CNT-TiO2 coating bonded onto stainless steel wire as a novel solid-phase microextraction fiber

A novel solid-phase microextraction (SPME) fiber based on carbon nanotubes-titanium oxide (CNT-TiO2) composite coating bonded onto stainless steel wire was prepared via electroless plating and sol-gel techniques. The SPME coating was characterized by scanning electron microscopy and Raman microscopy. Coupled to gas chromatography (GC), the fiber was investigated with seven polycyclic aromatic hydrocarbons (PAHs) in direct-immersion mode. The SPME-GC analytical method was evaluated under optimized extraction conditions. Compared with other reports, higher sensitivity (LODs, 0.002-0.004 μg L−1) and better linear range (0.01-100 and 0.01-200 μg L−1) were obtained by the proposed method. The fiber exhibited high thermal stability to 300 °C and excellent durability in HCl and NaOH solutions. The as-established SPME-GC method was used to analyze the real water samples and satisfactory results were obtained.