Uranyl-Selective Electrode Based on a New Bifunctional Derivative Combining the Synergistic Properties of Phosphine Oxide and Ester of Phosphoric Acid

Authors:

Abstract
Ion-selective electrodes based on the bifunctional chelating agent O-methyldihexylphosphine oxide O‘-hexyl-2-ethylphosphoric acid (HL) incorporated into a poly(vinyl chloride) membrane were developed. This new derivative is proposed as a single molecular unit combining the overall properties of the synergistic single components, di-2-ethylhexylphosphoric acid and trioctylphosphine oxide. Two different ionophores, HL and its uranyl complex (UO2L2), were studied. The response of the electrodes to uranyl ion was Nernstian for UO2L2 and super-Nernstian for HL ionophores, with detection limits of 3.0 × 10-6 and 2.0 × 10-5 M, respectively. Results indicate a more effective interaction with the analyte in the case of having a unique molecule incorporating the two functional groups immobilized into a polymeric membrane, rather than the separated two synergistic ligands. Flow-through tubular electrodes based on both ionophores were also used as potentiometric detectors in flow injection techniques.

This publication has 14 references indexed in Scilit: