title: Isotopic characterisation of kerogen-like material in the Murchison carbonaceous chondrite.
abstract: Isotopic data for C, H and N in acid-resistant residues from carbonaceous chondrites show substantial variability during stepwise pyrolysis and/or combustion.  After subtraction of contributions due apparently to inorganic C grains, of probably circumstellar origin, considerable isotopic variability remains, attributable to the kerogen-like organic fraction.  That variability may be interpreted in terms of three or four distinct components, based on C, H and N isotopes.  The relative proportions of those components vary significantly from sample to sample.  The different isotopic components are tentatively identified in terms of specific chemical/structural moieties within the kerogen-like material.  This combination of chemical, structural and isotopic information suggests a complex for meteoritic organic matter.  At least three components within the organic populations as a whole still carry a signature of apparently interstellar D-enrichment.  Part, at least, of the interstellar carrier consisted of reactive  entities, not solely polymers.
authors.affiliation: Institute of Geophysics, University of California, Los Angeles 90024, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Kerridge
authors.forename: S
authors.initials: S
authors.lastname: Chang
authors.forename: R
authors.initials: R
authors.lastname: Shipp
mesh_terms: D002244:Carbon / Q000032:analysis* / Q000737:chemistry; D002247:Carbon Isotopes; D003903:Deuterium; D019418:Evolution, Chemical; D055593:Geological Phenomena; D005844:Geology; D006859:Hydrogen / Q000032:analysis / Q000737:chemistry; D007554:Isotopes; D019110:Meteoroids; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D009587:Nitrogen Isotopes; D000069497:Origin of Life; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry*; D014316:Tritium
chemical_list: D002247:Carbon Isotopes; D007554:Isotopes; D009587:Nitrogen Isotopes; D011084:Polycyclic Aromatic Hydrocarbons; D014316:Tritium; D002244:Carbon; D006859:Hydrogen; D003903:Deuterium; D009584:Nitrogen