Potentiometric determination of Benzydamine hydrochloride using PVC membrane and coated wire sensors in pure form, pharmaceutical compounds and biological fluids

The construction and electrochemical response characteristics of PVC membrane and coated wire sensors for the determination of Benzydamine hydrochloride (Benz) are described. PVC membrane sensors, include sensors 1, 2 and 3, and coatedwire sensors include sensors 4, 5 and 6. Sensors 1 and 4 based on benzydamine phosphotungstate (Benz-PTA) as ion-pair, sensors 2 and 5 based on benzydamine phosphomolybdate (Benz-PMA) as ion-pair and sensor 3 and 6 based on benzydamine reineckate (Benz-RN) as ion-pair. Sensors 1, 2 and 3 (PVC membrane sensors) have a linear concentration range from 7.0×10 −6 to 1.0×10 −2 , 1.0×10 −5 to 1.0×10 −2 and 1.0×10 −5 to 1.0×10 −2 mol L −1 , with a Nernstian slope of 58.6±0.3, 59±0.4 and 58.7±0.2 mV/decade and a detection limit of 5.0×10 −6 , 7.2×10 −6 and 1.0×10 −5 mol L −1 , respectively. Sensors 4, 5 and 6 (coated-wire sensors) have the same linear concentration range from 1.0×10 −6 to 1.0×10 −2 mol L −1 , with the same detection limit of 1.0×10 −6 mol L −1 and with a Nernstian slope of 58.9±0.1, 60.0±0.5 and 59.5±0.4 mV/decade, respectively. The response is independent of the pH of test solution within the range 3–8 for PVC membrane sensors and within 2-8 for coated-wire(CW) sensors. All sensors show fast response time which is 5, 3, 3, 8, 6 and 7 s for sensors 1, 2 , 3, 4, 5 and 6, respectively. The sensors showed good selectivity towards benzydamine with respect to large numbers of species. . The sensors have been applied to the determination of benzydamine in pure solution, pharmaceutical compounds and biological fluids. keywords: Benzydamine hydrochloride; Potentiometry; Sensors; Biological fluids.