Liquid chromatographic determination of carotenoids and vitamins A and E in multivitamin tablets
Sun, J.
Journal - Association of Official Analytical Chemists 82(1): 68-72
1999
ISSN/ISBN: 0004-5756 PMID: 10028672 Document Number: 498497
Carotenoids and vitamins A and E in multivitamin tablets can be determined simultaneously by reversed-phased liquid chromatography (LC) with a programmable UV detector. Samples were dissolved in dimethyl sulfoxide and then extracted with hexane. A portion was injected onto a Symmetry C18, 150 X 4.6 mm id, 5 micrometer column and chromatographed with a mobile phase of acetonitrile 0.25% ammonium acetate in methanol and 0.05% triethylamine in dichloromethane. A step gradient was used. The system was operated at 25 degrees C with a flow rate of 1.5 mL/min. UV detection was at 325 nm for retinols, 285 nm for tocopherols, and 450 nm for carotenoids. Detection limits were less than 0.3 ng for retinol and retinyl acetate; 2 ng for alpha-tocopherol acid succinate; 10 ng for alpha-tocopherol, gamma-tocopherol, and alpha-tocopherol acetate; and 0.4 ng for alpha-carotene and beta-carotene. Intraday and interday coefficients of variation ranged from 1.40 to 5.20%. The sample preparation method and LC assay are practical for quality control and routine analysis of multivitamin tablets.