Simultaneous Determination of Retinols and Tocols in Egg and Milk Products Based on RP-HPLC Linked with Fluorescent and Photodiode Array

In this paper, we built a method of verifying the 4 retinols of vitamin A and 8 tocopherol isomers of vitamin E in the food industry based on RP-HPLC-PDA-FLR. The effect of laboratory light conditions on the target components was considered for the first time, and it was found that the loss rate of the target components was the smallest in the case of a white laboratory bench with red or LED light in the dark room. There was no finding of extraction recoveries of the target components with a significant difference under different saponification conditions. Meanwhile, it was found that using ethyl acetate/n-hexane mixed solvent as the extraction solvent could ensure the effective extraction of the target components. Finally, baseline separation of 12 components was achieved within 45 min using the C-30 column. With the help of methodological verification, we found that the recovery rate ranged from 76.45% to 93.52%, and RSD was between 0.19% and 12.99%; the Limit of Detection minimum value was 0.01 mg/100 g and the Limit of Quantitation minimum value was 0.03 mg/100 g. The detection method was successfully applied to the distribution detection of 4 kinds of retinols and 8 kinds of vitamin E in egg and dairy products and provided technical support for the accurate nutritional evaluation of vitamin A and vitamin E.