Fabrication of versatile and robust hydrophobic sodium oleate-modified MOF as fiber for solid phase microextraction of polycyclic aromatic hydrocarbons

In this study, a hydrophobic NH 2 -UiO-66@NaOA composite was developed as an advanced SPME coating for efficient extraction and sensitive detection of polycyclic aromatic hydrocarbons (PAHs) in environmental and food matrices. Surface functionalization with sodium oleate (NaOA) effectively addressed the moisture resistance limitations of conventional MOFs, forming a stable hydrophobic layer while maintaining crystalline integrity. The modified material exhibited enhanced PAHs extraction efficiency through synergistic π-π stacking and hydrophobic interactions. Combined with GC-FID analysis, the optimized method demonstrated excellent sensitivity (LODs: 0.014–0.083 ng mL −1 ), wide linear range (0.2–200 ng mL −1 , R 2  > 0.99), and good reproducibility (RSD ≤ 7.71 %). Successful application was demonstrated in environmental water samples (lake water, wastewater) and food matrices (honey, black tea), showing reliable performance in complex sample analysis. The developed modification strategy showed broad applicability, as confirmed through successful extension to other MOF structures (ZIF-8, NH 2 -MIL-88). These results highlight the composite's potential as a robust SPME coating for monitoring trace-level persistent organic pollutants in environment and food safety applications.