Chemically Deposited Sol–Gel Film on Porous TiO₂ Nanotube Arrays as an Efficient and Unbreakable Solid-Phase Microextraction Fiber

Abstract

In the present study, a novel technique was proposed to improve the performance of solid-phase microextraction fibers through the chemical deposition of polydimethylsiloxane/divinylbenzene film on modified TiO₂ nanotube arrays substrate. Two different techniques, including the self-assembled monolayer of 3-mercaptopropyl trimethoxysilane and NaOH treatment, were examined to modify the surface of TiO₂ nanotube arrays. The morphology of the prepared fibers was studied by scanning electron microscopy. The applicability of the novel fiber was evaluated through the headspace solid-phase microextraction of some polycyclic aromatic hydrocarbons as the model compounds followed by GC–MS determination. Influencing parameters on the extraction efficiency such as extraction time, temperature and salt content were studied and optimized. The thermal stability experiments demonstrated that the novel fiber was stable at 280 °C and reusable for more than 80 times without an obvious decrease in the extraction performance. The proposed method was successfully applied to the determination of PAHs in river water samples with good relative recoveries from 75.8 to 104.5% and the relative standard deviation values for all analytes were below 12%. Finally, the extraction performance of the prepared fiber was compared with those of commercially available fibers and similar previously reported fibers.