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Capillary Monoliths (capillary + monolith)
Selected AbstractsMonolithic poly(glycidyl methacrylate- co -divinylbenzene) capillary columns functionalized to strong anion exchangers for nucleotide and oligonucleotide separationJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2006Wolfgang Wieder Abstract In the present work, poly(glycidyl methacrylate- co -divinylbenzene) monoliths were synthesized and further derivatized to obtain strong anion exchange supports. Capillary monoliths (65×0.2 mm id) were prepared in situ by copolymerization of glycidyl methacrylate and divinylbenzene, employing 1-decanol and tetrahydrofuran as porogens. The free epoxy groups were derivatized in a two step synthesis to obtain quaternary ammonium functionalities. On testing the pressure stability of the synthesized monolith, a highly linear dependence between flow rate and pressure drop was obtained, indicating the high stability of the material even at high flow rates. The morphology of the copolymer was investigated by scanning electron microscopy. Mercury intrusion porosimetry showed a narrow pore size distribution, having a maximum at 439 nm. On recording a van Deemter plot the number of theoretical plates per meter was found to be 59 324. The produced strong anion exchange monoliths turned out to be highly suitable for the separation of nucleotides and oligonucleotides. [source] Sheathless electrospray ionization directly from a capillary monolith for fast liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2004Felix C. Leinweber [source] Highly cross-linked polymeric capillary monoliths for the separation of low, medium, and high molecular weight analytesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 15-16 2009Said H. Lubbad Abstract Highly rigid capillary monoliths with low swelling propensity were prepared within the confines of 200 ,m ID fused silica capillaries via thermally induced free radical polymerization of tetrakis(4-vinylbenzyl)silane (TVBS) in the presence of 1-dodecanol and toluene. ,,,,-Azobisisobutyronitrile (AIBN) was used as initiator. The resulting monoliths were optimized for the separation of low, medium, and high molecular weight analytes. The microstructure and porosity of the monoliths prepared were studied by SEM and inverse size-exclusion chromatography (ISEC). The porosity of the monolithic supports was tuned by varying the amount of initiator (i. e. AIBN) between 0.5 and 2 wt%. All monoliths were tested for a series of low molecular weight compounds including alkylbenzenes, amines, carboxylic acids, phenols, carbonyl compounds, and ,-blockers, as well as for the separation of medium molecular weight analytes such as peptides and high-molecular weight analytes such as proteins. Due to the microporous structure, the novel monoliths displayed high efficiency and performance particularly in the separation of low molecular weight analytes. Relevant chromatographic parameters including permeability, swelling propensity, and height equivalents to theoretical plates were determined. [source] | ||||||||||