application of central composite design for optimization of coacervative extraction of cu(ii) using anionic surfactant

the aim of this work was to develop a new and simple coacervative extraction method for the preconcentration and spectrophotometric determination of cu(ii) in water samples. dithizone was used as the chelating agent while an anionic surfactant, namely sodium dodecyl sulfate (sds), was used as extracting agent at room temperature. central composite design (ccd) based on response surface methodology (rsm) was employed to optimize main experimental parameters such as ph values of solutions, concentration of the surfactant and volume of the saturated salt. analytical characteristics of the method such as limit of detection, linear range, relative standard deviation (r.s.d.) and relative standard error (r.s.e.) were calculated under the optimum conditions. the calibration graph was linear in the range of 10-100 ng ml-1 with the detection limit of 3.8 ng ml-1. the interference effects of some anions and cations were also studied. the method was successfully applied for the determination of cu(ii) in water samples.