Comparison of two methods for analysis of aflatoxin M1 in milk

The cellulose chromatography method of the Association of Official Analytical Chemists for determination of Aflatoxin M1 was compared with a two-dimensional thin layer chromatography procedure. The minimum detectable Aflatoxin M1 by the Official procedure was approximately .01 mug/kg while the thin layer chromatography procedure has a claimed sensitivity of .004 mug/kg. Analyses of milk samples by thin layer chromatography agreed with results of the Official procedure in the range of .01 to .25 mug/liter. Each method consistently yielded recoveries greater than 87% and there was no significant difference between means or variances of each method. The thin layer chromatography method took less time than the Official method and showed a reproducible lower threshold sensitivity of .005 mug/liter.