title: Counterflow isotachophoresis in a monolithic column.
abstract: This study describes stationary counterflow isotachophoresis (ITP) in a poly(acrylamide-co-N,N'-methylenebisacrylamide) monolithic column as a means for improving ITP processing capacity and reducing dispersion. The flow profile in the monolith was predicted using COMSOL's Brinkman Equation application mode, which revealed that the flow profile was mainly determined by monolith permeability. As monolith permeability decreases, the flow profile changes from a parabolic shape to a plug shape. An experimental monolithic column was prepared in a fused-silica capillary using an ultraviolet-initiated polymerization method. A monolithic column made from 8% (wt.) monomer was chosen for the stationary counterflow ITP experiments. Counterflow ITP in the monolithic column showed undistorted analyte zones with significantly reduced dispersion compared to the severe dispersion observed in an open capillary. Particularly, for r-phycoerythrin focused by counterflow ITP, its zone width in the monolithic column was only one-third that observed in an open capillary. These experiments demonstrate that stationary counterflow ITP in monoliths can be a robust and practical electrofocusing method.
authors.affiliation: The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, USA.
authors.forename: Bingwen
authors.initials: B
authors.lastname: Liu
authors.forename: Yongzheng
authors.initials: Y
authors.lastname: Cong
authors.forename: Cornelius F
authors.initials: CF
authors.lastname: Ivory
mesh_terms: D057625:Isotachophoresis / Q000295:instrumentation / Q000379:methods*; D011506:Proteins / Q000302:isolation & purification; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D011506:Proteins; D012822:Silicon Dioxide
keywords: Counterflow; Dispersion; Electrofocusing; Isotachophoresis; Monoliths