title: High-speed isocratic and gradient liquid-chromatography separations at 1500bar.
abstract: The need to improve either sample throughput on separation efficiency has spurred the development of ultra-high-pressure LC instrumentation, allowing to operate up to column pressures of 1500bar. In the present study, the isocratic and gradient performance limits were assessed at UHPLC conditions applying columns packed with core-shell particles. First, the extra-column band broadening contributions were assessed and minimized. Using an optimized system configuration minimum reduced plate heights of 1.8 were recorded on 2.1×100 columns packed with 1.5μm core-shell particles. Increasing the pressure limit from 500 to 1500bar and at the same time reducing the particle size from 2.6 to 1.5μm has allowed the analysis time to be decreased by a factor of 1.5 in isocratic mode, while maintaining separation efficiency (N=54,000). The kinetic time-gain factor in isocratic mode was proportional to the ratio of the separation impedance of both columns multiplied with the pressure ratio applied. In addition, the effect of operating pressure on the time gain factor was assessed in gradient mode. Using optimized gradient steepness (tG/t0=12) and increasing the operating pressure from 500 to 1500bar a time gain factor of almost 13 was achieved for the separation of a mixture of waste-water pollutants without compromising peak capacity.
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Brussels, Belgium.
authors.forename: Jelle
authors.initials: J
authors.lastname: De Vos
authors.affiliation: Thermo Fisher Scientific, Germering, Germany.
authors.forename: Mauro
authors.initials: M
authors.lastname: De Pra
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Brussels, Belgium.
authors.forename: Gert
authors.initials: G
authors.lastname: Desmet
authors.affiliation: Thermo Fisher Scientific, Germering, Germany.
authors.forename: Remco
authors.initials: R
authors.lastname: Swart
authors.affiliation: Thermo Fisher Scientific, Runcorn, UK.
authors.forename: Tony
authors.initials: T
authors.lastname: Edge
authors.affiliation: Thermo Fisher Scientific, Germering, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Steiner
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Brussels, Belgium. Electronic address: seeltink@vub.ac.be.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Eeltink
mesh_terms: D001555:Benzene Derivatives / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007659:Ketones / Q000032:analysis; D007700:Kinetics; D010316:Particle Size; D011312:Pressure; D013997:Time Factors
chemical_list: D001555:Benzene Derivatives; D007659:Ketones
keywords: Accucore; Kinetic gain factor; Peak compression; Poppe plot; Sub-2μm particles; UHPLC