Preparation and evaluation of poly(N-isopropylacrylamide-co-hexanediol diacrylate-co-ethylene dimethacrylate) monolithic column and its applications in the separation of small molecules

Abstract

Poly(N-isopropylacrylamide-co-hexanediol diacrylate-co-ethylene dimethacrylate) [poly(NIPAAm-co-HDDA-co-EDMA)] monolithic column was prepared via in situ polymerization reaction. In order to investigate the porous properties of the monoliths prepared, the morphology was characterized by the scanning electron microscopy; the chemical group of the monolithic column was confirmed by a Fourier transform infrared spectroscopy method. The surface area was 39.1 m2/g by the nitrogen adsorption-desorption experiment. With methanol as the mobile phase, the permeability of the monolithic column was calculated as 3.2330 × 10-14m2. Then it was used as the stationary phase of high performance liquid chromatography. The results indicted that poly(NIPAAm-co-HDDA-co-EDMA) monolithic column was good to separate small molecules by controlling the temperature. Column efficiency for p-chloronitrobenzene was 4,680 plates/m. Repeatability was defined by determining run-to-run and column-to-column variation of the retention times of aromatic compounds, expressed as relative standard deviation (RSD = standard deviation/mean x 100%), and the values were <0.58% and 3.1%, respectively.