Rapid Quantitative TLC Method for Determining Aflatoxins in Cottonseed Products

Abstract

Abstract The official AOAC method for aflatoxins in cottonseed products was modified to provide a rapid quantitative method whereby an analysis can be completed in as little as 1 hr. The method incorporates a choice of either 5 min blender or 30 min shaker extraction and either half-plate (20 min) or full-plate (50 min) TLC development to provide a flexible method to meet different analytical requirements. The rapid method was compared with the official AOAC method and the ferric gel method of Velasco for determining aflatoxins in 10 samples of cottonseed kernels and 14 samples of meals. With kernels, all 3 methods were essentially equivalent up to a contamination level of 3800 μg/kg. For quantities above this level, results by the official method were 77% of those obtained by the other 2 methods. With meals, both the rapid and official methods were equivalent for aflatoxin B1, but interferences were encountered at the Rf value of B2 on TLC plates in 3 of the 14 samples analyzed by the rapid method. With the ferric gel method, interferences at the Rf values of aflatoxin B1 or B2 were encountered in 9 of the 14 samples, and the B1 estimates by this method averaged 87% of that found for the rapid or official methods.