Preparation and application of NiTi alloy coated with ZrO2 as a new fiber for solid-phase microextraction

In this study a NiTi alloy was applied as an SPME support due to its superelasticity and shape memory properties. This new metallic support was coated with ZrO2 by electrodeposition using chronoamperometry. It was then evaluated for extraction of three classes of compounds from gaseous samples: alcohols, BTEX and trihalomethanes (THM). For the optimization of the parameters affecting the extraction efficiency of the target compounds, the univariate approach was used. Five fibers were electrodeposited to evaluate the reproducibility of the coating procedure, resulting in a relative standard deviation lower than 11.9%. The repeatability for one fiber (n = 6) was lower than 8.5%. The detection limits were lower than 28.1, 20.8 and 0.18 mu g L-1 for alcohols, BTEX and THM, respectively, and the correlation coefficients were higher than 0.996. Taking into account the amount extracted per unit volume, the NiTi-ZrO2, fiber showed a better extraction profile in comparison with the commercial fibers 7 mu M PDMS, 85 mu m PA and 30-50 mu m DVB/CAR/PDMS. The new SPME fiber has a lifetime of over 300 extractions. Thus, it is a promising alternative for low-cost analysis, as it is robust, and easily and inexpensively prepared. (c) 2007 Elsevier B.V. All rights reserved.