Universal Biomarker Analysis: Aromatic hydrocarbons

Abstract

Universal Biomarker Analysis is a GC×GC-ToFMS method that provides absolute quantification and non-targeted pseudo MS-MS for all resolved hydrocarbon components in petroleum and rock extracts. This is achieved by merging two chromatographic datasets obtained under field ionization (FI), which provides molecular ions, and electron impact (EI), which provides diagnostic fragment ions. We recently demonstrated this technique for the analysis of saturated biomarkers (Walters et al., 2018). Here, we show its application to aromatic biomarkers. Universal Biomarker Analysis is compared to conventional GC–MS for frequently analyzed aromatic hydrocarbons, such as the alkylated naphthalenes and biphenyls, mono- and tri-aromatic steroidal hydrocarbons to illustrate where this new method provides demonstrated advantages. The technique is well suited for the analysis of rare species not commonly analyzed in targeted GC–MS/MS analyses. This is illustrated by the tentative identification of A/B-ring C26-C29 diaromatic steroidal hydrocarbons in a crude oil, compounds that have been previously identified as minor components of immature rock extracts, and indications of previously unknown C26 methyl-triaromatic steroidal hydrocarbons.