Construction of core-shell MOF/TAPP-COP hybrid materials for extraction and enrichment of bisphenols before HPLC...

Bisphenol analogs (BPs) are endocrine-disrupting chemicals widely present in food packaging and environmental waters, posing potential risks to human health. However, their trace-level detection in complex matrices remains challenging due to insufficient affinity of existing adsorbents toward BPs and severe matrix interference. To address this, a core-shell structured hybrid material, NH₂-UiO-66/TAPP-COP (UiO-MOF@TAPP-COP, NU66/TAPP-COP), was successfully constructed via an in-situ growth strategy, exploiting the Schiff-base reaction between the amino groups of NH₂-UiO-66 and the aldehyde groups of the linker to encapsulate a porphyrin-based covalent organic polymer (TAPP-COP) onto the surface of NH₂-UiO-66. The morphology, structure, and composition of the composite were systematically characterized. Benefiting from the synergistic effect between NH₂-UiO-66 and TAPP-COP, the composite exhibited excellent extraction performance (enrichment factors of 186-230) and ultrahigh adsorption capacity (490.6-909.6 mg/g). After systematic optimization of extraction parameters, the method achieved low limits of detection (0.1-0.15 ng/mL) and satisfactory recoveries (71.6%-115.7%) for the determination of BPs in milk and lake water samples. The adsorption behavior followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating a combination of physical and chemical adsorption, with chemisorption being the rate-controlling step. Mechanistic investigations, combined with DFT calculations, further revealed that π-π stacking and hydrogen bonding are the primary driving forces for BPs adsorption. The proposed method was successfully applied to the analysis of BPs in real skimmed milk and lake water samples, demonstrating its preliminary feasibility for trace-level monitoring in food and environmental matrices. This work provides a promising strategy for designing high-performance MOF/COP hybrid adsorbents for trace pollutant detection.