Immunoaffinity column cleanup with liquid chromatography using post-column bromination for aflatoxins in medicinal herbs and plant extracts.
A new and accurate method to quantitate aflatoxins in medicinal herbs is developed. This method consists of extraction of the sample with MeOH-H2O (70:30) followed by clean-up of the extracts with immunoaffinity columns and, finally, high-performance liquid chromatographic determination with fluorescence detection. Aflatoxins B1 and G1 are determined as their bromine derivatives, produced in an online post-column derivatization system. The overall average recoveries for three different medicinal herbs spiked at levels of 1.3 and 2.6 ng/g of total aflatoxins range from 93% to 97%. The detection limit is 0.15 ng/g for both G2 and B2 and 0.20 ng/g for both G1 and B1, based on a signal-to-noise ratio of 3:1 and a precision (within-laboratory relative standard deviation) ranging from 0.8% to 1.4%. The use of immunoaffinity columns provides excellent clean-up of these particular extracts, which are generally difficult to analyze. The method is applied successfully to 96 samples of natural drugs.
Zhang
Xuehui
X
Institute of Medicinal Plant Development, Chinese Academy of Medical Science and Peking Union Medical College, Xibeiwang, Haidian district, Beijing 100094, China. xuehui_z@yahoo.com.cn
Liu
Huiling
H
Chen
Jianmin
J
D016604:Aflatoxin B1 / Q000032:analysis; D000348:Aflatoxins / Q000032:analysis*; D001966:Bromine; D002846:Chromatography, Affinity / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007158:Immunologic Techniques; D010936:Plant Extracts / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*
D000348:Aflatoxins; D010936:Plant Extracts; C027955:aflatoxin G1; D016604:Aflatoxin B1; D001966:Bromine