Sustainable magnetic porous organic frameworks for rapid pre-concentration of benzoylurea pesticides in tea.

A magnetic porous organic framework (Fe3O4@POF) was synthesized and utilized as an efficient sorbent for the magnetic solid-phase extraction (MSPE) of benzoylurea insecticides from tea samples, followed by high-performance liquid chromatography coupled with ultraviolet detection. In this work, magnetic iron oxide (Fe3O4) nanoparticles were heterogeneously decorated around a porous organic framework (POF) template, creating a magnetic adsorbent that functions as a molecular sponge for the selective capture of benzoylurea insecticides. The physicochemical properties of the prepared sorbent were characterized. The synthesis parameters of the sorbent and the extraction conditions were systematically investigated and optimized to enhance extraction performance. Under the optimized conditions, the proposed method exhibited good linearity, low limits of detection, satisfactory enrichment factors, and good precision (RSD < 4.69%). The method was successfully applied to real samples, with recoveries in the range of 70.3-117.8%, while no residues of the investigated benzoylurea insecticides were detected. Furthermore, a rigorous greenness and whiteness assessment using AGREE, AGREEprep, and BAGI metrics confirmed the method's robust compliance with green analytical chemistry (GAC) principles. With its rapid processing time and exceptional sorbent reusability, this Fe3O4@POF-based strategy offers a superior, eco-friendly alternative for routine food safety monitoring and the detection of trace insecticides.