THE EFFECT OF HYDROSULPHURIZATION ON STABLE CARBON ISOTOPIC COMPOSITIONS OF FREE AND SULFUR-BOUND LIPIDS

1-Decene was subjected to hydrosulphurization under phase-transfer con ditions at room temperature. Compound-specific isotope analysis reveal ed that 1-decene becomes enriched in C-13 with increasing yields of su lphurization whilst the sulphur compounds formed are initially deplete d in C-13 compared to the starting substrate. The average carbon isoto pic fractionation effect of the reaction on the two carbon atoms invol ved is ca. -20 parts per thousand. Sedimentary sulphur compounds, howe ver, do not show this fractionation effect indicating that either a di fferent sulphurization reaction with different isotope effects has occ urred or that functionalized lipids may have been fully sulphurized.