محمد رضا حاج محمدی

Poly(ethylene glycol) grafted onto carboxyl-terminated multi-walled carbon nanotubes were prepared by the sol–gel technique as a stationary phase for stir bars. The analytical methodology included stir bar sorptive extraction with micellar desorption followed by liquid chromatography. Polycyclic aromatic hydrocarbons were used as the model compounds to evaluate the extraction performance. The extraction efficiency, for determination of polycyclic aromatic hydrocarbons from water samples, was optimized based on a chemometrics approach. The effect of the experimental parameters on the extraction response was investigated and the optimum extraction condition was selected. Under the optimum conditions, the proposed method showed a good linearity within the different ranges for different analytes (e.g. 0.05–500 ng mL-1 for phenanthrene), a square of the correlation coefficient was higher than 0.999, and an appropriate limit of detection in the range of 0.013–0.072 ng mL-1. The recoveries in all cases were above 94%, with relative standard deviations below 2.4%