Voltammetric Determination of Guaifenesin in Pharmaceuticals and Urine Samples Based on Poly(Bromocresol Purple) Modified Glassy Carbon Electrode

Introduction: The electro-oxidation behavior of expectorant drug Guaifenesin (GUF) was studied on poly(bromocresol purple) modified Glassy Carbon Electrode (GCE) by Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) methods. Materials and Methods: GCE was modified with electropolymerization of Bromocresol Purple (BP) monomer for sensitive determination of GUF with voltammetric methods. The oxidation process of GUF showed irreversible and diffusion controlled behavior. The linearity has been obtained in the range from 1.00 x 10-7 to 2.00 x 10-5 M with the limit of detection 3.658 x 10-9 M for DPV in 0.1 M phosphate buffer solution (PBS) at pH 3.0. Results and Conclusion: Fully validated differential pulse voltammetry was successfully applied for the determination of GUF in pharmaceutical dosage forms and urine samples obtained satisfying results.