A new extractant impregnated resin for separation of traces of uranium and thorium followed by their spectrophotometric determination in some geological samples

Abstract

A new extractant-impregnated resin, alizarin red S -impregnated XAD-2010, is used as an adsorbent to separate and preconcentrate U(VI) and Th(IV) ions prior to their spectrophotometric determination. Various instrumental techniques such as elemental analysis, FTIR, and SEM analysis were employed for full characterization of the synthetic extractant. Optimization of the adsorption and elution conditions of U(VI) and Th(IV) ions using synthesized alizarin red S -impregnated XAD-2010 were studied. Langmuir isotherm model has the best fitting experimental data with a maximum adsorption capacity of 20.2 mg g−1 for U(VI) and 18.25 mg g−1 for Th(IV). The adsorption process of each metal ion by synthesized alizarin red S -impregnated XAD-2010 showed an exothermic pseudo-second-order adsorption process. The tolerance limits for several metal ions on alizarin red S -impregnated XAD-2010 were calculated, giving high tolerance limit. The optimized method was applied on international certified samples and different rock types bearing thorium and uranium with accurate results.