Facile construction of bifunctional and stable covalent organic frameworks for efficient extraction and ultrasensitive determination of neonicotinoid insecticides

Efficient extraction and sensitive determination of neonicotinoid insecticides in intricate matrix remain a challenge due to their high-water solubility and trace level. Herein, an irreversible 4-carboxyl-quinoline linked COF, named CQ-COF TAPB-DHTA/DMTA , was synthesized via a one-pot multicomponent Doebner reaction. The CQ-COF TAPB-DHTA/DMTA incorporated abundant bifunctional hydroxyl and carboxyl groups while exhibiting enhanced hydrophilicity and excellent chemical stability. Then, solid-phase microextraction (SPME) fiber based on CQ-COF TAPB-DHTA/DMTA was prepared and exhibited exceptional durability and remarkable extraction performance for eight neonicotinoids. After coupling with ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), an ultrasensitive analytical method was developed with low limits of detection (0.51–3.5 ng L −1 ), wide linear range, and satisfactory correlation coefficients (R 2  ≥ 0.9910), and was successfully used for analysis of neonicotinoids in water and honey samples. This work highlights the potential of multifunctional and stable COFs for the extraction and analysis of polar pollutants from intricate matrices.