Preparation, Characterization, and Analytical Application of Ramipril Membrane-Based Ion-Selective Electrode

The fabrication and electrochemical evaluation of two PVC membrane-based Ion-Selective electrodes responsive for ramipril drug have been proposed. The sensitive membranes were prepared using ramipril-phosphomolibdate and ramipril-tetraphenylborate ion-pair complexes as electroactive sensing materials in plasticized PVC support. The electrodes based on these materials provide near-Nernestian response (sensitivity of 53 +/- 0.5-54 +/- 0.5 mV/concentration decade) covering the concentration range of 1.0 x 10(-2)-1.0 x 10(-5) mol L(-1) with a detection limit of 3.0 x 10(-6)-4.0 x 10(-6) mol L(-1). The suggested electrodes have been successfully used in the determination of ramipril drug in some pharmaceutical formulations using direct potentiometry with average recovery of >96% and mean standard deviation of <3% (n = 5).