Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Clean-up and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study.

The accuracy, repeatability and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine and beer have been established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked and naturally contaminated materials at levels ranging from „T0.01 ng/mL to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, filtered and cleaned-up by immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine and beer ranged from 88.2% to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3% to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL) and from 87.0% to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6% to 10.8% for white wine, from 6.5% to 10.8% for red wine and from 4.7% to 16.5% for beer. Relative standard deviations for between-laboratory reproducibility (RSDR) ranged from 13.1% to 15.9% for white wine, from 11.9% to 13.6% for red wine and from 15.2% to 26.1% for beer. HORRAT values were „T0.4 for the 3 matrixes.