Nova estratégia multicamada de aplicação da espectrometria de massas na química forense de petróleo

Abstract

In 2019, the northeast coast of Brazil was impacted by the appearance of a large volume of oil, which was recorded as the largest environmental disaster in the country involving this type of material. Samples of this oil were collected between the states of Sergipe and Pernambuco, as well as Samples of the main producing currents of the Sergipe-Alagoas Basin and two drums that landed on the coast of Sergipe and Rio Grande do Norte. In order to evaluate the existence of a relationship between these materials, the present work proposed the geochemical characterization of Samples by gas chromatography/mass spectrometry (GC/MS) and X-ray dispersive energy spectroscopy (EDX), as well as the application of a new multilayered strategy employing the mass spectrometry technique in its two most developed forms of analysis, the sequential mode by monitoring multiple reactions (MRM) and ultra-high resolution (UHRMS), to assign similarity relationships between the samples from SergipeAlagoas basin, barrel and spilled oil samples. The proposal was based on recent advances in mass spectrometry and the limitations of the method proposed by the European Normative Committee (Cen Method). Hopanes and steranes biomarker analyses by GC/MS/MS-MRM, EDX, as well as the data obtained from the reconstructed chromatogram to the m/z 85 ion, indicated that the spilled oils originated from the same event. The diagnostic ratios for thermal evolution and the contribution of organic matter, with emphasis on the presence of 18(H)- oleanane biomarker, support this statement. The use of UHRM data, as a new and additional analytical layer, contributed to the unambiguous attribution of similarity or dissimilarity between Samples when statistically treated by principal component analysis (PCA) and hierarchical clustering analysis (HCA). Based on the results, it is suggested that the spilled oils do not share similarities with oils produced in the Sergipe-Alagoas basin and present similarities with the oils contained in the drums.