Self‐Assembled Stable Magnetic COF Super‐Particles Through Electrostatic Interaction for Efficient Removal and Detection of PFAS Combined with LC‐MS/MS

Abstract The stability and biological toxicity of per‐ and polyfluoroalkyl substances (PFAS) are currently the most severe environmental issues, posing a huge threat to human health. The governance and detection of PFAS is currently a huge challenge. Herein, a dual‐functionalized spherical covalent organic framework (COF) is developed with fluorine and cationic groups, combined with magnetic nanoparticles to form binary magnetic COF super‐particles (SPs). The COF has high crystallinity, a spherical and hollow structure, and a strong positive charge. SPs exhibited broad‐spectrum and high adsorption capability toward PFAS (631 mg g ⁻¹ for perfluorooctanoic acid (PFOA)) and rapid equilibrium (<30 s), which maintained ≈100% capacity retention over five cycles. For detection, the SPs can be used as a pre‐concentration platform for PFAS through efficient magnetic solid‐phase extraction (MSPE), simplifying LC‐MS/MS analysis with a detection limit of 0.0009–0.13 ng L ⁻¹ for 18 PFAS compounds. The method achieved high recovery (80%–120%) in environmental and biological samples, demonstrating robust performance for PFAS removal and trace analysis.