Durability of membranes containing uranyl salophenes

Potentiometric, spectroscopic and microscopic studies concerning polymer me mbranes based on uranyl salophenes were per-formed. Uranyl salophenes-group of Schiff base complexes-revealed very good recognition abilities toward s ome hydrophilic anions and appeared to be very promising ionophores for pho sphate-selective electrodes. The influence of the ionophore structure and p olymer matrix composition on the durability and selectivity of PVC based me mbrane of phosphate-selective electrodes was investigated. The interaction of uranyl salophenes with water and Cl-, NO3-, H2PO4- anions was examined. When the membranes were conditioned in phosphate solution, the formation of a water-UO2-salophene complex, insoluble in both water and organic phase, and next the decomposition of the ionophore occurred. These results gave th e explanation of the mechanism of deterioration of phosphate-selective memb ranes. (C) 2001 Elsevier Science B.V. All rights reserved.