Liquid chromatographic determination of aflatoxins in artificially contaminated cocoa beans

A high pressure liquid chromatographic method is described for the extraction and determination of aflatoxins in artificially contaminated cocoa beans. Aflatoxins were extracted by using a CB extraction, column cleanup, and chromatography on a reverse phase column with UV detection at 365 nm for aflatoxins B1 and G1 and fluorescence detection for aflatoxins B2 and G2 (365 nm excitation and 455 nm emission). Recoveries from artificially contaminated cocoa beans of various roast conditions ranged from 77.50 to 107.35%. CV values ranged from 4.87 for G1 to 7.66 for G2 (n = 8). The method can be used for cocoa beans ranging from no roast to a heavy roast (12 min at 400 degrees F).