Hydrotrope-driven disruption of micellar encapsulants for voltammetric detection of triclosan

The effect of surfactant matrices on the voltammetry of an antimicrobial agent, triclosan (TCN) and its release into the aqueous continuous phase for voltammetric detection have been studied in this paper. As the surfactant concentration (wt%) was increased, the peak current was found to decrease in the order: Tween-80 > Tween-60 >>> sodium laurylsulphate. The results of these experiments are found to correlate with the published data obtained using microcalorimetry. Attempts have been made to overcome the trapping effect of surfactant matrices by designing a solution composition based on hydrotrope-driven disruption of micellar encapsulants for complete release of TCN into the analyte solution for voltammetric detection. The hydrotropes employed in this study are sodium p-toluenesulphonate and sodium benzenesulphonate. The experiments intended to show the effect of hydrotropes on the ‘pre-adsorbed’ triclosan-surfactant “pseudo-complex” proved that hydrotrope-driven disruption of micelles takes place even on the electrode surface. Thus, immersion of the surfactant-covered electrode into a hydrotrope solution can “strip” the antimicrobial agent off the surfactant. The results of these proof-of-concept experiments were applied to the analysis of low concentrations (0.1–0.8 mM) in product formulations containing TCN. A linear relationship was found between TCN concentration and current magnitude with a correlation coefficient of 0.97, the sensitivity of the measurement towards the TCN oxidation being 12.8 μA mM−1.