Covalent organic framework incorporated chiral polymer monoliths for capillary electrochromatography

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Chiral separations are crucial in pharmaceuticals.
• Developing efficient chiral stationary phases (CSPs) for capillary electrochromatography (CEC) remains a challenge.
• Covalent organic frameworks (COFs) offer unique properties for chromatographic applications.

Purpose of the Study:

• To synthesize and characterize a novel CSP for CEC by incorporating a COF, Schiff base network-1 (SNW-1), into a cellulase-based poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith.
• To evaluate the enantioseparation performance of the developed CSP for various chiral drugs.

Main Methods:

• Synthesis of SNW-1 and its incorporation into a poly(GMA-EDMA) monolith functionalized with cellulase.
• Characterization of the monolith using scanning electron microscopy, elemental analysis, and nitrogen adsorption.
• Optimization of SNW-1 concentration, cellulase immobilization pH, and CEC conditions.
• Enantioseparation of eight pairs of chiral drugs using the developed CSP in CEC.

Main Results:

• The SNW-1 incorporated monolith exhibited high surface area, conjugate structures, and amine groups, facilitating π-π electrostatic stacking and hydrogen bonding.
• Optimized conditions led to excellent enantioseparation of β-blockers, antihistamines, and anticoagulants.
• The CSP demonstrated satisfactory repeatability with relative standard deviations <4.5% for intra-day/inter-day/column-to-column and <6.8% for batch-to-batch runs.

Conclusions:

• The combination of monolith properties and SNW-1's characteristics provides a promising strategy for chiral separation in CEC.
• The developed cellulase@poly(GMA-EDMA-SNW-1) monolith is an effective CSP for separating diverse chiral drugs.
• This approach offers improved column efficiency and enhanced interactions for chiral analyte separation.