Covalent organic framework@Ti₃C₂T_x composite as solid phase microextraction coating for the determination of...

In this study, covalent organic framework@MXene (COF@Ti₃C₂T_x) composites were synthesized and employed as solid phase microextraction coatings for isolation of polycyclic aromatic hydrocarbons (PAHs) from honey samples. The developed composites possessed unique structural characteristics and multiple interactions (π-π and hydrophobic interaction, etc.), which provided them with excellent extraction capacity towards the targeted PAHs. Under optimized conditions, the resultant COF@Ti₃C₂T_x-coating fiber-based HS-SPME/GC-FID method exhibited a wide linear range (2.0-2000 ng g^-1), good linearities (r > 0.9964), and low limits of detection (0.20-0.60 ng g^-1). The recoveries of PAHs in the honey samples were in the range of 73.2-112%, with RSDs less than 9.4%. In addition, the findings showed that the composite-based fiber offers a long lifetime, high enhancement factors (483-598), and excellent fiber-to-fiber reproducibility (RSDs <10.5%, n = 3). This work not only details the development of a multi-functional composite, but it also presents an effective strategy for the determination of trace PAHs in complex food matrix.