Calcium measurement using ion selective electrode based on a benzo-18-crown-6 as an 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 1×10−1 M with a Nernstian slope of 29.8 mV/decade and detection limit is 4.0×10−6 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 of 5 to 12. The proposed electrode also was applied for the direct determination of Ca2+ cation in doubly distilled deionized water samples spiked with different concentrations of calcium. This electrode was also used for determination of Ca2+ in real samples with a very good recovery.