Highly efficient enrichment of eugenol anesthetics in aquatic products using magnetic nanospheres decorated covalent organic framework microflowers

Herein, uniform magnetic covalent organic framework (MCOF) microflowers were synthesized by facile inlaying aldehyde-functionalized Fe 3 O 4 nanoparticles onto the COF under mechanical stirring at room temperature. The MCOF microflowers kept flower-shaped morphology with high crystallinity and magnetism. In addition, the good water dispersibility and reusability made the MCOF microflowers to be good magnetic solid phase extraction (MSPE) adsorbents for the high-efficiency enrichment of eugenol anesthetics from aquatic products. The MCOF microflowers showed fast adsorption rate (10 min) and high extraction efficiency (above 84.02%) for eugenol anesthetics under optimal conditions. The MCOF microflowers displayed maximum adsorption capacities of 6.67, 12.31, and 16.78 µg g −1 for eugenol, eugenol acetate, and methyl isoeugenol, respectively. The MCOF microflowers based MSPE coupled with high-performance liquid chromatography method was proposed for enrichment and analysis of eugenol anesthetics in tilapia, shrimp and crab samples. The method showed a wide linear of 5.0–500.0 µg kg −1 and low detection limits of 2.4–3.6 μg kg −1 for eugenol anesthetics. The recoveries of spiked eugenol anesthetics ranged from 80.0% to 118.8% with relative standard deviations no>9.2%. Results indicate the high potential of MCOF microflowers to be an adsorbent for efficient extraction and analysis of eugenol anesthetics from complex aquatic product samples.