Ivo Nischang, Oliver Brüggemann,
"On the separation of small molecules by means of nano-liquid chromatography with methacrylate-based macroporous polymer monoliths"
, in Journal of Chromatography A, 2010, ISSN: 0021-9673
Original Titel:
On the separation of small molecules by means of nano-liquid chromatography with methacrylate-based macroporous polymer monoliths
Sprache des Titels:
Englisch
Original Kurzfassung:
Macroporous monolithic poly(butyl methacrylate-co-ethylene dimethacrylate) stationary phases were
synthesized in the confines of 100 microm I.D. fused-silica capillaries via a free radical copolymerization of
mono and divinyl monomeric precursors in the presence of porogenic diluents. These columns were
used in order to determine their suitability for the reversed-phase separation of small molecules in
isocratic nano-LC mode. Carefully designed experiments at varying realized phase ratio by a terminated
polymerization reaction, as well as content of organic modifier in the mobile phase, address the most
significant parameters affecting the isocratic performance of these monoliths in the separation of small
molecules. We show that the performance of methacrylate-based porous polymer monoliths is strongly
affected by the retention factor of the analytes separated. A study of the porous and hydrodynamic
properties reveals that the actual nature of the partition and adsorption of the small analyte molecules
between mobile and stationary (solvated) polymer phases are most crucial for their performance. This
is due to a significant gel porosity of the polymeric stationary phase. The gel porosity reflects stagnant
mass transfer zones restricting their applicability in the separation of small molecules under conditions
of strong retention.
Forschungs-