Capillary electrochromatographic separation of racemates on a norvancomycin-bonded monolithic column under reversed-phase conditions.
Following a modified sol-gel process, a silica backbone was prepared in a fused-silica capillary, and it was then chemically modified with a glycopeptide antibiotic, norvancomycin (NVC), by a one-step in situ derivatization process. Several selected neutral and basic racemates were assessed on this column under reversed-phase conditions. The influences of pH and composition of mobile phase on enantioselectivity factor (alpha) and resolution (R(s)) were also evaluated. A comparison was made between the NVC-bonded column with other similar capillary columns in published papers to demonstrate its better enantioselectivity. Furthermore, warfarin was chosen as model compound to study the self-preconcentration effect of racemates on this column. The preconcentration is marked in terms of peak heights, with up to 8-10-fold increase for the enantiomers of warfarin without obvious loss in column performance. Experimental data also show that the extent of preconcentration follows the retention factor (k) for a given enantiomer.
Ding
Guo-Sheng
GS
Analysis Center, Tianjin University, Tianjin 300072, China. dgs@tju.edu.cn
Tang
An-Na
AN
D053801:Capillary Electrochromatography / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000737:chemistry; D013237:Stereoisomerism; D014640:Vancomycin / Q000031:analogs & derivatives* / Q000737:chemistry; D014859:Warfarin / Q000302:isolation & purification*
D014859:Warfarin; D014640:Vancomycin; D012822:Silicon Dioxide; C511195:norvancomycin