Recent advances in synthesis and applications of hyper-crosslinked porous organic polymers for sample pretreatment: A review

Hyper-crosslinked porous organic polymers (HCPs) are nanoporous materials synthesized through Friedel-Crafts reactions, which covalently crosslink monomeric units to integrate the high porosity, large surface area, and tunable pore architecture of porous networks with the structural diversity, lightweight nature, and compositional flexibility inherent to polymeric systems. These materials exhibit excellent thermal/chemical stability, facile surface functionalization, and scalable synthesis protocols, enabling versatile applications in drug delivery, chromatography, catalysis, and gas storage. In recent years, HCPs have gained prominence as advanced sorbents in sample pretreatment, owing to their inherent physicochemical characteristics that align closely with the critical requirements for high-performance extraction or purification adsorbents. This review aims to present recent advancements in HCPs preparation, with a primary focus on their applications in analytical sample preparation. A systematic investigation of HCP-based adsorption mechanisms, structural design principles, and fabrication methodologies was conducted to establish robust structure-function correlations through performance evaluation across diverse extraction techniques, including column solid-phase extraction (SPE), magnetic SPE (MSPE), solid-phase microextraction (SPME), and other miniaturized SPE formats, for the pre-concentration of target analytes in food, environmental, and biological samples. Finally, we delineate current challenges and future research directions, proposing innovative engineering strategies to advance HCPs for addressing complex analytical matrix challenges.