title: Evaluation and comparison of the kinetic performance of ultra-high performance liquid chromatography and high-performance liquid chromatography columns in hydrophilic interaction and reversed-phase liquid chromatography conditions.
abstract: An intrinsic performance comparison is made of the reduction in analysis time that can be obtained when switching from HPLC to UHPLC column formats in HILIC and reversed-phase conditions. A detailed overview of the packing characteristics of both stationary phase types is given first. It is demonstrated that HILIC columns demonstrate higher external porosity values than their reversed-phase counterparts resulting in lower flow resistance values. Column total porosity values determined from the elution time of a small marker molecule are shown to depend strongly on the composition of the mobile phase. To omit errors that might arise from an over- or underestimation of the column void time, all plate height and kinetic plot data are therefore expressed as a function of the interstitial velocity. Although only a limited number of columns are evaluated in this study, it is shown that the column efficiency of the HILIC columns is lower than that of their reversed-phase counterparts, at least for the compounds evaluated here. Despite this lower efficiency, the kinetic performance of both stationary phase types is similar, due to the much lower viscosity of the mobile phases typically used in HILIC conditions. Finally, it is demonstrated that a similar, yet slightly larger reduction in analysis time can be obtained when switching from HPLC column formats to UHPLC formats in HILIC compared to reversed-phase conditions.
authors.affiliation: KU Leuven, Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium.
authors.forename: Huiying
authors.initials: H
authors.lastname: Song
authors.affiliation: KU Leuven, Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium.
authors.forename: Erwin
authors.initials: E
authors.lastname: Adams
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, 1050 Brussel, Belgium.
authors.forename: Gert
authors.initials: G
authors.lastname: Desmet
authors.affiliation: KU Leuven, Department for Pharmaceutical and Pharmacological Sciences, Pharmaceutical Analysis, Herestraat 49, Leuven, Belgium. Electronic address: deirdre.cabooter@pharm.kuleuven.be.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Cabooter
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D056148:Chromatography, Reverse-Phase / Q000295:instrumentation* / Q000379:methods; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D016062:Porosity
keywords: Flow resistance; HILIC; Kinetic plot; Porosity; RPLC