ZnO-coated glass fibers for the analysis of trihalomethanes by headspace-solid phase microextraction-gas chromatography.

Li(2)O-ZrO(2)-BaO-SiO(2) glass fibers were produced and their surfaces were coated with zinc oxide. The fibers' surface morphology was examined by scanning electron microscopy and the zinc oxide layer was characterized by mapping the K(α) and L(α) lines of zinc by energy dispersive X-ray spectroscopy. The results indicated that a homogeneous and porous layer of ZnO was formed on the fibers' surface. This layer was subjected to a simultaneous determination of trihalomethanes using headspace-solid phase microextraction-gas chromatography. The study was conducted after evaluating the ideal time of incubation (15 min), extraction (15 min) and desorption (10 min), as well as the effect of the addition of salt (15%, m/v) on the analytical response. A good linear dynamic range was observed individually for trihalomethanes aqueous solutions containing 20 μg L(-1) and 500 μg L(-1) of trichloromethane, 15 μg L(-1) and 250 μg L(-1) of dichlorobromomethane and dibromochloromethane and 10 μg L(-1) and 100 μg L(-1) of tribromomethane, with all the compounds showing correlation coefficients higher than 0.9900.