title: Capillary electrochromatographic separation of racemates on a norvancomycin-bonded monolithic column under reversed-phase conditions.
abstract: 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.
authors.affiliation: Analysis Center, Tianjin University, Tianjin 300072, China. dgs@tju.edu.cn
authors.forename: Guo-Sheng
authors.initials: GS
authors.lastname: Ding
authors.forename: An-Na
authors.initials: AN
authors.lastname: Tang
mesh_terms: 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*
chemical_list: D014859:Warfarin; D014640:Vancomycin; D012822:Silicon Dioxide; C511195:norvancomycin