Abstract

Six Nigerian oils were analyzed using the Gas chromatography mass spectrometry (GC/MS) with the aim of increasing our understanding on the effect of oil biodegradation on aromatic compounds. Results obtained revealed the presence of unresolved complex mixture (UCM) humps in the total ion current (TICs) of all the studied oils consistent with biodegradation. It was also observed that the effect of water washing on the aromatic compounds increases with biodegradation in the studied oils. This is attributed to the fact that biodegradation ensues concurrently with water washing. It was also observed that phenanthrene decreases with biodegradation in all the studied oils, while Methylphenanthrene and Methyldibenzothiophine (MDBT) increases with biodegradation. The studied oils are observed to be at different levels of biodegradation which accounted for the variance seen in some of the results.

Key words: Biodegradation, Unresolved Complex Mixture, Water Washing, Aromatics Hydrocarbon, thermal maturity.