Preparation and post-modified of dicationic ionic liquid stationary phase and their application in mixed-mode liquid chromatography

Abstract

This work prepared two dicationic ionic liquid stationary phases for mixed-mode chromatography via thioe-ene click reaction, one of which was post-modified by p-tolyl isocyanate. The successful synthesis of two stationary phases was demonstrated by several characterizations. The separation of a wide range of substances, including nucleosides and bases, alkylbenzene, polycyclic aromatic hydrocarbons, anilines, phenols, inorganic anions and organic acids, shows that homemade stationary phases can not only be applie to RPLC/HILIC/IEC mixed-mode chromatography, but also has better separation selectivity than commercial column. Therefore, the post-modification of p-tolyl isocyanate can greatly improve the separation effect in RPLC mode, which proves that this modification method is of research significance. The retention mechanisms of two stationary phases were investigated by varying the chromatographic conditions and linear solvation energy relationships (LSER). In addition, the stationary phase is able to detect preservatives in foods quickly and accurately. In actual sample testing, the limit of detection ≤ 0.074mg·L−1 and the inter-day precision was not more than 3.33 %.