Novel PVC membrane uranyl ion-selective sensor

The organic solvent dimethylsuphoxide (DMSO) was used as a novel ionophore in plasticized poly (vinyl chloride) (PVC) matrix membrane sensor for uranyl ions. The sensor displayed rapid and linear response for UO2(II) over a wide range from 1.0 × 10−1 to 1.0 × 10−7 mol l−1 with a Nernstian slope of 30 ± 0.2 mV per decade. It showed a good selectivity for UO2(II) ion over alkali, alkaline earth, transition and heavy metal cations. The DMSO-based sensor works well in the pH range 1.5–4.0 and its response is stable for at least 5 months. The nature of DMSO–UO2(II) complex was examined using infrared spectroscopy and sulfur analysis techniques. The proposed sensor was applied as an indicator electrode for potentiometric titration of UO2(II) ion with sodium hydroxide, sodium phosphate, potassium iodate and sodium carbonate compounds. It can be used to determine the solubility products of the produced uranyl precipitates. The sensor is used for the determination of uranium as uranyl ions in tested standard samples. The results are compared with those obtained by independent UV–vis Arsenazo III technique.