Cloud Point Extraction, Simultaneous and Preconcentration Spectrophotometric Determination of Nickel and Cobalt in Water Samples

Abstract

Cloud point extraction has been used for the preconcentration and simultaneous spectrophotometric determination of nickel and cobalt after the formation of a complex with sodium diethyldithiocarbamate (Na-DDTC) and latter analysis by spectrophotometer using Triton X- 114 as surfactant. The parameters affecting the separation phase and detection process were optimized. Under the optimum experimental conditions (i.e., pH = 5, 0.07 mM Na-DDTC, Triton X-114 = 0.25 % (w/v)), calibration graphs were linear in the range of 20-440 and 20-210 μg L^-1 with detection limits of 9.2 and 8.0 μg L^-1 for Ni and Co, respectively. The method was applied to the determination of Ni and Co in natural and waste water samples with satisfactory results.