title: Impact of conduit geometry on the performance of typical particulate microchip packings.
abstract: This work investigates the impact of conduit geometry on the chromatographic performance of typical particulate microchip packings. For this purpose, high-performance liquid chromatography (HPLC)/UV-microchips with separation channels of quadratic, trapezoidal, or Gaussian cross section were fabricated by direct laser ablation and lamination of multiple polyimide layers and then slurry-packed with either 3 or 5 microm spherical porous C8-silica particles under optimized packing conditions. Experimentally determined plate height curves for the empty microchannels are compared with dispersion coefficients from theoretical calculations. Packing densities and plate height curves for the various microchip packings are presented and conclusively explained. The 3 microm packings display a high packing density irrespective of their conduit geometries, and their performance reflects the dispersion behavior of the empty channels. Dispersion in 5 microm packings correlates with the achieved packing densities, which are limited by the number and accessibility of corners in a given conduit shape.
authors.affiliation: Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35032 Marburg, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Jung
authors.forename: Alexandra
authors.initials: A
authors.lastname: Höltzel
authors.forename: Steffen
authors.initials: S
authors.lastname: Ehlert
authors.forename: Jose-Angel
authors.initials: JA
authors.lastname: Mora
authors.forename: Karsten
authors.initials: K
authors.lastname: Kraiczek
authors.forename: Monika
authors.initials: M
authors.lastname: Dittmann
authors.forename: Gerard P
authors.initials: GP
authors.lastname: Rozing
authors.forename: Ulrich
authors.initials: U
authors.lastname: Tallarek
mesh_terms: D001554:Benzene / Q000032:analysis; D001555:Benzene Derivatives / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D016062:Porosity; D012117:Resins, Synthetic / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014466:Ultraviolet Rays; D014498:Uracil / Q000032:analysis
chemical_list: D001555:Benzene Derivatives; D012117:Resins, Synthetic; C029945:polyimide resin; D014498:Uracil; D012822:Silicon Dioxide; D001554:Benzene