Forensic studies of naphthenic acids fraction compounds in oil sands environmental samples and crude oil

The forensic studies of naphthenic acids fraction components in oil sands process water (OSPW) and crude oil has continued to receive significant attention due to increased need to explicate the toxicological claims of these components and their distributions in environmental samples and to address the problems faced in the petroleum industry. The characterization of naphthenic acid fraction components (NAFCs) in oil sand environmental samples and petroleum is challenging, and analytical techniques for their elucidation are continuously being explored. There is no single technique for the forensic analysis of these compounds in oil samples. With the emergence of new forensic techniques, a range of mass spectrometric methods with great potential for integration with other analytical tools such as gas chromatography, liquid chromatography, and ion mobility are now available for improved compositional information obtainable from complex samples. A detailed and valid forensic assessment involves comprehensive characterization of the molecular distribution and evaluation of environmental fate of sample components and source apportionment. For instance, in the field of petroleomics, ultrahigh-resolution mass spectrometry (MS) such as Fourier transform ion cyclotron resonance MS (FT–ICR–MS) has been extensively used for compositional analysis of crude oil and data from the analysis has been useful in determining environmental fate, sources, and toxicological potentials. Of specific significance is the application of multiple ionization techniques for elucidation of distribution of individual compound classes. Sometimes an online or offline fractionation of isolated extracts, with or without derivatization or solid phase extraction are employed to make them amenable to coupled chromatography-mass spectrometric analysis. These approaches with complementary multivariate statistical techniques have proved useful as diagnostic tools in forensic analysis for correlating and distinguishing samples in forensic activities, providing unparalleled information on sources and photo- and biodegradations of NAFCs in oil sand environmental samples and crude oil. The unambiguous characterization of species present in oil samples can create a database source from which unknown samples can be compared for proper identification. The development in forensic investigations of NAFCs in oil sand environmental samples and crude oil will continue alongside advances in analytical and statistical tools.