Preparation of well-controlled three-dimensional skeletal hybrid monoliths via thiol–epoxy click polymerization for highly efficient separation of small molecules in capillary liquid chromatography

• Two hybrid monoliths were facilely prepared via thiol–epoxy click polymerization reaction.
• The obtained monoliths possess high thermal and chemical stabilities.
• The highest column efficiency of ca. 182,700 N/m was achieved.
• The obtained monoliths exhibited high separation capabilities for various simple and complicated samples.

Two kinds of hybrid monoliths were first prepared via thiol–epoxy click polymerization using a multi-epoxy monomer, octaglycidyldimethylsilyl POSS (POSS-epoxy), and two multi-thiols, trimethylolpropanetris(3-mercaptopropionate) (TPTM) and pentaerythritoltetrakis(3-mercaptopropionate) (PTM), respectively, as the precursors. The resulting two hybrid monoliths (assigned as POSS-epoxy–TPTM and POSS-epoxy–PTM) not only possessed high thermal, mechanical and chemical stabilities, but also exhibited well-controlled 3D skeletal microstructure and high efficiency in capillary liquid chromatography (cLC) separation of small molecules. The highest column efficiency reached 182,700 N/m (for butylbenzene) on the monolith POSS-epoxy–PTM at the velocity of 0.75 mm/s. Furthermore, the hybrid monolith POSS-epoxy–PTM was successfully applied for cLC separations of various samples, not only standard compounds such as alkylbenzenes, PAHs, phenols and dipeptides, as well as intact proteins, but also complex samples of EPA 610 and BSA digest.