Analysis of Insoluble Organic Material in Carbonaceous Meteorites by Combined Vacuum Pyrolysis-Gas Chromatography-Mass Spectrometry

Persistent Link:
http://hdl.handle.net/10150/244076
Title:
Analysis of Insoluble Organic Material in Carbonaceous Meteorites by Combined Vacuum Pyrolysis-Gas Chromatography-Mass Spectrometry
Author:
Bandurski, Eric Lord
Issue Date:
1975
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the Antevs Library, Department of Geosciences, and the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author or the department.
Collection Information:
This item is part of the Geosciences Dissertations collection. It was digitized from a physical copy provided by the Antevs Library, Department of Geosciences, University of Arizona. For more information about items in this collection, please email the Antevs Library, antevs@geo.arizona.edu.
Abstract:
The polymer-like organic material in the Orgueil (Cl) chondrite was analyzed by high vacuum pyrolysis/gas chromatography/mass spectrometry, a new technique specially developed for this type of polymer analysis. Orgueil powder, previously solvent-extracted to remove all soluble organic compounds, whether indigenous or contaminant, was pyrolyzed in temperature steps at 150°, 300°, 450°, and 600°C. Gas chromatographic/mass spectrometric analysis of the vacuum pyrolyzates revealed a series of alkenes to C₈, an extensive series of alkylbenzene isomers, thiophene, alkylthiophenes, and benzothiophene, and the nitrogen compounds acetonitrile, acrylonitrile, and benzonitrile. Comparison of the Orgueil polymer fragments with those reported in polymer analyses of the Murchison and Allende meteorites suggests that qualitatively and quantitatively the Orgueil and Allende polymeric materials are very similar. The presence of acetonitrile, acrylonitrile, and benzonitrile, typical breakdown products of amino acids, in Orgueil pyrolyzates suggests the presence of amino acids in an insoluble form in the meteorite polymer matrix. Changes in the distribution of polymer fragments occurred during high vacuum pyrolyses as the temperature was increased stepwise from 150° to 600°C. These changes imply a progressive alteration in the character of the polymeric material toward a condensed aromatic structure through the preferential loss of aliphatic and heteroaromatic portions at lower temperatures. A possible inference is that the polymeric material in Orgueil is a complex mixture of polymerized materials having different thermal stability. Comparison of vacuum pyrolyzates of the Orgueil polymeric material with pyrolyzates of terrestrial kerogen indicates similarities in composition and structure. These similarities suggest the possibility that meteorite polymers may have formed near the surfaces of meteorite parent bodies by low temperature processes similar to those by which terrestrial kerogen is formed.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
analysis; analytical data; chemical analysis; chromatography; mass; meteorites; methods; organic compounds; organic materials; Orgueil; pyrolysis; sample preparation; spectroscopy; techniques; Chondrites (Meteorites) -- Analysis; Polymers -- Analysis
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Geosciences
Degree Grantor:
University of Arizona
Committee Chair:
Nagy, Bartholomew

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