Preconcentration and Determination of Chromium (III) from Sea Water Samples Using Ion Imprinted Activated Carbon

A simple ion imprinted amino-functionalized sorbent was synthesized by coupling activated carbon with iminodiacetic acid, a functional compound for metal chelating, through cyanoric chloride spacer. The resulting sorbent has been characterized using Fourier transform infrared spectroscopy (FT-IR), elemental analysis, thermogravimetric analysis (TGA) and evaluated for the preconcentration and determination of trace Cr(III) in environmental water samples. The optimum pH value for sorption of the metal ion was 6. The sorption capacity of functionalized sorbent was 32.36 mg.g-1. The chelating sorbent can be reused for 10 cycles of sorptiondesorption without any significant change in sorption capacity. A recovery of 104% was obtained for the metal ion with 0.5 M nitric acid as eluting agent. The equilibrium adsorption data of Cr(III) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined as 0.048 (L/mg), 2.849 (mg/g) (L/mg)1/n and 2.124 (L/g), respectively at 25°C.