B Chankvetadz | PubMed Health

PubMed2001

Enantioseparations in capillary electromigration techniques: recent developments and future trends.

This review summarizes the current status of enantioseparations using capillary electromigration techniques and gives the authors insights on the selected fundamental aspects and future trends in this field. The most recent developments in the field of chiral separations using capillary electrophoresis (CE) and capillary electrochromatography (CEC) are summarized. The status of chiral electromigration techniques is evaluated tacking into account the most recent developments in related techniques such as chiral HPLC, GC and SFC.

Electrophoresis, Capillary↗

PubMed2000

Separation and identification of etodolac and its urinary phase I metabolites using capillary electrochromatography and on-line capillary electrochromatography-electrospray ionisation mass spectrometry coupling.

Capillary high-performance liquid chromatography (capillary HPLC), pressure-assisted capillary electrochromatography (pCEC) and capillary electrochromatography (CEC) were performed in the same capillary packed with 5 microm octadecylsilica (C18) as stationary phase. These three separation modes were compared from the viewpoint of peak efficiency and separation selectivity in order to critically evaluate the advantages which CEC may offer compared to capillary HPLC for the solution of practical biomedical problems. The separation of the non-steroidal anti-inflammatory drug etodolac (ET, 1) and its phase I metabolites, 6-hydroxy etodolac (6-OH-ET, 2), 7-hydroxy etodolac (7-OH-ET, 3) and 8-(1'-hydroxyethyl) etodolac (8-OH-ET, 4) was selected as an example. Baseline separation of all compounds was achieved in different modes and conditions. The effect of pure electrophoretic separation mechanism on the overall separation selectivity observed in CEC has been shown. A high electroosmotic flow (EOF) was observed in C18 packed capillary even at pH 2.5 in various buffers. Furthermore, these separations were coupled on-line with electrospray ionisation mass spectrometry (ESI-MS) and the parent drug and its metabolites were identified in urine. For the coupling of CEC with ESI-MS a laboratory-made electrophoretic device was used in order to overcome some technical disadvantages of commercial instrumentation.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1997

Selected applications of capillaries with dynamic or permanent anodal electroosmotic flow in chiral separations by capillary electrophoresis.

The techniques for a dynamic and permanent reversal of the electroosmotic flow (EOF) were used for the reversal of the enantiomer migration order (EMO) of neutral and cationic analytes in chiral capillary electrophoresis (CE). Native beta-Cd and an anionic CD derivative, CM-beta-CD were used in both, bare silica- and positively coated capillaries. Advantages and disadvantages of a dynamic and permanent modification of the capillary inner surface are briefly discussed.

Benzoin↗