Abstract
The construction and performance characteristics of alprenolol selective electrodes were developed. Two types of electrodes i.e., plastic membrane (I) and coated wire (II) were constructed based on the incorporation of alprenolol hydrochloride with phosphomolybdic acid. The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time and foreign ions on the electrodes were investigated. The electrodes showed a Nernstian response with a mean calibration graph slope of 58.54 +/- 0.2 and 57.83 +/- 0.4 mV/decade at 25 degrees C for electrodes (I) and (II) respectively, over alprenolol hydrochloride concentration range from 3.0 x 10(-6) - 1.0 x 10(-2) and 5.0 x 10(-6) - 1.0 x 10(-2) mol/L, with detection limit of 1.6 x 10(-6) mol/L and 2.5 x 10(-6) mol/L for electrodes (I) and (II) respectively. The constructed electrodes gave average selective precision and accuracy within the pH range (3-8). Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in pharmaceutical preparations.