Amino-rich magnetic covalent organic framework: a promising adsorbent for high-efficiency extraction of four emerging phenolic pollutants in tea beverage, milk and chicken.

In this paper, amino functionalized magnetic covalent organic framework (M-COF-NH2) was developed as a magnetic solid-phase extraction (MSPE) adsorbent to enrich emerging phenolic pollutants. The M-COF-NH2 demonstrated superior extraction efficiency over amino-free COF and four commercial adsorbents, attributed to synergistic hydrogen bonding and π-π stacking interactions between M-COF-NH2 and phenolic pollutants. Based on MSPE with M-COF-NH2 as adsorbent and HPLC-MS detection, a sensitive method was developed for accurate quantitative analysis of phenolic organic pollutants in tea beverages, milk and chicken samples. The method achieved good detection performance with high sensitivity (low detection limits of 0.01-0.1 ng mL-1 for tea beverage and milk, 0.9-1.4 ng g-1 for chicken), good accuracy (method recovery of 86.7-110%), satisfactory precision (relative standard deviation of 2.5-7.9%), exhibiting considerable application prospects for analysis of phenolic pollutant in complex foodstuff matrices.