PVC Membrane Sensors for Potentiometric Determination of Bambuterol in Pharmaceutical Formulation

摘要

The construction and electrochemical response characteristics of Poly (vinyl chloride) membranesensors for bambuterol HCl (Bb) are described. The sensing membranes incorporate ion associationcomplexes of bambuterol cation and phosphomolybdic acid (PMA) (sensor 1) and phosphotungsticacid (PTA) (sensor 2) as electroactive materials. The sensors display a fast, stable and near-Nernstian response over a relative wide bambuterol concentration range (1 10 to 710 , and 1 10 to -6 -6 6.010 M), with detection limits of 510 , and 310 for sensor 1, and 2, respectively over a pHrange of 3.0 - 8.0. The sensors show good discrimination of bambuterol from several inorganic andorganic compounds. The direct determinations of 200 /ml of Bb show an average recovery 98.5 and99.0% and a mean relative standard deviation of 1 . 5 an d 1 . 7 % at 200.0 /ml for sensor 1 and 2respectively. The proposed sensors have been applied for direct determination of Bb in somepharmaceutical preparations. The results obtained by determination of Bb in tablets using theproposed sensors are comparable favorably with those obtained using the British Pharmacopeiamethod. The sensors have been used as indicator electrodes for potentiometric titration of bambuterol.