Occurrence of trichothecene mycotoxins in Brazilian corn-based food products

The trichothecenes deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), and toxins T2 (T2) and HT2 (HT2) were searched for in 78 samples of corn-based products sold in the city of Sao Paulo/Brazil. Acetonitrile:water was used for extraction and the clean-up was accomplished with Mycosep columns. Trifluoroacylation was employed before quantification and confirmation by gas chromatograph with a selective mass detector (ion trap) in electron ionization mode. The detection limits varied with the several toxin/matrix combinations and ranged from 20 to 120 ng/g. The recoveries ranged from 71 to 155%. Only two samples were found contaminated: a sample of corn grits with 555 ng/g of T2 and 767 ng/g of HT2 and a sample of corn flour that exhibited traces of DON and NIV. DAS was not detected in any sample. The results indicate a low occurrence of trichothecene mycotoxins in corn-based products commercialized in the city of Sao Paulo in spite of high levels of T2 and HT2 found in one sample and show no immediate cause of concern. Nonetheless more extensive surveys conducted for several years are advisable in order to furnish a more complete picture of the incidence of these toxins in Brazilian corn products.