Dispersive micro-solid phase extraction using cotton based carbon fiber sorbent for the determination of three polycyclic aromatic hydrocarbons in tea infusion by gas chromatography-quadrupole mass spectrometry

In this study, carbon fibers (CFs) were used as sorbent material for the dispersive micro-solid phase extraction (d-mu SPE) of anthracene, acenaphthene and phenanthrene from tea infusion samples prior to gas chromatography-quadrupole mass spectrometric detection. CFs were obtained by carbonizing cotton at 800 degrees C under the protection of nitrogen for 4 h. After characterization by the scanning electron microscopy-energy dispersive spectrometry, X-ray diffraction and N-2 adsorption-desorption, 20 mg of CFs were used to effectively adsorb PAHs in 5 min from 10 mL of tea infusion samples, 2 mL of toluene was used as desorbent. Under the optimum conditions, good linearity was obtained with R-2 between 0.9996 and 0.9998. The limits of detection were in the range of 0.012-0.014 mu g/L. RSD values for intra- and inter-day precision were <= 6.7% and <= 5 7.8%, respectively. In this work, cotton based CFs were prepared in a solventless and green way and the CFs based d-mu SPE procedure was simple, rapid and cost-effective, with no need of column-packing. The proposed method has been successfully applied to the analysis of PAHs in three kinds of tea infusion samples.