Simultaneous voltammetric determination of ascorbic acid and acetaminophen in pharmaceutical formulations with UiO-66-modified glassy carbon electrode

This article reports the synthesis of the University of Oslo-66 (UiO-66) and its application to simultaneous voltammetric determination of ascorbic acid (AA) and acetaminophen (AC). The zirconium terephthalate samples synthesized in different solvents (the N,N '-dimethylformamide, acetonitrile, and ethanol) are characterized with XRD, SEM, TG, nitrogen adsorption/desorption isotherm, and XPS techniques. Among solvents the N,N '-dimethylformamide solvent is favorable for the UiO-66 phase formation. The synthesized UiO-66 material with spherical particles with round 100-150 nm in diameters possesses a large specific surface area. The UiO-66 is used as electrode modifier to develop UiO-66 modified glassy carbon electrode for determining simultaneous AA and AC. The UiO-66 modified electrode demonstrates excellent electrocatalytic performance towards AA and AC oxidation compared with bare GCE. The anodic peak current varies linearly to AA and AC concentration in the range of 0.02 to 2.92 mu M. The level of detection (S/N = 3) was found to be 0.019 and 0.018 mu M, respectively. The proposed differential pulse voltammetry method was used to determine individually or simultaneously AA and AC in pharmaceutical formulations. The results are not significant different from those analyzed by high-performance liquid chromatography.