A simple vortex-assisted graphene oxide nanosheets dispersive micro-solid phase extraction combined with high-performance liquid chromatography for UV-Vis detection of tramadol in biological samples

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 µg l^?1 and the limit of detection was 0.16 µg 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.