Biodegradation effects on the distribution of aromatic carotenoids in crude oils

Abstract

In this study, we use a previously confirmed group of progressively biodegraded oils to investigate the biodegradation effects on the distribution of aromatic carotenoids. The results clearly show that compared to the saturated C40 β-carotane, all aromatic carotenoids detected in crude oils were affected by biodegradation. Significant changes mainly occur after moderate biodegradation and trace or undetectable levels of aromatic carotenoids and carotane would be expected in severely degraded oils. These results suggest that caution must be taken during evaluations on the degree of anoxia/euxinia in the depositional system by concentrations of aromatic carotenoids and/or related ratios when potentially biodegraded crude oils and outcrop rocks are used.