Summary In this work, we investigate in detail the acidic polar composition of five oil samples from distinct fields of the Sergipe-Alagoas Basin (Brazil) by FT-ICR MS using ESI(-). We aim to present the significance of acidic species to reveal geochemical information of petroleum fluids and to reconstruct the maturity and depositional environment of the source rocks by extracting features of biodegradation. The heteroatom class distribution of the oil samples shows great variability, with a higher abundance of N and O2 classes, followed by the O1, NO, and NO2 classes. The biodegradation was successfully assessed by the A/C ratio and SA index based on the O2 compounds, classifying the samples in four levels of biodegradation (from non to heavy biodegraded). The maturation was assessed by the distribution of the N compounds, showing that samples have reached the peak of the oil window, but the heavy biodegraded oil was misleading evaluated with higher maturity. The depositional environment was evaluated using the C27/C28 (DBE 4) ratio and the suggested Isoprenoidyl phenol index, differentiating the lacustrine oil samples from the marine evaporitic ones. However, care should be taken in the assessment of highly biodegraded oils since the acidic compounds are considerably affected.

The presence of acidic compounds as naphthenic acids in crude oil causes several problems for the petroleum industry, including corrosion in both upstream and downstream production processes. Based on this scenario, the main objective of this work was to investigate the removal of the acidic compound from two Brazilian heavy oils by adsorption processes using six potential adsorbents: powdered shale, activated carbon, bentonite, silica gel, powdered sandstone and powdered wood. These raw materials were previously characterized by conventional and surface analysis techniques, which show that they offer a good surface area and thermal stability. To evaluate the removal efficiency at the molecular level, the crude oil samples and the filtered oils were analyzed by negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry [ESI (-) FTICR MS]. The O2 class, which is related to the relatively high acidity of the samples, was the most abundant in both crude oil samples, moreover, this class was more retained by adsorbents. Silica gel, activated carbon and bentonite were the best adsorbents of acidic compounds from the tested oils, in agreement with their markedly higher surface area and porous volume. Additionally, a chromatographic analysis was performed and showed no changes in the oil profile.

Representative tar balls collected in two distinct years (2012 and 2014) in a beach along the State of Bahia, northeastern Brazil, were geochemically characterized in order to identify correlations between them and investigate potential sources. Terpanes and steranes biomarkers (detected by gas chromatography coupled to mass spectrometry, GC-MS), carbon stable isotope ratio (δ13C), Ni and V ratios and polar compounds by Fourier transform ion cyclotron resonance mass spectrometry using electrospray ionization in negative mode (ESI(-) FT-ICR MS) were evaluated. Three Brazilian oil samples from distinct sources were assessed as possible spill sources, comparing their results with the tar ball samples. Using chemometric techniques, it was verified correlation between the two set of tar ball samples, suggesting same source. However, no correlation with the oil samples was observed, with different geochemical profile among them. The heteroatom class distribution displayed severe degradation levels for tar balls and its seems that photo-oxidation and biodegradation processes were further relevant. Tar ball samples show multiple classes, most oxygenated, and with one sample showing considerable relative abundance of N1 class, suggesting it is from a more recent oil spill. In brief, our results suggest that the region, with very sensitive ecosystem, is possibly subjected to frequent spills from the same source.

Design of experiments (DOE) applied to mass spectrometry (MS), mainly focusing on the optimization of ionization techniques, has been applied to optimize experiments in order to provide the highest amount of information with the lowest number of experiments. However, DOE has not been used in petroleomics. For the first time, we applied DOE to optimize the main parameters associated with the crude oil analysis in a petroleomics approach. For the ionization technique, atmospheric pressure photoionization (APPI) has been selected and data were acquired in a high resolution (400,000 at m/z 400) and high mass accuracy (< 1 ppm) Fourier transform ion cyclotron resonance (FT-ICR) MS. Full and fractional two-level factorial designs were applied for the APPI(±) FT-ICR MS data set from two different crude oil samples with distinct physical and chemical characteristics. The standard ionization parameters that affect the MS responses of the crude oil analysis were optimized for both APPI(+)-MS and APPI(–)-MS. Such ionization parameters were then successfully applied to a crude oil and its saturated, aromatics, resin and asphaltene fractions, all with superior features of merit. Thus, the optimized APPI(±)-MS parameters should serve as reference and can be used as a guide for new studies in petroleomics.

The n-alkylcyclohexanes are poorly evaluated in biodegradation studies of Brazilian petroleum samples. In this context, this work aimed to use the homologue series of alkylcyclohexanes to assess extend of biodegradation of 26 petroleum samples from five Brazilian sedimentary basins, analyzed by gas chromatography coupled to mass spectrometry. The n-alkylcyclohexanes compounds were detected in all samples, with a distribution similar to the n-alkane profile, in which their abundance decreasing with increasing of the biodegradation extent. Based on this, it was suggested the use of the new parameter H30/DC together with the H30/AC already proposed, calculated by the ratio between C30 hopane to the dodecyl-cyclohexane, to assess biodegradation level according Peter and Moldowan scale (PM scale). In addition, it was observed an increasing in the relative abundance of DBE 2 from class O-2, analyzed by ESI(-) FT-ICR MS, mainly due to the formation of monocyclic acids with biodegradation, which correlates with the decrease of n-alkylcyclohexanes, a possible precursor of these acids.

Objective: To assess the influence of Roux-en-Y gastric by-pass (RYGB) on fecal bile acid (BA) profile and its relationship with postoperative remission of type 2 diabetes (T2D). Methods: Fecal samples were collected 3 and 12 months after RYGB from diabetic obese women who were responsive (n = 12) and non-responsive (n = 8) to postoperative remission of T2D. Fecal BA profile was accessed by liquid chromatography coupled to tandem mass spectrometry in a targeted approach. Results: Relative to pre-operative levels, a total of 10 fecal BA profiles decreased after RYGB (ANOVA, p <= 0.05) with significant fold-changes for glycochenodeoxycholic, glycocholic, taurocholic, and taurochenodeoxycholic acids at 3-months postoperatively, and for glycochenodeoxycholic, glycocholic and taurocholic acids at 12 months postoperatively (Benjamini-Hochberg, p < 0.05). Postoperative changes in fecal BA were different between responsive and non-responsive women, with a significant reduction in more sub-fractions of BA in responsive women than in non-responsive women, and a marked difference in the temporal behavior of cholic acid (CA) and chenodeoxycholic acid (CDCA), thus reflecting changes in CA/CDCA ratio, and tauroursodeoxycolic (TUDCA) levels between these responsiveness groups (ANOVA, p <= 0.05). Conclusion: RYGB induces a marked reduction in the concentration of fecal BA, which is heterogeneous according to T2D responsiveness. (C) 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

The performance of the high-field MegaOrbitrap Fourier transform mass spectrometer (FT-MS) with electrospray ionization (ESI) was evaluated to perform petroleum sample characterization via classical petroleomics approaches. Pertinent parameters that underpin the main figures of merit, that is, signal to noise ratios, dynamic range, spectral error, scan speed, mass accuracy and mass resolving power = R p, and provide subsidies to develop these analyzers were tested. Comparisons are made with data obtained using the most common petroleomics instrument, which is a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS), that has been used in the last decade in our laboratory for crude oil analysis providing R p of 340 000 at m/z 400 with transients of 3 s duration, and has been extensively demonstrated to fulfill all major requirements for precise petroleomics investigations. The high-field compact MegaOrbitrap mass analyzer, when operated at an R p = 840 000 at m/z 400 (R p > 1 000 000 at m/z 200) with a detection time of 3 s, was found to be well suited for adequate characterization of crude oil. Accurate class classification and mass accuracy below 1 ppm was obtained leading to proper, comprehensive petroleomics characterization.

In the last years most of the petroleum reserves discovered in Brazil, except for the large pre-salt reserves, as well in many parts of the world, contain unconventional oils with lower API gravity and high total acid number (TAN). The main species responsible by the high acidity are the naphthenic acids, which also leads to several problems in the petroleum industry, such as corrosivity in both up and downstream production processes. In this context, the aim of this work was to study the naphthenic acidity and corrosiveness of 35 Brazilian crude oil samples using the relative abundance of O-2 class, obtained via Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI) in negative ion mode, and correlate it with the TAN and corrosion rate in a stainless steel type (316L). It was observed poor correlation between O-2 class abundance and TAN, probably due to others heteroatom compounds that contribute to total acidity. Besides, % O-2 is likely more reliable to evaluate petroleum corrosivity than TAN, based on corrosion testes using a 316L steel cupons.

Asphaltenes are still problematic fractions and their composition is not fully unveiled as it relates to the original crude oil and the precipitation method. In this work, the composition of asphaltenes precipitated with n-heptane and n-pentane from ten crude oils from the Sergipe-Alagoas Basin were assessed by ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) using five ionization procedures (electrospray ionization (ESI), ESI(+) with formic acid, ESI(-) with ammonium hydroxide, and ESI(-) with tetramethylammonium hydroxide, and atmospheric pressure photoionization (APPI), APPI(+) and APPI(-)) in combination with a 7.2 T LTQFT Ultra Thermo Fisher spectrometer. The purpose was to evaluate compositional differences between C5- and C7-asphaltenes according to the adopted ionization methodologies. Asphaltenes were compared as a function of heteroatomic composition and aromaticity. Chemometrics strategies were employed to evaluate the heteroatom classes of higher variation among the groups. Ions that were shared by the asphaltenes and the crude oils and between the ionization methods were also evaluated for similarity. Results showed that n-heptane asphaltenes are more aromatic than n-pentane asphaltenes, which in turn were found to be more acidic and to display a higher heteroatomic complexity. Principal component analysis and the evaluation of shared ions showed that APPI(-) is able to detected asphaltene ions directly from the whole crude oil. It was also found that the use of different ionization methods with and without additives is fundamental to obtain more comprehensive chemical profiles in terms of classes and their constituents for crude oils and their asphaltenes and that the specific n-alkane used to precipitate asphaltenes leads to different chemical profiles.

Profiles for polar heteroatom compounds were obtained via Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) using electrospray ionization (ESI) in negative-ion mode for a set of 30 Brazilian oil samples from distinct sedimentary basins and used to estimate biodegradation extents. The samples were initially subjected to traditional geochemical biodegradation analysis to classify them in term of biodegradation levels as based on the Peters and Moldowan scale (PM scale). When the profiles were correlated with the PM scale, it was found that the O-1, N, NO2, NO3, and N3O2 classes decrease, whereas the O-2, O-3, and O-4 classes increase in relative abundance with biodegradation. The acyclic to cyclic acids (A/C) ratio of the O-2 class, mainly composed of naphthenic acids, provided a robust parameter to classify biodegradation levels of Brazilian oils. A modified saturated acid (SA) index was also used to classify biodegradation levels. For the O-1 class, two new monoaromatic (MA) indexes were proposed to predict the biodegradation extent. These MA parameters are based on the most readily degraded phenolic and/or benzylic O compounds by microorganisms and the persistence of O compounds with higher double bond equivalent (DBE) values in more degraded oils.

A total of 15 standard compounds with structures similar to those normally found in crude oils were analyzed using an ultrahigh-resolution and high-accuracy Fourier transform ion cyclotron resonance (7.2 T LTQ FT Ultra, Thermo Fisher, Bremen, Germany) mass spectrometer. Four different ionization techniques were used: electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and a novel technique that couples APCI and APPI, herein termed atmospheric pressure photo- and chemical ionization (APPCI). Relationships between chemical structures and ionization efficiencies were established for these techniques, which operate via different ionization mechanisms. The unsaturation level and position of the double bond were shown to be key factors on ionization efficiency for all ionization techniques. Comparisons between molecules with similar backbones but with different heteroatoms were also made. For the whole mixture, APPI showed the highest sensitivity for the positive ion mode and ESI showed the highest sensitivity for the negative ion mode. APPCI was found to be the most comprehensive ionization technique, whereas as expected, ESI preferentially ionized the most polar compounds. APPCI produced, however, more than one ionic species per molecule, a disadvantage in terms of data complexity. Such "splitting" was observed for APPI and APCI. Ions with the same molecular formula formed from different molecules were also detected by APPCI, producing composite abundances that would mislead chemical and geochemical conclusions based on petroleomic approaches. We suggest that, although less comprehensive, ESI is overall the most suitable ionization technique for petroleomic studies.

The presence of fullerenes as natural constituents of carbonaceous materials or their formation as laser artifacts during laser desorption ionization (LDI) mass spectrometry (MS) analysis is reinvestigated and reviewed. The results using asphaltene samples with varying composition as well as standard polycyclic aromatic hydrocarbons (PAH) and fullerene samples as models have demonstrated that indeed C-n ring fullerenes are not natural constituents but they are formed as common and often as predominant artifacts upon laser radiation, and a series of incorrect assignments based on LDI-MS data of several carbonaceous materials seems unfortunately to have been made. When the present results are evaluated also in the light of the vast literature on LDI-MS of carbonaceous materials, the formation of fullerene artifacts seems particularly common for LDI-MS analysis of asphaltenes and other carbonaceous samples with considerably high levels of PAH and varies according to the type of laser used, and the intensity of the laser beam.

The main phenolic constituents of S. obovatum leaf extracts, analyzed by FT-ICR MS, were correlated with their antioxidant and in vitro antiproliferative activities.

Esse trabalho tem como objetivo conhecer e avaliar a ionizacao dos compostos polares no petroleo for Espectrometria de Massas por Ressonância Ciclotronica de Ions com Transformada de Fourier (FTICR MS do ingles Fourier Transform Ion Cyclotron Resonance Mass Spectrometry), relacionando essa ionizacao com parâmetros experimentais e caracteristicas intrinsecas das moleculas. No Capitulo 1 o tipo de amostra de interesse (petroleo) e abordado, tanto em suas caracteristicas quanto em sua analise, definindo petroleomica e sua funcao. A espectrometria de massas e apresentada, entao, como ferramenta de grande utilidade nos estudos petroleomicos, em especial aquela de ultra alta resolucao como FTICR MS (Fourier Transform Ion Cyclotron Resonance Mass Spectrometry) acoplada a fonte de ionizacao eletrospray (ESI). No Capitulo 2 a ferramenta estatistica do planejamento de experimentos e apresentada e, entao, utilizada em uma amostra real de petroleo de forma a relacionar os parâmetros operacionais da fonte de ESI com respostas avaliadas comumente em petroleomica. Aspectos interessantes das relacoes parâmetro-resposta surgem durante o estudo, mostrando que a analise de petroleo por ESI-FTICR MS, apesar de largamente utilizada na literatura, nao e trivial e precaucoes devem ser tomadas durante a otimizacao dos parâmetros experimentais. No Capitulo 3 as tecnicas de APCI (Atmospheric Pressure Chemical Ionization) e APPI (Atmospheric Pressure PhotoIonization) sao abordadas e utilizadas, juntamente com ESI, para avaliar a ionizacao de padroes de compostos similares aqueles encontrados nas principais classes de compostos polares do petroleo. A analise pelas tecnicas que ionizam de forma mais abrangente os compostos apresentaram comportamentos que tornam tais analises inviaveis. Uma reacao de metilacao que melhora a ionizacao de compostos sulfurados tambem e realizada em duas condicoes, comparando-se tais condicoes a partir dos espectros obtidos apos suas analises. Conhecendo a ionizacao desses compostos padroes, e possivel entender a petroleomica de forma mais ampla dando maior confiabilidade para estabelecer as relacoes composicao-comportamento do petroleo. Abstract

Postmortem dental examinations play an important role in individual identification. In forensic odontology, individual identification is based on a traditional visual comparison of the antemortem dental record and dental radiographs with those obtained by postmortem examinations. Digitization in forensic odontology has recently started. The aim of this systematic review was to reveal the progress in forensic odontology by using ante/postmortem information obtained by digital technologies. Thirty-six eligible studies were included. No methods with digital technology have been accepted worldwide because of various factors such as expensive special equipment and the cost of other components. Further research should be conducted and progress should be made in the field of forensic odontology along with the progression of general digital technology.

IM-MS, was performed in a new uniform-field drift tube, IM-QTOF instrument. It can resolve and characterize crude oil and its contaminants, as well as petrofuels and their additives.