Preconcentration and Differential Pulse Voltammetry of Tegaserod at a Glassy Carbon Electrode

Abstract

The adsorptive and electrooxidation behavior of tegaserod was studied at glassy carbon electrode in Britton–Robinson (B–R) buffer over the pH range 2.0–10.0 using cyclic and differential pulse voltammetry. Oxidation of the drug was effected in a main quasi‐reversible, adsorption‐controlled step. The analysis procedure based on an open circuit accumulation step in stirred sample solution in B–R, pH 9.0. This was followed by medium exchange to a pure electrolyte solution (B–R, pH 7.0) and, subsequently, an anodic differential pulse voltammetry was effected to obtain the voltammetric peak at +0.155 V (vs. Ag–AgCl). The anodic peak current was found to increase linearly over two orders of magnitude from 1.0 × 10⁻⁹ to 1.0 × 10⁻⁷ M with a detection limit of 3.0 × 10⁻¹⁰ M. The developed method was applied to tegaserod determination in spiked human serum.

Keywords:

• Tegaserod
• Differential pulse voltammetry
• Glassy carbon electrode
• Stripping voltammetry
• Serum analysis