Capillary zone electrophoresis and micellar electrokinetic capillary chromatography for determining water-soluble vitamins in commercial capsules andtablets

A rapid method was developed for simultaneously determining thiamine, ribof lavin, pyridoxine, nicotinamide, nicotinic acid, and ascorbic acid. It was tested on 15 samples. The peaks of all components were cleanly separated wi th good resolution by capillary zone electrophoresis (CZE) and micellar ele ctrokinetic chromatography (MECC), CZE was performed with 0.02 M berate buf fer, and MECC was performed with 4% acetonitrile in 0.02 M borate/phosphate buffer containing 0.1 M sodium dodecyl sulfate. Average recoveries for all components were 80.3% to 103.7% with coefficients of variation being less than 5%. Thiamine, nicotinic acid, and pyridoxine contents were consistent with those labeled on the packages, but nicotinamide, riboflavin, and ascor bic acid contents of some samples were less.