| Abstract: | Procedures from 2 methods, one for aflatoxins B1 and M1 in eggs and one for aflatoxicol in milk, blood, and liver, have been combined to determine the 3 toxins in eggs. The sample is blended with sodium chloride-saturated water and this mixture is then blended with acetone. After separation from the solid residue, the aqueous acetone extract is defatted with petroleum ether. The toxins are next partitioned into chloroform and separated from interferences on a silica gel column. Aflatoxicol is determined by fluorescence measurement after separation on a C18 reverse phase liquid chromatographic column, and aflatoxins B1 and M1 are determined by fluorescence densitometry after separation on a silica gel thin layer chromatographic plate. In a recovery study with eggs, mean recoveries of aflatoxicol added at levels of 0.1, 0.05, and 0.025 ng/g were 87, 77, and 78%, respectively. Mean recoveries of aflatoxins B1 and M1 added at a level of 0.1 ng/g were 75 and 87%, respectively, and at an added level of 0.05 ng/g were 86 and 75%. The within-laboratory precision (repeatability) ranged from 2 to 13%. |
