SIMULTANEOUS DETERMINATION OF RETINOL ESTERS AND TOCOCHROMANOLS IN FOODS USING NITRO-COLUMN HPLC

All food components with vitamin A and E activity, i.e. all-trans reti nol, its cis isomers and their esters as well as the four tocopherols, the four tocotrienols, and alpha-tocopheryl acetate, were separated b y HPLC using a nitro-column and a three-step gradient elution with n-h exane and tert-butylmethylether mixtures. beta-carotene and the retino l isomers were determined with an UV/Vis detector, all other compounds with a fluorescence detector connected in series. Fats, oils, and lip id extracts from foods can be injected onto the HPLC column without an y clean-up.