Adequação e apresentação de parâmetros de validação intralaboratorial de um ensaio para a quantificação de Aflatoxinas em Castanha-do-brasil (Bertholletia excelsa Bonpl.) através de Cromatografia Líquida de Alta Eficiência

Abstract

The aflatoxins are secondary metabólitos produced by fungi of the Aspergillus sort, over all for Aspergillus flavus and Aspergillus parasiticus and in lesser amount for Aspergillus nomius. They are known, currently, 17 similar composites assigned by the term aflatoxins, however, the main types of interest doctor-bathroom are identified as AFB1, AFB2, AFG1 and AFG2. Had to the potential risk to the health human being, the aflatoxin levels are monitored in many countries. More than 50 countries already had established maximum levels of contamination in foods and animal rations. However, for the efficient control and monitoramento of susceptíveis foods to the contamination they are necessary analytical techniques with sensitivity, specificity, rapidity, easiness of use, exactness and precision. In the present work an analytical assay consisting by an extration based on the method praised for RODRIGUEZ AMAYA & VALENTE SOARES (1989) was developed, followed of quantification for CLAE, for the determination of aflatoxins AFB1, AFB2, AFG1 and AFG2, in samples of chestnut-do-Brazil artificially contaminated. The samples had been with 5,3 mg/ kg of AFG1, 6,9mg/ kg of AFB1, 4,8mg/ kg of AFG2 e 5,0mg/ kg of AFB2.The following found parameters of validation for the developed method had been determined: Selectivity, Recovery, Linearity of the Curve of Calibration, Limit of detention, Limit of Quantification, Effect of Matrix, Robustness and Precision, through the Shunting line Relative Standard (RSDr). The comparison of methods of extration and quantification of aflatoxins AFB1, AFB2, AFG1 and AFG2 using Thin Layer Chromatography (TLC) and and High performance Liquid Chromatography (HPLC). Analysis of variance of Tukey was made 5% significance between the 4 tested methods and calculated the recovery of the same ones. The values of recovery had been of 101,89; 100,25; 86,63 and 93.42%, respectively for AFG1, AFB1, AFG2 and AFB2. The methodology consisting of extration for the method modified based in the method praised for RODRIGUEZ AMAYA & VALENTE SOARES (1989), followed of quantification for CLAE, was that one that it showed better resulted of recovery, showing statistical better that the too much tested methodologies. The calibration curve presented correlation coefficients varying between 0,9936 and 0,9997, confirming its linearity, the Limit of Detention defined was of 0,263; 0,345; 0,241 and 0,254mg/×kg-1, respectively.