A new membrane sensor for UO22+ ions based on 2-hydroxyacetophenoneoxime-thiourea-trioxane resin

Poly(vinylchloride) (PVC) and polystyrene based uranyl ion-selective electrodes have been constructed using 2-hydroxyacetophenoneoxine-thiourea-trioxane resin as electroactive material. For PVC based membranes dibutylphthalate (DBP) and dioctylphthalate (DOP) were used as plasticizing solvent mediators. These membrane electrodes work in the concentration range of ca. 10(-5)-10(-1) M with a response time as fast as 30 s. The useful working pH range is 2.5-3.5 and the electrodes perform satisfactorily up to 20 %(v./v.) partially nonaqueous content. The electrodes were used over a period of 4 months with good reproducibility (standard deviation = 0.5 mV). Further, the selectivity coefficient values of the order 0.1 for mono- and bivalent ions indicate moderate selectivity for UO22+ ions over the interfering ions.