Electrochemical Reduction and Voltammetric Determination of Metronidazole Benzoate at Modified Carbon Paste Electrode

Abstract

A metalloporphyrin incorporated carbon paste sensor has been developed for the determination of metronidazole benzoate (MTZB). Zn(II) complex of 5,10,15,20-tetrakis (3-methoxy-4-hydroxy phenyl) porphyrin (TMHPP) was used as the active material. The MTZB gave a well-defined reduction peak at−0.713 V in 0.1 mol l⁻¹ phosphate buffer solution of pH around 7. Compared with bare carbon paste electrode (CPE), the TMHPP Zn(II) modified electrode significantly enhanced the reduction peak current of MTZB as well as lowered its reduction potential. Under optimum conditions the reduction peak current was proportional to MTZB concentration over the range 1 × 10⁻³ mol l⁻¹ to 1 × 10⁻⁵ mol l⁻¹. The detection limit was found to be 4.36 × 10⁻⁶ mol l⁻¹. This sensor has been successfully applied for the determination of MTZB in pharmaceutical formulations and urine samples.

Keywords:

• Carbon paste electrode
• cyclic voltammetry
• electrochemical reduction
• metalloporphyrin
• metronidazole benzoate

The authors are grateful to the Defense Research and Development Organization (DRDO) India for the financial assistance in the form of project, IIT Chennai, India and Sophisticated Test and Instrumentation Centre (STIC), Cochin University (P.O), India for providing all help with the analysis of compounds.

Notes

∗Average of six replicates.