Ion-imprinted carboxymethyl chitosan-silica hybrid sorbent for extraction of cadmium from water samples

A new ion-imprinted carboxymethyl chitosan-functionalized silica gel sorbent was synthesized by surface imprinting technique using Cd(II) as the template, carboxymethyl chitosan (CMCS) as the functional monomer and glutaraldehyde as the cross-linking agent for the selective adsorption of Cd(II) from aqueous solution. The optimum batch experimental conditions (pH, amount of adsorbent, contact time) and column experimental conditions (concentration and volume of elution solution) were evaluated. The maximum static adsorption capacity of the ion-imprinted sorbent for Cd(II) was 20.7 mg/g. The enrichment factor of Cd(II)-imprinted polymer for Cd(II) was 257. The relative selectivity factor values of Cd(II)/Pb(II), Cd(II)/Co(II) were 5.3 and 1.5, respectively. The recoveries of water samples were about 98.0-104.0% (R.S.D. <= 0.8). The proposed method was successfully applied to determination of Cd(II) in water samples with satisfactory. (c) 2013 Elsevier B.V. All rights reserved.