Magnetic covalent organic framework nanocomposites as a new adsorbent for the determination of polycyclicaromatic hydrocarbons in water and foodsamples

A magnetic covalent organic framework nanocomposite (Fe3O4@COF(Tp-NDA)) was synthesized via a solvothermal method, used as a magnetic adsorbent for the extraction of polycyclic aromatic hydrocarbons (PAHs) from lake water, tea, coffee, and fried chicken, and detected using a high performance liquid chromatography-ultraviolet detector. The synthesized magnetic adsorbent was characterized via transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption-desorption isotherm analysis and vibrating sample magnetometry. Parameters that affected the extraction conditions and desorption conditions were optimized. Adsorption equilibrium could be attained within 3 min. The prepared magnetic material could be reused 10 times. The limits of detection and quantification were 0.05-0.25 μg L-1 and 0.17-0.83 μg L-1, respectively. The recovery was 74.6-101.8% with a relative standard deviation of below 4.2%. The method was successfully used to detect PAHs in various samples.