Facile and large-scale synthesis of trifluoromethyl-grafted covalent organic framework for efficient microextraction and ultrasensitive determination of benzoylurea insecticides

[Display omitted] •COF-(CF3)2 was synthetized via Suzuki-Miyaura cross-coupling reaction for the first time.•Synthesis process was simplified and suitable for large-scale production and application.•A reliable method based on SPME- UHPLC-MS/MS was established for BUs determination.•Multiple interactions were calculated and provided a multiscale understanding of adsorption. Owing to the excessive usage of benzoylurea insecticide (BUs), ecological and environmental problem has been attractedincreasingpublic attention. Herein, a novel trifluoromethyl-grafted covalent organic framework (COF), named COF-(CF3)2, was synthetized through Suzuki-Miyaura cross-coupling reaction based on post-synthetic modification (PSM) strategy under mild condition. The synthesized operation was simplified to make it suitable for large-scale production and application. Characterization methods, such as fourier transform-infrared spectrum, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, were implemented to confirm the successful synthesis of COF-(CF3)2. Considering the enhanced electrostatic interaction and fluorine–fluorine interactions, COF-(CF3)2 was applied as solid phase microextraction (SPME) coating. An analytical method coupling direct immersion (DI)-SPME with ultra-high performance liquid chromatography-tandem mass spectrometrywas established for effective enrichment and ultrasensitive determination of seven BUs in environmental water. Satisfactory analytical parameters for target BUs were obtained, including wide linearity of 1–1000 ng L−1 with correlation coefficient (R2) of 0.9991–0.9999, low limits of detection (LOD) of 0.06–0.50 ng L−1, high enrichment factors (EFs) of 44–105 and satisfactory precision with relative standard deviations (RSD) ≤ 10.2%. The excellent performance of the proposed method was validated by the recovery test in real water samples with recoveries of 76.2–107.6% and RSD ≤ 11.1%. Furthermore, multiple interactions between COF-(CF3)2 and BUs molecules were analyzed combined with theoretical simulations to explain the adsorption mechanism. It illustrated that exceptional BUs adsorption performance of COF-(CF3)2 might be attributed tosynergistic effect of mesoporous structure and trifluoromethyl modification. This work represents a rational design of functional materials through a novel and versatile PSM approach for the effective enrichment and ultrasensitive analysis of BUs in env