Applicability of voltammetric determination of diclofenac at carbon paste electrodes to the analysis of aqueous solutions purified by adsorption and/or ionic liquid-based ion exchange

This contribution summarises the results from an initial electrochemical study of anti-inflammatory drug diclofenac at carbon paste electrodes focused on the applicability to the determination of this substance in environmental samples, namely, in aqueous solutions containing diclofenac. The substance of interest could be readily oxidized at carbon paste electrodes modified in situ with cetyltrimethylammonium bromide enhancing the response of diclofenac. The respective voltammetric method has been characterised with respect to the linear range, detection capabilities, and the overall analytical performance. Applicability of the procedure developed was examined on a set of model samples polluted with diclofenac before and after treatment with charcoal and/or various lipophilic ionic liquids to define the efficiency of such purification process. Graphical abstract