Preparation of magnetic metal‐organic framework MIL‐101(Fe) and its application in the extraction of anthraquinones in rhubarb
Xi Zhou, Shi‐Jun Yin, Guo‐Ying Chen, Shangyou Xiao, Feng Yang
Abstract
In this work, a magnetic octahedral metal‐organic framework (Fe 3 O 4 @NH 2 ‐MIL‐101(Fe)) was synthesized for the magnetic solid‐phase extraction of three anthraquinones, including aloe‐emodin, emodin, and physcion, in rhubarb. The Fe 3 O 4 @NH 2 ‐MIL‐101(Fe) exhibits a high specific surface area of 259.2 m 2 /g with an average pore size of 6.0 nm and high magnetic responsivity of 23.4 emu/g, which may be used as an adsorbent for rapid preconcentration and separation of target analytes. The main parameters for magnetic solid‐phase extraction of anthraquinones, including the amount of adsorbent, extraction time, extraction temperature, extraction pH, elution solvent, and elution time, were systematically optimized. The whole extraction process requires a very low amount of adsorbent and a small volume of the sample. Besides, under the optimized conditions, the method shows satisfactory spiked recovery for anthraquinones in the range of 93.3–109.1% and the limits of detection are 1.7–3.4 ng/mL. The relative standard deviations for intra‐ and inter‐day precision are 0.2–1.3% and 0.2–0.6%, respectively. The experimental results indicate that the developed method is feasible for the analysis of anthraquinones in rhubarb.