Selective separation and preconcentration of cyanide by a column packed with cyanide-imprinted polymeric microbeads

Abstract

Using the strategy of template polymerization, specific metal-complexing polymer which is poly(methacryloylhistidine-Ni(II)-CN-) (P(MAH-Ni(II)-CN-)) has been prepared. This polymer is able to specifically recognize the cyanide ion. For this purpose, nickel(II)-methacryloylhistidine dihydrate complex monomer was synthesized and then reacted with KCN. Monomer-template complex phase was polymerized in dispersion medium. After polymerization, the template (CN-) was removed from the P(MAH-Ni(II)-CN-) microbeads getting CN- ion imprinted metal-chelate polymer. CN- imprinted metal-chelate polymer can be used several times without considerable loss of adsorption capacity. When the adsorption capacity of CN- imprinted microbeads were compared with nonimprinted microbeads, CN- imprinted microbeads have higher adsorption capacity. The K-d values for the CN--imprinted microbeads show increase in K-d for CN- while K-d decreases for SCN-, S2-, Cl-, NO3- and SO42- ions and the k' values are greater than 1 for imprinted microbeads of CN-/SCN-, CN-/S2-, CN-/Cl-, CN-/NO3- and CN-/SO42- are 43.37, 54.78, 109.1, 117.2 and 167.9, respectively. Determination of CN- ion in waste water showed that the interfering matrix had been almost removed during preconcentration. This means that CN- can be determined even in the presence of SCN-, S2-, Cl-, NO3- and SO42- ions