NOVEL PVC-BASED MEMBRANE SENSORS SELECTIVE FOR VANADYL IONS

Poly(vinyl chloride) based membranes of di-(2-ethylhexyl)phosphoric ac id (DEHPA) and dibutyl(-butyl)phosphonate (DBBP) have been prepared an d investigated as VO2+-selective sensors. The membranes containing DEH PA/DBBP and sodium tetraphenylborate, an anion excluder, show near-Ner nstian/Nernstian response in the concentration range similar to 10(-5) -10(-1) M. The sensors exhibit a fast response time and good selectivi ty for VO2+ over a number of other cations. Quantitative determination of vanadium in waste V2O5 catalyst has been achieved by these sensors and they have also been used as indicator electrodes for the determin ation of the end point in the potentiometric titration of VO2+ against EDTA. (C) 1998 Elsevier Science B.V. All rights reserved.