Liquid chromatographic method for the determination of carotenoids, retinoids and tocopherols in human serum and in food.

A liquid chromatographic (LC) method has been developed for the quantitative measurement of the six major carotenoids in human serum (lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene) as well as retinol, retinyl palmitate, alpha-tocopherol, gamma-tocopherol, and delta-tocopherol. Several polar carotenoids, 2',3'-anhydrolutein, alpha-cryptoxanthin, and geometric isomers of lycopene and beta-carotene are also separated. Retinoids and carotenoids are monitored using a programmable ultraviolet-visible detector, while tocopherols are monitored using a fluorescence detector. The method uses a gradient containing acetonitrile, methanol, and ethyl acetate. Ammonium acetate is introduced with the methanol to minimize carotenoid losses on the LC column aggravated by the use of acetonitrile and ethyl acetate. The method is also applicable to the analysis of foods.