Membrane-protected carboxylated COF-based micro-SPE coupled with HPLC-MS/MS for simultaneous determination of 16...

Carcinogenic heterocyclic aromatic amines (HAAs) inevitably form during thermal processing, particularly in sugar- and meat-rich Cantonese baked products, making sensitive quantification of trace HAAs essential for food safety. Here, we synthesized a carboxyl-functionalized covalent organic framework (COF) via post-modification, namely TpBD-COOH, and evaluated it as an adsorbent for HAA enrichment. Despite exhibiting a low surface area (96 m²·g^-1), TpBD-COOH exhibited high affinity and rapid adsorption (10-20 min) for 16 HAAs, with adsorption behavior well described by fitting pseudo-second-order and Freundlich models. Furthermore, a membrane-protected micro-solid-phase extraction (M-μSPE) method coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis was developed, achieving low limits of detection (0.04-1.39 μg·kg^-1), satisfactory recoveries (72.6-118.7%), and good analytical stability for profiling of multiple HAAs. These results indicate that the proposed M-μSPE-HPLC-MS/MS method shows strong potential for food safety monitoring of thermally processed bakery products.