Single-Walled Carbon Nanotube/Silica Composite as a Novel Coating for Solid-Phase Microextraction Fiber Based on Sol-Gel Technology

摘要

Single-walled carbon nanotubes (SWCNTs)/silica composite coating for solid phase microextraction synthesized by sol-gel technology was developed for air sampling and determination of perchloroethylene, benzotrichloride, chloromethyl methyl ether and trichloroethylene. Application of this method was investigated under different laboratory conditions. Predetermined concentrations of each analyte were prepared in a homemade standard chamber and the influence of temperature, humidity, extraction time, storage time, desorption temperature and desorption time was investigated. Under optimal conditions, the use of SWCNTs/silica composite fiber showed high sensitivity and fast sampling of halogenated volatile organic compounds from air. For linearity test, the regression correlation coefficient was more than 98% for analytes of interest and linear dynamic range for the proposed fiber and the applied gas chromatography-flame ionization detector (GC-FID) technique was from 1 to 100 ng/mL Method detection limits ranged from 0.11 to 0.2 ng/mL and method quantification limits were between 0.34 and 0.7 ng/mL. SWCNTs/silica composite fiber was highly reproducible; relative standard deviations were between 5.6 and 11.7%. The developed method was applied to determine perchloroethylene concentration of real air samples of a dry cleaning shop and the results compared with the data obtained with commercially available carboxen/polydimethylsiloxane (CAR/PDMS).