Green technology for monitoring the quality of water: determination of toxic trace analyte concentrations using multielemental mixed micelle cloud point extraction

摘要

A simple multielemental mixed micelle cloud point extraction procedure has been developed for the simultaneous separation and preconcentration of toxic trace analytes from natural and wastewater samples prior to their determination by electrothermal atomic absorption spectrometry. The analytes Cr, Be, Pb, Cd, Tl, and Hg were converted simultaneously, as hydrophilic anionic iodide species formed with KI in the presence of HCl. The method is based on the formation of extractable ion associates of anionic iodide species with solubilizing cationic and hydrophobic sites of mixed micelles. The mixed micelles are formed by cationic, Aliquat-336 (N-methyl-N,N,N-trioctylammonium chloride) and nonionic, Triton X-114. The ion associates formed are preconcentrated from bulk aqueous phase into a small mixed micelle-rich phase, avoiding the addition of an external chelating agent. The parameters affecting the process are evaluated and optimized. The recoveries of anaytes are in the range of 86-102% at 0.1-10gL(-1). The accuracy of the procedure has been verified by using certified reference materials, such as National Institute of Standards and Technology (NIST) 1640a natural water, Community Bureau of Reference (BCR)-713 final effluent, and BCR-715 industrial effluent and being applied to industrial wastewater.