title: Hybrid molecularly imprinted poly(methacrylic acid-TRIM)-silica chemically modified with (3-glycidyloxypropyl)trimethoxysilane for the extraction of folic acid in aqueous medium.
abstract: In the present study a hybrid molecularly imprinted poly(methacrylic acid-trimethylolpropane trimethacrylate)-silica (MIP) was synthesized and modified with (3-glycidyloxypropyl)trimethoxysilane (GPTMS) with posterior opening of epoxy ring to provide hydrophilic properties of material in the extraction of folic acid from aqueous medium. The chemical and structural aggregates of hybrid material were characterized by means of Fourier Transform Infrared (FT-IR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA) and textural data. Selectivity data of MIP were compared to non-imprinted polymer (NIP) through competitive sorption studies in the presence of caffeine, paracetamol or 4-aminobenzamide yielding relative selectivity coefficients (k′) higher than one unit, thus confirming the selective character of MIP even in the presence of structurally smaller compounds than the folic acid. The lower hydrophobic sorption by bovine serum albumin (BSA) in the MIP as compared to unmodified MIP proves the hydrophilicity of polymer surface by using GPTMS with opening ring. Under acid medium(pH 1.5) the sorption of folic acid onto MIP from batch experiments was higher than the one achieved for NIP. Equilibrium sorption of folic acid was reached at 120 min for MIP, NIP and MIP without GPTMS and kinetic sorption data were well described by pseudo-second-order, Elovich and intraparticle diffusion models. Thus, these results indicate the existence of different binding energy sites in the polymers and a complex mechanism consisting of both surface sorption and intraparticle transport of folic acid within the pores of polymers.
authors.affiliation: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitário, Londrina, PR CEP 86051-990, Brazil.
authors.forename: Fernanda Midori
authors.initials: FM
authors.lastname: de Oliveira
authors.affiliation: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitário, Londrina, PR CEP 86051-990, Brazil.
authors.forename: Mariana Gava
authors.initials: MG
authors.lastname: Segatelli
authors.affiliation: Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitário, Londrina, PR CEP 86051-990, Brazil; Instituto Nacional de Ciência e Tecnologia (INCT) de Bioanalítica, Universidade Estadual de Campinas (UNICAMP), Instituto de Química, Departamento de Química Analítica, Cidade Universitária Zeferino Vaz s/n, CEP 13083-970 Campinas, SP, Brazil. Electronic address: ctarleyquim@yahoo.com.br.
authors.forename: César Ricardo Teixeira
authors.initials: CRT
authors.lastname: Tarley
mesh_terms: D000327:Adsorption; D000818:Animals; D002417:Cattle; D005492:Folic Acid / Q000032:analysis / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D054802:Molecular Imprinting / Q000379:methods*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012710:Serum Albumin, Bovine; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011109:Polymethacrylic Acids; D012821:Silanes; C030613:polymethacrylic acid; D012710:Serum Albumin, Bovine; D012822:Silicon Dioxide; D005492:Folic Acid; C071717:trimethoxysilane
keywords: Batch experiments; Folic acid; Hybrid molecularly imprinted polymer; Kinetic