A novel multiwalled carbon nanotubes bonded fused-silica fiber for solid phase microextraction-gas chromatographic analysis of phenols in water samples

The present work reports on the synthesis of chemically bonded multiwalled carbon nanotubes (MWCNTs)/fused-silica fibers and their use in solid phase microextraction of seven phenols from water samples coupled with gas chromatography (GC). The synthetic strategy was verified by infrared (IR) spectroscopy and field emission scanning electron microscopy. Adsorption factors (pH, ionic strength, stirring rate, adsorption time and temperature) and desorption factors (time and temperature) of the fibers were systematically investigated. Detection limits to seven phenols were less than 0.05 μg L⁻¹, and their calibration curves were all linear (R² ≥ 0.9984) in the range from 0.05 to 5000 μg L⁻¹. This method was then utilized to analyze two real water samples from Yellow River and sanitary wastewater, resulting in satisfactory results. Compared with normal solid phase materials, this MWCNTs-bonded fused-silica fibers showed a number of advantages: wide linear range and low detection limit for extracting phenols couple with GC, and good stability in acid, alkali, organic solvents and at high temperature.