Synthesis of NH2-functionalized magnetic nanoparticles based on pesticide polarity for analyzing trace-level pesticides from vegetables and complex biological samples

Abstract

In this study, an effective analytical approach based on targeting of 10 mid-polar pesticides residues from vegetables and biological samples using Fe3O4@SiO2-NH2 nanoparticles established by the three-step synthesis method and detected by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was proposed. Fe3O4@SiO2-NH2 nanoparticles were characterized by a size of 12–13 nm, a magnetic saturation of 43 emu/g, and sufficient NH2 groups coupled to the surface. Using the Fe3O4@SiO2-NH2, the magnetic dispersive solid phase extraction (MDSPE) for 10 mid-polar pesticides was based on targeting of 500 μL of samples (pH 7.1) vibration with 30 mg of Fe3O4@SiO2-NH2 during 10 min. This method demonstrated good recoveries (72.3–113.3 %) with relative standard deviations (RSDs) of 0.0–6.6 %, linearity ranging from 0.01 to 10 ng/mL with R2 values of 0.9945–0.9999, and limit of detection (LODs) ranging from 0.01 to 0.08 ng/mL using UPLC-QTOF-MS analysis. The proposed method was successfully applied to detect trace-level pesticide residues in real samples, such as chives, cabbage, and rat serum.