Preparation of core-shell magnetic ion-imprinted polymer for selective extraction of Pb(II) from environmental samples

A novel magnetic ion-imprinted polymer (Fe3O4@SiO2@IIP) was synthesized by using 3-(2-aminoethylamino)propyltrimethoxysilane (AAPTS) as the functional monomer, tetraethylorthosilicate (TEOS) as the cross-linker and Pb(II) as the template and evaluated for selective extraction of Pb(II) from environmental sample by magnetic solid phase extraction (M-SPE) procedure. The factors affecting separation and preconcentration of the target heavy metals involving pH, eluting solvent and sample volume were studied in detail. Under the optimized experimental conditions, the kinetics adsorption and adsorption capacity of the Fe3O4@SiO2@IIP toward Pb(II) were estimated. The results indicated that the adsorption mechanism is corresponding with the second-order adsorption process with correlation coefficient (r(2) = 0.990), and the maximum adsorption capacity is 19.61 mgg(-1). The relative selectivity factor (beta) values of Pb(II)/Cu(II), Pb(II)/Zn(II), Pb(II)/Cd(II) and Pb(II)/Hg(II) are 7.41, 6.76, 3.75 and 6.39, respectively. The Fe3O4@SiO2@IIP was applied for extracting and detecting of Pb(II) in real environmental samples combined with atomic adsorption spectrometer successfully with high recoveries of 98.0%. (C) 2011 Elsevier B.V. All rights reserved.