Collaborative Study of Three Screening Methods for Aflatoxin in Corn

The 3 rapid screening methods studied all involved chromatography of partially purified extracts on minicolumns. In one method acetonitrile-water is used to extract aflatoxin from corn and a lead acetate precipitation removes impurities from the extracts. The second method specifies acetone-water as the extracting solvent and ammonium sulfate as the precipitant. The third method is based on acetone-water as the extracting solvent and ferric gel as the precipitant. The most sensitive method was the ferric gel precipitation, which could detect 5 ppb aflatoxin, but it was very time-consuming. The most satisfactory method (timewise) used the ammonium sulfate and had a sensitivity of 10 ppb. This method also led to the best differentiation between levels of aflatoxin. These 2 methods have been adopted as official first action.