Electrochemical determination of guaifenesin in a pharmaceutical formulation and human urine based on an anodized nanocrystalline graphite-like pyrolytic carbon film electrode

Abstract

A simple and sensitive electrochemical method was developed for the determination of guaifenesin based on a pyrolytic carbon film (PCF) electrode. A comparative study was made with some conventional and nano-structured graphitic carbon-based electrodes, which included glassy carbon (GC), carbon paste, edge-plane pyrolytic graphite, basal-plane pyrolytic graphite, nanographene-modified GC, and carbon nanotube-modified GC electrodes. The PCF electrode, after a simple and fast anodic activation, showed remarkable electroanalytical performance. Under the optimized conditions, the oxidative peak currents at the anodized PCF electrode increased linearly with the concentration of guaifenesin in the range from 0.1 to 25 μM, with a detection limit of 0.023 μM. The determination of guaifenesin in a pharmaceutical formulation and human urine sample at the anodized PCF electrode was investigated and the results showed high percentage of recoveries.