Chemical fingerprints and chromatographic analysis of crude oils and petroleum products

Résumé

Crude oil is an extremely complex combination of a wide range of constituents. Petroleum products are derived from crude oil by a variety of refining processes. The chemical compositions of oil released into the environment are affected by weathering and mixing with background substances. Variation among crude oils provides a basis for differentiation and identification of oils and the sources of spilled oils. Refined oil petroleum partially inherits fingerprints from the parent crude oil, and weathered oil could retain the unique characteristics of the source oil, which enables a potential to trace its origin. The most important criteria for a forensic oil analysis are the concentration, distribution profiles, and diagnostic ratios of source-specific petroleum compounds. In recent decades, the technologies of oil analysis have continually progressed due to advanced and automated instrumental techniques. This chapter overviews oil chemistry and analytical methodologies for separation, identification, and quantitative analysis of selected petroleum hydrocarbons in crude oils and various refined petroleum products. We also discuss the effect on oil chemical composition of weathering processes such as evaporation, photodegradation, and biodegradation.