en عمومى General پژوهشي Research <strong>Background:</strong> Aflatoxins (AF&rsquo;s) are secondary metabolites produced by certain species of fungi on grains and animal feeds. Because of serious impact of AF&rsquo;s on health, they should be monitored closely in potentially hazardous foods and feeds.<br> <strong>Method:</strong> In this study, AF&rsquo;s in imported animal feeds including cereals, corn gluten and meals (pastes derived from the cotton, colza and sunflower seeds) from several Iranian ports were investigated. To determine AF&rsquo;s contamination in feeds, the HPLC method coupled with immunoaffinity column clean up and post column derivatization were used.<br> <strong>Results:</strong> The results showed that 44.2% of samples were positive for AF&rsquo;s at levels of 0.5 to 103.8&mu;g/Kg. Nine of the positive samples (3.7%) showed total AF&rsquo;s concentrations (B₁, B₂, G₁ and G₂) higher than the limit established by the regulated Iranian standards.<br> <strong>Conclusions:</strong> The results of the present investigation showed that the level of aflatoxin contamination in these feeds samples was variable. Among the samples, corn was more susceptible to various AF species than other tested substrates. Aflatoxins, Aflatoxin B1, Animal Feeds, Immunoaffinity HPLC 33 38 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-514-1&slc_lang=en&sid=1 Mansooreh Mazaheri 100319475328460011342 100319475328460011342 No PhD of Biophysics, Standard Research Institute (SRI), Karaj, Iran. Masoumeh Mahmoudi Maymand mah_maymand@standard.ac.ir 100319475328460011343 100319475328460011343 Yes MSc of Toxicology, Standard Research Institute (SRI), Karaj, Iran.