The liquid chromatographic analysis of vitamin K-1 in soy based infant formula using matrix solid phase dispersion

A liquid chromatographic method is described for vitamin K-1 in soy based i nfant formula. The vitamins are extracted from infant formula by matrix sol id phase dispersion (MSPD) and quantitated by reversed phase chromatography with fluorescence detection. Vitamin K-1 is converted to the fluorescent h ydroquinone with a post column zinc reductive reactor. The limit of detecti on is 12 pg and the limit of quantitation is 38 pg on- column. Linear respo nse ranged from 0.70 - 11.0 ng/mL (r(2) = 0.998). Recoveries were determine d on an analyte-fortified blank material for soy based infant formula and a veraged 92.5% (n = 25) for vitamin K-1. The method provides a rapid, specific, and easily controlled assay for the analysis of vitamin K-1 in fortified soy based infant formula.