Synthesis of a graphene-based nanocomposite for the dispersive solid-phase extraction of vancomycin from biological samples.

The approach of this work was to study the capability of graphene-based materials in the field of biological sample preparation. A polypyrrole/graphene composite was synthesized and characterized. The potential of the nanocomposite was investigated as a sorbent in dispersive solid-phase extraction followed by high-performance liquid chromatography with UV detection for vancomycin as a model drug. The effect of different parameters influencing extraction efficiency such as sample pH and sample volume, ionic strength, extraction time, type, and volume of desorption solvent and desorption time were investigated. A comparison study was also conducted between polypyrrole/graphene and some different novel and classic sorbents. Under optimized conditions, the calibration curve for vancomycin showed linearity in the range of 0.05–10 μg/mL. In addition, limits of detection, and quantification were 0.003 and 0.01 μg/mL, respectively. The intraday and interday relative standard deviations at a concentration of 0.05 μg/mL (n = 3) were 1.6 and 2.1%, respectively. Furthermore, the proposed method was successfully applied for the determination of vancomycin in plasma and urine samples. The relative recoveries indicated the feasibility of graphene-based sorbents in biological sample analysis.