Quantitation of Radio-Labelled Vitamin K1 and Vitamin K1 Epoxide in Plasma by High Pressure Liquid Chromatography

SummaryA convenient, accurate and reproducible high pressure liquid chromatographic method for the quantitation of radio-labelled vitamin K1 and vitamin K1 epoxide in plasma is described. The method involves the determination of total ether extractable radioactivity, and a chromatographic separation to determine the relative quantities of radio-labelled vitamin K1 and vitamin K1 epoxide. The method is useful over a wide range of ratios of the two compounds, and has a coefficient of variation of approximately 5%.