Enhanced sensitivity for the determination of endogenous phylloquinone (vitamin K1) in plasma using high-performance liquid chromatography with dual-electrode electrochemical detection

• DOI: 10.1039/an9851001181
• Publication Date: 2004-03-23T17:19:45Z
• Authors: John P. Hart; Martin J. Shearer; Patrick T. McCarthy
• Keywords: 0404 agricultural biotechnology; Electrochemistry; Humans; Vitamin K 1; 04 agricultural and veterinary sciences; Oxidation-Reduction; 01 natural sciences; Chromatography, High Pressure Liquid; 0104 chemical sciences

High-performance liquid chromatography (HPLC) with dual-electrode electrochemical detection has been used, in the redox mode, to determine normal and sub-normal circulating plasma levels of phylloquinone (vitamin K1) and concentrations down to 20 pg ml–1 have been measured in plasma. The coefficient of variation, for endogenous levels, was 10%(mean 330 pg ml–1; n= 6). When compared with a single glassy carbon electrode, operated in the reductive mode, the sensitivity of the dual-electrode cell was greater by at least an order of magnitude. Thus the volume of plasma required for the assay could be reduced.