| In order to better separate the fat-soluble vitamin E isomers in vegetable oils, a method for rapid separation and determination of vitamin A and vitamin E in vegetable oil by ultra high performance convergence chromatography was established. The sample was dissolved in isopropanol and passed through a 0.22 μm organic phase filter membrane, and then directly injected for analysis. The analysis conditions were as follows: HSS C18 SB chromatographic column (3.0 mm×100 mm, 1.8 μm), with CO2 and 0.2% formic acid methanol solution as mobile phase, gradient elution, flow rate 1.0 mL/min, column temperature 50 ℃, detection wavelength 290 nm. The results showed that vitamin A and vitamin E showed a good linear relationships in the determination range, the correlation coefficients were not less than 0.999 5, the sample recovery was 82.00%-106.82%, the RSD was 0.94%-3.57%, and the RSD of intraday precision and daytime precision were 1.94%-3.51% and 3.74%-5.13%, respectively. The contents of vitamin A and vitamin E in 26 vegetable oil samples were determined by the established method. The vitamin E content was the highest, in which α-tocopherol and γ-tocopherol was the main tocopherol, while β-tocopherol conternt was lower. The method is simple, efficient, sensitive and reproducible. The method can be used for the separation and determination of vitamin A and vitamin E in vegetable oil. |
