Organic Sulfur Markers as Proxies of Depositional Paleoeenvironments Related to Recôncavo and Amazon Basins, Brazil.

This study employed organic sulfur markers (S-markers) associated with geochemistry parameters to evaluate the paleoenvironment of different depositional settings in 24 samples collected in vertical sections of outcrops of the Candeias and Barreirinha Formations in Recôncavo and Amazon basins, respectively. A total of twenty-one S-markers from benzothiophene (BT), dibenzothiophene (DBT), and benzonaphtothiophenes (BNT) classes were optimized and quantified by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). S-markers efficiently evaluated and differentiated the depositional paleoenvironment in the source rocks based on the individual compound, in cross-validation with saturated biomarkers, and associated with parameters such as total organic carbon (TOC) and Rock-Eval pyrolysis.

An Integrated Assessment of Different Depositional Paleoenvironment Using Nitrogen Markers and Biomarkers after Chromatographic Methods Optimization.

In this study, chromatographic methods were first optimized to ensure the robustness of the identification and quantification of nitrogen markers and biomarkers. Then, the optimal conditions were applied to 14 crude oil samples deposited in distinct paleoenvironments from Brazil, Venezuela, and Colombia to perform an integrated geochemical assessment. Analytical standards, certified reference material, and retention indices were used to confirm the identification of biomarkers and N-markers.

Deep eutectic solvent for the extraction of polycyclic aromatic compounds in fuel, food and environmental samples.

Polycyclic aromatic compounds (PACs) encompass a wide variety of organic analytes that have mutagenic and carcinogenic potentials for human health and are recalcitrant in the environment. Evaluating PACs levels in fuel (e.g.

Multivariate optimization of a green procedure for determination of emerging polycyclic aromatic nitrogen heterocycles in PM from sites with different characteristics.

Emerging polycyclic aromatic nitrogen heterocycles (PANHs) contributes significantly to the health risk associated with inhaling polluted air. However, there is a lack of analytical methods with the needed performance to their determination. This study presents the optimization and validation for the first time of a green microscale extraction procedure for the determination of twenty-one PANHs, including carbazole, indole, and quinolone classes, in particulate matter (PM) samples by gas chromatography-mass spectrometry.

Quantification of polycyclic aromatic sulfur heterocycles in fine airborne urban particles (PM) after multivariate optimization of a green procedure.

Polycyclic aromatic sulfur heterocycles (PASHs), such as benzothiophenes (BT), dibenzothiophenes (DBT) and benzonapthothiophenes (BNT), can be emitted from vehicular traffic and deposited in fine particles matter (PM). The presence of these compounds in PM is an environmental concern due to air pollution and its toxic properties. In this study, a green microscale solid-liquid extraction method was developed to determine twenty-three PASHs in PM.

Microscale solid-liquid extraction: A green alternative for determination of n-alkanes in sediments.

In this study, a green microscale solid-liquid extraction method using a miniaturized device combined with cleanup via dispersive micro-solid-phase extraction (MSLE-DµSPE) was developed for the determination by gas chromatography-quadrupole mass spectrometry (GC-MS) of n-alkanes in marine sediments. The main factors affecting the performance of this novel method were optimized using multivariate statistical tools. The MSLE-DµSPE method was validated considering the matrix-matched calibration, recovery, detection and quantification limits, ruggedness and accuracy.

Microscale extraction combined with gas chromatography/mass spectrometry for the simultaneous determination of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles in marine sediments.

This paper describes a novel method based on an ultrasound-assisted extraction microscale device (UAE-MSD) for the rapid and simultaneous determination of polycyclic aromatic hydrocarbons (PAH) and polycyclic aromatic sulfur heterocycles (PASH) in marine sediments. Solvent extraction conditions were optimized by applying a simplex-centroid mixture design. Optimum conditions were used to validate and determine the concentrations of 17 PAH and 7 PASH.

Effects of an experimental oil spill on the structure and function of benthic assemblages with different history of exposure to oil perturbation.

The present study compared the short-term effects of a diesel oil spill on the strucure and function of nematode and macrobenthic assemblages between tidal flats with different history of exposure to oil perturbation. A manipulative field experiment was conducted, where oil exposed treatments were contrasted with controls, during four successive times, two before and two after the oil spills. During the oil spill the death and the presence of diverse debilitated macrofaunal organisms were observed in the oil treatments.

Comprehensive two-dimensional gas chromatography for the analysis of nitrogen-containing compounds in fossil fuels: A review.

The present review reports, for the first time, various comprehensive two-dimensional gas chromatography (GC×GC) applications for different fossil fuel matrices (crude oil, heavy gas oil (HGO), light and middle distillates, coal and shale oil) for the determination of nitrogen-containing compounds. The focus is on the various types of detectors (universal and specific), and their applicability for the separation and speciation of nitrogen compounds (N-compounds) was evaluated. The capability of GC×GC to provide additional chemically specific information using different detector types, including a flame ionization detector (FID), a nitrogen chemiluminescence detector (NCD), a nitrogen-phosphorus (NPD) detector and detectors in combination with mass spectrometry (MS), is described.

Quantification of nitrogen compounds in diesel fuel samples by comprehensive two-dimensional gas chromatography coupled with quadrupole mass spectrometry.

Although several methods for the analysis of nitrogen compounds in diesel fuel have been described in the literature, the demand for rapid, sensitive, and robust analyses has increased in recent years. In this study, a comprehensive two-dimensional gas chromatographic method was developed for the identification and quantification of nitrogen compounds in diesel fuel samples. The quantification was performed using the standard addition method and the analysis was conducted using comprehensive two-dimensional gas chromatography coupled with fast quadrupole mass spectrometry.

Risk Factors for Adopting Extreme Weight-Control Behaviors among Public School Adolescents in Salvador, Brazil: A Case-Control Study.

Objective: This study identifies the risk factors for extreme weight-control behaviors among adolescents in public school in Salvador, northeastern Brazil.

Methods: A case-control study nested to a cross-sectional study, including 252 adolescents of both sexes, age between 11 to 17 years, with 84 cases and 168 age-matched controls was conducted. The variable outcome is represented by extreme weight-control behaviors, integrated by following the variables: self-induced vomiting and the use of laxatives, diuretics, or diet pills.

Determination of aromatic sulphur compounds in heavy gas oil by using (low-)flow modulated comprehensive two-dimensional gas chromatography-triple quadrupole mass spectrometry.

The present research is focused on the development of a flow-modulated comprehensive two-dimensional gas chromatography-triple quadrupole mass spectrometry (FM GC × GC-MS/MS) method for the determination of classes of aromatic organic sulphur compounds (benzothiophenes, dibenzothiophenes, and benzonaphthothiophene) in heavy gas oil (HGO). The MS/MS instrument was used to provide both full-scan and multiple-reaction-monitoring (MRM) data. Linear retention index (LRI) ranges were used to define the MRM windows for each chemical class.

Speciation of nitrogen-containing compounds in an unfractionated coal tar sample by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOFMS) has shown great skill in analyzing complex mixtures such as fossil fuels, especially for compounds at low concentrations. The analysis of N-polyaromatic compounds (NPAC) in coal and crude oil is a great challenge for analytical chemistry due to its environmental and technological importance, and also its diversity of concentration in the matrix. This study is the first report in the applicability of GC×GC/TOFMS for detection of NPAC in a coal tar sample with no fractionation.

[Coordination of family healthcare units done by nurses: challenges and potential].

This paper starts from the reflection that although the National Policy for Primary Health Care does not define the nurse as the coordinator of Family Health Units, USF very often this professional ends up by taking over this position due to several factors that compose nursing practices. It aimed at analyzing the nurses'coordination of Family Health Units beginning from a descriptive analysis with qualitative approach. The study was carried out with eight nurses from the Primary Health Care network of Porto Alegre-RS through semi-structured interview while the observations were registered in a field diary.

Factors associated with body image dissatisfaction among adolescents in public schools students in Salvador, Brazil.

Objective: To identify the prevalence of body image dissatisfaction and associated factors among students in Salvador, Brazil.

Methods: A cross-sectional study involving a random sample of 1,494 (852 girls and 642 boys) adolescents between 11 and 17 years of age who were students in the public schools in Salvador, Brazil. Participants completed the Body Shape Questionnaire and the Eating Attitudes Test-26.

The prevalence of overweight and obesity in adolescents in Bahia, Brazil.

Aim: A cross-sectional study was conducted with 1,477 middle school students enrolled in the public school network in Salvador, Bahia, Brazil to assess the prevalence of overweight and obesity.

Methods: The sample was determined using a two-stage cluster sampling technique for selecting schools and classes. A posteriori error was estimated.

Preliminary studies of bio-oil from fast pyrolysis of coconut fibers.

This work studied fast pyrolysis as a way to use the residual fiber obtained from the shells of coconut ( Cocos nucifera L. var. Dwarf, from Aracaju, northeastern Brazil).

Palladium(II) chemically bonded to silica surface applied to the separation and identification of polycyclic aromatic sulfur heterocycles in heavy oil.

Separation of polycyclic aromatic sulfur heterocycles among themselves and also from interferents in petrochemical matrices is a challenging task because of their low concentration, matrix complexity, and also due to the presence of polyaromatic hydrocarbons, as they present similar physico-chemical properties. Therefore, the objective of this work was preparation, characterization, and application of a stationary phase for separation of these compounds in a heavy gas oil sample and their identification by comprehensive two-dimensional gas chromatography. The stationary phase was prepared by grafting mercaptopropyltrimethoxisilane onto a silica surface, followed by palladium(II) chloride immobilization.

Comparison between pre-fractionation and fractionation process of heavy gas oil for determination of sulfur compounds using comprehensive two-dimensional gas chromatography.

The separation of the organic sulfur compounds (OSC) of petroleum or its heavy fractions is a critical step and is essential for the correct characterization of these compounds, especially due to similar physical and chemical properties of polycyclic aromatic sulfur heterocycles (PASH) and polycyclic aromatic hydrocarbons (PAH). This similarity results in coelutions among PAH and PASH and for this reason former steps of fractionation are required before gas chromatographic analysis. The objective of this study was to evaluate the potential of GC×GC for the separation and identification of OSC in a heavy gas oil sample without fractionation, after pre-fractionation in an alumina column and also after fractionation process.

Identification of organic sulfur compounds in coal bitumen obtained by different extraction techniques using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection.

The determination of organic sulfur compounds (OSC) in coal is of great interest. Technically and operationally these compounds are not easily removed and promote corrosion of equipment. Environmentally, the burning of sulfur compounds leads to the emission of SO(x) gases, which are major contributors to acid rain.

Investigation of sulphur compounds in coal tar using monodimensional and comprehensive two-dimensional gas chromatography.

Coal is a non renewable fossil fuel, used mainly as a source of electrical energy and in the production of coke. It is subjected to thermal treatment, pyrolysis, which produces coke as a main product, in addition to a condensed liquid by-product, called tar. Tar is a complex mixture of organic compounds which contains different chemical classes, presenting aromatic and sulphur heterocyclic compounds.