Novel Gadolinium PVC‐Based Membrane Sensor Based on Omeprazole as an Antibiotic

A novel gadolinium ion-selective electrode based on the antibiotic omeprazole as membrane carrier was prepared. The electrode has a linear dynamic range between 1.0×10−1 and 1.0×10−5 M, with a Nernstian slope of 19.3 ± 0.3 mV decade−1 and a detection limit of 5.0×10−6 M. The potentiometric response is independent of the pH of the solution in the pH range 4.0–10.0. The electrode possesses the advantages of short conditioning time, fast response time and especially, very good selectivity over a large number of other cations. The electrode can be used for at least 2 months without any considerable divergence in potentials. It was used as an indicator electrode in potentiometric titration of Gd(III) ions with EDTA.