Separation and identification of petroleum biomarkers by comprehensive two-dimensional gas chromatography

Abstract

Comprehensive two-dimensional gas chromatography (GC×GC) has been used to separate and identify biomarker molecules in crude oil. The biomarkers examined include alkylated aromatics (naphthalenes, biphenyls, fluorenes, phenanthrenes, chrysenes), sulfur-containing aromatics (dibenzothiophenes, benzonaphthothiophenes), steranes, triterpanes, and triaromatic steranes. These biomarkers, which are frequently used in forensic oil spill analysis and petroleum exploration, were separated into easily recognizable bands in the GC×GC chromatogram. Methods used to identify the bands included peak matching with chemical standards, comparison with GC/MS extracted ion chromatograms, and the application of chemical logic based on the known volatility and polarity properties of the biomarkers.