Immobilized soft-metal affinity system for amino acids based on an 8-hydroxyquinoline-Pd(II) complex; characterization using glycine as a model

The affinity of glycine for a chromatographic resin modified by covalent attachment of a complex of 8-hydroxyquinoline with Pd(II) was evaluated. The loading capacity of the resin for Pd(II) and the corresponding reaction equilibria were determined. Experimental, as well as theoretical studies, for the processes of partition and elution of the amino acid were also undertaken. It was found that for both the partition and elution processes, theoretical predictions based on equilibrium reactions confirmed the experimental data. This study demonstrates that a soft metal, Pd(II), immobilized on a chromatographic resin through its interaction with 8-hydroxyquinoline, can be used to adsorb and elute the amino acid glycine. This could serve as a model for the separation of amino acids based on immobilized soft-metal affinity chromatography principles.