Preparation of Hierarchically Porous Monolithic Corn Straw@COF Composite for Fat-Rich Food Pretreatment in Non-Targeted Analysis.

In the food safety non-targeted analysis, it is urgent to develop suitable adsorbent materials for sample pretreatment, so as to achieve efficient removal of interference matrices in food samples and "full recovery" of potential chemical hazards. Traditional adsorption materials exhibit limitations such as poor removal efficiency and high cost. To address these issues, this study presents the preparation of a hierarchically porous monolithic corn straw@COF (CS@COF) composite for efficient sample pretreatment of fat-rich foods. CS@COF combines the advantages of corn straw (CS) and covalent organic frameworks (COFs), offering a high specific surface area and porosity. CS serves as a carrier for in-situ growth of COF, resulting in a material with easy operation and low cost. CS@COF demonstrates strong adsorption capacity, effectively removing over 98% of triglycerides within 8 minutes from fat-rich food samples like soybean. Moreover, it achieves "full recovery" of 190 chemical hazards with 89% recoveries within the ideal range. The reusability of CS@COF for 5 cycles after elution further underscores its practicality. This innovative CS@COF composite shows great potential in sample pretreatment for non-targeted food safety analysis, providing a cost-effective and efficient solution.