▎ 摘　　要

The authors describe a three-dimensional single layer graphitic carbon nitride-modified graphene composite (g-C3N4@G) deposited on a stainless steel wire by a sol-gel technique. The coated fiber was applied to direct immersion solid-phase microextraction of trace levels of polycyclic aromatic hydrocarbons (PAHs) from cosmetics samples prior to their determination by gas chromatography with mass spectrometry (GC-MS). Due to pi stacking interaction and hydrophobic interaction between the g-C3N4@G coating and the analytes (naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene), the fiber displays an excellent adsorption capability for the analytes. Under optimized conditions, the method has a wide linear range, low LODs (from 1.0 to 2.0 ng L-1), good repeatability and high recoveries. It was successfully applied to the determination of PAHs in cosmetics. The g-C3N4@G fiber also exhibited good durability.