SPEEDING UP OF A THALLIUM SPECIATION USING ION EXCHANGE COLUMN SYSTEM

Abstract

A method for the speciation of thallium was proposed using a mini-column filled with Dowex Monosphere 550A (OH) anion exchange resin. A highly sensitive, selective and simple column-solid phase extraction method has been developed to separate trace amounts of thallium species. Dowex Monosphere 550A (OH) anion exchange separation technique followed by analysis with ICP-MS was evaluated for the study of thallium speciation in river waters. Experimental conditions such as pH, eluent type, flow-rate, sample volume, effect of matrix ions, etc., have been optimised for quantitative recovery. The retained analytes on the resin were recovered with 10 ml of thiourea solution at only one step. Thus, the experimental results showed that Dowex anion exchange resin can be used to separate Tl (1) and Tl (III) species. The dominant thallium form found (75.3-81.6 ng L-1) in the samples was Tl (III). The enrichment factor obtained in this work is 100-fold better than that of similar methods compared in literature. This developed method was applied to synthetic solutions, real sample solutions and standard reference material for thallium speciation and determination study.