MIGRATION BEHAVIOR OF NIACIN DERIVATIVES IN CAPILLARY ELECTROPHORESIS

The migration behaviour of niacin derivatives was investigated by capi llary zone electrophoresis (CZE) and micellar electrokinetic chromatog raphy (MEKC). When the pH of the buffer solution is lower than the pK( a) of the pyridine ring in the niacin derivatives, they are positively charged by protonation on the pyridine ring and migrate electrophoret ically. The mobilities of niacin derivatives in CZE were controlled by the pH of the migrating buffer. Good separation of thirteen niacin de rivatives was achieved at pH 2.8. Further, to shorten the analytical t ime and to achieve a more complete separation, an investigation by MEK C using sodium dodecyl sulfate micelles was performed. All thirteen ni acin derivatives were eluted within 30 min and a satisfactory separati on was achieved.