| The sample pretreatment conditions and chromatographic conditions of three methods for determining four aflatoxins (AFB1,AFB2,AFG1,AFG2)in vegetable oil based on post-column photochemical derivatization HPLC, post-column I2 derivatization HPLC and non-derivatization UPLC were improved and the three methods were compared. The results showed that when the sample was pretreated with no nitrogen blowing, injected to liquid chromatography with 50% methanol solution and the experiment was completed under improved chromatographic conditions, all the four aflatoxins in oil samples could be separated and quantitated, and the pretreatment process was simplified. The detection limits of AFB1 for post-column photochemical derivatization HPLC, post-column I2 derivatization HPLC and non-derivatization UPLC were 0.035,0.018,0.045 μg/kg, respectivly, and they were 0.016,0.014,0.017 μg/kg for AFB2 , 0.067,0.024,0.080 μg/kg for AFG1, and 0.029,0.026,0.029 μg/kg for AFG2. The three methods had good linear relationship (r2> 0.99) , the recoveries were in the rang of 90.7%-116.1%, and the relative standard deviation was below 12%. The results of three methods for the determination of four aflatoxins in peanut oil were basically equi valent.The three methods for determining four aflatoxins in vegetable oil could meet the need of grain and oil inspection and had practical application value. |
