONeal,M.J.,Advances in Mass Spectrometry,AMSPA,Waldron,1959,p.175.3For 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.4The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 using a summation of mass fragment groups most characteris-tic of each molecular type.Calculations are carried out by theuse of inverted matrices(derived from ion intensity calibrationsensitivities)that are specific for any average carbon number.Thesaturatefractionisobtainedbyliquidelutionchromatography,see Test Method D2549.5.Significance and Use5.1 Aknowledge of the hydrocarbon composition of processstreams and petroleum products boiling within the range of205 C to 540 C(400 F to 1000 F)is useful in following theeffect of changes in process variables,diagnosing the source ofplant upsets and in evaluating the effect of changes in compo-sition on product performance properties.5.2 This test method,when used together with Test MethodD3239,provides a detailed analysis of the hydrocarbon com-position of such materials.6.Apparatus6.1 Mass SpectrometerThe suitability of the mass spec-trometer to be used with this method shall be proven byperformance tests described both herein and in Practice E137.6.2 Sample Inlet SystemAny inlet system may be used thatpermits the introduction of the sample without loss,contamination,or change in composition.The system mustfunction in the range from 125 C to 350 C to provide anappropriate sampling device.6.3 Microburet or Constant-Volume Pipet.7.Reagents7.1 n-Hexadecane.(WarningCombustible.Vapor harm-ful.)8.Calibration8.1 Calibration matrix inverses are attached in Table 1which may be used directly provided the followi