Electrophoretic deposition hyphenated with electrochemical anodization for the fabrication of phenyl-functionalized mesoporous silica onto Nitinol fibers for selective solid-phase microextraction of polycyclic aromatic hydrocarbons

Abstract

Electrophoretic deposition (EPD) was hyphenated with electrochemical anodization for the fabrication of phenyl modified mesoporous silica (MPS-Ph) particles onto Nitinol (NiTi) wire as a solid-phase microextraction (SPME) fiber. The anodized NiTi wire offers an ideal conductive fiber substrate with a large available contact surface for subsequent EPD and surface modification of MPS particles. The resulting NiTi-based fiber showed better extraction selectivity and efficiency for polycyclic aromatic hydrocarbons (PAHs) compared with commercial polydimethylsiloxane and polyacrylate fibers. Under optimized conditions for SPME of PAHs, the proposed method presented wide linear ranges from 0.02 to 500 μg L⁻¹ with correlation coefficients higher than 0.999. The limits of detection ranged from 3.6 ng L⁻¹ to 5.2 ng L⁻¹. Relative standard deviations (RSDs) for single fiber repeatability varied from 4.3% to 5.4% for intra-day and inter-day measurements (n = 5), and RSDs for fiber-to-fiber reproducibility from 6.0% to 6.9% (n = 5). Moreover, the resulting fiber was stable for at least 200 extraction and desorption cycles in SPME and was fabricated in a precisely controllable manner. The proposed method was successfully applied to the selective preconcentration and sensitive determination of target PAHs in river water, rain water and wastewater samples with recoveries from 89.4% to 102%.