Low crosslinking imprinted coatings based on liquid crystal for capillary electrochromatography

Area of Science:

• Analytical Chemistry
• Polymer Chemistry
• Chiral Separations

Background:

• Low loading capacity in molecularly imprinted stationary phases is a significant limitation.
• High crosslinking levels in conventional molecularly imprinted polymers restrict polymer backbone distortion, hindering performance.
• Developing molecularly imprinted polymers with improved capacity and efficiency is crucial for chiral separations.

Purpose of the Study:

• To synthesize molecularly imprinted polymer coatings with a low crosslinking level using liquid crystals.
• To evaluate the performance of these low crosslinking coatings in separating enantiomers via capillary electrochromatography.
• To demonstrate a simplified and effective method for producing high-performance chiral stationary phases.

Main Methods:

• Synthesis of molecularly imprinted polymer coatings utilizing liquid crystals with inherent recognition abilities.
• Fabrication of open-tubular imprinted capillaries with a low crosslinking degree (20%).
• Enantiomer separation using capillary electrochromatography with the developed imprinted capillaries.

Main Results:

• Successful separation of enantiomers using a low crosslinking (20%) open-tubular imprinted capillary.
• Achieved high resolution (up to 6.36) for (S)-amlodipine enantiomer separation in under 2.5 minutes.
• Demonstrated strong recognition ability (selectivity factor 1.81) and high column performance (up to 23,300 plates/m).
• Comparable imprinting performance to conventional molecularly imprinted polymer stationary phases was observed.
• Successful preparation and separation using (S)-naproxen and (S)-ofloxacin as template molecules, yielding resolutions of 1.41 and 1.55, respectively.

Conclusions:

• The synthesis of low crosslinking molecularly imprinted polymer coatings based on liquid crystals offers a simplified process for high-performance applications.
• This approach effectively produces chiral stationary phases with performance comparable to existing state-of-the-art chiral stationary phases.
• The liquid crystal-based molecularly imprinted polymers represent a promising strategy for overcoming the loading capacity limitations in chiral separations.