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Comparability of measurement results and their metrological traceability to the International System of Units (SI) are fundamental tools to ensure reliable decisions in the social sphere, commerce, and science. The use of appropriate references in analytical chemistry, such as certified reference materials (CRMs) of high purity substances, is one of the required procedures to obtain traceable measurements. When commercial standards with non-certified purity values are used, traceability must be achieved by determining the purity of the standard using a potential primary reference measurement procedure or other appropriate methods. Quantitative nuclear magnetic resonance (qNMR) is a technique with the potential to be used in primary measurement procedures. This work presents the determination of purity by 1H qNMR for nitrofuran metabolites 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), and 1-aminohydantoin (AHD). Furthermore, a recent qNMR method developed by our group to improve the quantitative performance of measurements using 13C nucleus was used to determine the purity of semicarbazide (SEM) nitrofuran metabolite. Purity values obtained by qNMR for AOZ, AMOZ, and AHD standards were compared to values obtained by the mass balance approach using a suite of analytical methods: Karl Fischer (KF) coulometric titration and thermogravimetry (TG) for the determination of water and residual solvents, gas and liquid chromatography for the determination of impurities structurally related to the metabolites. The results obtained by qNMR and mass balance were consistent.Graphical abstract.

The treatment of a man who attempted suicide after experiencing symptoms of anxiety and aggressiveness associated with the use of androgenic-anabolic steroids (AAS) is described. This report includes 30 days of inpatient treatment and a 6-month follow-up. Regular use of fluoxetine apparently prevented the onset of anxiety, depression, aggressiveness, and suicide ideation, even with the concurrent use of AAS. The urinary concentration of androgens, metabolites of AAS, and fluoxetine were monitored through analysis of urinary samples by the Brazilian Laboratory of Doping Control. Our results are congruent with previous findings describing the risk of suicide prompted by AAS use as well as the efficacy of fluoxetine in the treatment of mood disorders associated with the use of anabolic steroids.

Testolactone is a potent steroid aromatase (CYP19A1) inhibitor, and its main effect is a reduction in estradiol and estrone and an increase in testosterone and androstenedione levels. In this work, we evaluated a zebrafish water tank (ZWT) as a model to investigate testolactone biotransformation and the possibility to increase knowledge regarding the applicability of the ZWT on steroid hormone elimination research, as well as on the impact of steroid hormones on the endogenous metabolism of zebrafish. High-resolution mass spectrometry combined with SIEVE software was used to discriminate the peaks of interest based on significant changes in the relative signal intensity of the m/z values between different ZWT experiments. The metabolites, 4,5-dihydrotestolactone and 1,2,4,5-tetrahydrotestolactone, the same metabolites as those described in humans, were detected in ZWT, both in quite similar proportions. The presence of testolactone in the ZWT caused a rise in testosterone and androstenedione in the water tank, similar to that in human serum. These data suggest that, while the concentration of testolactone was high enough to inhibit the aromatase enzyme, an accumulation of androgens in the water occurred, indicating that the ZWT can be considered a model to investigate the impact of steroids on live organisms.

Carbon isotope ratio (CIR) confirmation is one of the most complex and delicate analyses in the doping control field, due to the nature of the molecules to be confirmed, normally present in urinary samples as a consequence of an endogenous production. The requirements for method validation established by the World Anti-Doping Agency (WADA) have been pushing the accredited laboratories to improve their methods. The choice of the method is always a cost benefit ratio involving a hard-working and time-consuming analysis and the guarantee of reporting of reliable results. This work presents the method fully validated by the Brazilian Doping Control Laboratory as part of the preparation for the Rio de Janeiro Summer Olympic and Paralympic Games 2016. Sample preparation encompassed solid-phase extraction, liquid-liquid extraction, enzymatic hydrolysis, acetylation, and purification by preparative high-performance liquid chromatography, and analyses were performed by gas chromatography/combustion/isotope ratio mass spectrometry. This proved to be a robust method to CIR confirmation in a big event, as demonstrated by the analysis of 179 samples during the Games 2016, from clearly negative results and adverse findings for testosterone (T) and related substances, boldenone and its metabolite, 19-norandrosterone and formestane. Two atypical findings were also reported for T and metabolites.

Forensic and anti-doping laboratories have used strategies based on targeted approaches in data processing, which means that only targeted compounds have been analyzed. The new challenges lie beyond the anticipation of molecular targets, such as the detection of designer drugs. In this research, after automatic extraction of all signals obtained by liquid chromatography–high-resolution mass spectrometry (LC–HRMS), the atypical pattern of stimulant-positive samples is evaluated to indicate potential doping substances by principal component analysis (PCA) when compared to negative samples. The capacity for discrimination of positive samples by PCA was evaluated using 24 samples reported as an adverse analytical finding (AAF) for stimulants from different sports against their corresponding negative controls. The method was then evaluated on routine analysis of 620 samples. AAF samples for stimulants presented an atypical pattern positioning when compared to negative samples in the multidimensional space of PCA. The method was able to identify 22 samples reported as AAF before checking the targeted substance windows. In that scenario, it also allows the detection of designer stimulants when the present procedure is applied complementarily in screening routine analysis. The present approach was applied simultaneously with the targeted procedure through the evaluation of 620 samples without jeopardizing the results deadline. Non-targeted analysis of stimulants by PCA as applied to athlete urine samples was demonstrated for the first time to be capable of flagging positive samples in sport competitions, showing its promise as a complementary screening tool alongside classical methods and as a straightforward approach for selecting samples for long-term storage.

Certified reference materials (CRM) provide measurements of quality and metrological traceability relative to the International System of Units (SI). The results of a feasibility study for the development of an incurred CRM for the mass fraction of nitrofuran metabolites in chicken muscles are presented in this work. A small-scale batch of material was produced from freeze-dried chicken breast muscles containing residues of 3-amino-2-oxazolidinone (AOZ) and 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) metabolites after the controlled in vivo administration of furazolidone and furaltadone antibiotics. A small-scale batch from a blank matrix, without the metabolites, was also produced. The granulometry, stability of residual moisture content, effect of the treatment by irradiation at 3 kGy, 5 kGy and 7 kGy, and degree of inhomogeneity of the property values and residual moisture were evaluated. All statistical approaches for homogeneity and stability assessments were performed based on the principles of ISO Guide 35:2006.

Zebrafish (Danio rerio) water tank (ZWT) approach was investigated as an alternative model for metabolism studies based on six different experiments with four model compounds. Sibutramine was applied for the multivariate optimization of ZWT conditions, also for the comparison of the metabolism among ZWT, humans and mice, beyond for the role of CYP2B6 in ZWT. After the optimization, 18 fish and 168 hours of experiments is the minimum requirement for a relevant panel of biotransformation products. A comparison among the species resulted in the observation of the same hydroxylated metabolites, with differences in metabolites concentration ratio. However, the ZWT allowed tuning of the conditions to obtain a specific metabolic profile, depending on the need. In addition, by utilizing CYP2B6 inhibition, a relevant ZWT pathway for the demethylation of drugs was determined. The stereospecificity of the ZWT metabolism was investigated using selegiline and no racemization or inversion transformations were observed. Moreover, the investigation of metabolism of cannabimimetics was performed using JWH-073 and the metabolites observed are the same described for humans, except for the hydroxylation at the indol group, which was explained by the absence of CYP2C9 orthologs in zebrafish. Finally, hexarelin was used as a model to evaluate studies by ZWT for drugs with low stability. As a result, hexarelin displays a very fast metabolization in ZWT conditions and all the metabolites described for human were observed in ZWT. Therefore, the appropriate conditions, merits, and relevant limitations to conduct ZWT experiments for the investigation of drug metabolism are described.

The misuse of the steroid hormone testosterone for performance enhancement has been frequently reported in the past, and its administration is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA). Testosterone is produced endogenously in human. Endogenous and exogenous testosterone together with their metabolites can be unambiguously distinguished by means of their carbon isotope ratios if compared to endogenous reference compounds. Established isotope ratio mass spectrometry methods for analyzing urinary steroids for doping control purposes consist of up to two time-consuming HPLC purification steps to achieve the required purity of all analytes. In order to accelerate the sample preparation, multidimensional gas chromatography was applied. This technique is known to be suitable for the separation of complex matrices. Multidimensional gas chromatography consists of two gas chromatographs connected by a pressure-controlled heart-cutting device. In the first dimension, a less polar capillary column was installed for peak purification. In the second dimension, separation was achieved employing a column of medium polarity. Retention time stability and transfer windows were monitored by a flame ionization detector. Detection was performed simultaneously by isotope ratio mass spectrometry and a single quadrupole mass spectrometer for analyte identity confirmation and assessment of peak purity. Instead of two working days required for the HPLC-based routine method, the sample preparation is shortened by the herein presented approach to one working day. For glucuronic acid-conjugated steroids, sample pretreatment is based on solid-phase extraction, liquid-liquid extraction, enzymatic hydrolysis, and derivatization of the target analytes to their corresponding acetates. These steroid acetates are divided according to their polarity into two fractions by solid phase extraction. Further, sulfoconjugated steroids are processed by Pseudomonas aeruginosa arylsulfatase and extracted following a recently established procedure. Following WADA guidelines, the method was validated by determining the parameters linear range, limit of quantification, intra- and interday precision, accuracy and specificity utilizing linear mixing models. Additionally, a reference population (n = 74) was investigated and the obtained data were compared to the established method. An excretion study was also conducted with 4-androstenedione to prove the fit for purpose of the methodology. The results demonstrate that the method is suitable for an application in routine doping control analysis.

Exertional rhabdomyolysis may occur when an individual is subjected to strenuous physical exercise. It is occasionally associated with myoglobinuria (i.e. "cola-colored" urine) alongside muscle pain and weakness. The pathophysiology of exertional rhabdomyolysis involves striated muscle damage and the release of cellular components into extracellular fluid and bloodstream. This can cause acute renal failure, electrolyte abnormalities, arrhythmias and potentially death. Exertional rhabdomyolysis is observed in high-performance athletes who are subjected to intense, repetitive and/or prolonged exercise but is also observed in untrained individuals and highly trained or elite groups of military personnel. Several risk factors have been reported to increase the likelihood of the condition in athletes, including: viral infection, drug and alcohol abuse, exercise in intensely hot and humid environments, genetic polymorphisms (e.g. sickle cell trait and McArdle disease) and epigenetic modifications. This article reviews several of these risk factors and proposes screening protocols to identify individual susceptibility to exertional rhabdomyolysis as well as the relevance of proteomics for the evaluation of potential biomarkers of muscle damage.

Comparability of measurement results and their metrological traceability to the International System of Units (SI) are fundamental tools to ensure reliable decisions in the social sphere, commerce, and science. The use of appropriate references in analytical chemistry, such as certified reference materials (CRMs) of high purity substances, is one of the required procedures to obtain traceable measurements. When commercial standards with non-certified purity values are used, traceability must be achieved by determining the purity of the standard using a potential primary reference measurement procedure or other appropriate methods. Quantitative nuclear magnetic resonance (qNMR) is a technique with the potential to be used in primary measurement procedures. This work presents the determination of purity by

The misuse of sport-related gene transfer methods in elite athletes is a real and growing concern. The success of gene therapy in the treatment of hereditary diseases has been most evident since targets in gene therapy products can be used in healthy individuals to improve sports performance. Performing these practices threatens the sporting character of competitions and may pose potential health hazards. Since the World Anti-Doping Agency pronouncement on the prohibition of such practices in 2003, several researchers have been trying to address the challenge of developing an effective method for the detection of genetic doping. This review presents an overview of the published methods developed for this purpose, the advantages and limitations of technologies and the putative target genes. At last, we present the perspective related to the application of the detection methods in the doping control field.

Pyrethroids are chiral insecticides due to the occurrence of up to three asymmetric carbons. Each stereogenic centre generates two possible spatial configurations (R- or S-enantiomers), which are non-superimposable mirrored forms. Two chiral carbons on the cyclopropane ring generate four enantiomers on Type I pyrethroids, while a third chiral centre on Type II pyrethroids generates eight enantiomers. The chiral nature of enzymatic sites favours specific insecticidal activity only for some enantiomers in commercial formulations. On the other hand, there is an overabundance of enantiomers with no desired activity or even undesired side effects. In this sense, in addition to the previously described toxicity of insecticide enantiomers to nontarget organisms, adverse effects, such as endocrine disruption, have been reported for enantiomers with low or no insecticidal action. In addition, the different metabolic pathways of pyrethroid enantiomers have consequences for their persistence and bioaccumulation profiles in biological systems. Therefore, a stereochemical approach is required to better understand the undesired impacts of pyrethroids on the environment and on human health, since the studies point to patterns of toxicity and persistence at enantiomeric levels. The occurrence of degradation/persistence patterns in environmental samples may be useful for understanding enantiomeric fate, contributing to more accurate risk assessments aimed at preventing or mitigating the impacts of continuous pyrethroid release into the environment.

Made available in DSpace on 2018-11-26T16:01:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Embrapa Cafe Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Cafestol and kahweol (C&K), two coffee diterpene alcohols with structural similarity which exhibit anticarcinogenic effects, were isolated from green coffee Arabica beans, followed by their lipase-catalysed esterification and purification by preparative high-performance liquid chromatography (HPLC). The isolation and enzymatic synthesis parameters of C&K esters were studied, with the latter optimised by a Central Composite Design; both procedures were monitored by gas chromatography. Scale up and improved isolation conditions resulted in 1.29 g of C&K, with 98% purity from 300 g of green Arabica beans. The highest C&K ester yields were observed using an alcohol: fatty acid molar ratio of 1:5, 73.3 mg mL(-1) of CAL-B enzyme, 70 degrees C and 240 rpm for 3 days in toluene, leading to 85-88% conversion among a variety of tested C&K esters, including n-C-14:0-C-20:0, C-18:1, C-18:2 and C-18:3. Univ Fed Rio de Janeiro, Inst Quim, Lab Anal Aromas, Ave Athos da Silveira Ramos 149,Bloco A,Sala 626, BR-21941895 Rio De Janeiro, RJ, Brazil Univ Fed Rio de Janeiro, Inst Quim, LADETEC, Ave Horacio Macedo 1281, BR-21941598 Rio De Janeiro, RJ, Brazil Univ Fed Rio de Janeiro, Escola Quim, Dept Engn Bioquim, Ave Athos da Silveira Ramos,Bloco E,Sala E203, BR-21941909 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Dept Engn Bioproc & Biotecnol, Campus Botucatu,Rua Jose Barbosa de Barros 1780, BR-18610307 Lageado, SP, Brazil Monash Univ, Sch Chem, Australian Ctr Res Separat Sci, Wellington Rd, Clayton, Vic 3800, Australia Embrapa Agroind Alimentos, Ave Amer 29501, BR-23020470 Rio De Janeiro, RJ, Brazil Univ Fed Rio de Janeiro, Inst Quim, Lab Biocatalise & Sintese Organ, Ave Athos da Silveira Ramos 149, BR-21941895 Rio De Janeiro, RJ, Brazil Univ Estadual Paulista, Dept Engn Bioproc & Biotecnol, Campus Botucatu,Rua Jose Barbosa de Barros 1780, BR-18610307 Lageado, SP, Brazil

NMR is a primary method of measurement that provides quantitative traceable results without the need for a standard of the same measurand. Despite the advantages of the 1H nucleus, such as high sensitivity, short relaxation times and widespread distribution in organic compounds, some molecules present only labile H atoms, or the 1H peaks of a sample may overlap with impurities. With the CHORAD scheme – a combination of the pulse sequence CHORUS and adiabatic modulation for 1H decoupling – this study has shown that 13C NMR can be used for quantitative analyses with a bias smaller than 2% and expanded uncertainty of 0.7% (for a confidence level of 95%). Since 13C is found with significant non-statistic isotope fractionation, all the peaks of the sample and internal standard should be integrated and their bulk 13C abundances obtained by isotope ratio mass spectrometry (IRMS) must be considered to meet quantitative requirements. Future experimental work may be performed to test this procedure for complex matrix samples. This approach also proved to be suitable for studies of site-specific 13C distribution and led to better heteronuclear decoupling when compared with the use of adiabatic decoupling with ordinary hard 90° pulses, a combination extensively reported in the literature over the last decade. An examination of the molecules studied in this work and others from the literature revealed an overall trend in the 13C intramolecular profile – hydrogen-containing positions are often 13C-depleted. A potential contribution of 1JCH coupling to these results is discussed.

A homologous series of tetracyclic polyprenanes from C24 to C41 was identified in crude oils from Espirito Santo Basin (Brazil) by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–TOFMS) and gas chromatography–tandem mass spectrometry (GC–MS-MS) analyses. These products were separately characterized by elution order in first- and second-dimension retention times (1tR and 2tR, respectively), time-of-flight mass spectra (TOFMS), MRM chromatograms, product ion spectra including diagnostic ions at m/z 191, m/z 259 and m/z 149 + 14n (n = 0–17), the latter a key mass fragment for the evaluation of side chain extension at the C-18 position in tetracyclic polyprenoids. The tetracyclic compounds were thus identified as scalarane-like structures related to abundant C30 tetracyclic polyprenoids, an important indicator of input from fresh to brackish water paleoenvironments.

Comprehensive two-dimensional gas chromatography (GC×GC) approaches with cryogenic modulation were developed for the qualitative analysis of selected low volatility compounds in raw coffee bean extracts, without derivatisation. The approaches employed short first (1D) and second (2D) dimension columns, specifically a 1D 65% phenyl methyl siloxane column (11m) and a 2D 5% phenyl methyl siloxane column (1m), which allowed elution of high molar mass compounds (e.g.>600Da). Solutes included hydrocarbons, fatty acids, diterpenes, tocopherols, sterols, diterpene esters, and di- and triacylglycerides. An oven temperature program up to 370°C was employed. The effects of experimental conditions were investigated, revealing that the GC×GC results strongly depended on the cryogenic trap T, and oven T program. An appropriate condition was selected and further applied for group type analysis of low volatility compounds in green Arabica coffee beans. Retention indices were compiled for 1D GC analysis and were similar for the composite column data in GC×GC. The elution of some compounds was confirmed by use of authentic standards. The approach allowed direct analysis of coffee extract in ethyl acetate solution, with improved analyte peak capacity (approximately 200 compounds were detected) without prior fractionation or pre-treatment of the sample. This avoided potential hydrolysis of high molar mass conjugate esters as well as degradation of thermally labile compounds such as the derivatives of the diterpenes cafestol and kahweol.

One of the greatest challenges in anti-doping science is the large number of substances available and the difficulty in finding the best analytical targets to detect their misuse. Therefore, metabolism studies involving prohibited substances are fundamental. However, metabolism studies in humans could face an important ethical bottleneck, especially for non-approved substances. An emerging model for metabolism assessment is the zebrafish, due to its genetic similarities with humans. In the present study, the ability of adult zebrafish to produce metabolites of sibutramine and stanozolol, substances with a well-known metabolism that are widely used as doping agents in sports, was evaluated. They represent 2 of the most abused classes of doping agents, namely, stimulants and anabolic steroids. These are classes that have been receiving attention because of the upsurge of synthetic analogues, for which the side effects in humans have not been assessed. The samples collected from the zebrafish tank water were hydrolysed, extracted by solid-phase extraction, and analysed by liquid chromatography with high resolution mass spectrometry (LC-HRMS). Adult zebrafish could produce several sibutramine and stanozolol metabolites, including demethylated, hydroxylated, dehydroxylated, and reduced derivatives, all of which have already been detected in human urine. This study demonstrates that adult zebrafish can absorb, oxidise, and excrete several metabolites in a manner similar to humans. Therefore, adult zebrafish seem to be a very promising tool to study human-like metabolism when aiming to find analytical targets for doping control. Copyright © 2017 John Wiley & Sons, Ltd.

This paper summarises the results obtained from the doping control analyses performed during the Summer XXXI Olympic Games (August 3-21, 2016) and the XV Paralympic Games (September 7-18, 2016). The analyses of all doping control samples were performed at the Brazilian Doping Control Laboratory (LBCD), a World Anti-Doping Agency (WADA)-accredited laboratory located in Rio de Janeiro, Brazil. A new facility at Rio de Janeiro Federal University (UFRJ) was built and fully operated by over 700 professionals, including Brazilian and international scientists, administrative staff, and volunteers. For the Olympic Games, 4913 samples were analysed. In 29 specimens, the presence of a prohibited substance was confirmed, resulting in adverse analytical findings (AAFs). For the Paralympic Games, 1687 samples were analysed, 12 of which were reported as AAFs. For both events, 82.8% of the samples were urine, and 17.2% were blood samples. In total, more than 31 000 analytical procedures were conducted. New WADA technical documents were fully implemented; consequently, state-of-the-art analytical toxicology instrumentation and strategies were applied during the Games, including different types of mass spectrometry (MS) analysers, peptide, and protein detection strategies, endogenous steroid profile measurements, and blood analysis. This enormous investment yielded one of the largest Olympic legacies in Brazil and South America. Copyright © 2017 John Wiley & Sons, Ltd.

A simple multiresidue and multiclass procedure is described for the simultaneous determination of anabolic agents and β2-agonists from 4 classes of prohibited substances of illegal use in food-producing animals, according to Council Directive 96/23/EC. The method involves analysis of hydrolysed urinary anabolic compounds using liquid–liquid extraction, with subsequent conversion to trimethylsilylether derivatives that are analysed by GC-MS/MS. The oven was set to an initial temperature of 140°C, was increased at a rate of 10°C/min to 300°C, and was held 3 min using an Ultra-1 capillary column. Optimization tests demonstrated good peak resolution and shape for all compounds. A pre-validation study was conducted to obtain an analytical test curve, which showed adequate results for all analytes. Cochran's test (C calculated

The hydrocarbon composition of atmospheric particulate matter (PM) and Volatile Organic Compounds (VOC) from urban areas of Rio de Janeiro City were studied to assess different pollution levels. PM samples were acquired using a standard high-volume air sampler (Hi-Vol), extracts were prepared and fractionated into aliphatic and aromatic compounds, and VOC compounds were collected in adsorbent tubes. High-resolution gas chromatography and GC coupled to mass spectrometry (GC-MS) were used to analyze the organic compounds from the PM and VOCs. The results showed that all samples contained n -alkanes, but the distribution was different for each sample, which reflects both biogenic (vascular plant wax input) and fossil fuel contamination sources (vehicular exhaust). Fossil fuel biomarkers, such as hopanes, were observed in all samples, but steranes were not detected in Marina da Gloria. The presence of benzo[ a ]pyrene was observed, and all measured concentrations were below the upper permissible limit. Benzene was also observed, and the upper limit value (5 μg/m 3 ) was exceeded in Jacarepagua (JP) and Maracana (MC) according to the Ambient Air Quality and Cleaner Air for Europe limit value (EC, 2008). Regarding the Ambient Air Quality Criteria (AAQCs), all analyzed samples had concentration values above the limit of 2.30 μg/m 3 . A decrease in pollution level was observed in the following order: Maracana (MC), Guadalupe (GP), Jacarepagua (JP), Barra da Tijuca (BT), Vila Militar (VM) and Marina da Gloria (MG).

Eleven Brazilian oil samples from different sources, biodegradation and maturity levels were analyzed by comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-TOFMS). Geochemical characterization associated with principal component analysis (PCA) allowed the identification of the three most mature oils. The GC×GC chromatographic conditions used in this study allowed us to perform group-type (or chemical class) separation in the following second dimension (2D) order: (i) tricyclic terpanes; followed by (ii) steranes with 3 rings containing 6 carbon atoms and 1 ring containing 5 carbon atoms; (iii) tetracyclic terpanes with 4 rings containing 6 carbon atoms; (iv) pentacyclic terpanes with 4 rings containing 6 carbon atoms and 1 ring containing 5 carbon atoms; and finally (v) pentacyclic terpanes with 5 rings containing 6 carbon atoms. This information was used to tentatively identify the ring structure of eight unusual compounds found in the saturated fraction of the oils. These compounds had the double bond equivalent (DBE) value four, which was calculated based on molecular ions M+ at m/z 274, 288 and 316, indicating possible tetracyclic structures. Two of them presented a diagnostic peak at m/z 191 and six at m/z 203. A trend between the ratios of two of these unusual compounds and the C24 tetracyclic terpane versus 4,6/1,4 dimethyldibenzothiophene ratio shows promise as a maturation parameter. Thus, these unusual compounds are prone to respond to the maturation on a scale from mature to overmature, when compared with traditional maturation parameters.

Women are employed in increasing numbers as gasoline station attendants, a work category with risk of exposure to benzene. We have assessed the effect of gender on biomarkers of occupational benzene exposure. Gasoline station attendants (20 men and 20 women) and 40 control individuals (20 men and 20 women) with no history of occupational benzene exposure were evaluated. Benzene exposure was monitoring by environmental and biological measurements. Urinary trans,trans-muconic acid levels, well-known genetic and hematological alterations linked to benzene exposure, and non-cancer effects on the immune, hepatic, and renal systems were investigated. Our results suggest a potential effect of gender on some effects of occupational benzene exposure, particularly the hematological parameters and trans,trans-muconic acid levels. Despite limitations of our study, our findings provide important considerations about occupational exposure of women to benzene and may contribute to the development of occupational protection standards.

The possibility of detecting drugs of abuse in bone marrow represents an important issue in forensic toxicology. Bone marrow is an alternative matrix for cases in which the matrices commonly used in forensic practice are unavailable or unfeasible for analysis. The aim of this study was to develop a method for bone cleaning and bone marrow pretreatment and subsequently validate a quantitative method for the simultaneous analysis of fenproporex and amphetamine in porcine bone marrow. Bones were cleaned with proteolytic enzymes and then were cut into small fragments in order to remove the bone marrow. A homogenate was obtained after adding an acidic solution to the bone marrow. Then, the bone marrow homogenate was cleaned with ethyl ether and, after pH adjustment, extracted by liquid–liquid extraction (LLE) with ethyl ether. The dry residue obtained after solvent evaporation was derivatized with N-methyl-bis-trifluoroacetamide (MBTFA)/N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and then analyzed by gas chromatography-mass spectrometry (GC-MS). The developed method allowed the identification and quantification of target analytes in the studied matrix. The validation procedure showed good linearity (r2 > 0.99) and recovery (>80%) for fenproporex and amphetamine. The limits of detection and quantitation were 1 ng mg−1 and 5 ng mg−1, respectively, for both analytes. The obtained results are of great importance and may be suitable for potential use in forensic practice.

Liquid chromatography coupled to Orbitrap high resolution mass spectrometry was shown to be an adequate technique to control the adulteration of whey protein food supplements with prohibited substances, not declared on the labels. An extraction method combined with an instrumental analysis that allowed for the determination of 105 substances in whey protein food supplements, was established. The pre-treatment of the samples consisted of protein precipitation and solid-phase extraction using weak cation exchange functionalized polymeric sorbent cartridges. The samples were directly analyzed by LC-Orbitrap-HRMS. The selectivity, limit of detection, repeatability, recovery, carryover and matrix effect were estimated as the validation parameters. The repeatability obtained was 96.19% and the recovery 83.80%, but carryover and the matrix effect were not observed. The present method was successfully applied to the analysis of commercial samples, verifying adulteration by diuretics (conivaptan and politiazide) and a stimulant (benfluorex) in seven of the eleven brands evaluated. Resumo A cromatografia líquida acoplada à espectrometria de massas de alta resolução do tipo Orbitrap demonstrou ser uma técnica adequada para o controle de adulteração de substâncias proibidas não declaradas nos rótulos de suplementos proteicos derivados de soro de leite. Foi estabelecido um método de extração combinado a uma análise instrumental que permitiu a determinação de 105 substâncias em suplemento proteico derivado de soro de leite. O pré-tratamento das amostras consistiu na precipitação de proteínas e na extração em fase sólida, utilizando-se cartuchos com sorventes poliméricos baseados em troca catiônica. As amostras foram diretamente analisadas por CL-EMAR-Orbitrap. Foram estimados, como parâmetros de validação, seletividade, limite de detecção, repetitividade, recuperação, arraste e efeito de matriz. A repetitividade obtida foi de 96,19% e a recuperação foi de 83,80%. Arraste e efeito de matriz não foram observados. O presente método foi aplicado com sucesso na análise de amostras comerciais, nas quais foram verificadas adulterações, em sete das 11 marcas avaliadas, em diuréticos (conivaptan e politiazida) e estimulante (benfluorex).

Fossil fuel emissions derived from crude oil have a significant impact on the environment, climate change, air pollution, and others. Under these circumstances, there is a great interest in alternative energy resources, especially those that are able to reduce the emission of atmospheric pollutants. The aim of this study is to evaluate the burning emissions of the following binary mixture and biofuels: commercial diesel (diesel with 5% of biodiesel, B5), pure soy biodiesel (B100), additivated biodiesel (B100 adt) stored at 40 °C for 1, 2, and 3 weeks, and additivated ethanol (Ethanol adt). The burning emissions were evaluated by the levels of benzene, toluene, ethylbenzene, and xylenes (BTEX) and total particulate matter (TPM). The quality of the biofuels was given by oxidative stability during storage. The combustion products were originated from a diesel cycle stationary engine, operating in 1800 rpm and 0% load. For a greater reliability in the results, some figures of merit were evaluated for the determination of BTEX by gas chromatography and flame ionization detection (GC-FID) and the particulate matter was determined by gravimetric analysis. Results show that operating time of the engine influences combustion efficiency. During the initial 15 min, cold engine start, there was increasing in BTEX and TPM emissions, when comparing B100 and B5. Regarding to the storage period of 1–2 weeks, B100, B100 adt, and B5 showed reduction of approximately 36%, 16%, and 4% for TPM, respectively. Evaluating each component of BTEX, the benzene emissions were greater for biofuels, which is in agreement with previous studies. As observed for TPM, the storage time of 1–2 weeks was beneficial for the mitigation of aromatic emissions. A reduction about 60% percent was measured for benzene and ethylbenzene. However, these emissions can also be influenced by the engine operating conditions (load and speed), engine type, and characteristics of biofuels. Additivated ethanol also presented low emissions for these pollutants as well as the lowest percentage of emissions of TPM. It is noteworthy that Ethanol adt present the lowest percentage of benzene emission.

Petrochemical industries generate wastewaters containing pollutants that can severely impact the biological treatment systems. Some streams from specific production units may contain nonbiodegradable or toxic compounds that impair the performance of the wastewater treatment plant and should be segregated and treated by specific techniques. In this work, the utilization of chemical oxidation (H2O2/UV) was investigated for removing 4-vinylcyclohexene (VCH) from a liquid stream coming from the production of hydroxylated liquid polybutadiene (HLPB). Besides VCH, this stream also contains ethanol, hydrogen peroxide, and many other organic compounds. Experiments were carried out in a small-scale photochemical reactor (0.7 L) using a 25-W low-pressure mercury vapor lamp. The photochemical reactor was operated in batch, and the reaction times were comprised between 10 and 60 min. Assays were also performed with a synthetic medium containing VCH, H2O2, and ethanol to investigate the removal of these substances in a less complex aqueous matrix. By-products formed in the reaction were identified by gas chromatography and mass spectroscopy (GC-MS). VCH was significantly removed by the oxidation process, in most assays to undetectable levels. Ethanol removal varied from 16 to 23 % depending on the reaction conditions. Acetic acid, acetaldehyde, and diols were detected as by-products of the industrial wastewater stream oxidation. A drop on the toxicity of the industrial stream was also observed in assays using the organism Artemia salina.

Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was successfully applied to eight real Brazilian Fischer-Tropsch (FT) product samples for the quantitative analysis of O-containing compounds. It not only allowed identifying and quantifying simultaneously a large number of O-containing compounds but also resolved many co-eluting components, such as carboxylic acids, which co-elute in one-dimensional gas chromatography. The homologous series of alcohols and carboxylic acids as trimethylsilyl derivatives were detected and identified at trace levels. The absolute quantification of each compound was accomplished with reliability using analytical curves. Linear alcohols (from C5 to C19), branched alcohols (C6-C13) and carboxylic acids (C4 to C12) were obtained in the range of 1.58 mg g(-1) to 14.75 mg g(-1), 0.51 mg g(-1) to 1.12 mg g(-1) and 0.21 mg g(-1) to 1.63 mg g(-1) of FT product samples, respectively. GC×GC-TOFMS provided a linear range (from 0.3 ng µL(-1) to 10 ng µL(-1)), good precision (

Diagenetic aromatic carotenoids and degradation products, which are derived from the carotenoids of photosynthetic sulfur bacteria, were characterized in the aromatic fraction of Brazilian Cretaceous crude oils (NE Brazil, Sergipe-Alagoas Basin) by high-temperature comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (HT-GC × GC–TOFMS). Unresolved complex mixtures (UCM), coeluting compounds, and limited mass spectrometric identification were noted by traditional one-dimensional (1D) GC–MS screening of aromatic compounds. Group-type separation on a two-dimensional chromatographic plane, first- and second-dimension retention times (1tR and 2tR, respectively), and mass spectra enabled the assignment of alkylated mono-, di-, tri-, and tetra-aryl hydrocarbons with confidence. A series of diagenetic C40 carotenoids and degraded products, which are likely indicators for green-brown sulfur bacteria, were detected. This finding corroborates previous results, and isorenieratane was relatively more abundant than 2,3,6-trimethylaryl isoprenoids. Moreover, atropisomeric biphenyls (m/z 237), which coeluted using 1D GC–MS analyses, were resolved by GC × GC and identified by mass spectrometry. The identification of minor abundances of chlorobactane, diagenetic biphenyl chlorobactane, and related compounds, for the first time in these Brazilian Cretaceous oils, may indicate a contribution of green sulfur bacteria (Chlorobiaceae) and photic zone euxinia in shallow waters.

Cafestol and kahweol (C&K) are natural coffee diterpenes with high commercial value. There is thus interest in their synthesis although their isolation from natural products remains an alternative to recovering high quantities of C&K. The present work aimed at developing an isolation procedure to obtain C&K for both analytical purposes and in gram-scale from coffee beans. The procedure was divided into three steps: an initial saponification reaction optimized by Factorial Design, a choice of solvent for extraction of a crude C&K mixture based on Hansen Solubility Parameters, and a subsequent purification by column chromatography and preparative liquid chromatography in recycling mode to improve C&K mixture purity and for separate preparative collection of each diterpene. The first two steps are useful to maximize yield for C&K quantification, and the complete procedure allowed isolation of 1.5 g of C&K per 300 g of green coffee beans. This isolation procedure can be repeated 25 times using ca. US$1k in reagents, with an estimated value of product varying from US$227k to US$322k for a diterpene mass of 37.5 g, at the prevailing commercial rate.

Erythropoiesis-stimulating agents (ESAs) have been used in horses for doping purposes to increase the performance of these animals in endurance sports. Currently, enzyme-linked immunosorbent assay (ELISA) and mass spectrometry methods are used to detect ESA abuse in equines. However, the sarcosyl polyacrylamide gel-electrophoresis (SAR-PAGE) technique could also be used, since its application in human doping control is well established and has proven to be more sensitive. In this work, the SAR-PAGE method was used to detect recombinant human erythropoietin (rHuEPO), novel erythropoiesis stimulating protein (NESP), continuous erythropoietin receptor activator (CERA), and fusion protein of erythropoietin with human immunoglobulin heavy chain Fc region (EPO-Fc) in horse blood and urine. The purification technique for human blood using MAIIA kits worked well for horse samples. The major challenge was horse urine immunopurification, which proved difficult due to filter clogging, but heating and cooling of the horse urine followed by filtration in 30-kDa molecular weight cut-off filters solved this problem. The limits of detection (LODs) of 1.3, 1.6, 6.6, and 13.3 pg/mL for rHuEPO, NESP, CERA, and EPO-Fc, respectively, obtained in spiked urine and 40, 100, 80, and 400 pg/mL for rHuEPO, NESP, CERA, and EPO-Fc, respectively, acquired in spiked blood are lower than the LODs reported in the literature using liquid chromatography-mass spectrometry (LC-MS) methods. In addition, the presence of ESAs was detected up to 9 days after the administration of microdoses of Hemax (rHuEPO), NESP, and CERA in horse blood and urine. SAR-PAGE may be implemented in the routine analysis of horse doping control laboratories for screening and confirmation of ESA abuse, mainly due to its high sensitivity for both matrices compared to published mass spectrometric methods.

A novel dynamic approach is described to profile volatile organic compound (VOC) and semi-VOC (SVOC) emission during coffee roasting aimed at analysing components present in the roasting plume, and to monitor their evolution during the process. Two sorbents - coconut shell charcoal (CSC) and styrene-divinylbenzene resin (XAD-2) - were evaluated while collecting substances in four sequential time intervals (0-3, 3-6, 6-9 and 9-12 min). Extracted VOCs (200 Da) and SVOCs were analysed by gas chromatography (GC), and comprehensive two-dimensional gas chromatography (GC × GC) with flame ionisation (FID) and time-of-flight mass spectrometry (TOFMS) detection. Results showed CSC extraction presented poor recovery of VOCs and SVOCs released during roasting. However, XAD-2 was able to collect both groups, including SVOCs of400 Da. GC × GC resolved many co-eluting compounds observed in 1D GC and allowed chemical group type cluster analysis, revealing that many non-polar VOCs are observed within the 0-3 min interval, and that the release of polar and higher molar mass SVOCs were mostly found within the 3-6 min interval. These group-type cluster analyses offer a broad spectrum chemical profile of the released substances. It may also reveal detailed insights into the roast process evolution over time.

Variations in endogenous levels of catecholamines may be caused by changes in the organism, which are associated with the development of certain diseases by exogenous sources that are related to the intentional administration of some catecholamine. This study presents the development, validation and application of an analytical method to detect and to analyze the catecholamines and its metabolites simultaneously. The sample extraction consisted basically in hydrolysis and solid-phase extraction using a weak cation exchange functionalized polymeric sorbent cartridges. The catecholamines analysis was performed on orbitrap high resolution mass spectrometry HRMS-orbitrap equipped with electrospray. Modifications in different electrospray variables (S-lens, sheath gas flow and capillary temperature) were performed following the Doehlert experimental design (DOI). The validation parameters evaluated were repeatability, intermediate precision, matrix interference, limit of quantification, linearity, carryover and robustness. The most favorable conditions found according to the DOI for all analytes were S-lens fixed at 80 rf, sheath gas flow at 20 au and capillary temperature at 300 °C. The repeatability obtained from 100%, intermediate precision was 70%, matrix interference was observed, limit of quantification of the 5 ng·mL−1, linearity was 80%, robustness was 80% and carryover was not observed. DOI showed the most favorable conditions for the analysis of all the target compounds, contributing to the establishment of the method parameters. When applied in real samples, the method proved to be rapid, sensitive and selective even in the presence of urine interferents.

Ephedrines are widely used in therapy. Because of their stimulant properties, these substances are relevant in different forensic fields. At present, the state of the art for ephedrines quantification relay based on a liquid chromatography mass spectrometry, mainly because of the dilute-and-shoot approach. Notwithstanding, several gas chromatography based methods have already been described, all of them include cleanup steps, with the potential disadvantage of incurring errors and increasing the workload. In this paper, a straightforward method for ephedrine quantification based on gas chromatographic mass spectrometry, without cleanup and based on Doehlert matrix optimization is presented. Only 10 µL of a urine sample is necessary and for N-methyl-N-(trimethylsilyl)trifluoroacetamide/N-methyl-bis-trifluoracetamide derivatives, the intermediate precision was 2.77% for ephedrine, 9.20% for cathine, 8.29% for norephedrine and 4.27% for pseudoephedrine. The limit of detection was 20 ng mL-1 for ephedrine, 30 ng mL-1 for cathine and 40 ng mL-1 for norephedrine and pseudoephedrine.

Glycerol is a naturally occurring polyol in the human body, essential for several metabolic processes. It is widely used in the food, pharmaceutical, and medical industries and in clinical practice as a plasma volume expander (PVE). Athletes, however, may use glycerol to mask the presence of forbidden substances or to enhance performance, inclusively through hyperhydration achieved by glycerol ingestion with added fluid. These practices are considered doping, and are prohibited by the World Anti-Doping Agency (WADA). Therefore, glycerol was introduced in the prohibited list. Doping through glycerol ingestion can readily be identified by detection of elevated glycerol concentrations in urine. In this paper, a protocol for the fast detection of glycerol in urine is proposed. It consists of a previous visual colourimetric screening, followed by a quantitative/qualitative confirmation analysis by mass spectrometry. The screening procedure involves a reaction in which polyhydric alcohols are oxidized by periodate to formic acid and formaldehyde, which is detected by the addition of a fuchsin solution. For the subsequent qualitative/quantitative confirmation analysis, a gas chromatography-mass spectrometry based approach with a non-deuterated internal standard and a drying step of only 10 min is proposed. The linear correlation was demonstrated within WADA´s threshold range. The calculated RSD were 2.1% for within-day precision and 2.8% for between-day precision. The uncertainty estimation was calculated, and a value of 2.7% was obtained. The procedure may also be used for the analysis of other polyols in urine, as for example the PVE mannitol.

The Gulf of Mexico is one of the world's largest petroleum regions. Cantarell is an important oil field located in the Akal Pillar province. This region is characterized by several oil seeps. However, there is no consensus on the Cantarell oil seep subsurface provenance. Surface oil samples (seepage) and subsurface oil samples (reservoirs) from the Akal Pillar province were analyzed using gas chromatography with a flame ionization detector (GC-FID) and gas chromatography with a mass spectrometry detector (GC-MS). The data obtained were used to identify and characterize biomarker and diamondoid distributions. Multivariate statistical analyses of geochemical results were made to identify the Cantarell oil seep origin. Geochemical analysis showed small differences between the results which could help the correlation studies between the samples. Cluster analysis indicated a good correlation of the seepage samples with a unique subsurface oil sample, CAN8, from the reservoir in the Paleocene/Cretaceous breccia.

This study presents the bioreduction of six β-ketoesters by whole cells of Kluyveromyces marxianus and molecular investigation of a series of 13 β-ketoesters by hologram quantitative structure-activity relationship (HQSAR) in order to relate with conversion and enantiomeric excess of β-stereogenic-hydroxyesters obtained by the same methodology. Four of these were obtained as (R)-configuration and two (S)-configuration, among them four compounds exhibited >99% enantiomeric excess. The β-ketoesters series LUMO maps showed that the β-carbon of the ketoester scaffold are exposed to undergo nucleophilic attack, suggesting a more favorable β-carbon side to enzymatic reduction based on adopted molecular conformation at the reaction moment. The HQSAR method was performed on the β-ketoesters derivatives separating them into those provided predominantly (R)- or (S)-β-hydroxyesters. The HQSAR models for both (R)- and (S)-configuration showed high predictive capacity. The HQSAR contribution maps suggest the importance of β-ketoesters scaffold as well as the substituents attached therein to asymmetric reduction, showing a possible influence of the ester group carbonyl position on the molecular conformation in the enzyme catalytic site, exposing a β-carbon side to the bioconversion to (S)- and (R)-enantiomers.

This is a first look at a non-targeted screening method based on Orbitrap gas chromatography-mass spectrometry (GC-MS) technology for a large number of banned compounds in sports found in urine, including exogenous anabolic steroids, β-agonists, narcotics, stimulants, hormone modulators, and diuretics. A simple sample preparation was processed in four steps: an enzymatic hydrolysis, liquid-liquid extraction, evaporation, and trimethylsilylation. All compounds were able to meet the World Anti-Doping Agency's sensitivity criteria with mass accuracies less than 1 ppm and with sufficient points across the peak by running the Orbitrap GC-MS in full-scan mode. In addition, we discuss our initial findings of using a full-scan selected ion monitoring-tandem mass spectrometry (SIM-MS/MS) approach as a way to obtain lower detection limits and reach desirable selectivity for some exogenous anabolic steroids.

As most of the oils in the Reconcavo Basin are genetically related and have experienced nearly equivalent thermal stress, it is difficult to differentiate them using standard techniques. However, differentiation can be accomplished using new analytical techniques, including comprehensive two-dimensional gas chromatography (GC×GC)-time of flight mass spectrometry (TOFMS). In this investigation, GC×GC-TOFMS was applied for the characterization of 20 selected Reconcavo Basin crude oils from a wide geographical distribution. Source and maturation parameters were determined based on the analysis of saturated hydrocarbons, aromatic compounds and diamondoids using GC×GC-TOFMS. Chemometric techniques were applied in order to expand the overall understanding of the sample characteristics. It was found that β-carotane and gammacerane were highly important for differentiating oils from the central portion of the basin, while two southern oils were differentiated by their sulfur-containing aromatic compounds. Diamondoid analysis was fundamental to evaluating maturity. The results of this study show how previously overlooked, minor oil components are important for differentiating genetic groups, compounds that were neglected prior to the application of GC×GC-TOFMS.

Coffee is the second most consumed brew in the world, after water. Cafestol and kahweol are two diterpenes that have been identified, until now, exclusively in the coffee tree. They are co-extracted from the coffee beans that are roasted and ground for the beverage preparation. Their pharmacological properties are related to anticancer and anti-inflammatory activities, although they also increase the serum cholesterol. Several researches reported that coffee brew preparation methods influence directly the levels of the diterpenes. This paper describes a compilation of the main results published for different coffee brews and all variables related to their preparation. Major differences in the reported concentrations have been noted.