EQUILIBRIUM AND KINETIC-STUDIES ON LIGAND-EXCHANGE REACTION OF ALUMINUM(III)-5-SULFOQUINOLINE-8-OL COMPLEX WITH FLUORIDE-ION BY REVERSED-PHASE ION-PAIR LIQUID-CHROMATOGRAPHY

The reversed-phase ion-pair liquid chromatographic behavior of the com plex of aluminum ion with 5-sulfoquinoline-8-ol (HQS) was investigated on the column packed with a polystyrene-divinylbenzene copolymer with the mobile phase containing fluoride ion. It was found that the fluor ide ion replaces one or two HQS molecules from the aluminum-HQS comple x to form the mixed ligand complexes, which resulted in the appearance of two or more peaks in the chromatograms obtained for aluminum ion. The compositions of the mixed ligand complexes were estimated from the dependence of the areas of the peaks on the mobile phase concentratio ns of HQS and fluoride ion. The equilibrium and rate constants for the ligand exchange reaction were also evaluated and the reaction mechani sm was presented. Aluminum ion could be completely separated from gall ium ion by utilizing the ligand exchange reaction.