Preparation and application of a novel ionic liquid-type dicationic surfactant in extractive preconcentration of trace uranium (VI)

Abstract

Abstract Trace uranium determination in aquatic media has a special interest due to its chemo- and radio-toxicity hazard, yet a challenging issue. Surfactant-based extraction is an eco-benign, fast, simple, effective, and economical preconcentration methodology for trace analysis. Here, a novel ionic liquid of dicationic surfactant-type was successfully prepared, characterized, and applied to the preconcentration and determination of uranium (VI) in water samples. The surface-active and micellar behavior of the prepared surfactant were examined via tensiometry and conductivity analyses. The calculated Gibbs standard free energy of the prepared surfactant adsorption and micellization indicated that both phenomena were spontaneous. A binary cationic surfactant system was obtained by mixing the prepared surfactant and CTAB and was employed for uranium extraction. Uranium (VI) species was initially complexed with thorin, extracted into the surfactant-rich phase, and then analyzed spectrophotometrically. The effect of different analytical parameters was evaluated and optimized. At the optimal experimental settings, the linearity of the obtained calibration curve was 2–200\xa0µg L−1 while the detection limit was 0.611\xa0µg L−1. The method was applied satisfactorily\xa0 for uranium (VI) determination in aqueous samples and the obtained recoveries ranged from 98.50\xa0±\xa00.14 to 99.18\xa0±\xa00.91%.