Preparation of metal-organic framework UiO-66-incorporated polymer monolith for the extraction of trace levels of fungicides in environmental water and soil samples

A zirconium terephthalate metal-organic framework-incorporated poly(N-vinylcarbazole-co-divinylbenzene) monolith was fabricated in a capillary by a thermal polymerization method. The optimized monolith had a homogeneous structure, good permeability, and stability. The monolith could be used for the effective enrichment of fungicides through pi-pi interactions, electrostatic forces, and hydrogen bonds. The potential factors that affect the extraction efficiency, including ionic strength, solution pH, sample volume, and eluent volume, were investigated in detail. The monolith-based in-tube solid-phase microextraction coupled with ultra-high-performance liquid chromatography and high-resolution Orbitrap mass spectrometry was performed for the analysis of five fungicides (pyrimethanil, tebuconazole, hexaconazole, diniconazole, and flutriafol) in environmental samples. Under the optimized conditions, the linear ranges were 0.005-5 ng/mL for pyrimethanil, 0.01-5 ng/mL for flutriafol, and 0.05-5 ng/mL for other fungicides, respectively, with coefficients of determination = 0.9911. The limits of detection were 1.34-14.8 ng/L. The columns showed good repeatability (relative standard deviations = 9.3%, n = 5) and desirable column-to-column reproducibility (relative standard deviations 5.3-9.4%, n = 5). The proposed method was successfully applied for the simultaneous detection of five fungicides in water and soil samples, with recoveries of 90.4-97.5 and 84.0-95.3%, respectively.