All-in-one strategy to construct bifunctional covalent triazine-based frameworks for simultaneous extraction of per- and polyfluoroalkyl substances and polychlorinated naphthalenes in foods.

Per- and polyfluoroalkyl substances (PFASs) and polychlorinated naphthalenes (PCNs) are of growing concern due to their toxic effects on the environment and human health. There is an urgent need for strategies to monitor and analyze the coexistence of PFASs and PCNs, especially in food samples at trace levels, to ensure food safety. Herein, a novel ß-cyclodextrin (ß-CD) derived fluoro-functionalized covalent triazine-based frameworks named CD-F-CTF was firstly synthesized. This innovative framework effectively combines the porous nature of the covalent organic framework and the host-guest recognition property of ß-CD enabling the simultaneous extraction of PFASs and PCNs. Under the optimal conditions, a simple and rapid method was developed to analyze PFASs and PCNs by solid-phase extraction (SPE) based simultaneous extraction and stepwise elution (SESE) strategy for the first time. When coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), this method achieved impressive detection limits for PFASs (0.020 -0.023 ng/g) and PCNs (0.016 -0.075 ng/g). Furthermore, the excellent performance was validated in food samples with recoveries of 76.7-107 % (for PFASs) and 78.0-108 % (for PCNs). This work not only provides a simple and rapid technique for simultaneous monitoring of PFASs and PCNs in food and environmental samples, but also introduces a new idea for the designing novel adsorbents with multiple recognition sites.

Multiple-component covalent organic frameworks for simultaneous extraction and determination of multitarget pollutants in sea foods.

Persistent organic pollutants (POPs), such as perfluoroalkyl and polyfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and bisphenols (BPs), have been raising global concerns due to their toxic effects on environment and human health. The monitoring of residues of POPs in seafood is crucial for assessing the accumulation of these contaminants in the study area and mitigating potential risks to human health. However, the diversity and complexity of POPs in seafood present significant challenges for their simultaneous detection. Here, a novel multi-component fluoro-functionalized covalent organic framework (OH-F-COF) was designed as SPE adsorbent for simultaneous extraction POPs. On this basis, the recognition and adsorption mechanisms were investigated by molecular simulation. Due to multiple interactions and large specific surface area, OH-F-COF displayed satisfactory coextraction performance for PFASs, PCBs, and BPs. Under optimized conditions, the OH-F-COF sorbent was employed in a strategy of simultaneous extraction and stepwise elution (SESE), in combination with HPLC-MS/MS and GC-MS method, to effectively determined POPs in seafood collected from coastal areas of China. The method obtained low detection limits for BPs (0.0037 -0.0089 ng/g), PFASs (0.0038 -0.0207 ng/g), and PCBs (0.2308 -0.2499 ng/g), respectively. This approach provided new research ideas for analyzing and controlling multitarget POPs in seafood. ENVIRONMENTAL IMPLICATIONS: Persistent organic pollutants (POPs), such as perfluoroalkyl and polyfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and bisphenols (BPs), have caused serious hazards to human health and ecosystems. Hence, there is a need to develop a quantitative method that can rapidly detect POPs in environmental and food samples. Herein, a novel multi-component fluorine-functionalized covalent organic skeletons (OH-F-COF) were prepared at room temperature, and served as adsorbent for POPs. The SESE-SPE strategy combined with chromatographic techniques was used to achieve a rapid detection of POPs in sea foods from the coastal provinces of China. This method provides a valuable tool for analyzing POPs in environmental and food samples.