Magnetic solid-phase extraction of tetracyclines from milk using metal-organic framework MIL-101(Cr)-NH 2 functionalised hydrophilic magnetic nanoparticles.

Novel metal-organic framework MIL-101(Cr)-NH ₂ functionalised hydrophilic polydopamine-modified Fe ₃ O ₄ magnetic nanoparticles (Fe ₃ O ₄ @PDA@MIL-101(Cr)-NH ₂ ) were synthesised and used as magnetic solid-phase extraction (MSPE) adsorbents for extracting tetracyclines (TCs) from milk samples. The integrated Fe ₃ O ₄ @PDA@MIL-101(Cr)-NH ₂ exhibited convenient magnetic separation and exceptional multi-target binding capabilities. Furthermore, the PDA coating significantly enhanced the hydrophilicity and extraction efficiency of the material, thereby facilitating the extraction of trace TCs. Various factors affecting MSPE, such as adsorbent dosage, extraction time, pH value, and desorption conditions, were optimised. The developed MSPE method coupled with high-performance liquid chromatography demonstrated good linearity (R ²  ≥ 0.9989), acceptable accuracy (82.2%-106.1%), good repeatability (intra-day precision of 0.8%-4.7% and inter-day precision of 1.1%-4.5%), low limits of detection (2.18-6.25 μg L ^-1 ), and low limits of quantification (6.54-18.75 μg L ^-1 ) in TCs detection. The approach was successfully used for the quantification of trace TCs in real milk samples.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Ltd.)