Thin layer chromatographic determination of aflatoxin B1 in eggs

A method for determining aflatoxin in dairy products was modified for eggs, initially by additional cleanup steps. The modified method proved practical for use in survey analyses and was sufficiently sensitive to detect aflatoxin B1 at levels less than 1 ng/g in eggs from hens on experimentally contaminated feed and in spiked eggs; interfering compounds in eggs received from many different producing areas were eliminated. Although recovery was greater than 75% when the aflatoxin was extracted immediately after spiking, recovery was usually less than 30% when the aflatoxin was extracted after more than 24 hr. Adding sodium chloride, sodium sulfate, or urea to the extracting solvent remedied this defect, which is thought to be related to the binding of aflatoxin to egg protein.