HPLC Determination of 4 Aflatoxins in 3 Vegetable Oils

HPLC with fluorescence detector was applied to the determination of 4 aflatoxins (i.e., AF B1, AF B2, AF G1 and AF G2) in 3 vegetable oils (i.e., peanut oil, olive oil and sesame oil). The sample was extracted with 55% (φ%) methanol solution and purified by IAC. Aflatoxins in the eluate were separated on YMC ODS-AQ S-3 column with a mixture of CH3OH-CH3CN-H2O(25+17+60) containing 120 mg of KBr and 350 μL of HNO3 as mobile phase. After derivatization, fluorescence detections with λex of 362 nm and λem of 440 nm were adopted in the determination. Linear relationships between values of peak area and mass concentration of the 4 aflatoxins were obtained in the definite ranges, with lower limits of determination (10S/N) of 0.4 μg·kg-1 for B1 and G1, and 0.2 μg·kg-1 for B2 and G2. Tests for recovery were performed by standard addition method at 3 concentration levels, giving values of recovery and RSD′s (n=10) in the range of 74%-112% and 3.6%-15%, respectively.