A solid phase microextraction fiber coated with graphene-poly(ethylene glycol) composite for the extraction of volatile aromatic compounds from water samples.

Poly(ethylene glycol)-grafted graphene (PEG-g-G) was prepared and used as the solid phase microextraction (SPME) fiber coating for the extraction of seven volatile aromatic compounds (VACs) from water samples followed by the determination with gas chromatography-flame ionization detection. The PEG-g-G coating was characterized by both the thermal gravimetric analysis and scanning electron microscopy. The results verified that the PEG was successfully grafted onto the surface of graphene and the coating had a highly porous structure. Several important experimental parameters that could influence the SPME efficiency were investigated and optimized. Under the optimized conditions, the limits of detection were in the range from 1.0 to 6.0 ng L(-1). The relative standard deviations for intraday and interday variations were in the range of 1.8-5.8% and 5.1-8.3%, and for fiber-to-fiber variations, were between 6.5 and 11.9%, respectively. The results indicated that the PEG-g-G fiber had the advantages of high extraction efficiency and good thermal stability and durability. It can be reused more than 200 times without a significant loss of extraction efficiency. The method was successfully applied to the analysis of seven VACs in tap, river and mineral water samples.