Simultaneous voltammetric determination of hydroquinone and catechol by using a glassy carbon electrode modified with a ternary nanocomposite prepared from oxidized multiwalled carbon nanotubes, manganese dioxide and manganese ferrite

An electrochemical sensor is described for simultaneous determination of hydroquinone (HQ) and catechol (CT) via differential pulse voltammetry (DPV). It is making use of a ternary composite material prepared from oxidized multiwalled carbon nanotubes, manganese dioxide (MnO₂) and manganese ferrite (MnFe₂O₄). The material was obtained by a one-step hydrothermal reaction and used to modify a glassy carbon electrode (GCE). The composite was characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy and scanning electron microscopy. The peak currents for HQ and CT are highest at 172 and 276 mV (vs. Ag/AgCl) at a pH value of 6.0. Response increases linearly in the 1–400 μM HQ and CT concentration ranges, and the detection limits are 0.64 and 0.48 μM, respectively. The modified GCE is highly selective, repeatable and reproducible. A single sensor was used to make 23 subsequent measurements, and the relative standard deviations were 1.8% and 2.3% for HQ and CT, respectively.

.