Simultaneous determination of epinephrine and acetaminophen concentrations using a novel carbon paste electrode prepared with 2,2'-[1,2 butanediylbis(nitriloethylidyne)]-bis-hydroquinone and TiO(2) nanoparticles.

A carbon paste electrode (CPE) modified with 2,2'-[1,2 butanediylbis(nitriloethylidyne)]-bis-hydroquinone (BBNBH) and TiO(2) nanoparticles was used for the sensitive voltammetric determination of epinephrine (EP). The electrochemical response characteristics of the modified electrode toward EP and acetaminophen (AC) were investigated by cyclic and differential pulse voltammetry (CV and DPV). The results showed an efficient catalytic activity of the electrode for the electrooxidation of EP, which leads to a reduction in its overpotential by more than 270mV. The effects of pH and potential sweep rate on the mechanism of the electrode process were investigated. The modified electrode exhibits an efficient electron-mediating behavior together with well-separated oxidation peaks for EP and AC. At the optimum pH of 8.0 in a 0.1M phosphate buffer solution, the DPV anodic peak currents showed a linear relationship versus EP concentrations in the range of 1.0-600.0microM and a detection limit of 0.2microM.