title: Iniferter-mediated grafting of molecularly imprinted polymers on porous silica beads for the enantiomeric resolution of drugs.
abstract: A surface-imprinted chiral stationary phase for the enantiomeric resolution of the antidepressant drug, citalopram, is presented in this work. N, N'-diethylaminodithiocarbamoylpropyl(trimethoxy)silane has been used as silane iniferter for the surface functionalization of the solid silica support. A molecularly imprinted polymer thin film, in the nm scale, was then grafted on the silanized silica using itaconic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linker in the presence of the template S-citalopram. The total monomer amount was calculated to obtain the desired thickness. Non-imprinted stationary phases were prepared similarly in the absence of S-citalopram. Characterization of the materials was carried out by scanning electron microscopy, thermogravimetric analysis, elemental analysis and Fourier transform infrared spectroscopy. Stationary phases have been applied to the chromatographic separation of the target. Conditions for best chromatographic resolution of the enantiomers were optimized, and it was found that a mobile phase consisting of a mixture of formate buffer (40 mM, pH 3) and acetonitrile (30:70 v/v) at 40 °C provided best results. Binding behaviour of the developed material was finally assessed by batch rebinding experiments. The obtained binding isotherm was fitted to different binding models being the Freundlich-Langmuir model, the one that best fitted the experimental data. The developed material has shown high selectivity for the target enantiomer, and the stationary phase could be undoubtedly exploited for chiral separation of the drug.
authors: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz (Álava), Spain.
authors: Raquel
authors: R
authors: Gutiérrez-Climente
authors: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz (Álava), Spain.
authors: Alberto
authors: A
authors: Gómez-Caballero
authors: INFU, Faculty of Chemistry, Technical University of Dortmund, Dortmund, Germany.
authors: Mahadeo
authors: M
authors: Halhalli
authors: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University, Malmö, Sweden.
authors: Börje
authors: B
authors: Sellergren
authors: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz (Álava), Spain.
authors: M Aránzazu
authors: MA
authors: Goicolea
authors: Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, Vitoria-Gasteiz (Álava), Spain.
authors: Ramón J
authors: RJ
authors: Barrio
mesh_terms: D018687:Antidepressive Agents, Second-Generation / Q000737:chemistry*; D015283:Citalopram / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D054802:Molecular Imprinting; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013237:Stereoisomerism; D013386:Succinates / Q000737:chemistry
chemical_list: D018687:Antidepressive Agents, Second-Generation; D008689:Methacrylates; D011108:Polymers; D013386:Succinates; D015283:Citalopram; D012822:Silicon Dioxide; C004919:ethylene dimethacrylate; C005229:itaconic acid
keywords: MIP; chiral stationary phase; citalopram; iniferter