Validation study of immunoaffinity column chromatography coupled with solution fluorometry or HPLC for the detection of aflatoxin in peanuts and corn.

Neogen Corp. has developed the Neocolumn for Aflatoxin DR for the detection of total aflatoxin by HPLC or solution fluorometry. The purpose of this study was to validate the method under the requirements of the AOAC Research Institute Performance Tested Methods (PTM) program. There are several AOAC Official Methods for detection of total aflatoxin in corn; they consist of rapid and analytical-based methods and two rapid methods (PTMs 030701 and 050901) that have been performance tested by the AOAC Research Institute. A widely used reference method, however, is AOAC Official Method 991.31, which uses immumoaffinity cleanup followed by HPLC or solution fluorometry and is referred to as the reference method in this document. In internal studies, the Neocolumn method coupled with solution fluorometry demonstrated a relative recovery from peanuts of 101.6% of the reference value, with a CV of 3.9% across all levels analyzed; when coupled with HPLC, the Neocolumn method demonstrated a relative recovery from peanuts of 103.0% of the reference value with a CV of 3.5% across all levels analyzed. The Neocolumn method coupled with solution fluorometry demonstrated a relative recovery from corn of 116.9% of the reference value with a CV of 6.1% across all levels analyzed; when coupled with HPLC, the Neocolumn method demonstrated a relative recovery from corn of 91.2% of the reference value, with a CV of 5.4% across all levels analyzed. Calculations were made by comparison with the mean result obtained by the HPLC reference method, which showed respective CV values of 3.9 and 2.0% for recoveries from peanuts and corn, respectively.