Electrochemical study of atenolol at a carbon paste electrode modified with mordenite type zeolite

The electrochemical behavior of atenolol (ATN) at the surface of a carbon paste electrode modified with mordenite zeolite (MOR-MCPE) is described. The prepared electrode shows a good electrocatalytic activity toward the oxidation of atenolol, which is leading to considerable improvement of sensitivity (anodic current). Whereas at the surface of unmodified electrode an electrochemical activity for atenolol cannot be observed, a sharp anodic wave is obtained using the prepared modified electrode. The mechanism of oxidation of ATN at the surface of the MOR-MCPE containing various percents of mordenite is thoroughly investigated by cyclic and differential pulse voltammetry. Acetate, hydrogen phosphate and ammonium buffers were tested as the supporting electrolyte to find the optimal pH value. The optimal pH value was 5.0 for acetate buffer. A linear voltammetric response for ATN was obtained in the concentration range of 0.4 to 80 mu M with a slope of 0.676 mu A/mu M. The LOD and LOQ of the electrode were 0.1 mu M (26.6 mu g/L) and 0.35 mu M (93.1 mu g/L), respectively. The results obtained for ATN in pharmaceutical formulations (tablets) was in agreement with compared reference method. In conclusion, this study has illustrated that the proposed electrode modified with mordenite is suitable for selective measurements of ATN. (c) 2010 Elsevier B.V. All rights reserved.