Taking advantage of CTAB micelles for the simultaneous electrochemical quantification of diclofenac and acetaminophen in aqueous media†
From spectrophotometric and electrochemical techniques, it was shown that cetyltrimethylammonium bromide, CTAB, hemimicelles, formed on the surfaces of a carbon paste electrode (CPE), selectively adsorbed diclofenac, DCF, molecules from a neutral aqueous solution of DCF and acetaminophen, ACT. This CTAB–DCF interaction is so important that it modified the DCF electrochemical oxidation mechanism from a mass-transferred controlled one (in the absence of CTAB) to an adsorption controlled mechanism which allows the simultaneous quantification of both drugs. This novel methodology was used for the individual and simultaneous quantification of DCF and ACT in both aqueous media and synthetic urine. Moreover, it is shown that the analytical method proposed in this work is similar or even better than other more sophisticated and expensive techniques available.