Dissociation Kinetic Analysis of Ce(III) Complex with Quin2 by Microchip Capillary Electrophoretic Reactor

Abstract

Dissociation kinetic analysis of a complex of Ce3+ 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, kd, of Ce3+-Quin2 complex in alkaline conditions at pH 8.3 – 9.8 were determined. The linear relationship of kd with the concentration of hydroxide ion indicates the existence of a hydroxide ion-assisted path in the dissociation reaction of Ce3+-Quin2 complex in alkaline conditions. The solvolytic dissociation rate constant, and the hydroxide ion-assisted dissociation rate constant of Ce3+-Quin2 complex were determined to be 1.55 × 10–3 and 3.24 × 102 s–1 in the analysis of the dependence of kd with the concentration of hydroxide ion, respectively