Hierarchically porous ionic-liquid@3D-COF fiber coating for high-performance accelerated extraction and sensitive analysis of polycyclic aromatic hydrocarbons in thermally processed meats

By precisely regulating ionic liquids (ILs) as dual functional mediators (green solvents/pore structure directing agents), we have achieved synthesis of three-dimensional hierarchical porous covalent organic frameworks (3D-COF). The prepared IL@3D-COF exhibited a multiscale nanopores structure and larger specific surface area, which was used as the solid-phase microextraction (SPME) coating material for the dual-mode SPME of polycyclic aromatic hydrocarbons (PAHs) from thermal processed meats. Especially, the incorporation of ILs functional groups provided abundant active adsorption sites, while the unique hierarchical pore architecture of IL@3D-COF significantly enhanced mass transfer kinetics. Under the accelerated extraction of high mass transfer rate and multiple interactions (π-π stacking, hydrogen bonding, and hydrophobic interactions), extraction equilibrium can be achieved in just 8   min. When combined with gas chromatography tandem mass spectrometry (GC-MS/MS), the 16 PAHs in meat samples have wide linear range (0.2-500   μg   kg -1 ) with low quantitative limits of 0.02-0.78   μg   kg -1 . Compared with other coating materials, IL@3D-COF coating materials are not only efficient and time-saving in the extraction process, with excellent extraction effects, but also have mild synthesis conditions and are environmentally friendly. It can provide a new alternative for sensitive analysis of PAHs in thermal processed meat products.