Abd-Elgawad Radi * and Hassan El-samboskany Pages 1 - 8 ( 8 )
Background: Rafoxanide (RFX) is an active agent against Fasciola hepatica, but it is prohibited for treatment of dairy animals whose milk is provided for human consumption.
Objective: A reliable, fast, and simple method needs to be developed to monitor RFX residues in milk samples before distribution to consumers.
Methods: In this work, the electrochemical oxidation of RFX was studied at glassy carbon electrodes (GCE) in Britton-Robinson buffer (BR) solutions over the pH range 2.0-12.0 using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The oxidation of the drug was accomplished in a single irreversible, adsorption-controlled step within the pH range 4.0-9.0. Therefore, the application of GCE for a sensitive and selective quantification of RFX by adsorptive stripping voltammetry was reported. The accumulation of the analyte was performed in Britton–Robinson buffer (pH 5.0) at a potential of -0.3 V (vs. Ag-AgCl-KClsat) for 300 s and the measurement was carried out, after medium exchange, in BR solution of pH 7.0 using DPV.
Result and Conclusion: This format was satisfactorily applied for the determination of RFX in bovine milk. Limit of detection (LOD) of 1.25 µg kg -1 of milk and mean recoveries of 97.8 to 107.5% were achieved.
Rafoxanide, anodic adsorptive stripping voltammetry, bovine milk, glassy carbon electrode, cyclic voltammetry, differential pulse voltammetry.
Department of Chemistry, Faculty of Science, Damietta University, 34517 New Damietta, Department of Chemistry, Faculty of Science, Damietta University, 34517 New Damietta