Simultaneous Determination of 10 Fat-Soluble Vitamins by Ultra-Performance Liquid Chromatography in Multivitamins...

A novel and accurate ultra-high performance liquid chromatography (UHPLC) method combined with UV detector was developed for the simultaneous determination of 10 fat-soluble vitamins (retinyl acetate, retinyl palmitate, beta carotene, alpha tocopherol, alpha tocopheryl acetate, alpha tocopheryl acid succinate, ergocalciferol, cholecalciferol, phytonadione, and menaquinone-7) in multivitamin with mineral capsules. The chromatographic separation was achieved on a Waters XBridge Sheild C18 (100 × 2.1 mm, 1.7 µm) column. The mobile phase comprised of 0.1% formic acid (v/v) in water and 0.1% formic acid in acetonitrile (v/v) delivered in a gradient mode. An enhanced and simple sample preparation procedure involving enzyme digestion of the gel coating of the capsules and ultra-sonication was developed compared to the complex and time-consuming saponification methods. The method was validated to fulfill International Conference on Harmonization (ICH) requirements and included specificity, linearity, accuracy, precision, and robustness. The linearity of the method was excellent (R² > 0.999), the RSD for the precision was < 5% and the recovery of the vitamins was in the range of 99.2%-101.9%, demonstrating that the method is suitable for analysis of fate-soluble vitamins in multivitamin capsules. The developed method could be incorporated into the USP-NF Multivitamin with minerals capsules monograph.