Butyl methacrylate based monoliths with different cross-linking agents using DMF-aqueous buffer as porogen

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Capillary electrochromatography (CEC) requires robust and efficient monolithic stationary phases for high-performance separations.
• Developing novel monolithic materials with tailored properties is crucial for advancing CEC techniques.

Purpose of the Study:

• To synthesize and evaluate butyl methacrylate (BMA)-based capillary monoliths using a simple porogen system.
• To investigate the effect of different cross-linking agents, specifically varying alkyl chain lengths, on the electrochromatographic performance of BMA monoliths.
• To optimize the monolithic stationary phase for the separation of alkylbenzenes, phenols, and benzoic acids.

Main Methods:

• Synthesis of monolithic stationary phases using a porogen composed of N,N-Dimethylformamide (DMF) and aqueous buffer.
• Polymerization of butyl methacrylate (BMA) with various cross-linking agents: ethylene glycol dimethacrylate, butanediol dimethacrylate, and hexanediol diacrylate (HDDA).
• Evaluation of electrochromatographic separation performance using alkylbenzenes, phenols, and benzoic acids as analytes.

Main Results:

• The use of hexanediol diacrylate (HDDA), the cross-linker with the longest alkyl chain, resulted in monoliths with superior electrochromatographic separation performance.
• The poly(BMA-co-HDDA) monolithic stationary phase demonstrated successful separation of alkylbenzenes, phenols, and benzoic acids.
• Achieved a high column efficiency of up to 270,000 plates/meter with the optimized poly(BMA-co-HDDA) monolith.

Conclusions:

• A simple porogen system is effective for synthesizing high-performance monolithic stationary phases for CEC.
• The choice of cross-linking agent significantly impacts the separation capabilities of the monolith, with longer alkyl chains (HDDA) being advantageous.
• The developed poly(BMA-co-HDDA) monolith represents a promising stationary phase for efficient CEC separations of various organic compounds.