Poly (dopamine quinone-chromium (III) complex) microspheres as new modifier for simultaneous determination of phenolic compounds.

In this study, poly(dopamine-quinone chromium (III))-microspheres (PDQCM) were used for the modification of graphite paste electrode (GPE) for simultaneous voltammetric determination of 4-Amino Phenol (AP), Phenol (Ph) and 4-Nitro Phenol (NP). The PDQCM and the GPE modified with PDQCM were characterized by field emission scanning electron microscopy, Energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy and electrochemistry methods such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The proposed modified electrode exhibits high electrocatalytic activity toward electrooxidation of AP, Ph, and NP to three well-separated peaks in the potential range from 0.2 to 1.3V using CV and DPV methods in phosphate buffer solution with pH 2.0. Under the optimum conditions, detection limits of 0.5, 0.6 and 0.8µM were obtained for AP, Ph, and NP, respectively. Moreover, GPE/PDQCM was successfully used for simultaneous determination of AP, Ph, and NP in tap and river waters.