Mesoporous carbon–zirconium oxide nanocomposite derived from carbonized metal organic framework: A coating for solid-phase microextraction

•Mesoporous carbon–ZrO2 nanocomposite was synthesized and used as a SPME fiber.•The coating was synthesized from carbonization of Zr-based metal organic framework.•The fiber was applied for the determination of BTEX compounds in water samples.•The fiber showed better extraction efficiency than PDMS commercial fiber.

In this paper, a mesoporous carbon–ZrO2 nanocomposite was fabricated on a stainless steel wire for the first time and used as the solid-phase microextraction coating. The fiber was synthesized with the direct carbonization of a Zr-based metal organic framework. With the utilization of the metal organic framework as the precursor, no additional carbon source was used for the synthesis of the mesoporous carbon–ZrO2 nanocomposite coating. The fiber was applied for the determination of BTEX compounds (benzene, toluene, ethylbenzene and m, p-xylenes) in different water samples prior to gas chromatography-flame ionization detection. Such important experimental factors as synthesis time and temperature, salt concentration, equilibrium and extraction time, extraction temperature, desorption time and desorption temperature were studied and optimized. Good linearity in the concentration range of 0.2–200 μg L−1 and detection limits in the range of 0.05–0.56 μg L−1 was achieved for BTEX compounds. The intra- and inter-day relative standard deviations were in the range of 3.5–4.8% and 4.9–6.7%, respectively. The prepared fiber showed high capability for the analysis of BTEX compounds in different water and wastewater samples with good relative recoveries in the range of 93–107%.