Determination of aflatoxin B1 in highly contaminated peanut samples using HPLC and ELISA

Abstract

The precision, accuracy, detection limit and peanut matrix influence of an ELISA were analysed in the determination of aflatoxin B1. The assay was performed on two different reference samples: peanut extract and peanut paste, that were spiked with known amounts of aflatoxins. The lower detectable level was 0.5 μg kg-1. The average intra-assay precision expressed as coefficient of variation (CV) was 11.7% for concentrations between 2.54 and 901 μg kg-1 and the average inter-assay precision was 29.7% for the same range of concentrations. The average accuracy measured by a recovery assay in samples that contained only aflatoxin B1 was 107%. The correlation between the ELISA and high-performance liquid chromatography (HPLC) applied to 28 peanut samples artificially contaminated with Aspergillus flavus and A. parasiticus spores showed a high correlation (r = 0.977, P < 0.0001). The detection limits and matrix influence associated with our ELISA procedure were more sensitive than those reported for other ELISA procedures due to specific antiserum treatment.