Hollow zirconium-porphyrin-based metal-organic framework for efficient solid-phase microextraction of naphthols

In this work, a hollow zirconium-porphyrin-based metal-organic framework (HZ-PMOF) was prepared as a coating for solid-phase microextraction (SPME) fiber to determine two naphthols. HZ-PMOF coating provided good extraction performance for naphthols because of the rich forces including π-π interactions, hydrogen bonding, and electrostatic interaction between the materials and targets. Furthermore, due to the special shape of the hollow structure, HZ-PMOF coating showed time-saving SPME equilibrium time and higher extraction capacity than zirconium-porphyrin-based metal-organic framework (Z-PMOF) coating without hollow structure. Combining with gas chromatography-tandem mass spectrometry (GC-MS/MS), an analytical method of naphthols with low detection limit (1.0 ng L^-1), wider linear range (3.0-1000.0 ng L^-1) and good reproducibility (RSD ≤8.6%) was established. Subsequently, naphthols in water samples from five cities in China were successfully detected by this developed method with satisfactory recoveries (81.1%-117.9%) and precision (RSDs, 3.2-9.6%). The results indicated that the prepared HZ-PMOF-coated fiber has good application prospects, and would broaden the application of materials with special morphology in the field of pretreatment.