Magnetic cationic covalent organic framework for efficient enrichment and detection of phenolic endocrine disruptors in foodstuffs.

Endocrine disrupting chemicals (EDCs) have received significant attention in the food field due to their potential health risks. Herein, we proposed a novel core-shell structure magnetic cationic covalent organic framework (EB-DHTA-iCOF@Fe3O4) designed for the efficient enrichment of trace-level EDCs in foodstuffs and analyzed using HPLC-MS/MS. Due to the phenolic EDCs structure possessing hydroxyl functional groups which become protonated under alkaline conditions, resulting in the formation of negatively charged anions. The EB-DHTA-iCOF@Fe3O4 positively charged surface can have a good enrichment effect on EDCs with phenolic structures through electrostatic interactions, π - π interactions, and hydrogen bonding. This unique combination of interactions enhances the iCOF ability to selectively capture and enrich phenolic EDCs from complex matrices, thereby improving the sensitivity and efficiency of their detection in analytical applications. Under optimal magnetic solid-phase extraction (MSPE) conditions, the method showed excellent linearity (5-250 μg kg-1, R2 ≥ 0.9993) and a low detection limit (0.03-1.2 μg kg-1) for phenolic EDCs, with recovery rates between 86.0 % and 106.8 % and a relative standard deviation under 5.8 %. The approach highlights the potential of the ionic covalent organic framework as an adsorbent for MSPE, offering a promising approach for the detection and analysis of trace-level EDCs in foodstuffs.