Capillary electrophoresis combines advantages of traditional techniques for determination of vitamins (HPLC, fluorometry, and photometry). In comparison with fluorometry/photometry CE as well as HPLC ensures simultaneous determination of all compounds during analysis. At the same time CE shows higher efficiency, shorter analysis time, and less consumption of reagents, than HPLC.

Water-soluble vitamins are suitable for separation by CE because of their good solubility in water and water-organic mediums as well as sufficiently high contents in fodders and food additives. Possibilities of CZE and MEKC were studied on the mixture of thiamine, riboflavin, pantothenic acid, nicotinic acid, nicotinamide, pyridoxine, pyridoxal, folic acid, rutin, quercetin, ascorbic acid and biotin. The optimization of the BGE composition and concentration, working voltage, temperature and addition of macrocycles using CZE allowed us to separate all vitamins and their vitamers except nicotinamide (a neutral compound). Using more selective mode - MEKC - allow to separate both an ionic and the neutral water-soluble vitamins completely in the presence of 80 mM SDS as a surfactant. Certain options of Capel CE instrument (Lumex Ltd.) which facilitate vitamins analysis were: highly precise changeable temperature of a capillary cooling, ability to apply controlled pressure and programmable ability to change of wave-length during analysis. At the sample preparation stage analytes were extracted with water solution of sodium tetraborate over a sulphite-ion.