Application of an NiTi alloy coated with ZrO2 solid-phase microextraction fiber for determination of haloanisoles in red wine samples

This study describes an application of ZrO2 electrolytically deposited onto an NiTi alloy (NiTi-ZrO2) as a solid-phase microextraction (SPME) fiber to the determination of 2,4,6-trichloroanisole, 2,4,6-tribromoanisole and pentachloroanisole in red wine samples at the ng L-1 level. Separation and detection was carried out by gas chromatography and electron capture, respectively. The parameters affecting extraction efficiency, such as extraction time and temperature, salting-out effect and sample pH, were simultaneously optimized firstly by means of a two-level full factorial experimental design including a center point, and subsequently through a Doehlert design for three-variables. Excellent robustness, evaluated through a factorial design study, was obtained for all variables considered in the extraction procedure. Detection limits in the range of 6.8 to 8.0 ng L-1 were obtained. Precision was excellent, relative standard deviations being lower than 7.0%. Good accuracy was obtained with calibration against a synthetic solution and 25% dilution of wine samples. The extraction capability of the fiber was stable for more than 700 extractions. Thus, it is an excellent alternative for use in SPME.