Determination of Ochratoxin A in Plant Products: Immunoaffinity Column and Liquid Chromatography with Fluorescence Detector

Ochratoxins are mycotoxins produced by various fungi of the genus Aspergillus and Penicillium, e.g., A. ochraceus, A. carbonarius, and P. verrucosum. Ochratoxin A (OTA) is nephrotoxic in all animal species tested and there is evidence that these effects are associated with oxidative stress. OTA can be found in a variety of foodstuffs including cereals, preserved meats, fresh and dried fruit, and cheese. To analyze OTA, a method employing extraction with a solution of 3% sodium bicarbonate solution:methanol (1:1, v/v) followed by immunoaffinity column (IAC) clean-up and liquid chromatography with fluorescence detector analysis, has been established. Various plant products and beverages such as coffee, cereals, pulses, dried fruits, nuts, feedstuffs, and others have been in routine analysis for almost two decades now. Specifically, for grape juice and wine matrices, the OTA extraction was based on sample diluting using a solution of 1% polyethylene glycol:5% sodium bicarbonate. Two liquid chromatographic systems with fluorescence detection can be used for OTA separation, detection, and quantification.