Development of a sensitive high-performance liquid chromatographic method for detection of aflatoxins in pistachio nuts.

A very sensitive method is described for the detection of aflatoxins in pistachio nuts. The method employs the extraction procedure used in the BF method (described in the Association of Official Analytical Chemists' Book of Methods) followed by an acid alumina column clean-up to remove sample components which would otherwise interfere in the final determinative step. The quantitation of the aflatoxins is carried out by high-performance liquid chromatography on a C18 reversed-phase column after conversion of aflatoxins B1 and G1 to their more fluorescent derivatives, B2a and G2a. The limit of detection was found to be 0.5 microgram/kg. The chromatograms were found to be free of interfering peaks and multiple injections showed excellent reproducibility.