The environmental stability of selected hydrocarbon fingerprinting source ratios

Laboratory and field studies have been performed to quantitatively determine the extent of biological and physical processes leading to oil degradation in the environment. The triterpane C30 17α(H), 21β(H)-hopane has been used as an internal biomarker to monitor the degradation of both specific petroleum compounds and total oil. In refined petroleum products which lack hopane, C4-phen-anthrenesanthracenes have been used as the degradation resistant marker compound. The increase in the conserved internal marker concentration relative to its concentration in the source oil is a measure of the amount of oil lost due to weathering and biodegradation. Relative degradation rates of individual hydrocarbon compounds have also been evaluated and reported using this approach. A detailed understanding of the biodegradation characteristics of hydrocarbons in the environment has allowed us to construct a series of diagnostic ratios to fingerprint the source and to evaluate the fate and transport of spilled oils and refined products in the environment. The stability of several commonly used oil fingerprinting ratios is evaluated and a suite of new oil characterization ratios is presented. Field data from several marine oil spills and laboratory studies demonstrate the utility of this approach in environmental assessment studies