Highly efficient solid-phase microextraction of polycyclic aromatic hydrocarbons in water based on worm-like nickel-titanium oxide nanocomposites coating grown on a nickel-titanium alloy wire by low-voltage anodization.

A novel worm-like nickel-titanium oxide nanocomposite coating was directly grown on a nickel-titanium alloy wire by low-voltage electrochemical anodization in alkaline ethylene glycol and water solution. The in situ growth of nickel-titanium oxide nanocomposites greatly depended on the volume ratio of ethylene glycol to water and temperature. Coupled to high-performance liquid chromatography with UV detection by static desorption in the mobile phase, the adsorption performance of the as-prepared fiber was evaluated for solid-phase microextraction of representative environmental analytes in water. The results indicate that the as-prepared fiber exhibits higher extraction capability for polycyclic aromatic hydrocarbons than commercial polydimethylsiloxane and polyacrylate fibers. After optimizing the extraction parameters, the calibration graphs of the developed method was linear in the range of 0.05-200 μg/L with correlation coefficients above 0.998. Limit of detection ranged from 0.013 to 0.145 μg/L for seven target analytes. Relative standard deviations of intraday and interday analyses varied from 4.0 to 5.3% and from 4.7 to 6.3% with the single fiber, respectively. The relative recoveries of 84.4-109% were achieved for highly efficient enrichment and determination of target analytes in spiked river and snow water. Moreover, the as-prepared fiber can be used more than 200 times.