Silver nanoparticles functionalized with sodium mercaptoethane sulfonate to remove copper from water by the formation of a micellar phase

Abstract

This work presents a novel procedure for the removal of Cu2+ from water, an essential element in human nutrition considered toxic in high concentrations, based on a microextraction technique involving the formation of a micellar phase. To achieve the total elimination of copper from aqueous samples, a Cu2+-complexing reagent based on silver nanoparticles functionalized with sodium mercaptoethane sulfonate (AgNPs@MESNa) was used. The complex formed by Cu2+ and the reagent was extracted into a micellar microphase formed by Triton X-114, a harmless surfactant. Volumes of 200 µL of the 10−4 mol L−1 suspension of AgNPs@MESNa and 100 µL of a solution of Triton X-114 at 30% m/m were employed to successfully remove 10 mg L−1 of Cu from 20 mL of water samples. The time and temperature needed to achieve 100% microextraction efficiency were 10 min and 40◦ C, respectively. The procedure is considered environmentally friendly due to the low volume of the extracting phase and the simple experimental conditions that achieve total removal of Cu2+ from water samples.