The construction, evaluation and analytical application of a new potentiometric sensor for the determination of betahistine are described. The membrane electrode acts based on betahistine-tetraphenylborate ion-exchangers as electroactive material. This electrode has a linear dynamic range between 1.0 x 10-6-1.0 x 10-1 mol L-1 betahistine with a Nernstian slope of (29.74 ± 1.47) mV decade-1 and a detection limit of 5.8 x 10-7 mol L-1. The potentiometric response is independent of the pH of the solution in the pH range of 4.27 to 9.02. The electrode shows easy construction, low-cost, fast response time (within 10 s) and can be used for a period of eight weeks without significant change in its performance characteristics. The proposed sensor displayed good selectivities over a variety of other organic and inorganic compounds (carboxylates and inorganic anions). Application of this potentiometric sensor for the betahistine determination in pharmaceuticals, urine, and blood serum samples is reported with satisfactory results.
betahistine determination; ion selective electrode; potentiometry; pharmaceutical and biological fluids
