Validation of Biomarkers for the Revision of the CEN/TR 15522-2:2012 Method : A Statistical Study of Sampling, Discriminating Powers and Weathering of new Biomarkers for Comparative Analysis of Lighter Oils

Abstract: The revision of the CEN/TR 15522-2:2012 methodology contains new biomarkers to facilitate forensic fingerprinting of the variety of oil types that can be a part of different crimes and the purpose of this project is to validate the biomarkers of the new methodology. Biomarkers were validated by examining corresponding diagnostic ratios compatibility with the internationally used sampling cloth, discriminating power, correlation and simulated weathering sensibility through GC-SIM-MS analysis followed by statistical evaluation with t-tests, diagnostic power, Pearson correlation matrices and MS-PW plots respectively. Results based on most of the diagnostic ratios showed good compatibility with the internationally used sampling cloth, expected patterns of biodegradation and photo-oxidation except for observed photo-oxidation of hydro PAHs and that normative ratios and informative ratios with high diagnostic powers, but with strong correlations for some of the tested ratios, could be identified in diesel oils. Due to delimitations however such as the limited number of oils with similar origins that were analyzed the results should be regarded as guidelines that can be expanded.