Relationship between chemical composition of alkylated CHN compounds and mineral composition in the Murchison meteorite.

Abstract

Meteoritic organic matter is thought to have interacted with water and minerals during aqueous alteration on the parent body, but the role of minerals in the chemical evolution of organic matter is not understood. In this study, we directly compared the chemical composition of CHN compounds with mineral composition in the same sample to elucidate the role of minerals in the formation of CHN compounds in the Murchison meteorite. HPLC-MS analysis of methanol extracts of the Murchison meteorite detected alkylpyridines, alkylimidazoles, and alkylpiperidines. Compared with the XRD analysis of the mineral residue after extraction, the abundance of alkylpiperidines tended to be higher in samples rich in phyllosilicate, suggesting that phyllosilicate may have caused the reduction of CHN compounds. In addition, the abundance of alkylpyridines and alkylimidazoles was negatively correlated, suggesting that the formation pathways of the two compounds are different.