HPLC Determination of Aflatoxin B₁ in Tea with Pre-column Derivatization

HPLC was applied to the determination of aflatoxin B1 in tea with pre-column derivatization. The sample was extracted with acetonitrile (85+15) solution. The supernatant was purified with MycoSepTM226 column, then derivatized by adding n-hexane and trifluoroacetic acid. C18 column was used as stationary phase and the analyte was determined with fluorescence detector. Linear relationship between values of peak area and mass concentration of aflatoxin B1 was kept in the range of 0.20-10.0 μg·L-1 with detection limit (3S/N) of 0.1 μg·kg-1. Tests for recovery were made at the concentration levels of 0.5,1.0 and 5.0 μg·L-1 of aflatoxin B1 standard, giving values of recovery and RSD′s (n=6) in the ranges of 91.9%-102% and 1.5%-6.9% respectively.