Fabrication of Magnetic Al-Based FeO@MIL-53 Metal Organic Framework for Capture of Multi-Pollutants Residue in Milk Followed by HPLC-UV.

The efficient capture of multi-pollutant residues in food is vital for food safety monitoring. In this study, in-situ-fabricated magnetic MIL-53(Al) metal organic frameworks (MOFs), with good magnetic responsiveness, were synthesized and applied for the magnetic solid-phase extraction (MSPE) of chloramphenicol, bisphenol A, estradiol, and diethylstilbestrol. Terephthalic acid (HBDC) organic ligands were pre-coupled on the surface of amino-FeO composites (HBDC@FeO). FeO@MIL-53(Al) MOF was fabricated by in-situ hydrothermal polymerization of HBDC, Al (NO), and HBDC@FeO. This approach highly increased the stability of the material. The magnetic FeO@MIL-53(Al) MOF-based MSPE was combined with high-performance liquid chromatography-photo diode array detection, to establish a novel sensitive method for analyzing multi-pollutant residues in milk. This method showed good linear correlations, in the range of 0.05-5.00 μg/mL, with good reproducibility. The limit of detection was 0.004-0.108 μg/mL. The presented method was verified using a milk sample, spiked with four pollutants, which enabled high-throughput detection and the accuracies of 88.17-107.58% confirmed its applicability, in real sample analysis.