This paper describes the monitoring of ethyl carbamate concentration in sugar cane spirit from industrial distilleries in Brazil. In total, 18 distilleries from Minas Gerais and São Paulo states were evaluated, with, a total of 336 samples from August 2017 to August 2019. The ethyl carbamate was analyzed using a previously validated mass spectrometric method. Analytical curves presented coefficient of determination (R2) values higher than 0.99, and quality control samples showed a relative standard deviation (RSD) below 9%. Concentrations of ethyl carbamate ranged from not detected to 1608 µg L-1, with mean values of 294.2, 280.7 and 230.0 µg L-1 in 2017, 2018, and 2019, respectively. On average, 46, 44 and 69% of samples presented levels of ethyl carbamate below 210 µg L-1. A variety of factors may have led to distillery A having a low level (ca. 115 µg L-1) of ethyl carbamate, including controlled temperature, yeast strain, post-harvesting quality, sugar cane variety choice, and the treatment process on the sugar cane juice, which goes towards the addition of Ca(OH)2, heating and freezing. These results showed the importance of internal quality control, and that sugar cane juice treatment may be a way to decrease ethyl carbamate in the distilleries.

Vegetable oil analyses, especially due to the complexity of the oil components, are commonly laborious, requiring several analytical techniques. In this work, electrospray ionization mass spectrometry with direct injection (DIMS), along with 18-crown-6 ether (crown ether) chelating agent and trifluoroacetic acid (TFA), was used to characterize and semi-quantitatively evaluate commercial vegetable oils. As a result, an unprecedented DIMS method of triacylglycerols (TAGs) analysis for semi-quantitative profiling of fatty acids in commercial oils (e.g., soybean, sunflower, corn, oil, canola), without sample derivatization, was developed. The results of the ion abundances related to the analyzed TAGs, with quantitative percentage analyzed by gas chromatography with flame ionization detector (GC-FID), allowed generating correction factors for each oil. DIMS analysis with crown ether/TFA resulted in the elimination of isobaric interferences from sodium and potassium adducts, facilitating the ion assignments, due to the one-ion-per-molecule observation in the mass spectrum. Chemometric analyses by principal component analysis (PCA) and heatmap, to evaluate the ionic profile of the oils, grouped them accordingly to their TAG content. Olive oil was identified as the most different from the other oils. Overall, a semi-quantitative approach to investigate the vegetable oils, reaching low percentage variation for DIMS, with 2 min analyses and 30 min sample preparation, was proposed.

Foi desenvolvido um método de extração limpo, assistido por microondas, para a determinação de herbicidas triazínicos em amostras de solos. A estratégia de extração foi baseada em ambiente micelar associado às microondas, seguido da determinação dos herbicidas por CLAE, de tal forma que o procedimento pudesse ser considerado limpo. Foram utilizadas duas porções (10 e 8 mL) da solução extratora de SDS (dodecil sulfato de sódio) 0,06% (m/v) associada a 0,500 g da amostra e da seguinte programação do forno de microondas: 540 W (6 min), 0 W (1 min), 630 W (2 min). As curvas analíticas apresentaram-se lineares na faixa de 0.05 até 10.0 mg L-1 para atrazina, ametrina e simazina. Os limites de detecção e quantificação foram estimados como 0,90, 0,57 e 0,235 µg g-1 e 3,1, 1,9 e 0,8 µg g-1 para atrazina, ametrina e simazina, respectivamente. O método proposto é preciso (RSD < 8%, n = 3) e os resultados obtidos concordam com aqueles do método clássico. Testes de recuperação dos herbicidas para amostras de solo forneceram valores entre 82,0 e 94,0%.

It was developed a green microwave-assisted extraction method for determination of triazine herbicides in soil samples. The extraction strategy was based on micellar medium associated to microwaves followed by the herbicides determination by HPLC in such way that the procedure could be considered as green. Two portions (10 and 8 mL) of aqueous SDS (sodium dodecyl sulphate) 0.06% (m/v) were used as extracting solutions associated to 0.500 g of sample and the following microwave oven program: 540 W (6 min), 0 W (1 min), 630 W (2 min). The analytical curves were linear in the analytical range of 0.05 up to 10.0 mg L-1 for atrazine, ametryne and simazine. The limits of detection and quantification were estimated as 0.90, 0.57 and 0.235 µg g-1 and 3.1, 1.9 and 0.8 µg g-1 for atrazine, ametryne and simazine, respectively. The proposed method is precise (RSD < 8%, n = 3) and the obtained results are in agreement with the classical one. Recovery tests for soil samples indicated that the percentage of recuperation were between 82.0 e 94.0%.