Square-wave voltammetric determination of propranolol and atenolol in pharmaceuticals using a boron-doped diamond electrode

The independent determination of two β-blocker agents, namely propranolol (PROP) and atenolol (ATN), in pharmaceutical formulations using square-wave voltammetry and a cathodically pretreated boron-doped diamond electrode is described. These electroanalytical determinations of propranolol or atenolol were carried out in 0.1 mol L−1 H2SO4 or 0.5 mol L−1 NaNO3 (pH 1.0, adjusted with concentrated HNO3), respectively. Excellent linear calibration curves, ranging from 0.20 to 9.0 μmol L−1 for PROP and from 2.0 to 41 μmol L−1 for ATN, with detection limits of 0.18 and 0.93 μmol L−1, respectively, were obtained. The obtained recoveries range from 93.9% to 105.0%, for PROP, and from 92.5% to 106.0%, for ATN. The proposed method was successfully applied in the determination of both β-blockers in several pharmaceutical formulations (tablets), with results in close agreement at a 95% confidence level with those obtained using official spectrophotometric methods.