Synthesis, characterization and analytical application of zirconium (IV) antimonoarsenate as a potentiometric sensor

A new inorganic ion exchanger, zirconium (IV) antimonoarsenate has been synthesized at different pH values. An amorphous sample prepared at pH 1 having an ion-exchange capacity of 0.40 meq/g was selected for further studies. The material is characterized using various analytical techniques, like XRD, IR, TGA and SEM, in addition to the ion-exchange capacity and distribution coefficient (K-d) studies. Further the exchanger has been used as an electro-active material for the determination of Cerium (III) ions with epoxy resin, PVC and polystyrene as binding materials. A membrane having a composition: ZrSbAs (50%) and polystyrene (50%) gives the best performance. It works well over a wide Cc (III) ion-concentration range of 5 x 10(-5)-1 x 10(-1) M with a super-Nernstian slope of 52.0 mV/decade. It has a fast response time of 10 s and has an average lifetime of four months. The proposed sensor shows a good selectivity for cerium (III) ions with respect to alkali, alkaline earth, some transition and rare earth metal ions that are normally present along with cerium in its ores. The electrode has also been used as an indicator electrode in potentiometric titrations of Ce (III) ions against oxalic acid. (c) 2006 Elsevier B.V. All rights reserved.