Metal-organic framework derived magnetic nanoporous carbon as an adsorbent for the magnetic solid-phase extraction of chlorophenols from mushroom sample

In this work, a metal-organic framework derived nanoporous carbon (MOF-5-C) was fabricated and modified with Fe₃O₄ magnetic nanoparticles. The resulting magnetic MOF-5-derived porous carbon (Fe₃O₄@MOF-5-C) was then used for the magnetic solid-phase extraction of chlorophenols (CPs) from mushroom samples prior to high performance liquid chromatography-ultraviolet detection. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N₂ adsorption were used to characterize the adsorbent. After experimental optimization, the amount of the adsorbent was chosen as 8.0 mg, extraction time as 10 min, sample volume as 50 mL, desorption solvent as 0.4 mL (0.2 mL×2) of alkaline methanol, and sample pH as 6. Under the above optimized conditions, good linearity for the analytes was obtained in the range of 0.8-100.0 ng g^-1 with the correlation coefficients between 0.9923 and 0.9963. The limits of detection (S/N=3) were in the range of 0.25-0.30 ng g^-1, and the relative standard deviations were below 6.8%. The result showed that the Fe₃O₄@MOF-5-C has an excellent adsorption capacity for the analytes.