New particle-loaded monoliths for chiral capillary electrochromatographic separation.
Fritless particle-loaded monoliths for chiral capillary electrochromatographic (CEC) separation were prepared. Silica particles containing a chiral selector are suspended in a monomer solution, which is drawn into the capillary followed by in situ polymerization. Thereby the silica-based particles containing the chiral selector are embedded in a nonchiral continuous bed. This kind of chiral stationary phase is inexpensive, easy, and reproducible to prepare and circumvents the preparation of frits. As a model, teicoplanin aglycone as chiral selector bonded to 3 microm silica particles was used. The applicability of this approach is demonstrated by means of the chiral separation of aliphatic and aromatic amino acids and dipeptides. As a further application, the chiral selector ristocetin A bonded to 3 microm silica particles was used for the enantiomeric separation of chiral alpha-hydroxy acids. Since alpha-hydroxy acids migrate toward the anode, a cationic charge-providing agent was copolymerized with the matrix. This served to reverse the direction of the electroosmatic flow (EOF).
Institute of Pharmaceutical Chemistry and Pharmaceutical Technology, Karl-Franzens University, Graz, Austria. martin.schmid@uni-graz.at
Martin G
MG
Schmid
Julia
J
Koidl
Christina
C
Freigassner
Sandra
S
Tahedl
Lena
L
Wojcik
Thomas
T
Beesley
Daniel W
DW
Armstrong
Gerald
G
Gübitz
D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation*; D008854:Microscopy, Electron; D012310:Ristocetin / Q000737:chemistry; D013237:Stereoisomerism
D012310:Ristocetin; C016719:ristocetin A