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

Abstract

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%.