Simultaneous separation of water‐ and fat‐soluble vitamins in isocratic pressure‐assisted capillary electrochromatography using a methacrylate‐based monolithic column

A method of simultaneous separation of water‐ and fat‐soluble vitamins using pressure‐assisted CEC with a methacrylate‐based capillary monolithic column was developed. In the proposed method, water‐soluble vitamins were mainly separated electrophoretically, while fat soluble‐ones were separated chromatographically by the interaction with a methacrylate‐based monolith. A mixture of six water‐soluble and four fat‐soluble vitamins was separated simultaneously within 20 min with an isocratic elution using 1 M formic acid (pH 1.9)/acetonitrile (30:70, v/v) containing 10 mM ammonium formate as a mobile phase. When the method was applied to a commercial multivitamin tablet and a spiked one, the vitamins were successfully analyzed, and no influence of the matrix contained in the tablet was observed.