Efficient extraction of perfluoroalkyl carboxylic acids from food samples using a fluorinated magnetic metal-organic...

A fluorine-functionalized magnetic metal-organic framework (Fe₃O₄@ZIF-8&F₁₃) was prepared through a facile strategy and served for magnetic solid-phase extraction (MSPE) of perfluoroalkyl carboxylic acids (PFCAs). The synthesized material showed large surface area (924.69 m²/g), abundant fluorine content (6.60 %), high adsorption capacity (163.69-368.93 mg/g) and strong magnetic response (24.3 emu/g), facilitating efficient extraction of PFCAs via multiple interactions. Further, this MSPE approach with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was conducted to quantify trace PFCAs in foods. Under optimal parameters, this method exhibited a superior linearity (0.02-25 ng/g, R²≥ 0.9911) and low limit of detection (0.005-0.021 ng/g) with excellent precision (RSD ≤ 4.17 %) in food matrix. Moreover, satisfactory spiked recoveries (88.4-114.9 %) were obtained in pre-treated milk, tomato and fish samples. Our study provides a feasible approach to design specific adsorption targeting PFCAs, as well as a promising potential to monitor fluoroalkyl family in complex matrix.