Pesticides analysis in beans by gas chromatography couplet with tandem mass spectrometry

Abstract

Beans are part of the basic diet alimentation for Brazilian population, as they gather proteins, carbohydrates, vitamins, mineral salts, fibers, amino acids and essential nutrients such as iron and calcium, being a complete food that can be compared with the amount of protein that the meat has. Considering the beans world production, in development countries represent almost 50%, being that Myanmar, India and Brazil the top three position. The use of pesticides is widely spread in these countries to reduce agricultural losses due to pests that interfere with grain production. Therefore the risk that could be generated from foods pesticides residues makes their analyses of quantification mandatory. The purpose of this work was to develop an analytical method to quantitatively characterize fungicides pesticides residues, flutriafol, procymidone and tebuconazole that were used to angular spot control, anthracnose, rust and alternaria spot, white mold fungi, present in beans, by means of gas chromatography coupled with a triple quadrupole mass spectrometer. Samples of beans, Phaseolus vulgaris L, types white, black, string and Vigna angularis, type adzuki, had been bought in grains store and supermarkets at metropolitan São Paulo city. The validation of analytical method was explored for sensitivity, selectivity, precision. The extraction procedure was performed in two different forms, QuEChERS, and solid-liquid extraction with low temperature. Through this methodology, reached below the maximum limit allowed by Brazilian law 0.5mgkg-1 for procymidone and 0.1mgkg-1 for flutriafol and tebuconazole. Several samples of four types of beans were tested and all of them had procymidone identified and 7% of samples higher than the law limit.