Abstract
Insoluble organic matter isolated from five Antarctic carbonaceous chondrites was heated and compounds released were examined by GC and GU/MS. Over 120 compounds, mainly aromatic compounds and sulfur-containing heterocycles, were identified in pyrolyzates of the Yamato-791198 sample. Yamato-791198 and Yamato-74662 released a relatively large amount of organic compounds over the temperature range of 300-600℃, while the other three samples (Yamato-793321, Belgica-7904, and Yamato-86720) released almost no compounds. The results indicate that insoluble organic matter in Yamato-791198 and Yamato-74662 have a thermally labile fraction, whereas the other three do not and insoluble organic matter are graphitic. The difference may be related to thermal history on their parent bodies. Also insoluble organic matter from the Murchison carbonaceous chondrite was analyzed by the same method and the results are generally similar to those of the Yamato-791198 sample.
