▎ 摘　　要

In this paper, a graphene-based magnetic nano-composite (Fe3O4@G) was synthesized by covalent bonding. The presence of Fe3O4 was characterized by fourier transform infrared spectroscopy, X-ray diffraction, thermo-gravimetric analysis, scanning electron microscopy (SEM), and transmission electron microscopy. Subsequently, the Fe3O4@G was used as adsorbent for the extraction of eight organochlorine pesticides in orange juice samples prior to their gas chromatography mass spectrometry detection. Various experimental parameters affecting the extraction efficiencies, such as the amount of Fe3O4@G, extraction time, the pH of the sample solution and desorption conditions were investigated. Under optimized experimental conditions, good linearity existed in the range of 1.0-200.0 ng mL(-1) for all the analytes with the correlation coefficients (R-2) ranging from 0.9904 to 0.9992. The limits of detection (S/N = 3) of the method for the compounds were between 0.01 and 0.05 ng mL(-1). Good reproducibilities were obtained with the relative standard deviations (RSDs) below 9.6 %. The recoveries of the method were in the range between 73.8 and 105.4 % with RSDs less than 7.7 %.