Liquid Chromatographic Analysis of Vitamin K1in Medical Foods Using Matrix Solid-Phase Dispersion

A liquid chromatographic method for vitamin K1in medical foods is described. The vitamins are extracted from medical food by matrix solid-phase dispersion (MSPD) and quantitated by reversed-phase chromatography with fluorescence detection. Vitamin K1is converted to the fluorescent hydroquinone with a post-column zinc reductive reactor. The limit of detection is 6.6 pg and the limit of quantitation is 22 pg on column. Linear response ranged from 45 to 908 pg on column (r2=0.998). Recoveries were determined on an analyte-fortified zero control reference material (ZRM) for medical foods and averaged 97.9% (n=25) for vitamin K1. The method provides a rapid, specific and easily controlled assay for the analysis of vitamin K1in fortified medical foods.