Potentiometric Application of CeFeMoP and CeAlMoP in Zr(IV) Ions Analysis: A Comparative Study

Abstract

Two cerium-based ionophores Cerium(III) ironmolybdophosphate (CeFeMoP) and Cerium(III) aluminomolybdophosphate (CeAlMoP), were synthesised, having ion exchange capacities of 5.76±0.1 and 5.6±0.2 meq/gm respectively. Electroanalytical studies of synthesised heteropolyacid salts have been done using epoxy resin as binder material to form membranes of variable compositions. The potentiometric observation supports the behaviour of 40% membrane in both cases. CeFeMoP-based electrode showed a linear range from concentration 1x10-6 to 1x10-1 M and a limit of detection 6.31×10-7 M. In contrast, these parameters in the case of CeAlMoP are of linear range from 1x10-7 M to 1x10-1 M, response time 22 seconds and a limit of detection 5.01 × 10-7 M. Membranes yielded a rapid response time of 15 seconds in the case of CeFeMoP. The membranes performed very well in the case of internal concentration variations of the same solution and several other types of non-aqueous media. The FIM method proves the selectivity of the electrode even in the presence of interfering ions. CeFeMoP based sensor performed over a constant potential behaviour in pH values ranging between 3.32-8.26 while CeAlMoP based electrode worked in the pH range of 3.25-10.54 for a constant internal concentration of Zr(IV) ions. The two sensors also performed well as indicator electrodes as well as in real-time sample analysis. Hence, it is concluded that these sensors derived from CeFeMoP and CeAlMoP are quite effective in analyzing the Zr(IV) ions in various samples with quick response time and a lifetime of around 8 and 7 months respectively. A real field study was also performed by using an ICP-MS analyzer.