Analysis of saturated biomarkers and polycyclic aromatic compounds in forensic applications of oil spill to the environment using GC×GC-qTOFMS and chemometrics

Abstract

Petroleum is the main source energy in the world, and its extraction, transportation and use inevitably causes release to the environment. Since most of the oil spills comes from continuous release to the ecosystems, investigations about the input sources and environmental impacts are important. Oil spill investigations aims to determine oil-source correlations, the diagenetic/pyrogenetic origins of the spilled oils as well as their weathering levels. This project proposes the use of the enhanced chromatographic tool: comprehensive two-dimensional gas chromatography - quadrupole time-of-flight mass spectrometry (GC×GC-qTOFMS); coupled with chemometrics to perform more effective oil spill investigations. This has come in need for specific cases of types of oil spills, where the spilled oils are closely related, or in cases where spilled oils do not contain compounds that are commonly used in the conventional forensic case (this is especially relevant for diesel spills, where common petroleum biomarkers are not present). The proposed strategy (GC×GC-qTOFMS and chemometric data analysis) must overcome the inherent analytical limitation of the 1D GC-MS for forensic environmental applications, also exploiting the advantages of the multivariate analysis when handling complex matrices such as crude oils and petroleum derivatives. Method performance will be evaluated on descriptive power of the model including, but not limited to, explained variance of the data set, method uncertainties, method robustness and practical feasibility.