Determination of acid dissociation constants of flavin analogues by capillary zone electrophoresis.

Acid dissociation constants (pK ) of nine kinds of flavin analogues as molecular catalyst candidates were determined by CZE. Although some of the analogues are instable and degradable under the light exposure or in alkaline aqueous solutions, the effective electrophoretic mobility of the flavin analogue of interest has been measured with the residual substance. The pK values of the flavin analogues were analyzed through the changes in the effective electrophoretic mobility with varying pH of the separation buffer.