Preparation and Study of a Diclofenac Selective Membrane Electrode

The characteristics, performance and application of membrane electrode based on ion associate of diclofenac with basic dye Rhodamine 6G are described. The electrode response to diclofenac has the sensitivity of 60±1.0 mV decade-1 over the range of 5× 10-4–5×10-2 M at pH 8–11.6, and the detection limit of 2.0×10-5 M. The electrode is easy assembled at a relatively low cost has fast response time (2–4 s) and can be used for a period up to 5 months without any considerable divergence in potential. The proposed sensor displayed good selectivity for diclofenac in the presence of different substances. It was used to determine diclofenac in pharmaceuticals by means of the standard addition method. The analytical results obtained by using this electrode are in good agreement with those given by the Ukraine Pharmacopoeia.