Natural deoxynivalenol (DON) contamination of wheat samples grown in 1998 as determined by high-performance liquid chromatography.

A high-performance liquid chromatography--diode array detection (HPLC-DAD) method was developed for determining the deoxynivalenol (DON) content of wheat and other cereals. The samples were extracted with a mixture of acetonitrile and water (84 + 16). Part of the extract was evaporated and purified on Florisil and activated charcoal columns. HPLC separation was performed on a C18 column, using acetonitrile-water (8 + 92) as eluent. Diode array detection (DAD) was performed at 218 and 236 nm, by determination of the UV spectrum. Quantitative analysis was carried out by the external standard method, using the UV spectrum obtained by DAD for confirmation. The recovery rate of DON was 75 +/- 3.1% and the detection limit was 0.05 mg/kg DON. Using this method, the DON content of 99 feeding wheat samples grown in the northeastern part of Hungary in 1998 was determined. Eighty-eight percent of the samples originating from three counties contained 0.94 mg/kg DON on the average. The highest individual value was 4.3 mg/kg. DON contamination of wheat was of higher prevalence (100%) and severity (0.27-4.3 mg/kg) in the southeastern county of Békés than in Szabolcs county located in the northeastern part of Hungary (ratio of positive samples: 82%; DON concentration: 0.05-1.3 mg/kg). The higher than usual DON contamination of feeding wheat can be explained by the rainy summer weather. DON contamination of feeding wheat poses a major risk to the production and animal health status of pig herds.

Data on the contamination of maize with fumonisin B1 and other fusariotoxins in Hungary.

The fumonisin B1, zearalenone, deoxynivalenol and T-2 toxin content of maize samples collected in the period of storage and harvesting was determined by high-performance liquid chromatography (HPLC) methods. Of the mouldy maize samples collected in the period of storage, 70.8% contained fumonisin B1 (0.05-19.8 mg/kg; average concentration: 2.6 mg/kg), 87.5% contained zearalenone (0.01-11.8 mg/kg, average concentration: 1.26 mg/kg), 70% contained deoxynivalenol (0.07-21.2, average concentration: 4.33 mg/kg), and 41.7% contained T-2 toxin (0.06-0.39, average concentration: 0.2 mg/kg). These mycotoxins often occurred together in the samples. In the non-mouldy samples, both the positivity rate and the mycotoxin concentration were markedly lower. In the harvesting period, the mycotoxin content of maize ears more or less affected by moulds (so-called "affected sample") and of the average sample was determined separately for each maize-field involved in the study. Of the affected samples, 70% contained fumonisin B1 (0.095-52.4 mg/kg; average: 6.64 mg/kg), 17% contained zearalenone (0.006-0.079 mg/kg; average: 0.03 mg/kg), 13% contained deoxynivalenol (0.05-0.118 mg/kg; average: 0.09 mg/kg), and 39% contained T-2 toxin (0.05-0.551 mg/kg; average: 0.165 mg/kg). Fumonisin B1 and T-2 toxin often occurred together in the affected maize samples. Of the "average samples", 30% were contaminated with fumonisin B1 (0.06-5.1 mg/kg; average: 1.52 mg/kg) and 9% with T-2 toxin (min.-max.-average: 0.05 mg/kg). The results call attention to the fact that maize cultivated in Hungary is often contaminated with fumonisin B1. High concentrations of fumonisin B1 were found primarily in the mouldy or affected maize ears; therefore, the development of diseases caused by fumonisin B1 should be reckoned with primarily if such maize is fed. Besides fumonisin B1, mouldy or affected maize usually contains also other fusariotoxins, which raises the possibility of mycotoxin interactions. Because of the high prevalence of fumonisin B1 in maize grown in Hungary, the authors suggest that samples of maize used for feeding horses and pigs should be checked for fumonisin B1 content.