title: Anion exchangers with branched functional ion exchange layers of different hydrophilicity for ion chromatography.
abstract: Novel polystyrene-divinylbenzene (PS-DVB) based anion exchangers differing from each other in the structure of the branched functional ion exchange layer are prepared to investigate the role of linker and functional site on ion exchange selectivity. The proposed method of synthesis includes the obtaining of aminated PS-DVB particles by means of their acylation with following reductive amination with methylamine. Further modification of the obtained secondary aminogroups is provided by the alkylation with either 1,4-butanediol diglycidyl ether (1,4-BDDGE) or resorcinol diglycidyl ether (RDGE), which form the linkers of different hydrophobicity, and amination of terminal epoxide rings with trimethylamine (TMA), dimethylethanolamine (DMEA), methyldiethanolamine (MDEA) or triethanolamine (TEA). The variation of the structure and hydrophobicity of the linker and terminal quaternary ammonium sites in the functional layer allows the alteration of selectivity and separation efficiency of the obtained adsorbents. The ion exchange selectivity and separation efficiency of the anion exchangers are evaluated using the model mixtures of anions (F(-), HCOO(-), Cl(-), NO2(-), Br(-), NO3(-), HPO4(2-) and SO4(2-)) in potassium hydroxide eluents. The adsorbents show the decrease of selectivity with increasing the hydrophilicity of the terminal functional site. The anion exchangers having more flexible and hydrophilic 1,4-BDDGE linker provide smaller separation factors for most of the analytes as compared with RDGE-containing adsorbents with the same terminal ion exchange sites, but are characterized with higher column efficiencies and better peak symmetry for polarizable anions. In case of 1,4-BDDGE-modified anion exchangers of the particle size of 3.3μm functionalized with DMEA and MDEA the calculated values of column efficiencies for polarizable NO3(-) and Br(-) are up to 49,000 and 53,000N/m, respectively, which is almost twice higher than the values obtained for the RDGE-containing analogues.
authors.affiliation: Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, GSP-1, Moscow 119991, Russia.
authors.forename: O I
authors.initials: OI
authors.lastname: Shchukina
authors.affiliation: Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, GSP-1, Moscow 119991, Russia. Electronic address: zatirakha@analyt.chem.msu.ru.
authors.forename: A V
authors.initials: AV
authors.lastname: Zatirakha
authors.affiliation: Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, GSP-1, Moscow 119991, Russia.
authors.forename: A D
authors.initials: AD
authors.lastname: Smolenkov
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), University of Tasmania, Hobart 7001, Australia.
authors.forename: P N
authors.initials: PN
authors.lastname: Nesterenko
authors.affiliation: Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1/3, GSP-1, Moscow 119991, Russia.
authors.forename: O A
authors.initials: OA
authors.lastname: Shpigun
mesh_terms: D002072:Butylene Glycols / Q000737:chemistry; D002852:Chromatography, Ion Exchange / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D007474:Ion Exchange; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D012118:Resorcinols / Q000737:chemistry
chemical_list: D002072:Butylene Glycols; D011137:Polystyrenes; D012118:Resorcinols; C432006:divinylbenzene-polystyrene copolymer; C013488:diglycidyl resorcinol ether; C014376:1,4-bis(2,3-epoxypropoxy)butane
keywords: Anion exchanger; Branched ion exchange groups; Determination of anions; Ion chromatography; Poly(styrene-divinylbenzene)