Abstract:

Silica-based monolithic column with high rigidity and good permeability was prepared by a
modified sol-gel technology, characterized by shorter fabrication process and higher success rate. A
macrocyclic antibiotics-based chiral monolithic column was successfully prepared by modifying the
monolithic matrix with a homemade macrocyclic antibioticsnorvancomycin by adopting a single-step
on-column derivatization process. The newly synthesized column was assessed for its
enantioselectivity in chromatographic modes of reversed-phase and polar organic-phase. The effect of
the mobile phase composition on the retention and enantio-selectivity of the system was also
investigated in detail. It was shown that β-receptor blockers can be best resolved under the mobile
phase composition of methanol-acetonitrile-triethylamine-acetic acid (80∶20∶0.1∶0.1, v/v). Under
reversed-phase conditions, a nearly linear increase of electroosmotic flow (EOF) was observed with
the pH changing from 4.0 to 7.0, which shows that the predominant source of EOF is still resulting
from the silica backbone while the chiral selector of norvancomycin contributes little. A number of
racemic pharmaceuticals with different structures were separated in reversed-phase mode with
different resolutions. It was shown experimentally that the column prepared in this way had broader
enantioselectivity as well as better batch-to-batch reproducibility.

Key words:
preparation, chiral separation , norvancomycin, silica monolithic column, capillary electrochromatography (CEC)