Metal-organic framework UiO-66 coated stainless steel fiber for solid-phase microextraction of phenols in water samples

Effective solid-phase microextraction (SPME) of polar phenols from water samples is usually difficult due to the strong interaction between polar phenols and aqueous matrix. Here, we report the fabrication of a metal-organic framework UiO-66 coated stainless steel fiber via physical adhesion for the SPME of polar phenols (phenol, o-cresol, p-cresol, 2,6-dimethylphenol, 2,4-dichlorophenol and 2,6-dichlorophenol) in water samples before gas chromatographic separation with flame ionic detection. Headspace SPME of 10 mL sample solution with the fabricated UiO-66 coated fiber gave the enhancement factors of 160 (phenol) - 3769 (2,4-dichlorophenol), and the linear ranges of 1-1000 μg L−1 (2,6-dimethylphenol, 2,4-dichlorophenol and 2,6-dichlorophenol), 1-500 μg L−1 (o-cresol and p-cresol) and 5-500 μg L−1 (phenol). The detection limits ranged from 0.11 μg L−1 (2,6-dimethylphenol) to 1.23 μg L−1 (phenol). The precision (relative standard deviations, RSDs) for six replicate determinations of the analytes at 100 μg L−1 using a single UiO-66 coated fiber ranged from 2.8% to 6.2%. The fiber-to-fiber reproducibility (RSDs) for three parallel UiO-66 coated fibers varied from 5.9% to 10%. The recoveries obtained by spiking 5 μg L−1 of the phenols in the water samples ranged from 80% to 115%.