Calcium measurement using ion selective electrode based on a macromolecule ionophore

A new PVC based membrane using benzo-18-crown-6 as an ionophore has been developed as a calcium ion selective electrode. The electrode comprises of ionophore (4%), PVC (30%) and plasticizer (63%). The electrode shows a linear dynamic response in the concentration range of 1×10−5 M to 1×10−1M with a Nernstian slope of 29.8 mV/decade and a detection limit as 4×10−6 M. The proposed sensor shows reasonably good selectivity with respect to alkali, alkaline earth and transition metal ions. It can be used in the pH range 5–12. The proposed electrode also was applied for the direct determination of Ca2+ cation in doubly distilled deionized water samples spiked with different concentrations calcium. This electrode was also used for determination of Ca2+ in real samples with a very good recovery.

Keywords:

Calcium (II) cation , Ion selective electrode , Potentiometry