Fast construction of core-shell structured magnetic covalent organic framework as sorbent for solid-phase extraction of zearalenone and its derivatives prior to their determination by UHPLC-MS/MS

Magnetic covalent organic framework nanocomposite denoted as Fe3O4@TAPB-Tp with core-shell structure was fabricated via a simple template-mediated precipitation polymerization method at mild conditions. The polyimine network shell was created through the polymerization of 1,3,5-tris(4-aminopheny1)-benzene (TAPB) and 1,3.5-triformyl-phloroglucinol (Tp) in tetrahy-drofuran (THF) by the Schiff-base reaction. Featuring with large specific surface area (163.19 m(2) g(-1)), good solution dispersibility, and high stability, the obtained Fe3O4@TAPB-Tp exhibited high adsorption capacities and fast adsorption for zearalenone and its derivatives (ZEAs). The adsorption isotherms showed multilayer adsorption dominated at low concentration and monolayer adsorption at high concentration between the interface of ZEAs and Fe3O4@TAPB-Tp. With the Fe3O4@TAPBTp as sorbent, a magnetic solid-phase extraction-ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established for simultaneous adsorption and detection of five ZEAs in complex samples. The proposed method displayed favorable linearity, low limits of detection (0.003 similar to 0.018 mu g kg(-1)), and good repeatability (2.37 similar to 10.4%). The developed method has been applied for real sample analysis, with recoveries of 81.27 similar to 90.26%. These results showed that Fe3O4@TAPB-Tp has a good application potential for the adsorption of ZEAs in food samples.

Automated summary

The Fe3O4@TAPB-Tp composite with core-shell structure was prepared via template-mediated precipitation polymerization method, showing high adsorption capacity for ZEAs. A magnetic solid-phase extraction-UHPLC-MS/MS method using Fe3O4@TAPB-Tp as sorbent was developed for simultaneous adsorption and detection of ZEAs in complex samples, demonstrating good linearity, low detection limits, and satisfactory recoveries.