[Recent progress on sample pretreatment methods of emerging pollutants in food based on porous framework materials]

Emerging pollutants （ECs） generally refer to chemicals or microorganisms that have known potential toxicity and health hazards. The defining characteristics of ECs include environmental persistence， bioaccumulation and biological toxicity. Primary categories of ECs comprise endocrine disrupting chemicals （EDCs）， persistent organic pollutants （POPs） and antibiotics. Dietary intake represents a predominant pathway for human exposure to ECs. This necessitates the development of highly sensitive and reliable analytical methods. Conventional analytical instruments are fundamental for ECs determination. These include high performance liquid chromatography （HPLC）， liquid chromatography-tandem mass spectrometry （LC-MS/MS）， and gas chromatography-tandem mass spectrometry （GC-MS/MS）. However， the direct analysis of ECs in food remains a significant challenge. This is due to their wide sources， numerous types， complex structures， and ultra-low concentrations alongside substantial matrix interferences. Consequently， it is urgent to develop efficient sample pretreatment techniques to extract， enrich and purify ECs in food， in order to reduce matrix interference and construct the foundation for establishing highly sensitive， accurate， and stable analytical methods. Among various pretreatment techniques， solid-phase extraction （SPE） has gained prominence. It offers notable advantages over liquid-liquid extraction （LLE）. These advantages include simple operation， low consumption of organic solvents and higher enrichment factors. To address specific analytical needs， several advanced SPE modalities have been developed， including magnetic solid-phase extraction （MSPE）， solid-phase microextraction （SPME）， dispersive solid-phase extraction （dSPE）， and stir bar sorptive extraction （SBSE）. Each variant offers unique benefits in terms of automation， speed， or selectivity. The performance of any SPE-based method is fundamentally governed by the adsorbent material. In recent years， porous framework materials have emerged as a revolutionary class of sorbents. They offer exceptional properties for extraction technology. Porous framework materials mainly include metal organic frameworks （MOFs）， covalent organic frameworks （COFs）， and， hydrogen-bonded organic frameworks （HOFs）. These materials are distinguished by their high specific surface area， tunable pore size and abundant sites for functionalization. Their structural periodicity and designability enable precise interaction with target analytes. This review provides a comprehensive and systematic overview of recent progress. It focuses on MOFs， COFs， and HOFs as next-generation adsorbents for ECs analysis. The article begins by introducing the fundamental structures and general properties of these three material classes. It details the synthesis strategies for both pristine materials and their composites. A major emphasis is placed on rational design principles. These principles aim to enhance adsorption performance. Key strategies discussed include ligand functionalization， defect engineering， and the construction of composite/hybrid materials. The review explains how these strategies modulate the adsorption mechanism， including size-exclusion， electrostatic interaction， π-π stacking， hydrogen bonding， and coordinative interaction. Subsequently， the application progress of these designed materials is thoroughly summarized. It is organized according to major ECs categories： EDCs， POPs， and antibiotics. For each category， representative studies from the past three years are highlighted. The discussion covers material design， extraction format （MSPE， dSPE， SBSE， SPME， etc.）， analytical technique coupling， and key performance metrics. Metrics include adsorption capacity， selectivity， and reusability. The successful determination of ECs in complex food samples is demonstrated. Finally， the review critically examines significant outstanding challenges and suggests corresponding directions for future research. These include the long-term stability of some frameworks in complex matrices. Scalable and green synthesis methods are also needed. Furthermore， seamless integration of these materials into automated， online analytical platforms requires development. Future research should prioritize several areas. Deeper mechanistic understanding via in-situ characterization and computational modeling is essential. The development of robust， environmentally friendly synthesis pathways is crucial. Enhancing material stability and selectivity for real-world applications is a key goal. Finally， translating powdered materials into practical， engineered devices is an important step. In conclusion， porous framework materials hold immense promise. They are poised to redefine sample pretreatment for food safety analysis. This review aims to serve as a valuable reference. It is intended for researchers developing new adsorbent materials and analytical methods for ECs.