Novel Room-Temperature-Prepared Covalent Organic Framework as Adsorbent for Rapid Extraction of Aromatic Esters in Baijiu

Abstract

Developing a rapid, efficient, and environmentally friendly analytical methodology for the determination of aromatic esters (AREs) in Baijiu presents a significant challenge. In this study, we developed a room-temperature method to synthesize core-shell Fe₃O₄@TPB-Dha in 1 h using pre-prepared Fe₃O₄ nanoparticles, enabling rapid and sensitive detection of AREs. The Fe₃O₄@TPB-Dha demonstrated exceptional adsorption capabilities (52.63–58.82 mg/g) with a brief adsorption duration (4 min) for four AREs as magnetic solid phase extraction (MSPE) adsorbent. Moreover, density functional theory (DFT) calculations revealed the key adsorption mechanisms to be hydrogen bonds, van der Waals forces, and π–π interactions. Ultimately, the method enabled the rapid and accurate quantification of the four AREs in real Baijiu samples, with concentrations spanning from 0.17 ± 6 × 10⁻⁴ to 2.40 ± 0.03 mg/L, and exhibited relative standard deviations below 6.57% (n = 3). These findings suggest that Fe₃O₄@TPB-Dha holds promise as an effective adsorbent for efficient extraction and precise quantification of aromatic esters in Baijiu.