Click postsynthesis of microporous organic network@silica composites for reversed-phase/hydrophilic interaction mixed-mode chromatography

• Published in: Analytical and bioanalytical chemistry Vol. 415; no. 18; pp. 4533 - 4543
• Main Authors: Sun, Hao-Fei, Cui, Yuan-Yuan, Li, Hong-Liang, Yang, Cheng-Xiong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2023; Springer; Springer Nature B.V
• Subjects: Alkaloids - analysis; Analysis; Analytical Chemistry; Benzene; Biochemistry; Characterization and Evaluation of Materials; Chemical properties; Chemical reactions; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chromatography; Chromatography, High Pressure Liquid - methods; Chromatography, Reverse-Phase - methods; Composite materials; Endocrine disruptors; Food Science; High performance liquid chromatography; Hydrophilicity; Hydrophobic and Hydrophilic Interactions; Hydrophobicity; Identification and classification; Laboratory Medicine; Liquid chromatography; Methods; Microspheres; Monitoring/Environmental Analysis; Monomers; Packed columns; Pore size; Properties; Research Paper; Separation; Silica; Silicon dioxide; Silicon Dioxide - chemistry; Stationary phase; Sulfhydryl Compounds; Sulfonamides; Topology; Young Investigators in (Bio-)Analytical Chemistry 2023; China; Thiol-yne click reaction; Mixed-mode chromatography; Composite; Microporous organic network; Postsynthesis
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-023-04680-0

Recently, the good physical and chemical properties, well-defined pore architectures, and designable topologies have made microporous organic networks (MONs) excellent potential candidates in high-performance liquid chromatography (HPLC). However, their superior hydrophobic structures restrict their application in the reversed-phase mode. To solve this obstacle and to expand the application of MONs in HPLC, we realized the thiol-yne “click” postsynthesis of a novel hydrophilic MON-2COOH@SiO 2 -MER (MER denotes mercaptosuccinic acid) microsphere for reversed-phase/hydrophilic interaction mixed-mode chromatography. SiO 2 was initially decorated with MON-2COOH using 2,5-dibromoterephthalic acid and tetrakis(4-ethynylphenyl)methane as monomers, and MER was then grafted via thiol-yne click reaction to yield MON-2COOH@SiO 2 -MER microspheres (5 μm) with a pore size of ~1.3 nm. The -COOH groups in 2,5-dibromoterephthalic acid and the post-modified MER molecules considerably improved the hydrophilicity of pristine MON and enhanced the hydrophilic interactions between the stationary phase and analytes. The retention mechanisms of the MON-2COOH@SiO 2 -MER packed column were fully discussed with diverse hydrophobic and hydrophilic probes. Benefiting from the numerous -COOH recognition sites and benzene rings within MON-2COOH@SiO 2 -MER, the packed column exhibited good resolution for the separation of sulfonamides, deoxynucleosides, alkaloids, and endocrine-disrupting chemicals. A column efficiency of 27,556 plates per meter was obtained for the separation of gastrodin. The separation performance of the MON-2COOH@SiO 2 -MER packed column was also demonstrated by comparing with those of MON-2COOH@SiO 2 , commercial C18, ZIC-HILIC, and bare SiO 2 columns. This work highlights the good potential of the thiol-yne click postsynthesis strategy to construct MON-based stationary phases for mixed-mode chromatography. Graphical Abstract