A New Easy-to-Prepare Homogeneous Continuous Electrochromatographic Bed for Enantiomer Recognition
Author
Summary, in English
Completely homogeneous polyacrylamide-based gels were used for capillary electrochromatography (CEC) of drug enantiomers. Like continuous beds (also called continuous polymer rods, silica rods, monoliths) they do not require frits to support the bed, because it is covalently linked to the capillary wall. Along lifetime is an important feature of the beds. The gel matrices can be prepared in any laboratory and for specific interactions they can be derivatized with appropriate ligands. The application range is, therefore, broad. For chiral electrochromatography, negatively and positively charged polyacrylamide gels copolymerized with 2-hydroxy-3-allyloxy-propyl-b-cyclodextrin (allyl-b-CD) were prepared. The latter monomer was synthesized from b-CD and allyl-glycidyl ether by a very simple one-step procedure. Eight acidic, neutral and basic drug compounds were resolved into their enantiomers, most of them with baseline separation. Interestingly, the resolution is independent of the electroendosmotic velocity, i.e., rapid analyses will not give low resolution. Upon increasing this velocity, the plate height for the fast enantiomer did not change (or decreased slightly), whereas that for the slow enantiomer increased. Only the last term in the van Deemter equation contributed significantly to the total plate height. The composition of the gel was chosen such that the "pores" became large enough to guarantee a satisfactory electroendosmotic flow (EOF). This open gel structure explains why acetone diffused as in free solution, i.e., independently of the presence of the gel matrix. This finding also indicates that the separation of small molecules in polyacrylamide gels cannot be explained by "molecular-sieving", but rather by some type of adsorption ("aromatic adsorption"?).
Publishing year
2000
Language
English
Pages
3116-3125
Publication/Series
Electrophoresis
Volume
21
Issue
15
Links
Document type
Journal article
Publisher
John Wiley & Sons Inc.
Topic
- Medical Engineering
Keywords
- Enantiomer separation
- Continuous beds
- Homogeneous gels
- Electrochromatography
- Allylated-b-cyclodextrin
- van Deemter equation
Status
Published
ISBN/ISSN/Other
- ISSN: 0173-0835