Abstract

Preliminary screening of aflatoxin B₁ levels in maize (Zea mays L.) sold in some markets of Benue State, Nigeria, was carried out using thin layer chromatography (TLC). Concentrated chloroform extracts of 10, 15 and 40 μl were used in diethylether - methanol - water solvent system in the ratio of 96:3:1. Moisture contents of the stored and oven-dried fresh maize collected from the markets were in the range of 7.64 to 13.40% which are below the maximum recommended level (13.50%) for stored maize. The result of TLC revealed that aflatoxin B₁ was not detected, as no spot was observed in these samples. This suggests that aflatoxin B₁ contents of both the oven-dried fresh and stored maize are either negligible or below the detection limit of 3.125 μg/kg for the TLC method employed. Hence, aflatoxin B₁ levels in the samples, if present, fall below the permissible limit (4 to 5 μg/kg) by National Agency for Food and Drug Administration and Control (NAFDAC) - Nigeria. Further review of this work will be carried out by the authors using a more sensitive technique like high performance liquid chromatography (HPLC) to detect the exact status of aflatoxins in maize from these markets as they are representative of maize belt in Benue State so as to compare them with other world standards. 

Key words: Maize, aflatoxin B₁, Aspergillus flavus, thin layer chromatography (TLC), moisture content.