title: Characterization of hexacationic imidazolium ionic liquids as effective and highly stable gas chromatography stationary phases.
abstract: Polycationic ionic liquids (ILs) are an attractive class of ILs with great potential applicability as gas chromatography stationary phases. A family of hexacationic imidazolium ILs derived from the cycloalkanol family was chemically first prepared in a straightforward manner and then applied for analytical separation purposes. Four tuneable engineering vectors, namely cation ring size structure, anion nature, spatial disposition of cycloalkanol substituents and O-substitution, were considered as experimental parameters for the design of the desired ionic liquids. A total number of five new phases based on a common benzene core respectively exhibited column efficiencies around to 2500 plates/m, broad operating temperature ranges and also, even more importantly, good thermal stabilities (bleeding temperature between 260 and 365°C), finding variations in the selectivity and analytes elution orders depending on the IL structures. Their solvation characteristics were evaluated using the Abraham solvation parameter model, establishing clear correlations between their cation structure and retention capability with respect to certain analytes. The study of relationships between the ILs structure and solvation parameters gives us an idea of the IL stationary phase to be used for specific separations.
authors.affiliation: Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: González-Álvarez
authors.forename: Domingo
authors.initials: D
authors.lastname: Blanco-Gomis
authors.forename: Pilar
authors.initials: P
authors.lastname: Arias-Abrodo
authors.forename: Daniel
authors.initials: D
authors.lastname: Díaz-Llorente
authors.forename: Nicolás
authors.initials: N
authors.lastname: Ríos-Lombardía
authors.forename: Eduardo
authors.initials: E
authors.lastname: Busto
authors.forename: Vicente
authors.initials: V
authors.lastname: Gotor-Fernández
authors.forename: María D
authors.initials: MD
authors.lastname: Gutiérrez-Álvarez
mesh_terms: D002412:Cations; D002849:Chromatography, Gas / Q000379:methods*; D004355:Drug Stability; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D052578:Ionic Liquids / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification*; D008956:Models, Chemical; D015394:Molecular Structure; D013816:Thermodynamics
chemical_list: D002412:Cations; D007093:Imidazoles; D052578:Ionic Liquids