Hydroxylated Hierarchical Flower-Like Cof for Solid‐Phase Extraction of Α2- and Β2- Adrenergic Receptor Agonists in Milk

Abstract

The effective detection of adrenergic receptor agonists (ARAs) residues in milk is of great significance for protecting human health. In this work, the milk was first deproteinated and extracted by methanol, and then concentrated by the self-made solid-phase extraction (SPE) cartridge. The hydroxylated covalent organic framework (COF) was synthesized by polymerization of tris(4-aminophenyl)amine and 1,3,5-tris(4-formyl-3-hydroxyphenyl)benzene and served as the SPE cartridge packing. This hydroxylated COF was featured with hierarchical flower-like morphology, easy preparation, and copious active adsorption sites. The adsorption model fittings and molecular simulation were applied to explore the adsorption characteristics. A sensitive method was fabricated for the determination of four α2- and five β2-ARAs residues in milk by liquid chromatography–tandem mass spectrometry. The linear ranges of the ARAs were from 0.25 to 50 μg·kg−1; the intra-day and the inter-day repeatability were in the range of 2.9−7.9% and 2.0−10.1%, respectively. This method was successfully applied to determine the ARAs residues in commercial milk samples.

Keywords: adrenergic receptor agonists, hydroxylated COF, SPE, LC-MS/MS, Milk