DETERMINATION OF AFLATOXIN IN COMMERCIALLY AVAILABLE WHEAT SAMPLES FROM MARKETS OF GONDAR TOWN USING LC-MS/MS

: Wheat is one of the major cereal crops of the world ranking second after rice both in area coverage and production among cereal grains. It is also an important cereal crop in Ethiopia in terms of cultivated area, production and consumption, which is the fourth most widely grown crop after teff, maize, and sorghum. It has great importance in the human diet, contributing as a direct source of energy, protein, vitamins, minerals and fiber. However, this cereal crop is vulnerable to degradation by aflatoxins mainly by Aspergillus flavus, Aspergillus Parasiticus and Aspergillus nomius, which have adverse health effects on humans and livestock that ingest aflatoxin contaminated food products and feeds. The contamination of aflatoxins can occur through its growth, harvest, transport and storage. Aflatoxins are carcinogenic substances and are extremely toxic to humans when consuming aflatoxin contaminated foods. Therefore, this study has been undertaken to determine aflatoxin (B1, B2, G1 and G2) in wheat samples collected from two market places (namely, Arada and Azezo) of Gondar town, by using LC-MS/MS. The extraction solvents were acetonitrile and water (84:16 v/v %). Good linearity from the calibration curve was obtained in standard solution of aflatoxins in range between 0.1 and 15 ng/mL, with regression coefficient (R 2 ) values of > 0.999. Limit of detection of the aflatoxins were 0.1208, 0.0302, 0.0328 and 0.1272 µg/kg for aflatoxin B1, B2, G1 and G2, respectively. The average percentage recoveries of spiked samples were range between 70.80 and 77.23 %. Aflatoxins were not detected in both wheat samples from Arada and Azezo. 15 pre-harvest 15 post-harvest