LIQUID-CHROMATOGRAPHIC ANALYSIS OF ALL-RAC-ALPHA-TOCOPHERYL ACETATE, TOCOPHEROLS, AND RETINYL PALMITATE IN SRM-1846

A liquid chromatographic method is described for the analysis of all-r ac-alpha-tocopheryl acetate, tocopherols, and retinyl palmitate in the infant formula standard reference material 1846. The vitamins are ext racted in isopropanol and hexane/ethyl acetate without saponification and quantitated by normal phase chromatography with fluorescence detec tion. Retinyl palmitate, all-rac-alpha- tocopheryl acetate, and natura lly occurring tocopherols are quantitated isocratically with a mobile phase of 0.5% isopropanol in hexane. The results were within the certi fied ranges for all-rac-alpha-tocopheryl. acetate and retinyl palmitat e. Recoveries averaged 97.5% for retinyl palmitate and 101% for all-ra c-alpha- tocopheryl acetate (n = 20). The method provides a rapid, spe cific, and easily controlled assay approach to the analysis of vitamin A and vitamin E in fortified infant formula. Additionally, the method eliminates the use of chlorinated solvents.