title: Exploring the pressure resistance limits of monolithic silica capillary columns.
abstract: We report on an experimental approach to measure the pressure stability and mechanical strength of monolithic silica capillary columns with different diameters (50 and 100μm i.d.) and considering two different domain sizes, typical for the second generation monoliths or smaller. The approach consists of exposing the capillaries to ultra-high pressures (gradually stepwise increased from 20 to 80MPa), with intermediate measurements of the column efficiency, permeability and retention factors to check the mechanical stability of the bed. It was observed that all tested columns withstood the imposed pressure stress, i.e., all the tested parameters remained unaffected up till the maximal test pressure of 80MPa. The applied pressure gradient corresponded to 320MPa/m. The two 100μm i.d.-capillary columns were also exposed to pressures between 80 and 90MPa for a prolonged time (8h), and this did not cause any damage either.
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hara
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Eeltink
authors.affiliation: Vrije Universiteit Brussel, Department of Chemical Engineering, Pleinlaan 2, B-1050 Brussels, Belgium. Electronic address: gedesmet@vub.ac.be.
authors.forename: Gert
authors.initials: G
authors.lastname: Desmet
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D010539:Permeability; D011312:Pressure; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide
keywords: Efficiency; Permeability; Silica monolith; Ultra-high pressure