Objective: To develop a method for the simultaneous determination of aflatoxin B1, B2, G1, G2 and ochratoxin A in Glycyrrhiza uralensis by HPLC-FLD after immunoaffinity column with online post-column photochemical derivatization.
Method: Sample was extracted with MeOH: H2O (80:20) and cleaned up by immunoaffinity column. The toxins were separated by reversed-phase HPLC and the mobile phase was consisted of methanol and 0.5% acetic acid solution with gradient elution. The determination was carried out by fluorescence detector after photochemical derivatization.
Result: The detection limits of aflatoxin G2, G1, B2, B1 and ochratoxin A were 0.02, 0.06, 0.015, 0.03 and 0.25 microg x kg(-1), respectively. The recoveries of analytes were from 76.0% to 103% and the relative standard deviations (RSDs) were below 13%.
Conclusion: The method is a simple, accurate and can be used to determine the contents of aflatoxin B1, B2, G1, G2 and ochratoxin A in G. uralensis simultaneously.