Partially fluorinated UiO-66-NH2(Zr): Positive effect of the fluorine moiety on the adsorption capacity for environmental pollutants of metal-organic frameworks

Increasing the stability of materials and affinity to the target has always been the pursuit. In this paper, the strategy of partially fluorinated metal-organic framework materials (MOFs) was introduced into the field of sample preparation for the first time, and the potential of this method to prepare materials with improved stability and extraction performance against environmental pollutants was verified. The UiO-66(NH2)0.58(4F)0.42 coating was successfully prepared on carboxyl functionalized stainless steel fiber through covalent bonding method. Owing to the introduction of F element, the UiO-66-(NH2)0.58(4F)0.42 coating exhibited enhanced metal node acidity, hydrophobicity and stability, thus its extraction performance for phthalates (PAEs) was higher than that of pure UiO-66-NH2 and commercial fiber coatings. The UiO-66-(NH2)0.58(4F)0.42-coated fiber was coupled with GC-MS to detect PAEs, and the wide linear range (0.03-1000 ng/L), good correlation coefficients (0.9732-0.9998) and low detection limit (0.0039-0.016 ng/L) were obtained. The established method had also been successfully applied to detection of trace PAEs in plastic bags packed milk and bottled liquor with satisfactory recoveries (83.7 +/- 5.1-118.1 +/- 4.1 %). This research provides a new path for the preparation of environmental pollutant enrichment and removel materials with good performance.

Automated summary

This study introduces the strategy of partially fluorinated metal-organic framework materials into the field of sample preparation, and verifies the potential of this method in preparing materials with improved stability and extraction performance against environmental pollutants. The prepared UiO-66-(NH2)0.58(4F)0.42-coated fiber showed enhanced extraction performance for phthalates and was successfully applied in detecting trace PAEs in various samples.