A Cooperative Method for Detemination of Aflatoxin Bi in Tea by Immunoaffinity Column Purification and HPLC-FLD with Post-Column Photochemical Derivatization

摘要

A method for determination of aflatoxin B1 in tea by using HPLC-FLD with photochemical derivatization after immunoaffinity column purification was developed, and the determination conditions of sample were optimized in this paper. The sample was purified by immunoaffinity column using the mobile phase composed of methanol and water (60:40, v/v), then quantified with fluorescence detection after photochemical derivatization. The results showed that this method to determine aflatoxin Bi was finished within 12.5 min under the optimum conditions. The standard curve had a good linearity when the aflatoxin Bi was in the range of 0.2—20 pg/L. The correlation coefficient, the limits of detection and quantification, the recovery rate and the relative standard deviation of the method were 0.9999, 0.03 ng/g (S/N=3), 0.11ng/g (S/N=10), 80%—90% and 1.4%—2.4% (n=5), respectively. This is a very simple method and it has high sensitivity and good repeatability, which is applicable to determine the content of aflatoxin Bi in tea sample.