Synthesis of Modified Magnetic Graphene Oxide with Mesoporous Silica for Extraction of the Pharmaceutical Compound Quercetin.

In this study, magnetic mesoporous silica-Fe₃O₄-graphene oxide nanoparticles (Fe₃O₄@GO@mSiO₂) were synthesized and used as sorbents for magnetic solid-phase extraction (MSPE) of trace amounts of quercetin in natural samples (spinach, green pepper, dill, and red onion). The sorbent produced was characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS). The effects of various experimental factors on the percent recovery of quercetin, including extraction time, desorption time, sample solution pH, and adsorbent amount were investigated. The Fe₃O₄@GO@mSiO₂ strategy showed excellent stability and sensitivity for the determination of quercetin, with a suitable linear range of 20-800 µg L^-1 and a detection limit of 5.2 µg L^-1. The data indicate that Fe₃O₄@GO@mSiO₂ has a specific surface area and suitable adsorption capacity for the determination of quercetin.