Supported nanohydroxyapatite on anodized titanium wire for solid-phase microextraction.

In this paper, a simple and versatile route was introduced to prepare solid-phase microextraction coatings on the chemically inert titanium wire. Titania nanotube array film can be created on metallic substrates by electrochemical anodization in fluoride-containing electrolytes and subsequently support various secondary reactions to prepare functional surfaces. In the present work, titania nanotube array-coated titanium wire was successfully modified by nanostructured hydroxyapatite by a simple solution-based in situ chemical deposition method. This coating has a high surface-to-volume ratio with a thickness of about 10 μm. Extraction performance of the fiber was assessed on several polycyclic aromatic hydrocarbons in water solutions. The nanohydroxyapatite-coated fiber showed good precision (<7.4 %), low detection limits (1.79-4.89 ng/L), and wide linearity (0.1-200 μg/L) under the selected conditions. The repeatability of fiber to fiber was 1.9-18.2 %. The new solid-phase microextraction fiber has a lifetime of over 150 extractions due to the hydroxyapatite nanoslices uniformly and strongly deposited on the wire surface. The environmental water sample was used to test the reliability of the solid-phase microextraction-gas chromatography method; some analytes were detected and quantified.