Hybrid monolithic columns with nanoparticles incorporated for capillary electrochromatography

Area of Science:

• Analytical Chemistry
• Materials Science
• Separation Science

Background:

• Development of advanced stationary phases is crucial for improving chromatographic separation efficiency.
• Nanoparticles offer high surface area and tunable properties for enhanced chromatographic performance.
• Polymethacrylate monoliths provide a robust and versatile platform for chromatographic applications.

Purpose of the Study:

• To synthesize and characterize novel polymethacrylate monolithic columns incorporating core-shell Fe(3)O(4)@SiO(2)/NH(2) and SBA-15 silica nanoparticles.
• To investigate the potential of these nanoparticle-modified monoliths as stationary phases for capillary electrochromatography (CEC).
• To evaluate the impact of nanoparticle incorporation on separation selectivity and column efficiency.

Main Methods:

• Core-shell silica nanoparticles (Fe(3)O(4)@SiO(2)/NH(2)) and wormlike/hexagonal SBA-15 silica nanoparticles were synthesized.
• Nanoparticles were incorporated into polymethacrylate monoliths prepared from butyl methacrylate (BMA) and ethylene dimethacrylate (EDMA).
• Optimized experimental conditions were used for stable column preparation.
• Capillary electrochromatography (CEC) was employed to evaluate the performance of the monolithic columns using organic acid mixtures and a complex plant extract.

Main Results:

• Novel monolithic columns, poly(BMA-EDMA-Fe(3)O(4)@SiO(2)/NH(2)) and poly(BMA-EDMA-SBA-15/NH(2)), were successfully prepared.
• The columns exhibited a mixed-mode separation mechanism combining reverse-phase and ion-exchange properties.
• High column efficiencies, reaching up to 290,000 plates/m, were achieved in CEC.
• The incorporation of nanoparticles significantly enhanced selectivity and efficiency due to their high specific surface area.
• The Fe(3)O(4)@SiO(2)/NH(2) modified column demonstrated potential for separating complex biological samples, such as the aqueous extract of Rhizoma Gastrodiae.

Conclusions:

• Incorporating Fe(3)O(4)@SiO(2)/NH(2) and SBA-15 silica nanoparticles into polymethacrylate monoliths creates effective stationary phases for CEC.
• The mixed-mode separation mechanism and high surface area of nanoparticles contribute to enhanced chromatographic performance.
• These novel monolithic columns show promise for the analysis of complex samples in analytical chemistry and method development.