Determination of Aflatoxins B1 in Tea by High Performance Liquid Chromatography-Fluorescence Detector with Post-column Photochemical Reaction

A new method for the sensitive determination of Aflatoxins B1 in tea by high performance liquid chromatography with photoelectric reactor and fluorescence detector was established.A solution of V(acetonitrile)∶ V(H2O)=86∶ 14 was used to extract Aflatoxins B1 from tea.The extracted solution was then purified by a multifunctional and immuneaffinity column,respectively.The peak area and the concentration of Aflatoxins B1 showed a good linear relationship within the range from 0.591 μg/L to 5.91 μg/L with a linear correlation coefficient(r) of 0.9994.The recoveries at the concentrations studied [low level(7.090 μg/kg),high level(14.180 μg/kg)] were between 85.6% and 98.9% with a relative standard deviations ranging from 1.7% to 1.8%.The limit of detection(LOD) is 0.1 μg/kg(S/N=3).The limit of quantitation(LOQ) is(0.591 μg/kg).The new method was used to analyze eight tea samples collected from the local markets and negative results were obtained.The meth od is suitable for detection of Aflatoxins B1 in tea with high selectivity and sensitivity.