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

Abstract

In this study, velvet-like carbon nitride (V-g-C3N4) was prepared from urea aqueous solutions by one-step thermal polycondensation. The V-g-C3N4 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-C3N4 (60.66 m2/g) was 1.8 times that of the carbon nitride (g-C3N4) prepared by the traditional method. V-g-C3N4 was modified on the surface of stainless-steel wire by a sol-gel technique to obtain a solid-phase microextraction (SPME) coating for the extraction of five polycyclic aromatic hydrocarbons (PAHs) from water samples. The chromatography signal of the PAHs extracted using the V-g-C3N4 coating was 1.5 times that when using a g-C3N4 coating, and 5–10 times that when using commercial PDMS. Under the optimized extraction conditions, the linear range of the method developed for the determination of five PAHs was 0.05–100 µg/L, the limits of detection were 0.005–0.012 µg/L, and the recoveries from actual water samples were 85.94–103.47%. Furthermore, the developed SPME device is remarkably durable and can be reused up to 160 times.