title: A new magnetic ion-imprinted polymer as a highly selective sorbent for determination of cobalt in biological and environmental samples.
abstract: A magnetic ion-imprinted polymer (Fe3O4@TiO2@SiO2-IIP) functionalized with -NH groups for the selective determination of Co(II) ions from environmental and biological samples is presented. This sorbent was synthesized by surface imprinting technique combined with sol-gel process using 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) as a functional ligand, tetraethyl orthosilicate as across-linking agent, and Co(II) ion as the template. The prepared magnetic ion-imprinted polymer was characterized by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). Fe3O4@TiO2@SiO2-IIP showed higher capacity and selectivity than that of Fe3O4@TiO2@SiO2-NIP. The important parameters influencing the recovery such as pH, the volume and eluent concentration, contact time, and the amount of sorbent on extraction percentage of Fe3O4@TiO2@SiO2-IIP were studied and optimized. The linear range (LR), relative standard deviation(RSD) and limit of detection (LOD=3 S(b)/m) for flame atomic absorption spectrometric determination of Co(II) ion, after its selective extraction by the prepared IIP polymer, were evaluated as 1-130 µg L(-1), 1.22% and 0.15 µg L(-1), respectively. The maximum capacity of Fe3O4@TiO2@SiO2-IIP and Fe3O4@TiO2@SiO2-NIP is 35.21 mg g(-1) and 10.34 mg g(-1), respectively. The separation factor of Fe3O4@TiO2@SiO2-IIP for Co(II)/Pb(II), Co(II)/Ni(II), and Co(II)/Cd(II) are 41.17, 79.74, and 56.48, respectively. In addition, the spent magnetic ion-imprinted polymer can be refreshed by simply washing with an aqueous HNO3 solution, and there is no significant decrease in adsorption capacity after a test of upto seven cycles, demonstrating that the Fe3O4@ TiO2@SiO2-IIP is stable and reusable.
authors.affiliation: Faculty of Sciences, IKIU, Qazvin, Iran.
authors.forename: Nafiseh
authors.initials: N
authors.lastname: Khoddami
authors.affiliation: Department of Analytical Chemistry, University College of Science, University of Tehran, Iran. Electronic address: shemiran@khayam.ut.ac.ir.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Shemirani
mesh_terms: D000327:Adsorption; D000641:Ammonia / Q000737:chemistry; D000818:Animals; D002138:Calibration; D002384:Catalysis; D003035:Cobalt / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D004777:Environment; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D059346:Magnets / Q000737:chemistry*; D008892:Milk / Q000737:chemistry; D054802:Molecular Imprinting; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013997:Time Factors
chemical_list: D011108:Polymers; D003035:Cobalt; D012822:Silicon Dioxide; D000641:Ammonia; D052203:Ferrosoferric Oxide
keywords: Core–shell; Magnetic ion-imprinted polymer; Sol–gel process; Surface imprinting technique