MOF-525 mixed-matrix membrane-based extraction combined GC-MS for determination of pesticides in root and tuber crops

As global food, it has important implications for monitoring and testing of pesticide pollution in the root and tuber crops. Herein, a novel mixed-matrix membrane based on metal-organic frameworks (MOF-525-MMM) was successfully prepared for a simplified dispersive solid-phase extraction (d-SPE) of ten kinds of pesticides in root and tuber crops. The MOF-525-MMM was well characterized and major factors affecting extraction process were systematically investigated. Under optimal conditions, the MOF-525-MMM based d-SPE coupled with GC-MS exhibited excellent linearity (R2 ≥ 0.9947) and detection limits of 0.80-4.16 µg/L. Finally, the developed method was successfully applied to the determination of pesticides in potatoes and sweet potatoes, with recoveries in range of 65.3-92.5% and RSDs lower than 9.8%. In the extraction process, MOF-525-MMM exhibited excellent extraction efficiency and purified ratio. Therefore, the adsorption mechanism was studied, and the results indicated that it was attributed to the π-π stacking effect and hydrogen bond between MOF-525 and pesticides. It was demonstrated that this d-SPE-GC-MS method based on MOF-525-MMM offers great potential for efficient extraction and determination of pesticides in root and tuber crops.