Retention Behavior and Content Differences of Vitamin E Isomers in Vegetable Oil on BEH C₁₈ and CSH Fluoro-Phenyl Stationary Phases

The identification of isomers is a hot issue in food adulteration or screening. The retention behaviors of V_E isomers at different column temperatures(30,35,40,45,50 ℃)and different organic modifiers(methanol and acetonitrile)were studied by using BEH C₁₈ and CSH Fluoro-Phenyl stationary phases,the retention behaviors of the target compounds were evaluated by resolution,trailing factor and capacity factor,and the contents of V_E in different vegetable oil samples were determined under the optimal chromatographic conditions. The results showed that when CSH Fluovo-Phenyl was used as stationary phase and methanol as organic phase,except for β-V_E and γ-V_E could be partially separated,the other stationary phase and chromatographic conditions had no significant difference in selectivity. Moreover,the sample was extracted by ethanol,BEH C₁₈ as stationary phase,the column temperature was 30 ℃,the injection volume was 1.0 μL,the linear range of V_E isomer were 0.002~20 mg/L,the correlation coefficient was r>0.9993. Through the analysis of the actual samples,the method established in this study has the advantages of high efficiency,speed and low experimental cost,which could meet the requirements of rapid,accurate and high throughput detection of V_E in vegetable oils.