Determination of zinc, copper, and mercury in water samples by using novel micro cloud point extraction and UV-Vis spectrophotometry

Abstract

A novel micro cloud point extraction (MCPE) was developed as a fast, simple, and economical preconcentration method for spectrophotometric determination of Zn, Cu, and Hg in water samples. In contrary to traditional cloud point extraction, this method does not need heating. To achieve the cloud point in room temperature, the MCPE procedure was carried out in brine. Triton X-114 was employed as a non-ionic surfactant and the analytes were chelated by 4-(2-pyridylazo) resorcinol prior to extraction. The important factors influencing the extraction efficiency were investigated and optimized. Under the optimized condition, calibration curve was found to be linear in the concentration range of 0.15-0.60, 0.02-0.10, and 0.30-0.80 mg.L-1 for Zn, Cu, and Hg respectively with a limit of detection of 51.7, 9.8, and 13.1 μg.L-1.