Development of a cleanup and electrochemical determination of flutamide using silica thin film pencil graphite electrode functionalized with thiol groups

This work mainly deals with the application of cleanup, preconcentration and electrochemical determination of flutamide. A new system is developed to cleanup and detect of flutamide at the surface of a working electrode. Differential pulse voltammetry (DPV) was used as a detection system. A modified pencil graphite electrode (PGE) was used as a working electrode. The surface of the PGE was coated with sodium dodecyl sulfate (SDS)-modified silica thin film. Flutamide is extracted from sample to the modified silica thin film and reduced electrochemically, and then, it was oxidized at the electrode surface. The effect of sample pH, SDS concentration, percentage of ingredients fiber structure, applied potential on the formation of fiber, and applied potential time on the electrode surface to form the fiber were evaluated. Other essential factors for flutamide extraction such as extraction time, stirring rate, pretreatment potential and electrochemical parameters were optimized. Using the extraction system, the DPV responses of different concentrations of flutamide were linear in the range of 0.10–100.0 nmol L−1 and 0.10–100.0 μmol L−1 with a detection limit of 34 pmol L−1. The technique was successfully applied for the determination of flutamide in human urine and plasma samples. The technique was successfully applied for the determination of flutamide in human urine and plasma samples.