Rational design of a mesoporous COF with tailored porosity for synergistic extraction and analysis of organic ultraviolet stabilizers

Organic ultraviolet stabilizers (OUVSs) have raised significant concerns due to their widespread occurrence and potential endocrine-disrupting effects. Herein, a kind of novel mesoporous covalent organic frameworks (COF), i.e., Fe₃O₄@TFPB-BD, was rationally designed and fabricated for the vortex-assisted magnetic solid-phase extraction (MSPE) of seven kinds of OUVSs from water samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The pore size (42.1 Å) of the material was pre-designed using density functional theory (DFT) to match the molecular dimensions of the OUVSs (10.6-12.5 Å), facilitating rapid mass transfer. The adsorption mechanism was elucidated to involve synergistic π-π conjugation and hydrogen bonding interactions. Under optimized MSPE conditions, the developed method demonstrated exceptional performance with a remarkably short pretreatment time of only 8 min, excellent precision (intra-day RSDs of 4.2-14.4 %; inter-day RSDs of 1.8-14.8 %), and ultra-low detection limits between 0.23 and 0.35 ng/L. The method was successfully applied to the analysis of coastal seawater and swimming pool water, achieving satisfactory spiked recoveries ranging from 83.66 % to 118.48 %. This study presents a rapid, sensitive, and robust approach for monitoring trace-level OUVSs in complex aquatic environments.