Dissociation kinetic analysis of Ce(III) complex with Quin2 by microchip capillary electrophoretic reactor.

Dissociation kinetic analysis of a complex of Ce(3+) with a polyaminocarboxylic ligand, 8-amino-2-[(2-amino-5-methylphenoxyl)methyl]-6-methoxyquinoline-N,N,N',N',-tetraacetic acid (Quin2), was studied by microchip capillary electrophoretic reactor. Dissociation rate constants, k(d), of Ce(3+)-Quin2 complex in alkaline conditions at pH 8.3 - 9.8 were determined. The linear relationship of k(d) with the concentration of hydroxide ion indicates the existence of a hydroxide ion-assisted path in the dissociation reaction of Ce(3+)-Quin2 complex in alkaline conditions. The solvolytic dissociation rate constant, and the hydroxide ion-assisted dissociation rate constant of Ce(3+)-Quin2 complex were determined to be 1.55 × 10(-3) and 3.24 × 10(2) s(-1) in the analysis of the dependence of k(d) with the concentration of hydroxide ion, respectively.