Reusable and sustainable graphene oxide/metal–organic framework-74/Fe3O4/polytyramine nanocomposite for simultaneous trace level quantification of five fluoroquinolones in egg samples by high performance liquid chromatography

A nanohybrid material termed graphene oxide/metal-organic framework-74/Fe3O4/polytyramine (GO/MOF-74/Fe3O4/PTy) was fabricated and applied in magnetic dispersive micro-solid phase extraction (MD-μ-SPE) coupled with high performance liquid chromatography (HPLC) for simultaneous determination of fluoroquinolones compounds including, ofloxacin, ciprofloxacin, lomefloxacin, enrofloxacin and sperfloxacin in egg samples. The GO/MOF-74/Fe3O4/PTy nanocomposite was fabricated through an in situ synthesis of MOF-74 in the presence of magnetic GO and followed with an oxidative polymerization of tyramine using horsedish peroxide (HRP) enzyme. The modifier agents improved the merits of the nanoporous sorbent. Extraction protocols based on GO/MOF nanocomposites have various benefit such as, the high stability, the tunable porosity, the fast mast transfer and reasonable enrichment factor. The fabricated material was characterized via energy dispersive x-ray analysis (EDX), the scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and the x-ray diffraction (XRD). The calibration curves revealed linearity (0.9992 ≤ r2 ≤ 0.9997) in the ranges of 1.0-475.0, 0.5-350.0, 0.5-350.0, 0.5-375.0 and 1.5-300.0 ng mL-1 with limit of detections (LODs, S/N=3) of 0.3, 0.1, 0.2, 0.1 and 0.4 ng mL-1 for ofloxacin, ciprofloxacin, lomefloxacin, enrofloxacin and sperfloxacin, respectively. The intra-assay (≤7.7%, n = 9) and inter-assay (≤7.0%, n = 9) precisions along with accuracy less than 9.0% showed the reliability of the method.