Electrochemical Reduction and Oxidation of the Antibiotic Cefoxitin-Cu2+ Complex and its Analytical Applications

Abstract

The interaction of cefoxitin, being a compound of interest for antibiotic research, with Cu2+ resulted in the formation of a 1 : 1 complex. The electrochemical reduction at a hanging mercury drop electrode and oxidation at a renewable pencil graphite electrode of the formed cefoxitin-Cu2+ complex was investigated using cyclic voltammetry and differential pulse voltammetry in Britton-Robinson buffers (pH 2–9). For the electrochemical reduction or oxidation of the examined complex, a new well-defined voltammetric peak was obtained and the features of the surface redox and oxidation peaks were studied. Calculations of the values of stability constant and the change on Gibbs free energy for cefoxitin-Cu2+ complex suggest that the complexation is a spontaneous process. The sharp peak of the electroreduction and oxidation of the investigated complex associated with an effective interfacial accumulation of this complex facilitates the determination of the antibacterial drug cefoxitin in the bulk and blood serum samples. Cefoxitin was determined by electrochemical reduction and oxidation of the cefoxitin-Cu2+ complex, with detection limits of 6.94×10−9M and 9.07×10−8M respectively.