Desenvolvimento de metodologia para a determinação de aflatoxinas em amostras de amendoim usando espectrofluorimetria e análise dos fatores paralelos (PARAFAC)

Abstract

This research describes two case studies that are based on the determination of aflatoxins B1, B2, G1 and G2 in peanut samples, using the technique of molecular fluorescence spectroscopy. The first study aims to evaluate the methodology used for the quantification of total aflatoxins in peanuts, using the classical validation method by employing univariate calibration. The main performance parameters were evaluated to assure the ability to ensure implementation of this methodology in laboratories. The second study focuses on the separation and quantification of these aflatoxins with the combined application spectrofluorimetry and a chemometric method of second order (PARAFAC) using the multivariate calibration. This technique can be used as a viable alternative for the determination of aflatoxins B1, B2, G1 and G2 alone, which traditionally is done by high performance liquid chromatography with fluorescence detection. However, as these analytes exhibit a wide range of spectral overlap and the aflatoxins (B1 and G1) have intensity of fluorescence signal well below the others, the separation and quantification of the four aflatoxins was not feasible. The study was resumed with the use of aflatoxins B2 and G2 and the results were satisfactory. The method used for quantification of total aflatoxins showed good results, showing itself as an important tool for the determination of these analytes. Furthermore, it contemplates exactly what is required by Brazilian legislation for the analysis of aflatoxins B1, B2, G1 and G2, which as a requirement in the final analysis reports is the statement of the sum, in µg/kg, these aflatoxins, ie without the need to quantify them separately