Removal of copper(II) with acrylate based ph sensitive polymers and spectrophotometric determination of copper (II)

SUMMARYThe purpose of this study was to prepare a pH-sensitive hydrogel from 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AA), and ammonium acrylate,NH4Ac, redox initiators, Na2S2O8/Na2S2O5 ,and crosslinker, ethylene glycoldimethacrylate, EGDMA. The hydrogel exhibited the highest affinity for the removal ofCu(II) at pH=6.0. In all of the sorption studies, agitation was kept constant at 30minutes. The maximum Cu(II) sorption capacity of the hydrogel was obtained at 600µg/mL as 90,97 mg Cu(II)/g polymer.The extent of desorption was found as 96.55% at pH=1.25. It was seen thatincreasing the concentration of Ni(II) ion in the sorptiom medium beyond 50 µg/mL didnot changed sorption capacity of the polymer.In reusability studies, sorption-desorption cycle was repeated four times and theresults showed that the synthesized polymer can be used repeatedly without loosing itssorption capacity too much.Amount of complexing agent dimethylglyoxime, DMG, and medium pHwere optimized as 7.0 ml and 4.5, respectively. The linear range, LOD and LOQ weredetermined as 0.25-4.0 µg/mL, 0.069 µg/mL and 0.211 µg/mL, respectively.In recovery studies, relatively high percent recovery values, 98.7-104.5%, andrelatively low values of %RSD, 1.76-3.32%,. proved the accuracy and precision of theproposed method.The results showed that, the acrylate-based, pH-sensitive polymeric ion-exchange resin is very suitable for sorption and desorption of Cu(II) ions present in theaqueous media and the proposed method for the determination of Cu(II) in the presenceand absence of Ni(II) ions is very simple, rapid, precise and accurate.