Identification of dicyclic and tricyclic hydrocarbons in the saturate fraction of a crude oil by gas chromatography/mass spectrometry

A saturate fraction of an oil which was generated primarily from terrestrial organic matter was analyzed by gas chromatography/mass spectrometry. The authors searched for specific organic compounds that could be used as unambiguous indicators of terrestrial input. Two isomeric C/sub 15/ and two isomeric C/sub 15/ dicyclic hydrocarbons were identified as well as 11 tricyclic hydrocarbons. Structural characterizations were based on mass spectral data and structures of probable blo-chemical precursors. Skeletal structures of the tricyclic compounds occur in four distinct types. Only three of the four types may be used as terrestrial blomarkers. 4 figures, 1 table.