Quantification of aflatoxins in corn distributed in the city of Monterrey, Mexico

Abstract

In this study kerneled corn sold and distributed through wholesale outlets in the city of Monterrey, Mexico was analysed. The extraction of aflatoxins was performed with a mixture of methanol/water (80:20) and its derivatization was carried out with trifluoroacetic acid. The analysis was done by high performance liquid chromatography (HPLC) using fluorescence for detection. From the 41 samples analysed, aflatoxins B₁ and G₁, were found to be present. Aflatoxin B₁ concentrations ranged from 5.03 ng/g to 465.31 ng/g, aflatoxin G₁ concentrations ranged from 1.59 ng/g to 57.1 ng/g. It was found that 87.8% of the samples were contaminated with aflatoxins: in addition, 58.5% contained levels above Mexican legal limits which are, at present, 20 ng/g.

Keywords:

• aflatoxins
• stored corn
• chromatography