Magnetic hydroxyl-containing conjugated microporous polymers synthesized at room temperature for high-efficiency extraction of trace benzoylurea insecticides.

Developing accurate, stable, facile, and highly sensitive detection methods is crucial for monitoring low levels of benzoylurea insecticides (BUs) which are priority pollutants harmful to ecological environment and human health. Herein, Fe3O4@OH-CMPs with triazine and -OH functionalized groups and large specific surface area (351.9 m²·g-¹), were synthesized covalently at room-temperature and utilized in the magnetic solid-phase extraction process of BUs. DFT calculation and characterization analyses demonstrated that BUs were bonded to Fe3O4@OH-CMPs primarily via π-π stacking and O-H···F hydrogen bond. Quantitative approach revealed lower limits of detection (0.19 to 1.2 ng·L-¹), higher reusability, and was applicable to more complicated sample matrices in comparison with other methods. Furthermore, the successful determination of BUs emitted from water, fruit juices, and tea samples with recovery (71.7-112.4 %) indicated the wide applicability of Fe3O4@OH-CMPs. This work accomplished a swift and sensitive detection of BUs, highlighting the potential of Fe3O4@OH-CMPs in maintaining food and environmental safety.