A magnetic cationic cobalt-based metal-organic framework (Fe3O4@iMOF-Co) for magnetic solid-phase extraction of lignans from Schisandra chinensis

Lignans, as active components of Schisandra chinensis , exhibit hepatoprotective, antitumor, and antiviral pharmacological effects; however, the complexity and structural similarity of S. chinensis still result in technical bottlenecks for the efficient extraction of lignans. Thus, it is essential to develop a simple and efficient way for lignan extraction. In this paper, a magnetic cationic metal-organic framework (Fe 3 O 4 @iMOF-Co) was synthesized and applied to dispersive magnetic solid-phase extraction (DMSPE) technology, which possesses a unique positively charged framework as well as a magnetic response for specific enrichment of negatively charged lignans by electrostatic interactions and rapid separation. The prepared materials were characterized using various techniques. Under ideal DMSPE conditions, the HPLC-MS/MS approach exhibited strong linearity (R 2 ≥0.9951) and low detection limits (LOD) (0.08-0.33 μg⋅kg -1 ) for lignans. The DMSPE method has been effectively used for the extraction of lignans from actual S. chinensis samples with recoveries ranging from 86.2% to 113.4% and relative standard deviations (RSDs) below 7.3%. The above results indicate that the prepared nanoparticles have the advantages of a simple extraction method, high efficiency, and low solvent consumption. This provides efficient and feasible technological support for the development of S. chinensis functional foodstuffs or pharmacological efficacy and other studies. • A core-shell structured magnetic cation MOF (Fe 3 O 4 @iMOF-Co) was synthesized. • Fe 3 O 4 @iMOF-Co mainly adsorbs Schisandra chinensis through electrostatic effect. • The method has outstanding sensitivity, low detection limit, and excellent recovery rate. • The process has low solvent consumption, short extraction time and is green.