Determination of ochratoxin A in red wine and vinegar by immunoaffinity high-pressure liquid chromatography

A method is described for the determination of ochratoxin A (OTA) in red wi ne and vinegar using an acidic chloroform extraction, an immmunoaffinity cl ean-up step, and a high-performance liquid chromatographic determination wi th fluorescence detection. The detection limit was estimated at 0.002 mug/l iter. The mean recovery factors were found at 91.3 and 96.6% for wine and v inegar, respectively. Thirty-one samples of red wine originating from Medit erranean sea countries and 15 samples of vinegar were examined for the pres ence of OTA. All red wine samples contained OTA. Seventy-two percent of the se samples were found to he contaminated over 0.1 mug/liter. Among them, ni ne samples contained ochratoxin A in the range of 0.5 to 3.4 mug/liter, 12 samples in the range of 0.10 to 0.50 mug/liter (median: 0.176 mug/liter), a nd 9 samples in the range of 0.010 to 0.100 mug/liter (median: 0.041 mug/li ter). All 15 vinegar samples showed the presence of OTA. The most contamina ted ones were three balsamic vinegar samples containing 0.156 mug/liter, 0. 102 mug/liter, and 0.252 mug/liter of OTA. In the remaining 12 samples, och ratoxin A levels ranged from 0.008 mug/liter to 0.046 mug/liter (median: 0. 012 mug/liter). These data are in good agreement with the hypothesis that w ine originating from Southern countries might contain significant OTA conce ntration and showed the possible occurrence of traces of OTA in vinegar.