Phenyl-functionalization of titanium dioxide-nanosheets coating fabricated on a titanium wire for selective...

A novel titanium dioxide-nanosheets coating on a titanium wire (TiO2NS-Ti) was in situ fabricated by one-step electrochemical anodization in ethylene glycol with ammonium fluoride and followed by phenyl-functionalization for selective solid-phase microextraction (SPME). The fabricated TiO2NS coating exhibits higher specific surface area and more active sites, it also provides an ideal nanostructure and a robust substrate for subsequent surface modification. These characteristics were useful for efficient extraction. The SPME performance of phenyl-functionalized TiO2NS-Ti (ph-TiO2NS-Ti) fiber was evaluated by using ultraviolet filters, polychlorinated biphenyls and polycyclic aromatic hydrocarbons (PAHs) as model compounds coupled to high performance liquid chromatography with UV detection (HPLC-UV). It was found that the ph-TiO2NS-Ti fiber exhibited high extraction capability, good selectivity and rapid mass transfer for PAHs. The main parameters affecting extraction performance were investigated and optimized. Under optimized conditions, the proposed fiber showed good extraction efficiency comparable to those of commercial polydimethylsiloxane and polyacrylate fibers toward PAHs. The calibration graphs were linear over the range of 0.05-300 µg L(-1). The limits of detection of the proposed method were 0.008-0.043 µg L(-1) (S/N=3). Single fiber repeatability varied from 3.51% to 5.23% and fiber-to-fiber reproducibility ranged from 4.43% to 7.65% for the extraction of water spiked with 25 µg L(-1) each analyte (n=5). The established SPME-HPLC-UV method was successfully applied to selective concentration and sensitive determination of target PAHs from real environmental water samples with recoveries from 86.2% to 112% at the spiking level of 10 µg L(-1) and 50 µg L(-1). The relative standard deviations were below 9.45%. Furthermore, the ph-TiO2NS-Ti fiber can be fabricated in a reproducible manner, and has high stability and long service lifetime.