ABSTRACT
High-resolution ligand-exchange chromatography of organic sulfur compounds had to await the development of efficient stationary phases that can be used in non-polar solvents. In the practice of ligand-exchange chromatography, the most important oxygen ligands are the carbohydrates. The chapter presents a brief summary that may be useful to the chemist who needs to analyze carbohydrate mixtures and describes the techniques that use ligand exchange. Nitro groups and chlorine atoms both increase the retention of phenols, as do alkyl substituents. Phenols are important as environmental pollutants, and it seems that the possibilities of ligand exchange for concentrating, recovering, and analyzing them are only just being realized. Aromatic acids were separated by ligand-exchange complexation in the mobile phase by W. H. Lee in 1970. A most interesting use of outer-sphere coordination is the recovery of non-ionic surfactants from polluted water and the separation of homologous surfactants from one another.
