New Electrochemical Sensor of Prolonged Application for Metformin Determination Based on Hydrated Ruthenium Dioxide‐Carbon Black‐Nafion Modified Glassy Carbon Electrode
Anna Górska, Beata Paczosa‐Bator, Jan Wyrwa, Robert Piech
Abstract
Abstract Metformin (MET) is an antidiabetic drug most commonly used in treatment of diabetes mellitus type 2 (T2D). Adsorptive stripping voltammetric method using carbon black – hydrated ruthenium dioxide – Nafion modified glassy carbon electrode (CB‐RuO 2 ‐Nafion GC electrode) have been developed for metformin determination in pharmaceutical formulations. By using ruthenium dioxide, electrode's lifespan was extended to at least 3 weeks (change of metrological parameters estimated as 3–4 %) what is an excellent result concerning other solutions previously described in the literature. Moreover the fabrication of the sensor is simple and fast. Deposition step was carried out at the potential 0 mV for 15 s. The best results were obtained in 0.05 M acetate buffer (pH 4.6). Important aspect was fixed MET : Cu(II) ratio equal to 1 : 8, otherwise linear dependence between register current and MET concentration could not be obtained. In addition, a significant improvement in the parameters of the calibration curve was obtained. Limit of detection was equal to 0.7 μM. Developed method was successfully applied in analysis of 2 pharmaceuticals products and in wastewater and river water. Accuracy of the method was estimated using recoveries, which were in the range 101–110 %. In order to adapt developed system into hydrodynamic conditions, amperometry in hydrodynamic transport conditions and flow injection analysis (FIA) measurements have been conducted. Conducted FIA measurements prove that developed method has potential for application in automized flow systems without frequent calibration.