DETERMINATION OF MYCOTOXINS IN BOTANICAL ROOTS

Mycotoxins are toxic secondary metabolites produced by certain molds and are common contaminants of many important food crops, such as grains, nuts, and spices. Some mycotoxins are found in fruits, vegetables, and botanical roots. These contaminants have a broad range of toxic effects, including carcinogenicity, immunotoxicity, neurotoxicity, and reproductive and developmental toxicity. The public health concerns related to both acute and chronic effects of mycotoxins in animals have prompted more than 100 countries to establish regulatory limits for some of the well-known mycotoxins such as the aflatoxins (AFL). Our research focused on method development for two of these toxins: AFL and ochratoxin A (OTA) in botanical roots, specifically in ginseng and other selected roots. Methods using an immunoaffinity column (IAC) cleanup, liquid chromatographic separation, and fluorescence detection were modified and evaluated. Two types of IAC were evaluated: IAC for AFL and IAC for both AFL and OTA. Three derivatization techniques to enhance the fluorescence of the AFL were compared: pre-column trifluoroacetic acid, post-column bromination and post-column UV irradiation. No derivatization was needed for OTA. Results for AFL using the single analyte IAC and the three derivatization techniques were all comparable for ginseng and for other roots such as ginger, licorice, and kava-kava. Recoveries of added AFL for ginseng at levels from 2 ng/g to 16 ng/g were about 80%. Recoveries of added AFL for ginger, licorice and kava-kava were about 60%. Recoveries of added AFL for ginseng at 4-16 ng/g using IAC for both AFL and OTA were about 70%. Recoveries of added OTA for ginseng, ginger, and echinacea at 4 ng/g were about 55%.