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Tracing methods of non-European EVOOs commercialized worldwide are becoming crucial for effective authenticity controls. Limited analytical studies of these oils are available on a global scale, similar to those of European EVOOs. We report for the first time the fatty acid concentrations, bulk-oil 2H/1H, 13C/12C, and 18O/16O ratios and fatty acid 13C/12C ratios of 43 authentic monovarietal EVOOs from different geographical regions in Argentina and Uruguay. The samples were obtained from a wide range of latitudes and altitudes along an E-W profile, from lowlands near the Atlantic Ocean to the pre-Andean highlands near the Pacific Ocean. Principal component scores were used to cluster EVOOs into three groups- central-western Argentina, central Argentina, and Uruguay-based on nine stable isotope ratios and the oleic-linoleic acid concentration ratio. The bulk 2H/1H and 18O/16O values and 13C/12C of palmitoleic and linoleic acids provide good tools for differentiating these oils via linear discriminant analysis.

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The aim of this work was to validate the gas chromatography/combustion/isotope ratio mass spectrometry method in Havana Antidoping Laboratory and verify its implementation with a study of the Cuban population. The method was precise and accurate inside the linear working range; the limit of quantification and the uncertainty were compliant with TD2019IRMS. The study of the Cuban population showed no differences in δ13 C values between females and males. Only three values of Δδ13 C showed significant differences between sexes (PD-T, OHA-T, and 11-keto-Et-T). The values of δ13 C between -17.8‰ and -21.2‰ (upper and lower limits based on normal distribution) were consistent with other populations where C4 plant derivatives prevail in the diet.

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The present work evaluates the efficiency of some low-cost sampler container for a reliable carbon stable isotope analysis of methane. The procedure efficiency was evaluated for five containers, through 91 days, under two storage temperatures (4 °C and 25 °C) and the results are compared against a reference sampler by using univariate and multivariate statistical methods. Based on the univariate (ANOVA and comparison statistical methods) and multivariate (PCA and HCA) statistical methods, it was identified that (i) the isotopic value changes with time and, in this way, must be taken in account when choosing the appropriate sampler and (ii) the lower temperature reduces the isotopic fractionation process and is preferable for the gas sample storage. Among the storage systems, two options were found to be statistically equivalent to the reference container (IsoJar) for a time horizon of 91 days. We found that the exetainer (4 °C and 25 °C) storage systems are statistically equivalent to the reference container IsoJar and, in this way, it could be an alternative for the methane isotopic studies.

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Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up steps due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well-established instrumental configuration based on two independent GC ovens and one heart-cutting device was optimized. The first dimension (1D) separation was obtained by a non-polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid-polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set-up was applied for measuring testosterone, 5α- and 5ß-androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation steps comprising solid-phase extraction, hydrolysis, and liquid-liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography steps, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd.

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Neste trabalho, objetivou-se analisar isotopicamente méis comercializados nas regiões Sul e Sudeste do Brasil, para a detecção de fraude. Foram colhidas amostras comerciais com registro no Serviço de Inspeção Federal, Estadual ou Municipal. As amostras foram submetidas à combustão no Analisador Elementar EA 1108 CHN e analisadas no espectrômetro de massas de razão isotópica DELTA-S (Finningan Mat). Os valores isotópicos (δ13C) dos méis in natura foram comparados aos de suas respectivas proteínas (padrão interno). Foram consideradas adulteradas as amostras cuja diferença entre o valor isotópico da proteína e do mel foi igual ou inferior a -1‰. As amostras consideradas adulteradas pela análise isotópica foram submetidas a testes químicos qualitativos que não foram capazes de indicar adulteração para algumas delas. Das 61 amostras analisadas, 18,0 por cento encontram-se adulteradas, sendo 11,5 por cento na Região Sudeste e 6,5 por cento na Região Sul. Ao contrário dos testes químicos, a análise isotópica mostrou-se eficaz em identificar e quantificar a adulteração de méis comerciais.

The aim of this study was the isotopic evaluation of honey traded in the Southern and Southeastern Brazilian regions, to detect fraud. Commercial samples, registered in the municipal, State or Federal Inspection Service, were collected and submitted to combustion in the EA 1108 CHN Elemental Analyzer and analyzed in the DELTA-S (Finningan Mat.) isotope ratio mass spectrometer. The isotopic values (δ13C) of in natura honey were compared to their respective proteins (internal standard). Samples whose difference between the isotopic value of protein and honey was equal or inferior to -1‰ were considered adulterated. The samples considered adulterated were submitted to qualitative chemical tests which were unable to show adulteration for some of them. Among the 61 samples analyzed, 18.0 percent were adulterated; 11.5 percent in the Southeastern and 6.5 percent in the Southern region. Unlike chemical tests, isotopic analysis has shown to be efficient to identify and quantify adulteration in commercial honey.

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Oobjetivo deste trabalho foi determinar a quantidade de malte e de adjunto presentes nas cervejas comerciais brasileiras do tipo Pilsen e detectar possível adulteração em sua composição, tomando por base a legislação brasileira. Para isso, foi utilizada a metodologia de análise isotópica utilizando os isótopos estáveis dos elementos carbono e nitrogênio. Foram analisadas 161 amostras de cervejas provenientes de dezessete estados do Brasil. Concluiu-se que 95,6 por cento utilizaram malte e adjunto cervejeiro (derivados de milho ou açúcar de cana: 91,3 por cento e derivados de arroz: 4,3 por cento) em sua formulação e outros 4,3 por cento eram cervejas "puro malte". Das amostras analisadas, 3,7 por cento eram cervejas com menos de 50 por cento de malte em sua formulação (adulteradas), 28,6 por cento delas estavam na faixa de incerteza, para qualquer tipo de adjunto e 67,7 por cento apresentaram malte dentro do limite legal estabelecido.

The aim of this study was to determine the amount of malt and adjunct in Pilsen Brazilian commercial beer, and to detect likely adulteration in its composition, based on the Brazilian legislation. The methodology applied was the isotopic analysis which used carbon and nitrogen stable isotopes. One hundred sixty-one beer samples from seventeen Brazilian states were analyzed. It was concluded that 95.6 percent used malt and adjunct (corn or sugarcane derived: 91.3 percent and rice derived: 4.3 percent) in their formula and 4.3 percent were "pure malt" beer. Among the analyzed samples 3.7 percent were beers with less than 50 percent of malt in their formula (adulterated), 28.6 percent of them were in doubtful level for any adjunct and 67.7 percent contained malt in the legal established limit.