Enrichment And Detection Of Fluoroquinolone Antibiotics Using Magnetic Microporous Organic Network Complexes

Objective:This paper aims to synthesize magnetic microporous organic network（MON）composite material with excellent adsorption properties for fluoroquinolone antibiotics（FQs）,and then establish a new magnetic solid phase extraction（MSPE）method based on magnetic MON composite material,combined with high-performance liquid chromatography（HPLC）detection method for the detection of FQs residues in environmental water samples.Provide methodological support for FQs environmental pollution assessment.Methods:Magnetic composite Fe₃O₄@MON-NH₂@CM-β-CD was prepared by hydrothermal synthesis and organic synthesis.Scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray diffraction analysis（XRD）,Fourier transform infrared spectroscopy（FT-IR）,X-ray photoelectron spectroscopy（XPS）,and other characterization methods were used to characterize the materials.The adsorptionpropertiesofFe₃O₄,Fe₃O₄@MON-NH₂,and Fe₃O₄@MON-NH₂@CM-β-CD on FQs were compared,and the adsorption mechanism was explored.The residue of FQs in environmental water samples was determined by HPLC-UV under optimal MSPE conditions.Results:Magnetic composite Fe₃O₄@MON-NH₂@CM-β-CD was successfully synthesized in this experiment.As an adsorbent of MSPE,this material had strong interaction forces with FQs,includingπ-πpacking,hydrophobic interaction,host-guest inclusion and hydrogen bonding.Compared with Fe₃O₄and Fe₃O₄@MON-NH₂,it has excellent adsorption properties for FQs.The adsorption process was consistent with the quasi-second-order kinetic model and Langmuir isothermal adsorption model,and a new MSPE method for FQs in environmental water samples was established.HPLC-UV was applied to detect FQs residues in environmental water samples.The results showed that five FQs antibiotics Enoxacin（ENO）,Ofloxacin（OFL）,Norfloxacin（NOF）,ciprofloxacin（CIP）,Enoxloxacin（ENR）had good linearity in the concentration range of 0.02-1μg m L^-1.The detection limits（S/N=3）were 0.0014-0.0023μg m L^-1,and the recoveries were 93.1%-116.2%,RSDs≤8.39%（n=3）.Conclusions:MSPE-HPLC based on magnetic composite Fe₃O₄@MON-NH₂@CM-β-CD constructed in this study can be used for the detection of FQs antibiotic residues in the water environment.This method has certain practicability and operability and provides a new idea for the pretreatment method of FQs residues in environmental pollutants.