NOVEL WEAK ACID CATION-EXCHANGE COLUMN

A cation-exchange column with carboxylate cation-exchange sites was de veloped. Compared with conventional surface-sulfonated or latex agglom erated resins, this weak acid cation exchanger has a high selectivity for hydronium ions. Mono- and divalent cations such as alkali and alka line earth metals can therefore be determined simultaneously in less t han 10 min using a weakly acidic eluent under isocratic conditions. Be cause the ethylvinylbenzene-divinylbenzene substrate is highly cross-l inked, the new separator is solvent compatible, thus allowing the use of organic solvents to alter the selectivity of the separation and to remove organic contaminants from the column. The separation characteri stics of this column are presented and various applications are discus sed.