Dispersive Micro-Solid-Phase Extraction using Graphene Oxide/Polydopamine-Polyacrylamide Nanocomposite Coupled with HPLC-UV for Determination of Phenobarbital in Plasma Samples

Graphene oxide/polydopamine-polyacrylamide nanocomposite was synthesized by a simple method and used as adsorbent for dispersive micro-solid-phase extraction of phenobarbital in plasma samples. The adsorbent was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy–energy dispersive spectroscopy and thermal gravimetric analysis. The results show that functionalization of graphene oxide by polymeric materials can enhance the sorption properties and thermal stability of the prepared adsorbent. Influential parameters on the extraction efficiency of Phenobarbital including adsorbent amount, elution solvent and its volume, sorption and desorption times and pH of sample solution were investigated and optimized. Under the optimized conditions, limits of detection and quantitation values were 1.4 and 5ng/mL, respectively. Relative recovery data for several real samples were obtained within the range of 84.0-98.0% with a relative standard deviation less than 7.2%. The proposed method was successfully applied to quantitative determination of phenobarbital in plasma samples.