2023-07-122023-07-122022AGUIAR, Deborah V. A. de et al. Comprehensive composition and comparison of acidic nitrogen- and oxygen-containing compounds from pre- and post-salt Brazilian crude oil samples by ESI (-) FT-ICR MS. Fuel, Amsterdam, v. 326, e125129, 2022. DOI: 10.1016/j.fuel.2022.125129. Disponível em: https://www.sciencedirect.com/science/article/abs/pii/S0016236122019706?via%3Dihub. Acesso em: 28 jun. 2023.0016-2361e- 1873-7153https://www.sciencedirect.com/science/article/abs/pii/S0016236122019706?via%3DihubThe discovery of the pre-salt oil field renewed and expanded the outlook of the Brazilian petroleum industry due to the large volume of oil and its composition. The chemical composition characterization of crude oils from different reservoirs is crucial for the petroleum industry. In this study, comprehensive profiles of polar acidic nitrogen- and oxygen-containing compounds were accessed by electrospray ionization (ESI) in negative mode coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for a set of five Brazilian crude oil samples from the pre-salt layer, and these were compared to the chemical composition of four crude oils from post-salt reservoirs. The ESI (-) FT-ICR MS data showed that the N-containing compounds present high relative abundance among the heteroatomic compounds identified for pre- and post-salt crude oils, which was more notable for the pre-salt crude oils. Comparing the heteroatomic profiles of the pre- and post-salt crude oils, the N2, NO, and O classes were seen to decrease in relative abundance in the post-salt crude oil, whereas the NO2 and O2 classes increased in relative abundance. The acyclic to cyclic acid (A/C) ratio of the O2 class was used as a parameter to classify the pre- and post-salt crude oils. The high content of acyclic O2-containing compounds (A/C ratio > 1.2) indicated that the pre-salt crude oils are more preserved from microbial alteration, leading to the formation of O2-containing compounds, while an A/C ratio < 0.2 for post-salt crude oils categorized them as more biodegraded. A modified A/C ratio that included aromatic O2 compounds, analyzed in a ternary diagram, was also used to classify the oils according to their families: pre- and post-salt crude oils. Considering the O2-containing compounds with 1, 3, and 5 DBE (double bond equivalents), it was possible to group these oils according to their reservoirs. In addition, alkylphenols with DBE = 4, 5, and 6 also demonstrated a tendency to identify the oils according to their pre- and post-salt reservoirs. The petroleomic approach shown here by comprehensive FT-ICR mass spectrometry analysis is a powerful tool for differentiating crude oils from pre-salt and post-salt reservoirs.engAcesso RestritoArtigo10.1016/j.fuel.2022.125129