A review is presented of the chromatographic separation of substances interacting with the stationary phase through the coordination bond formation in the coordination sphere of a transition metal present in the system, covering the literature up to the end of 1976. Advances in liquid chromatography have been considered in more detail than those in gas—liquid and thin-layer chromatography, since the former provides usually more information about the stoichiometry and mechanism of ligand-exchange processes. The first part of the review describes theoretical questions and peculiarities of ligand-exchange chromatography, the second part deals with the practical applications of this new technique in organic chemistry and biochemistry, the study of coordination compounds, the separation of optical isomers, drugs, etc.

Ligand exchange chromatography

Immobilized metal ion affinity chromatography.

Light-scattering, X-ray diffraction, elemental analysis and infrared spectro- photometry characterization of chitosan, a chelating polymer.

Ion-exchange chromatography of nitrogen compounds

Studies on ligand-exchange chromatography

The rates of adsorption of antimony, cobalt, mercury and silver on cellulose, diethylaminoethyl and p-aminobenzyl celluloses and cellulose phosphate from diethyl ether have been measured. Columns were prepared with antimony and cobalt pre-treated celluloses and the chromatographic behaviour of dimethylamine, trimethylamine, aniline and ethylenediamine studied. It was shown that these metal-loaded celluloses can be used in ligand-exchange chromatography with organic solvents. Antimony pre-treated celluloses can also be used with aqueous solutions. X-ray diffraction spectra show that the technique proposed is undoubtedly ligand-exchange chromatography and not reversed-phase extraction.

R. A. A. Muzzarelli

Papers

Ligand-exchange chromatography on thin layers and columns of natural and substituted celluloses