Metal-Organic Framework-Derived Hollow Carbon Nanocubes for Fast Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons

Developing novel coating materials for fast and sensitive solid-phase microextraction (SPME) is highly desired but few are achieved. In this work, a new material of metal-organic framework (MOF)-derived hollow carbon nanocubes (HCNCs) was prepared as a fiber coating material for SPME. The HCNC-coated fiber (denoted as HCNCs-F) exhibited a better enrichment performance than solid carbon nanocube (SCNC)-coated fiber (denoted as SCNCs-F) and commercial fibers based on the abundant active sites of the hollow structure, hydrophobic interactions, and π-π interactions. Moreover, because of the reduced mass-transport lengths of the hollow mesoporous structure, the HCNCs-F demonstrated a faster mass transfer compared with the SCNCs-F. The HCNCs-F was used to determine the six hydrophobic polycyclic aromatic hydrocarbons (PAHs) with wide linear ranges (10-2000 ng L^-1 for naphthalene and 5-2000 ng L^-1 for the other five analytes), good reproducibility (relative standard deviation < 8.8%), and low detection limits (0.03-0.70 ng L^-1). Finally, the HCNCs-F was successfully applied for the determination of PAHs from the real water samples. It can be concluded from the results that MOF-derived hollow carbon materials are promising candidates for the fast SPME and can be used for practical applications in analytical chemistry.