Preparation of magnetic Co3O4/TiO2 nanocomposite as solid-phase microextraction fiber coupled with chromatography for detection of aromatic compounds in environmental samples

Abstract A solid-phase microextraction (SPME) fiber using cobalt titanate nanocomposite (Co3O4/TiO2) as sorbents is reported. The characterization of Co3O4/TiO2 is performed by various methods such as FT-IR, XRD, and HRTEM. Then, the titanate nanostructures are placed in polyvinyl chloride (PVC) matrix and are coated on a copper wire. The sorbent is used for headspace microextraction of BTEX hydrocarbons from soil samples. Also, the optimization of all effective parameters on the SPME fiber is performed. The results show calibration curves are linear in the broad ranges from 5.0 to 500.0 µg L−1 for benzene, ethylbenzene, and xylenes. Also, for toluene a linear calibration curve is obtained between 5.0 and 100.0 µg L−1. Therefore, the lower limit of quantification (LOQ) is obtained 5.0 µg L−1 for the analytes. The data indicate that the limit of detections (LOD) are obtained 0.84 µg L−1 for benzene, 2.94 µg L−1 for toluene, 1.53 µg L−1 for ethylbenzene, 2.44 µg L−1 for (m and p)-xylene, and 2.12 µg L−1 for o-xylene. On the other hand, the results obtained from gas chromatography analysis show that the relative standard deviations (RSDs) are