Cloud Point Extraction and Spectrophotometric Determination of Uranium (VI) in Water Samples after Mixed Micelle-Mediated Extraction Using Chromotrope 2R as Complexing Agent

A rapid, selective and sensitive method for the preconcentration and determination of uranium (VI) by cloud point extraction (CPE) was developed. The method was based on the color reaction of 5.00 ng mL uranium (VI) with 1.5×10 mol L of chromotrope 2R in the presence of 0.015 mol L potassium iodide at pH 8 in HEPES buffer and mixed micelle-mediated extraction of complex. The mixture of a nonionic surfactant (0.2 % (v/v) of (Triton X-114) and a cationic (2.0×10 mol L of CTAB) was utilized as a suitable micellar medium for preconcentration and extraction of uranium (VI) complexes. Effect of extraction and reaction parameters was studied and optimum parameters were established. The analytical characteristics of the method (e.g. linear range, limit of detection, preconcentration and improvement factors) were obtained. Linearity was obeyed in the range of 0.2−10 ng mL of uranium (VI) with a detection limit of 0.035 ng mL. The diverse ion effect of some anions and cations on the extraction efficiency of target ions was tested. The proposed method was successfully applied for the determination of uranium (VI) in various water samples. (doi: 10.5562/cca1922)