▎ 摘　　要

In this work, magnetic graphene oxide nanoparticles were successfully synthesized by a mechanochemical approach and used as an effective sorbent in magnetic dispersive solid phase extraction of insecticides from vegetable samples followed by high-performance liquid chromatography coupled with UV-Vis detection. Imidacloprid (IMI) and chlorpyrifos (CP) were selected as model insecticides to validate the extraction performance of the obtained nanoparticles. The synthesized magnetic graphene oxide nanoparticles were characterized. Various factors which could affect the recovery were investigated and optimized. Under the optimum conditions, the calibration curves were linear in the ranges of 0.002-5 and 0.004-10 mu g/mL for IMI and CP, respectively. Also, the limits of detection for IMI and CP were 1.5 and 4 mu g/L, and the limits of quantitation were 5 and 11 mu g/L, respectively. The linearity (R > 0.999) and precision (between 3.3 and 6.7%) were good. Notably, the developed method could be used to determine and monitor IMI and CP residues in Chinese cabbage, shiitake, and needle mushroom samples with satisfactory recoveries.