Poly(ethyleneimine) embedded octadecyl based stationary phase for multimodal chromatographic separation

In present research, a novel poly(ethyleneimine) (PEI) inserted octadecyl based phase named as Sil–PEI–STA was prepared for liquid chromatographic separation. Several approaches including elemental analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy as well as scanning electron microscopy were chosen to characterize the prepared materials. Then, polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes and positional isomers were analyzed as analytes for evaluating reversed phase chromatographic mode of the developed Sil–PEI–STA column. Interestingly, the column showed excellent properties for the separation of isomers. In addition, classical hydrophilic compounds (nucleosides and nucleobases) were selected to assess the hydrophilic selectivity of Sil–PEI–STA column. Moreover, anion exchange mode was evaluated by separating the mixture of benzoic acids. The Sil–PEI–STA column was further utilized for the separation of flavonoids and anilines compounds. The prepared column showed better separation for various compounds compared with the commercial C18 and NH2 columns under certain chromatographic conditions. In summary, the Sil–PEI–STA column provided flexible selectivity and better separation efficiency for hydrophobic, hydrophilic and charged compounds than commercial HPLC columns in certain conditions.