Poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] brushes grafted onto siliceous support for preconcentration and determination of cobalt (II) in human plasma and environmental samples

A chelating matrix prepared by surface grafting of polymer containing a functional monomer, poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-methylacrylamide] (poly(AGE/IDA-co-DMAA) onto a modified silica. The silica surface was modified by silylation with 3-mercaptopropyltrimethoxysilane followed by graft polymerization. Monomer of allyl glycidyl ether-iminodiacetic acid was synthesized by reaction of allyl glycidyl ether with iminodiacetic acid. The chelating sorbent can be reused for 15 cycles of sorption-desorption without any significant change in sorption capacity. The profile of cobalt uptake on the sorbent reflects good accessibility of chelating sites in poly(AGE/IDA-co-DMAA)-grafted silica gel. The equilibrium adsorption data of Co(II) on modified sorbent were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models. The method was applied for cobalt ions determination in human plasma and sea water sample with satisfactory results.