Separation of barium from associated elements using poly(dibenzo-18-crown-6) and column chromatography

Abstract

A simple column chromatographic method has been developed for the separation of barium from associated elements using poly(dibenzo-18-crown-6). The separations are carried out in a medium of hydrochloric acid and the adsorption of barium was quantitative from 4.5–10.0 mol l^–1 HCl. Amongst the various eluents tested, 0.5–0.2 mol l^–1 HCl and 0.5–8.0 mol l^–1 CH₃COOH were found to be particularly efficient for the elution of barium. The capacity of poly(DB-18-C-6) to separate barium was found to be 1.475 mmol g^–1 of crown polymer. Barium was separated from a number of elements in binary mixtures in which most of the elements showed a very high tolerance limit. It was possible to separate the barium from a number of elements that are usually associated with barium, in multicomponent mixtures. The method was extended to the determination of barium in various rock samples, minerals and a plastic stabilizer. The method is very simple, rapid, selective and has good reproducibility (approximately ±2%).