title: Identifying important structural features of ionic liquid stationary phases for the selective separation of nonpolar analytes by comprehensive two-dimensional gas chromatography.
abstract: A series of dicationic ionic liquid (IL)-based stationary phases were evaluated as secondary columns in comprehensive two-dimensional gas chromatography (GC×GC) for the separation of aliphatic hydrocarbons from kerosene. In order to understand the role that structural features of ILs play on the selectivity of nonpolar analytes, the solvation parameter model was used to probe the solvation properties of the IL-based stationary phases. It was observed that room temperature ILs containing long free alkyl side chain substituents and long linker chains between the two cations possess less cohesive forces and exhibited the highest resolution of aliphatic hydrocarbons. The anion component of the IL did not contribute significantly to the overall separation, as similar selectivities toward aliphatic hydrocarbons were observed when examining ILs with identical cations and different anions. In an attempt to further examine the separation capabilities of the IL-based GC stationary phases, columns of the best performing stationary phases were prepared with higher film thickness and resulted in enhanced selectivity of aliphatic hydrocarbons.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA.
authors.forename: Isaiah C
authors.initials: IC
authors.lastname: Ingram
authors.affiliation: Laboratório de Microfabricação (LMF), Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, São Paulo 13083-970, Brazil.
authors.forename: Leandro W
authors.initials: LW
authors.lastname: Hantao
authors.affiliation: Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA. Electronic address: Jared.Anderson@utoledo.edu.
authors.forename: Jared L
authors.initials: JL
authors.lastname: Anderson
mesh_terms: D002849:Chromatography, Gas / Q000295:instrumentation; D052578:Ionic Liquids / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D007648:Kerosene / Q000032:analysis; D008962:Models, Theoretical; D013696:Temperature
chemical_list: D052578:Ionic Liquids; D007477:Ions; D007648:Kerosene
keywords: Comprehensive two-dimensional gas chromatography; Dicationic ionic liquid; Multidimensional gas chromatography; Petrochemicals; Solvation parameter model