Room-temperature synthesis of sulfonated covalent organic framework for efficient enrichment of trace brominated phenols in aquatic products.

Brominated phenols (BPs), as ubiquitous environmental contaminants, accumulate in the food chain and pose potential health risks to humans through dietary exposure. Assessing the residual levels of BPs in foods is a prerequisite for determining the dietary exposure risk of BPs. However, the low abundance of BPs and complex food matrices hinder accurate analysis of BPs. In this study, a sulfonic acid-functionalized covalent organic framework (SCOF) was designed and synthesized for enriching BPs. To investigate the adsorption mechanism of SCOF, molecular simulations were used to calculate the binding sites and interaction energies between SCOF and BPs. The results showed that there may be multiple interactions between SCOF and BPs, such as π-π interactions, electrostatic attraction, and hydrogen bonding. To evaluate the level of BPs in aquatic products, a SCOF-based solid-phase extraction cartridge was developed and coupled with liquid chromatography-tandem mass spectrometry to establish a detection method for BPs. The developed method successfully quantified five target BPs in fish and shrimp samples. The method exhibited satisfactory recoveries and low detection limits (0.005-0.027 ng/g). This study provides a simple, cost-effective, and reliable alternative for the trace monitoring of BPs in aquatic products. It is expected to address the urgent need for reliable monitoring of BPs in the aquatic environment and food chain.