Amidoxime covalent organic framework@Fe3O4 based magnetic solid-phase extraction for rapid and sensitive determination of trace uranium in seafood

Abstract

The unintentional dissemination of uranium into environment poses substantial risks to both food sources and human populations. An advanced method for convenient and accuracy detection of uranium in food is thus a pressing need. Herein, a novel magnetic amidoxime functionalized COF (TpDb-AO@Fe3O4), prepared with 2,5-dinitrobenzonitrile, 1,3,5-triformylphloroglucinol and hydroxylamine hydrochloride, was synthesized as adsorbent for magnetic-solid phase extraction (MSPE) of UO22+. Furthermore, a TpDb-AO@Fe3O4 based MSPE coupled with UV-vis spectrophotometer was successfully developed to realize the determination of uranyl ions with low limit of detection of 1.63 μg L−1, wide linear range of 10 − 200 μg L−1. The spiking recoveries in real seafood samples (tuna, yesso scallop, kelp, eel, hairtail) ranged from 94.1% − 106.8%. The intraday (n=5) and interday (n=5) relative standard deviation (RSD) for determination of UO22+ were 3.33% and 6.23%, respectively. This approach represents an advancement in the rapid extraction and sensitive quantification of trace uranium contaminants in food matrices, thereby contributing to enhanced environmental monitoring and public health safeguards.