Covalent organic framework (COF)–decorated magnetic nanoparticles (Fe₃O₄@DhaTab) with core–shell structure have been synthesized by one-pot method. The prepared Fe₃O₄@DhaTab was well characterized, and parameters of magnetic solid-phase extraction (MSPE) for parabens were also investigated in detail. Under optimized conditions, the adsorbent dosage was only 3 mg and extraction time was 10 min. The developed Fe₃O₄@DhaTab-based MSPE-HPLC analysis method offered good linearity (0.01–20 μg mL⁻¹) with R² (0.999) and low limits of detection (3.3–6.5 μg L⁻¹) using UV detector at 254 nm. The proposed method was applied to determine four parabens in environmental water samples with recoveries in the range 64.0–105% and relative standard deviations of 0.16–7.8%. The adsorption mechanism was explored and indicated that porous DhaTab shell provided π-π, hydrophobic, and hydrogen bonding interactions in the MSPE process. The results revealed the potential of magnetic-functionalized COFs in determination of environmental contaminants.

Graphical abstract