Ordered mesoporous silica film as a novel fiber coating for solid-phase microextraction

Ordered mesoporous silica (OMS) film supported on anodized titanium wire was fabricated as a new solid phase microextraction (SPME) fiber for the extraction of chlorophenols (CPs) from aqueous media followed by the determination with gas chromatography flame ionization detection (GC-FID). The supported OMS film was prepared via a solvent evaporation-induced self-assembly approach (EISA) combined with dip-coating technology. Commonly used fragile fused silica fiber was replaced by anodized titanium wire. The coating materials were characterized by N-2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric (TG) analysis. The N-2 adsorption-desorption results show the OMS material has well-ordered mesostructure with uniform pore diameter. The SEM images verify that the OMS film was successfully grafted onto the surface of anodized titanium wire. The resultant method based on the OMS fiber exhibited wide linear ranges (0.2-200 mu g L-1), low detection limits (0.03-0.12 mu g L-1) and good repeatabilities (6.2-9.8% for one fiber, 8.9-13.2% for fiber-to-fiber). No significant change was observed after being subjected into high temperature or immersed in organic solvents. The new fiber was successfully applied to the extraction and determination of three CPs compounds in the natural water samples. Thus, the OMS fiber is a promising alternative to the commercial fiber as it is easily and inexpensively prepared with high extraction capacity and good stability.