RESUMO Os ditiocarbamatos são os fungicidas mais utilizados e mais detectados em alimentos no Brasil. Este estudo teve como objetivos analisar os níveis de resíduos de ditiocarbamatos em hortaliças produzidas na região de Vargem Bonita, Distrito Federal, e comparar os níveis encontrados com os limites máximos de resíduos (LMR) estabelecidos para esses alimentos. Foram coletadas 84 amostras de diferentes tipos de hortaliças diretamente de 23 produtores no período de junho a novembro de 2018. As análises foram realizadas utilizando o método espectrofotométrico, que determina o nível de CS2 produzido pela degradação em meio ácido do ditiocarbamato presente na amostra. No total, 21 amostras (25%) continham resíduos de ditiocarbamatos acima do Limite de Quantificação do método (LOQ, 0,05 mg/kg CS2). Cinco das 27 amostras de alface analisadas (18,5%) continham resíduos, com níveis de 0,06 a 0,50 mg/kg de CS2, abaixo do LMR para essa cultura. Resíduos também foram encontrados em amostras de salsa, coentro e chicória, em níveis de 0,09 ou 0,10 mg/kg CS2, culturas para as quais não existe registro de uso de ditiocarbamatos no Brasil. Amostras de rúcula, cebolinha, alho poró e agrião, que também não possuem registro para ditiocarbamatos, deram resultado positivo, porém essas culturas são conhecidas por fornecerem resultados falso positivos para CS2, e a ilegalidade dos resíduos não pode ser confirmada. Esse estudo mostrou o uso adequado de ditiocarbamatos em hortaliças por agricultores da Vargem Bonita, com exceção de salsa, coentro e chicória, culturas com número limitado de pesticidas registrados, o que, provavelmente, tenha sido a razão do uso ilegal dos ditiocarbamatos.

ABSTRACT Dithiocarbamates are the most used fungicide and one of the most detected in food in Brazil. This study aims to analyze the levels of dithiocarbamate residues in vegetables produced in the region of Vargem Bonita, Federal District, and to compare the levels found with the maximum residue limits (MRLs) established by the Brazilian legislation. Eighty-four vegetable samples were obtained directly from 23 Vargem Bonita producers from June to November 2018. The analyzes were carried out using a spectrophotometric method, which determines the level of CS2 produced by degrading the dithiocarbamate present in the sample. In total, 21 samples (25%) contained dithiocarbamate residues above the method’s limit of quantification (LOQ, 0.05 mg/kg CS2). Five of the 27 lettuce samples analyzed (18.5%) contained dithiocarbamates, at levels ranging from 0.06 to 0.50 mg/kg CS2, below the MRL for this crop. Residues were also found in parsley, coriander and chicory samples (0.09 or 0.10 mg/kg CS2), cultures for which there is no registered the use of dithiocarbamate in Brazil. Samples of arugula, chive, leek, and watercress, which also do not have registered use, tested positive; however, these crops are known to provide false positive results for CS2, and the illegality of the residues cannot be confirmed. This study shows proper dithiocarbamate use in vegetables by Vargem Bonita farmers, except for parsley, coriander, and chicory, crops with a limited number of registered pesticides, which was probably the reason for the illegal dithiocarbamate use.

Dithiocarbamates are widely used fungicides, including in passion fruit, whose fruits are mainly used for juice production, the leaves for the preparation of herbal tea and medicines. Also, the use of the peel in the food industry has been proposed. In this study, the spectrophotometric method for determination of dithiocarbamate residues, as CS2, in passion fruit (Passiflora edulis) was validated at a limit of quantification (LOQ) of 0.05 mg kg-1 CS2, and 108 samples (55 fruits and 53 leaves) collected from Brazilian growers were analyzed. About 25% of the fruit peel samples were positive (0.06 to 1.4 mg kg-1) and only one sample had residues in the pulp (0.09 mg kg-1), 43.4% of leaf samples contained residues. Washing of fruit reduced the residues in the peel by up to 100%, and drying the leaves increased residue levels by up to 60%. This is the first study that reports dithiocarbamate residues in passion fruit in Brazil, and the results are important for government authorities when planning monitoring programs, and for food and herbal medicine industries.

Medicines containing anabolic steroids are one of the main targets for counterfeiting worldwide, including Brazil. The aim of this work was to propose a method for discriminating original and counterfeit Durateston® ampoules by Fourier transform infrared spectroscopy (FTIR) followed by chemometric analysis. Ninety-six ampoules of Durateston®, 49 originals and 47 counterfeits, were analyzed by gas chromatography with mass spectrometry (GC-MS) and by FTIR. Principal component analysis was applied to the infrared spectra to detected different clusters, corresponding to original samples and different types of counterfeits. A partial least squares - discriminant analysis method was proposed to discriminate original samples from those counterfeits that were indistinguishable from the originals in the infrared analysis. A training subset comprised of one-third of the available spectra was used to establish a suitable model that correctly discriminated all samples in the test subset, resulting in 0% of false positive or negative results and 100% of efficiency rate, sensitivity and specificity. In addition to the low cost of the infrared technique, the proposed method is fast, reliable and suitable to replace GC-MS methods used in Durateston® ampoule analyses to detect counterfeiting.