PCN-224/β-Cyclodextrin dual-modified magnetic nanocomposite for efficient extraction and determination of nobiletin...

Polymethoxylated flavonoids such as nobiletin and tangeretin are the primary bioactive constituents of Chenpi. However, their accurate quantification in complex beverage matrices remains challenging. In this study, a novel dual-modified magnetic composite, Fe₃O₄@PCN-224@β-CD, was synthesized for the efficient extraction of these target analytes. The material integrated the high magnetization of Fe₃O₄ for rapid separation, the porous and π-electron-rich framework of PCN-224 for strong π-π interactions, and a β-cyclodextrin shell for enhanced hydrophobic inclusion and aqueous dispersibility. Coupled with UPLC-UV detection, a magnetic solid-phase extraction method based on this composite was established and optimized through single-factor experiments and response surface methodology. The developed method exhibited excellent linearity (R² ≥ 0.998), low detection limits (0.01-0.02 μg/mL), satisfactory precision and good recoveries (92.59-101.73%). Furthermore, the adsorbent demonstrated outstanding reusability over seven cycles. The high adsorption efficiency was attributed to the synergistic effect of π-π stacking and hydrophobic interactions within the composite. This study provided a robust and environmentally friendly strategy for the selective enrichment and accurate quantification of nobiletin and tangeretin in Chenpi-based beverages, highlighting the potential of PCN-224 and β-CD dual-functionalized magnetic composites for high-efficiency sample pretreatment in complex matrices.