Iron oxide nanopowder based electrochemical sensor for sensitive voltammetric quantification of midodrine

Abstract The present work describes the fabrication and electrochemical characterization of a novel iron oxide nanopowder-based carbon paste electrodes (CPE) for the sensitive voltammetric quantification of midodrine (MD) in pharmaceutical formulations and biological fluids. At the electrode surface, the postulated reaction mechanism involved the irreversible oxidation of the terminal amino group of midodrine through the participation of two-electron as elucidated by the sweep rate studies and molecular orbital calculations. Calibration graphs were linear in the MD concentration range from 0.16 × 10-6 to 2.12 × 10-6 mol L-1 with LOD 0.04 × 10-6 mol L-1. Prolonged stability with an operational lifetime of more than 4 months and high measurement reproducibility were the promising futures of the fabricated sensors. The proposed electroanalytical approach was free from interference and suggested for assaying of midodrine in its pharmaceutical formulations and biological samples with recovery agreed with the official methods.