In-syringe extraction using compressible and self-recoverable, amphiphilic graphene aerogel as sorbent for...

Graphene aerogels (GAs) have demonstrated great promise as sorbent materials. However, the intrinsically hydrophobic GAs are unsuitable for extraction of highly water-soluble analytes. Moreover, lack of compressibility limits the recyclability of GAs. In this work, an interesting type of water-induced self-recoverable amphiphilic GA was synthesized and employed as sorbent to extract nine priority phenols, listed as priority pollutants by the United States Environmental Protection Agency, from aqueous samples. The water-induced self-recoverability gives the GA the characteristic of a sponge, providing high recyclability and long-life. The aerogel was placed in a 2-mL microsyringe for in-syringe extraction of the phenols. The GA exhibits amphiphilicity due to the cross-linking by polyvinyl alcohol. At the same time, it exhibited selectivity to the water-soluble phenols. The extracted phenols were eluted with acetonitrile from the GA and the final extract was analyzed by high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The results showed that this method provided low limits of detection for the phenols (0.089-0.015 µg/L), good linearity (r² ≥ 0.9956) and low relative standard deviations (≤6.8%). The optimized method was applied successfully to river water samples. The simple in-syringe extraction procedure in combination with HPLC-UV analysis was demonstrated to be efficient, fast and convenient.