Studies on PVC-based chelating inorganic ion exchange resin membrane sensor for neodymium(III) ion

Abstract

A PVC-based sensor for Nd³⁺ ions based on chelating inorganic ion-exchange resin [tetracycline-sorbed zirconium(IV) tungstophosphate (TC-ZWP)] as an electroactive material has been prepared. The sensor exhibits a Nernstian response for Nd³⁺ ions over a wide concentration range (1×10^-1 - 5×10^-5<i> M</i>),<i> </i>when plotted on semi-log paper. The detection limit has been found to be 1×10^-5<i> M. </i>It has a response time of about 25 sec and can be used for at least 45 days without any divergence in its potential. The proposed membrane sensor reveals good selectivity for Nd³⁺ with regard to other trivalent lanthanide metal ions and could be

used in the <i>p</i>H range 3-7, as well as in the partially non-aqueous media. Analytical applications of the electrode have been evaluated for the quantitative determination of Nd³⁺ in Sibaiya phosphate ore. The sensor has also been successfully used as an indicator electrode in the potentiometric titration of Nd³⁺ against EDTA.