RETENTION BEHAVIOR OF METAL-COMPLEXES WITH 5-SULPHOQUINOLINE-8-OL IN REVERSED-PHASE ION-PAIR LIQUID-CHROMATOGRAPHY

The reversed-phase ion-pair liquid chromatographic behaviour of severa l metal complexes with 5-sulphoquinoline-8-ol (HQS) on an octadecyl-mo dified silica column was investigated by using a fluorescence detector . The aluminum complex gave two peaks on the chromatograms when eluent s containing phosphate buffer were used. The effects of the pH of the eluent, HQS concentration, the nature of anions in the eluent, and the column temperature on the retention behaviour of the aluminum complex are discussed on the basis of the equilibria and the kinetics of the complexation of the aluminum ion with HQS and anions in the eluent. Th e equilibrium constant for the interconversion reaction between the tw o Al(III)-HQS species which correspond to the two peaks observed and t he second stepwise formation constant for the Zn(II)-HQS complex were evaluated from the HPLC data obtained.