Amperometric determination of hydroquinone and catechol using a glassy carbon electrode modified with a porous carbon material doped with an iron species

A porous carbon material doped with an iron species (Fe/PC) was prepared by carbonizing a mixture of zeolitic imidazolate framework-8 in the presence of iron(II) ions. The resulting material was characterized by X-ray diffraction, nitrogen adsorption isotherms, transmission electron microscopy, and by Raman and X-ray photoelectron spectroscopy. Fe/PC was the deposited on the surface of glassy carbon electrode (GCE) to obtain a sensor for amperometric determination of phenolic compounds. The unique catalytic activity, good electrical conductivity and hierarchical structure of the Fe/PC composite results in good electrooxidative activity towards hydroquinone (HQ; typically at 44 mV) and catechol (CC; typically at 160 mV). Under optimal conditions, the amperometric responses are linear in the range from 0.1 to 120 mu mol.L-1 for HQ, and from 1.0 to 120 mu mol.L-1 for CC. The respective detection limits are 14 and 33 nmol.L-1. The sensor is highly selective against potential interferents and was successfully applied to the determination of HQ and CC contents in (spiked) water samples.