Developing a new micro cloud point extraction method for simultaneous preconcentration and spectrophotometric determination of uranium and vanadium in brine.

A fast, simple, and economical method was developed for simultaneous spectrophotometric determination of uranium(VI) and vanadium(V) in water samples based on micro cloud point extraction (MCPE) at room temperature. This is the first report on the simultaneous extraction and determination of U(VI) and V(V). In this method, Triton X114 was employed as a non-ionic surfactant for the cloud point procedure and 4-(2-pyridylazo) resorcinol (PAR) was used as the chelating agent for both analytes. To reach the cloud point at room temperature, the MCPE procedure was carried out in brine. The factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, the linear calibration curve was found to be in the concentration range between 100 - 750 and 50 - 600 μg L(-1) for U(VI) and V(V), respectively, with a limit of detection of 17.03 μg L(-1) (U) and 5.51 μg L(-1) (V). Total analysis time including microextraction was less than 5 min.