Voltammetric Determination of Guaifenesin on Poly (Nile blue) Modified Glassy Carbon Electrode in Pharmaceutical Dosage Forms

The electro-oxidation behavior of expectorant drug guaifenesin (GUF) was studied on poly(Nile blue) modified glassy carbon electrode by cyclic voltammetry and differential pulse voltammetry. Cams？ karbon elektrot was modified with electropolymerization of Nile blue for sensitive determination of GUF with voltammetric methods. The current peaks for GUF occurred at around 1.130 V for differential pulse voltammetry when the potential was scanned in the positive direction. The oxidation process of GUF has shown irreversible and diffusion controlled behavior. The linear response has been obtained in the range from 6 × 10-7 to 1 × 10-4 M with the limit of detection 1.24 × 10-8 for differential pulse voltammetry in 0.1 M phosphate buffer solution at pH 3.0. Fully validated differential pulse voltammetry was successfully applied for the determination of GUF from pharmaceutical dosage form and obtained satisfying results