Evaluatiòn of the homogeneity of the sample and intra-laboratory study of the intermediate precision in the determination of aflatoxins in peanuts for export

Abstract

In the present work, the pyramidal factorial experimental design has been applied to evaluate the homogeneity in the aflatoxin content in export peanut samples, using high-performance liquid chromatography with fluorescence detector (HPLC-FLD) as an analytical measurement technique. This design allowed to evaluate the precision of the test method and it was compared with reference values ​​of the Codex Alimentarius. First, the batch sample was divided into 3 subsamples, which were treated independently, taking into account the measuring instrument, the analyst, and different test portions. When applying the variance analysis of 4 factors, it was shown that the content of aflatoxins in the batch of peanuts under study is heterogeneously distributed. A 3F ANOVA design was applied to each subsample and the precision of the method was evaluated by calculating the relative standard deviations of repeatability (RSDr) and intra-laboratory reproducibility (RSDLab), finding that, despite some differences in the analysis of variance, the RSD values ​​are less than those established in the Codex. This means that the test method used complies with the accuracy parameters established in international standards.

UNIVERSITAS (León): Scientific Journal of UNAN León Vol.5(1) 2014, pp 11-25