Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (6): 20220008.doi: 10.7503/cjcu20220008

• Analytical Chemistry • Previous Articles     Next Articles

Preparation and Chromatographic Performance of Mixed-mode Silica Stationary Phase Modified by Double Cationic Ionic Liquid and Octadecyl Group

JI Shuangqi1, JIN Zhao1, GUAN Wenna2(), PAN Xiangyu1, GUAN Tong1   

  1. 1.School of Polymer Science and Engineering,Qingdao University of Science and Technology,Qingdao 266045,China
    2.Qingdao Institute of Bioenergy and Bioprocess Technology,Chinese Academy of Sciences,Qingdao 266101,China
  • Received:2022-01-05 Online:2022-06-10 Published:2022-03-15
  • Contact: GUAN Wenna E-mail:guanwn@qibebt.ac.cn
  • Supported by:
    the Instrument and Equipment Function Development Technology Innovation Project, Chinese Academy of Sciences

Abstract:

In this paper, a mixed-mode silica chromatography stationary phase(Sil-C18-IL-C4) modified by imidazole-based double cationic ionic liquid and octadecyl group was prepared by a step-by-step bonding reaction. The stationary phase was characterized by elemental analysis and infrared spectroscopy. The chromatographic separation performance of the stationary phase in reversed-phase mode(RPLC), hydrophilic mode(HILIC) and RPLC/HILIC mixed-mode were evaluated, respectively, and 6 base nucleosides were separated in HILIC mode. The influence of the volume fraction of the organic phase and the concentration of ammonium formate in the aqueous phase on the separation effect was also investigated. In addition, the repeatability of stationary phase separation was investigated. Elemental analysis and characterization of the prepared Sil-C18-IL-C4 stationary phase show that the nitrogen content was 1.65%, the carbon content was 11.16%, and the hydrogen content was 2.44%. In the characterization results of infrared spectroscopy, the asymmetric and symmetric stretching vibration peaks of —CH appeared at 2928 and 2856 cm?1, and the stretching of C=C on the imidazole ring appeared at 1440 and 660 cm?1. The vibration peaks and the bending vibration peaks of C=N indicate that both octadecyl and 1,5-bis(imidazol-1-yl)pentane were grafted onto the silica surface. The chromatographic performance evaluation results showed that the Sil-C18-IL-C4 mixed-mode silica stationary phase could simultaneously exhibit reversed-phase and hydrophilic-interaction chromatogra-phic separation performance, and could completely separate 6 kinds of base nucleosides. Moreover, under certain chromatographic conditions, the RPLC/HILIC mixed separation mode can be realized in a single run of a single chromatographic column. It has good application potential for solving hydrophilic substances such as base nucleosides in complex samples.

Key words: Imidazole-based double cationic ionic liquid, Mixed mode chromatography, Stationary phase, Base nucleoside

CLC Number: 

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