Electrochemical behavior of Moclobemide at mercury and glassy carbon electrodes and voltammetric methods for its determination

Electrochemistry and determination of cefdinir by voltammetric and computational approaches

The oxidation and reduction behavior of cefdinir (CEF) was studied by experimental methods and computational calculations at B3LYP/6–31+G (d)//AM1. Voltammetric studies were carried out based on two irreversible reduction peaks at approximately −0.5 and −1.2 V on a hanging mercury drop electrode (HMDE) and on one irreversible oxidation peak at approximately 1.0 V on a glassy carbon electrode (GCE) versus Ag/AgCl, KCl (3.0M) in Britton–Robinson (BR) buffer at pH 4.2 and 5.0, respectively. Differential pulse adsorptive stripping voltammetric methods have been developed and validated for determination of CEF in different samples. The linear range was established as 0.25–40.0 μM for HMDE and 0.40–10.0 μM for GCE. Limit of quantification was calculated to be 0.20 and 0.26 μM for HMDE and GCE, respectively. These methods were successfully applied to assay the drug in tablets and human serum with good recoveries between 92.7% and 107.3% having relative standard deviation less than 10%.

A cooperative computational and experimental investigation on electrochemical behavior of metoprolol and its voltammetric determination

The electrochemical behavior of metoprolol (MTP) was studied via experimental and computational approaches. Theoretical calculations were performed at the B3LYP/6-31+G(d)//AM1 level whereas experimental studies were carried out on a hanging mercury drop electrode (HMDE) and glassy carbon electrode (GCE). According to the computational results, both HOMO and LUMO of MTP were located at the phenyl ring. Hence, oxidation and reduction are expected to take place at the phenyl ring. Experimental studies on HMDE were based on reversible reduction at approximately –1.4 V and studies on GCE were based on irreversible oxidation at approximately 0.9 V versus Ag/AgCl (3 mol L−1 KCl) in Britton−Robinson buffer. Voltammetric methods with and without adsorptive stripping modes were developed. Proposed methods were successfully applied to tablet solutions and spiked human serum samples. Results are satisfactory with recovery values between 94.5% and 102.5% and a relative standard deviation lower than 6%.