Small-scale hydrous pyrolysis of macromolecular material in meteorites

The hydrous pyrolysis method, usually performed on several hundred grams of terrestrial rock sample, has been scaled down to accommodate less than two grams of meteorite sample. This technique makes full use of the high yield s associated with hydrous pyrolysis experiments and permits the investigati on of the meteorite macromolecular material, the major organic component in carbonaceous meteorites. The hydrous pyrolysis procedure transforms the hi gh molecular weight macromolecular material into low molecular weight fragm ents. The released entities can then be extracted with supercritical fluid extraction. In contrast to the parent structure, the pyrolysis products are amenable for analysis by gas chromatography-based techniques. When subject ed to hydrous pyrolysis, two carbonaceous chondrites (Orgueil and Cold Bokk eveld) released generally similar products, which consisted of abundant vol atile aromatic and alkyl-substituted aromatic compounds. These results reve aled the ability of small-scale hydrous pyrolysis to dissect extraterrestri al macromolecular material and thereby reveal its organic constitution. (C) 1999 Elsevier Science Ltd. All rights reserved.