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

1-Decene was subjected to hydrosulphurization under phase-transfer conditions at room temperature. Compound-specific isotope analysis revealed that 1-decene becomes enriched in C-13 with increasing yields of sulphurization whilst the sulphur compounds formed are initially depleted in C-13 compared to the starting substrate. The average carbon isotopic fractionation effect of the reaction on the two carbon atoms involved is ca. -20 parts per thousand. Sedimentary sulphur compounds, however, do not show this fractionation effect indicating that either a different sulphurization reaction with different isotope effects has occurred or that functionalized lipids may have been fully sulphurized.