In situ fabrication of nanostructured titania coating on the surface of titanium wire: A new approach for preparation of solid-phase microextraction fiber.

Nanostructured titania-based solid-phase microextraction (SPME) fibers were fabricated through the in situ oxidation of titanium wires with H(2)O(2) (30%, w/w) at 80 degrees C for 24h. The obtained SPME fibers possess a approximately 1.2microm thick nanostructured coating consisting of approximately 100nm titania walls and 100-200nm pores. The use of these fibers for headspace SPME coupled with gas chromatography with electron capture detection (GC-ECD) resulted in improved analysis of dichlorodiphenyltrichloroethane (DDT) and its degradation products. The presented method to detect DDT and its degradation products has high sensitivity (0.20-0.98ngL(-1)), high precision (relative standard deviation R.S.D.=9.4-16%, n=5), a wide linear range (5-5000ngL(-1)), and good linearity (coefficient of estimation R(2)=0.991-0.998). As the nanostructured titania was in situ formed on the surface of a titanium wire, the coating was uniformly and strongly adhered on the titanium wire. Because of the inherent chemical stability of the titania coating and the mechanical durability of the titanium wire substrate, this new SPME fiber exhibited long life span (over 150 times).