COMPLEXING AND CHELATING-AGENTS IMMOBILIZED ON SILICA-GEL AND RELATEDMATERIALS AND THEIR APPLICATION FOR SORPTION OF INORGANIC SPECIES

Solid materials bearing bonded organic functional groups are reviewed. The properties of the oxide supporting materials, silica gel in parti cular, their chemical and physical properties and the nature of the su rface residues are part of this review. Processes leading to modificat ion of the silica gel surface with mono- and polylayers of other oxide s resulting in materials with modified properties as well as their sus ceptibility to chemical modification are also presented. Data on silan ization procedures to bond supporting materials with commercial or syn thesized organosilicon compounds have been carefully collected and dis cussed. Special emphasis has been paid to reactions which change the c hemical nature of the bonded organic residues leading to valuable mate rials for partition, ion, ion-exchange, and affinity chromatography as well as for specific separation methods. Data on the collection, sepa ration and preconcentration of inorganic species using these materials are an important part of this review. The bonded organic residues usu ally include typical ligating groups which are able to form complexes with inorganic species. Although most of these ligating materials have been seldom used, they have been included in this review. Current and prospective trends in usage of chemically modified supports, primaril y for large scale procedures, are discussed. Important progress in the technology of inorganic supporting materials in the form of fibers or aggregates of high specific surface, which can be chemically modified , and which should stimulate future research in solid packings, has be en outlined.