Clotrimazole-Triiodide Ion Association as an Ion Exchanger for a Triiodide Ion-Selective Electrode

A novel triiodide ion-selective electrode based on a clotrimazole-triiodide ion pair as a membrane carrier was prepared. It has a linear response to triiodide from 8 × 10–6 to 5 × 10–3 M with a slope of–68.9 mV per decade and a detection limit of 5 × 10–6 M. The electrode response is independent of the pH of the solution in the pH range 2–9. It has a very short response time and can be used for at least 3 months without any considerable divergence in the potentials. The proposed sensor revealed very good selectivities for I3– over a variety of other anions. It was used as an indicator electrode in the potentiometric titration of triiodide ions and in an indirect potentiometric determination of clotrimazole in pharmaceutical preparations.