In-situ hydrothermal synthesis of titanium dioxide nanorods on titanium wire for solid-phase microextraction of polycyclic aromatic hydrocarbons.

Titanium dioxide nanorods were prepared on the surface of titanium wire by hydrothermal synthesis for use as a solid-phase microextraction (SPME) fiber. The morphology of the SPME coating was observed by scanning electron microscopy (SEM). Employed in conjunction with gas chromatography (GC), the fiber was investigated with five polycyclic aromatic hydrocarbons (PAHs) and three terphenyls in direct-immersion extraction mode. Various parameters were optimized, such as the extraction time, the stirring rate, the extraction temperature, the ionic strength of the sample solution, and the desorption time. Under the optimized conditions, the SPME-GC analytical method achieved a low detection limit (0.003 μg L-1) and wide linear ranges (0.01-100 μg L-1 and 0.01-200 μg L-1) along with good correlation coefficients (0.9892-0.9962). The established method was also used to analyze rainwater and an aqueous solution of coal ash. The results indicated that this fiber could be applied in real-world environmental monitoring. The proposed fiber also exhibited excellent durability. Graphical Abstract The schematic diagram of experimental process.