A fluorometric rapid screen method for aflatoxin in peanuts

Abstract Peanuts were screened for aflatoxin using a rapid, inexpensive fluorometric method. Peanuts were ground and extracted with methanol, and the extract was treated with acidified zinc‐acetate‐sodium chloride solution, filtered, and diluted with water. Fluorescence of the extracts was compared with that from aflatoxin‐free control peanuts. Test samples (160) of several varieties and grades of sources and were screened for the presence of aflatoxin. One hundred thirty‐five samples (84%) were identified by this method as aflatoxin positive (15 ppb+) or aflatoxin negative (<15 ppb). Although 22 samples (13.6%) were incorrectly labeled as aflatoxin positive, most of these showed evidence of the presence of mold metabolites other than aflatoxin. Three samples (1.8%) were incorrectly labeled as aflatoxin negative when they actually contained 20, 33, and 34 ppb aflatoxin.