Facile fabrication of magnetic covalent organic frameworks for magnetic solid-phase extraction of diclofenac sodium in milk

A robust magnetic solid-phase extraction (MSPE) method based on magnetic covalent organic framework (MCOF) coupled with high-performance liquid chromatography (HPLC)-ultraviolet (UV)/mass spectrometry (MS) was proposed for the determination of trace diclofenac sodium (DS) in milk. The prepared MCOF exhibited high extraction efficiency, which can be attributed to its high specific surface area as well as strong 7C-7C and hydrophobic interactions between MCOF and DS. In addition, the potential influencing factors, including sample volume, adsorbent dosage, extraction time, and elution parameters, were fully estimated. The experimental results demonstrated that the established method was sensitive for the quantification of DS with high accuracy. Remarkably, the detection limit of DS was found to be 10 ng/kg under the optimal conditions. More impressively, the developed method was successfully applied to monitor trace DS in milk, demonstrating its outstanding durability and practical potential as an appealing method to regular monitor trace pharmaceutical contaminants in real food samples.

Automated summary

A robust MSPE method based on MCOF coupled with HPLC-UV/MS was proposed for the determination of trace DS in milk. The method showed high accuracy and a low detection limit of 10 ng/kg, demonstrating its potential for monitoring trace pharmaceutical contaminants in real food samples.