▎ 摘　　要

This study developed a simple, rapid and sensitive method that utilizes vortex-assisted graphene oxide nanosheets dispersive micro-solid phase extraction of tramadol hydrochloride from biological samples. The data obtained from scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy confirmed the characteristics of graphene oxide nanosheets (GONSs). In order to increase the extraction efficiency, a vortex was applied in the extraction process. In this study, parameters affecting the extraction efficiency were identified and discussed. The optimal experimental parameters were as follows: pH, amount of GONSs, type and volume of desorption solvent, vortexing time, and addition of NaCl. Under optimized conditions, this method allowed the determination of tramadol in the range of 5-300 mu g l(-1) and the limit of detection was 0.16 mu g l(-1). The intra-day and inter-day precisions obtained were 2.4% and 3.8%, respectively. This method can be used as an analytical technique for the determination of tramadol in biological samples.