Separation of water-soluble vitamins via high-performance capillary electrophoresis.

A standard sample and method for performance evaluation in capillary zone electrophoresis is defined. The sample, containing thiamine, nicotinamide and nicotinic acid, was analysed in a 20 mM sodium phosphate buffer pH 7. The impact of pH, buffer type and ionic strength on electroosmotic flow, electrophoretic mobility, and peak shape was investigated. The separation of several water-soluble vitamins in phosphate buffer pH 7 was developed in order to analyse an over-the-counter vitamin preparation. Spectral analysis and peak purity tests were applied on-line for peak identification.