Metformin residue analysis in water by MWCNTs-based solid-phase micromembrane tip extraction and capillary electrophoresis methods

Metformin is the largest drug produced globally in metric tons. It has been reported in many water treatment plants and water resources. The analysis of metformin at trace level is important before supplying water to the communities. The present article describes solid-phase micromembrane tip extraction and capillary electrophoretic methods for the analysis of metformin in water using multi-walled carbon nanotubes as a sorbent in the sample preparation method. The maximum extraction of metformin was achieved at 10.0 mg/L metformin, 25 shaking time, 0.5 g/L CNTs dose, 7.0 sorption pH, 30-min desorption time and 12 desorption pH. The migration time of metformin was 8.4 min with 2.0 × 10–4, 1.35 × 10–4 and 15,600 as electrophoretic mobility (cm2V−1 s−1), electroosmotic mobility (cm2V−1 s−1) and the number of theoretical plates. These solid-phase micromembrane tip extraction and capillary electrophoretic methods were highly applicable to monitor metformin in the wastewater. The reported methods are efficient, reproducible and useful for the estimation of metformin in water and may be exploited for the analysis of the metformin water resource.