Cobalt phthalocyanine as a biomimetic catalyst in the amperometric quantification of dipyrone using FIA

AbstractA biomimetic sensor for the determination of dipyrone was prepared by modifying carbon paste with cobalt phthalocyanine (CoPc), and used as an amperometric detector in a flow injection analysis (FIA) system. The results of cyclic voltammetry experiments suggested that CoPc behaved as a biomimetic catalyst in the electrocatalytic oxidation of dipyrone, which involved the transfer of one electron. The optimized FIA procedure employed a flow rate of 1.5mLmin−1, a 75μL sample loop, a 0.1molL−1 phosphate buffer carrier solution at pH 7.0 and amperometric detection at a potential of 0.3V vs. Ag/AgCl. Under these conditions, the proposed method showed a linear response for dipyrone concentrations in the range 5.0×10−6–6.3×10−3molL−1. Selectivity and interference studies were carried out in order to validate the system for use with pharmaceutical and environmental samples. In addition to being environmentally friendly, the proposed method is a sensitive and selective analytical tool for the determination of dipyrone