(Normal-Phase) Capillary Chromatography Using Acrylic Polymer-Based Continuous Beds
Författare
Summary, in English
Microchromatographic separations of polar aromatic compounds (pyridine, 4-pyridylmethanol, 4-methoxyphenol, 2-naphthol, catechol, hydroquinone, resorcinol, 2,7-dihydroxynaphthalene) using continuous beds are described. The columns were prepared by a simple one-step in situ polymerization procedure: a solution of acrylic monomers, including the cross-linking agent piperazine diacrylamide, was polymerized in a fused-silica capillary pretreated with 3-(trimetoxysilyl) propyl methacrylate. The continuous bed formed contained a network of channels and was attached covalently to the wall of the silica capillary (100 mm I.D.) via its methacrylate groups. Therefore, the frit used in conventional, packed columns could be omitted. The separation mechanism is discussed, particularly with regard to whether the so-called aromatic
adsorption to the matrix itself is involved, an interaction first described by Gelotte [1] (the ligands, isopropyl and sulfonate groups, are not required for separation). This discussion is relevant to the question of whether the separation technique described should be classified as normal-phase or adsorption chromatography.
The mobile phase from the HPLC pump was split via an open capillary to get a flow rate through the continuous bed of about 100 nl /min. The beds were tested up to a pressure of 150 bar (8.8 bar /cm).
A continuous bed synthesized at a relatively low molar fraction of the cross-linker in the monomer mixture (16.5%) and high total concentration of the monomers (31.9% (w/v)) afforded the highest efficiency for the separation of the polar 21 organic compounds. Plate numbers up to 150 000 m were obtained and the run-to-run reproducibility was high. The selectivity of the separations was adjusted by changing the composition of the mobile phase (hexane–ethanol–methanol). The sample was applied by a diffusion-based injection technique.
adsorption to the matrix itself is involved, an interaction first described by Gelotte [1] (the ligands, isopropyl and sulfonate groups, are not required for separation). This discussion is relevant to the question of whether the separation technique described should be classified as normal-phase or adsorption chromatography.
The mobile phase from the HPLC pump was split via an open capillary to get a flow rate through the continuous bed of about 100 nl /min. The beds were tested up to a pressure of 150 bar (8.8 bar /cm).
A continuous bed synthesized at a relatively low molar fraction of the cross-linker in the monomer mixture (16.5%) and high total concentration of the monomers (31.9% (w/v)) afforded the highest efficiency for the separation of the polar 21 organic compounds. Plate numbers up to 150 000 m were obtained and the run-to-run reproducibility was high. The selectivity of the separations was adjusted by changing the composition of the mobile phase (hexane–ethanol–methanol). The sample was applied by a diffusion-based injection technique.
Publiceringsår
1999
Språk
Engelska
Sidor
25-33
Publikation/Tidskrift/Serie
Journal of Chromatography A
Volym
837
Issue
1-2
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Medical Engineering
Nyckelord
- Continuous beds
- Normal-phase chromatography
- Adsorption chromatography
- Microchromatography
- Capillary chromatography
- Aromatic adsorption
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0021-9673