An innovative reversed-phase monolithic column modified with 4-vinylbiphenyl and ionic liquid stationary phases for capillary electrochromatography

Abstract

A novel monolithic column was developed with 4-vinylbiphenyl and an ionic liquid as the functional monomers and ethylene dimethacrylate as the cross-linker by thermal copolymerization for reversed-phase capillary electrochromatography. For this monolithic column, an imidazole ionic liquid, 1-allyl-3-methylimidazolium chloride, was introduced as the generator of electroosmotic flow. The composition of the polymerization mixture for the preparation of the monolithic column was optimized in detail. Characterization using scanning electron microscopy and Fourier transform infrared spectroscopy indicated that the monolithic column is synthesized successfully with excellent porous structure. Successful baseline separation of aromatic compounds, phenols and anilines with high resolution and high column efficiency demonstrates that the obtained monolithic column has powerful reversed-phase chromatography performance. The relative standard deviation of the retention time for run-to-run (n = 5), day-to-day (n = 5) and column-to-column (n = 3) is in the range of 0.39–1.30%, 0.68–3.92% and 1.06–3.66%, respectively, which shows the monolithic column possesses good reproducibility. This novel monolithic column has been successfully applied for the separation of phenols in spiked lake water samples.