Velvet-like carbon nitride as a solid-phase microextraction fiber coating for determination of polycyclic aromatic hydrocarbons by gas chromatography.

In this study, velvet-like carbon nitride (V-g-CN) was prepared from urea aqueous solutions by one-step thermal polycondensation. The V-g-CN material was then characterized using a scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FT-IR), and nitrogen adsorption-desorption isotherms. The specific surface area of V-g-CN (60.