title: Comparison between polymerized ionic liquids synthesized using chain-growth and step-growth mechanisms used as stationary phase in gas chromatography.
abstract: In this study the merits of polymerized imidazolium based ionic liquid (PIL) stationary phases obtained via condensation and free radical polymerizations are compared as stationary phases in gas chromatography (GC). Poly(1-vinyl-3-butyl-imidazolium - bis(trifluoromethane)sulfonamide) (poly(ViC4Im(+) NTf2(-))) was obtained via a chain-growth mechanism while poly(propylimidazolium-NTf2) (poly(C3Im(+) NTf2(-))) was synthesized via a step-growth polymerization. The thermal stability of both polymers was assessed using thermal gravimetric analysis and compared with bleeding profiles obtained from the statically coated GC columns (30m×0.25mm×0.25μm). The performance was compared to what could be obtained on commercially available 1,5-di(2,3-dimethylimidazolium)pentane(2+) 2NTf2(-) (SLB-IL111) ionic liquid based columns. It was observed that the step-growth polymer was more thermally stable, up to 325°C, while the chain-growth polymer showed initial degradation at 250°C. Both polymers allowed reaching minimal plate heights of 0.400-0.500mm for retained solutes such as benzaldehyde, acetophenone, 1-methylnaphthalene and aniline. Assessment of the McReynolds constants illustrated that the polarity of the step-growth polymer was similar to the SLB-IL111 column, while displaying improved column stability. The PIL phases and particularly the so far little studied condensation based polymer shows particular retention and satisfactory column performance for polar moieties such as esters, amine and carbonyl functionalities.
authors.affiliation: Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4-Bis, 9000 Ghent, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Roeleveld
authors.affiliation: Research Institute for Chromatography, President Kennedypark 26, 8500 Kortrijk, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: David
authors.affiliation: Separation Science Group, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281 S4-Bis, 9000 Ghent, Belgium. Electronic address: Frederic.Lynen@UGent.be.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lynen
mesh_terms: D000098:Acetophenones; D000588:Amines / Q000737:chemistry; D000814:Aniline Compounds; D001547:Benzaldehydes; D002849:Chromatography, Gas / Q000379:methods*; D004952:Esters / Q000737:chemistry; D052578:Ionic Liquids / Q000138:chemical synthesis* / Q000737:chemistry*; D009281:Naphthalenes; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D013696:Temperature
chemical_list: D000098:Acetophenones; D000588:Amines; D000814:Aniline Compounds; D001547:Benzaldehydes; D004952:Esters; D052578:Ionic Liquids; D009281:Naphthalenes; D011108:Polymers; C025968:1-methylnaphthalene; C038699:acetophenone; C023650:aniline; C032175:benzaldehyde
keywords: Bis(trifluoromethane)sulfonimide; Gas chromatography; Imidazolium; McReynolds constants; Polymeric ionic liquid phase