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.