Determination of Aflatoxin B₁ in Highly Contaminated Peanut Samples Using HPLC and ELISA

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 g kg^-1. The average intra-assay precision expressed as coefficient of variation (CV) was 11.7% for concentrations between 2.54 and 901 g 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.