C30-steranes,novel markers for marine petroleums and sedimentary rocks

A series of C₃₀-steranes has been identified in petroleum through the application of metastable scanning gas chromatography-mass spectrometry. Their Chromatographic pattern in crude oil resembles an epimerized distribution of steranes. It is proposed that the biological precursors for the C₃₀-steranes are marine sterols which contain 30 carbon atoms, hence C₃₀-steranes are markers for input to sedimentary lipids from marine organisms.