Engineered hydrophobic porous Fe₃O₄ microparticles for solvent-confined dispersive liquid-phase microextraction

Liquid-phase microextraction (LPME) relies critically on precise solvent control to achieve efficient extractant recovery. To address this, we developed a magnetic microparticle-based dispersive liquid-phase microextraction (MP-DLPME) strategy, employing hydrophobic porous Fe₃O₄ microparticles (∼1 μm) as solvent-stabilizing microcarriers. These microparticles were functionalized via covalent grafting of 3-chloropropyltriethoxysilane (CPS) and optimized porosity, enabling rigid confinement of organic solvents (e.g., 1-octanol) through dual mechanisms: (I) hydrophobic solvent anchoring to modified surfaces and (II) capillary trapping within mesopores. When applied to hydrophobic polycyclic aromatic hydrocarbons (PAHs) and organophosphorus pesticides (OPPs), the system generates solvent-encapsulated magnetic aggregates that dynamically fragment into microdroplets under vortex-induced shear forces, facilitating efficient analyte extraction via magnetic collection. By integrating the high efficiency of dispersive extraction with the rapid recovery of magnetic separation, the MP-DLPME method provides a robust sample pretreatment solution for environmental water analysis.