Room-temperature synthesis of dual-functionalized magnetic microporous organic network for efficient extraction of vanillins in food

Microporous organic networks (MONs) are promising materials for the magnetic solid-phase extraction (MSPE) of trace targets from diverse complex samples. However, all the reported magnetic MONs (MMONs) are mono-functionalized and synthesized by refluxing at high temperatures, which is not an energy-efficient and envi-ronmentally friendly method. Here, for the first time, we report the room-temperature fabrication of a novel dual-functionalized MMON (MMON-B) for the efficient MSPE of typical vanillin additives from food samples prior to high-performance liquid chromatography (HPLC). The conjugated MMON-B with numerous -OH and -NH2 groups afforded good extraction for vanillins via 7C-7C, hydrophobic, and hydrogen-bonding interactions. The factors affecting the extraction were studied in detail. Under the optimal conditions, the developed MMON-B-MSPE-HPLC-UV method exhibited wide linear range (0.50-1200 mu g L-1), low limits of detection (0.10-0.15 mu g L-1), and good reusability and stability. Therefore, MMON-B was successfully used to enrich vanillins in complex food samples. The morphology and extraction efficiency of the room-temperature synthesized MMON-B were comparable with those of the MMON-B synthesized via the conventional reflux method, indicating that the room-temperature fabrication method is a good alternative to the reflux method. This study presents the feasi-bility of using a room-temperature method for synthesizing dual-functionalized MONs, and the findings may significantly promote the application of MONs in the MSPE of trace targets from complex matrices.

Automated summary

This study presents the room-temperature fabrication of a novel dual-functionalized magnetic microporous organic network (MMON-B) for efficient extraction of vanillin additives from complex food samples, facilitating subsequent high-performance liquid chromatography analysis. The results demonstrate the feasibility of using a room-temperature method for synthesizing dual-functionalized MMONs, potentially advancing their application in the magnetic solid-phase extraction of trace targets from complex matrices.