Deep eutectic solvent-based ionogel: Innovative potential as a promising chromatographic separation material
Zexin Huang, Qiaoling Liu, Z. J. Ke, Tiantian Si, Yue‐Fei Zhang, Wei Chen, Sheng Tang
Abstract
Background Ionogels, composed of cross-linked polymer networks with abundant anions and cations as dispersion media , have emerged as promising materials. The superior properties of ionogels suggest that they may offer valuable contributions to the development of novel chromatographic stationary phase . However, the potential application of ionogels as the charming materials in liquid chromatography has been limited, primarily due to the hydrophilic nature, leading to swelling and increased column pressure. To address this issue, a paradigm-shifting innovation was proposed by incorporating deep eutectic solvent (DES) to facilitate the formation of robust hydrogen bond networks, thereby reducing the swelling tendency of ionogel. Results In this study, an environmentally friendly DES was selected as the optimal alternative to the traditional ionic liquid for the formation of a DES-based ionogel. By combining the ionogel with the silica gel matrix, a DES-Ionogel@SiO 2 stationary phase was prepared. The whole synthesis process of DES-Ionogel@SiO 2 was conducted in the green DES. The swelling tendency of ionogel as a functionalized chromatographic material was significantly reduced, thereby mitigating the risk of undue column pressure. This innovation results in a DES-based stationary phase with enhanced stability and durability in aqueous media, which is pivotal for maintaining the performance and longevity of chromatographic column. The DES-Ionogel@SiO 2 stationary phase exhibits a distinctive mixed-mode retention mechanism, which is a highly desirable attribute in diverse chromatographic applications. This endows the developed chromatographic column with a broad applicability for the separation of complex samples, such as nucleosides , phenyl ketones , phthalates , alkylphenols , steroid hormones and position isomers. Significance This work presents an innovative approach and green in-situ growth strategy for the development of a versatile ionogel stationary phase, and marks the first time that DES-based ionogel has been synthesized and used to modify silica gel as a promising chromatographic separation material, showcasing the revolutionary potential of DES-based ionogel in the field of liquid chromatography .