Analysis of Cationic Vitamins in Cell Culture Medium Samples by Capillary Zone Electrophoresis

Abstract

This paper describes a capillary electrophoresis method for the determination of the cationic B-vitamins thiamine, nicotinamide, pyridoxine, pyridoxal, and pyridoxamine in untreated cell culture medium samples. The effects of the buffering capacity, the mobility of the coion, and the preconditioning solution on the robustness of the method were investigated. Using a 100mM phosphoric acid and 55mM triethanolamine background electrolyte at pH 2.3 and capillary preconditioning with 1M NaOH, all five vitamins could be separated with good resolution. Preliminary method validation data over the range 10110µM for undiluted samples, with 10μM being the lower range limit of quantification QL, showed accuracy recoveries of 94104, and migration time and peak area repeatabilities within 0.4 RSD and 2.6 RSD, respectively.