Solvent extraction separation of thallium(III) from associated elements with hexaacetyl calix(6)arene

Trace amount of thallium has been quantitatively extracted with hexaacetyl calix(6)arene at pH 2.0 with toluene as the diluent. Thallium is stripped from organic phase with 2M hydrochloric, nitric or perchloric acid and determined spectrophotometrically. The 3-5 min equilibration period is adequate for complete extraction. A large number of ions are tolerated during the process of extraction. However, uranium, antimony, tin and lead show strong interference. Thallium is extracted in the presence of multicomponent mixtures containing thorium, bismuth, manganese, chromium and iron and separated selectively with stripping agents (mineral acids). Gallium and indium have been separated by selective extraction with oxine. The proposed method is extended for the analysis of thallium from real samples of soil, sediments and analogous products. The method is simple, rapid and selective with relative standard derivation of +/-1.5%