Effect of capillary cross-section geometry and size on the separation of proteins in gradient mode using monolithic poly(butyl methacrylate-co-ethylene dimethacrylate) columns

Abstract

Porous polymer monolith have been prepared in capillaries with circular or square cross section and lateral dimensions of 50, 75, 100 μm as well as in a rectangular 38 × 95 μm capillary. These capillaries have been used to determine the effect of the size and shape of their cross section on the porous and hydrodynamic properties of poly(butyl methacrylate-co-ethylene dimethacrylate) monoliths. The capillaries were studied by scanning electron micrography and evaluated for their permeability to flow and their performance in the liquid chromatographic separation of a protein mixture comprising ribonuclease A, cytochrome c, myoglobin, and ovalbumin using a linear gradient of acetonitrile in the mobile phase. No differences resulting from channel geometry were found for the various capillary columns. These results demonstrate that standard capillaries with circular geometry are a good and affordable alternative conduit for modeling the processes carried out in microfluidic chips with a variety of geometries.

Methacrylate monolithic stationary phases for gradient elution separations in microfluidic devices

“…For the permeability of the 40% LMA monolith a value of 9.8 × 10 −14 m 2 was found, for the other monoliths the values were between 2 and 3 × 10 −13 m 2 . The value for the 40% LMA monolith is close to the results reported by Nischang et al, for capillaries with various diameters and cross-sectional geometries, also obtained with a polymerization mixture containing 40% methacrylate monomers [37]. On the other hand, the permeability for the 40% LMA monolith is similar to what we found earlier for 'low density' (20% BMA) methacrylate monoliths in capillaries, and that of the other monoliths prepared considerably higher [23,28].…”

Differences in porous characteristics of styrenic monoliths prepared by controlled thermal polymerization in molds of varying dimensions

“…The effects of capillary cross-section geometry and size on the porous and hydrodynamic properties of poly(butyl methacrylate-co-ethylene dimethacrylate) monoliths were recently investigated by Svec's group [36]. The results from their SEM investigations, chromatographic evaluations and hydrodynamic measurements of capillaries prepared in 50, 75 and 100 mm capillaries were reported to be similar within this range of ids.…”

“…Ideally, a material for separation of small and intermediate size solutes should entrain a combination of mesopores and macropores, each cohort with a narrow size distribution [8,32]. A variety of approaches have therefore been used for characterizing the meso-and macroporous structure of capillary monoliths, including electron microscopy in scanning (SEM) [13,[34][35][36] and transmission (TEM) [37][38][39] modes, mercury intrusion porosimetry (MIP) [40], inverse size exclusion chromatography [40][41][42][43][44][45][46][47][48][49][50][51] and conductivity measurements of monolithic capillaries filled with electrolyte followed by relating the conductivity ratio to total column porosity via Archie's equation [52].…”

Equilibria and kinetics of phenol adsorption on a toluene-modified hyper-cross-linked poly(styrene-co-divinylbenzene) resin

“…A preliminary experiment had proved that the adsorption can reach equilibrium within 8 h. After filtration of the resin from the mixture, the solution was analyzed by UV spectrometry on a UV2450 spectrophotometer (Shimadzu Scientific Instrument Inc., Japan) at a wavelength of 269.9 nm. The concentration of the residual solution was measured and the equilibrium adsorption capacity was calculated as [19]:…”