Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
J Chromatogr A. 2023 Sep 13;1706:464283. doi: 10.1016/j.chroma.2023.464283. Epub 2023 Aug 5.
Herein, we prepared a carboxyl functionalized magnetic covalent organic framework (FeO@iCOF-COOH) by combining multivariate synthetic strategy with post-synthetic modification. It was used as an adsorbent for magnetic solid phase extraction (MSPE) of six fluoroquinolones (FQs), and showed good absorption performance at neutral pH. Carboxyl groups are found to be crucial for the adsorption of fluoroquinolones. The adsorption mechanism was primarily attributed to strong hydrogen bonding, π-π interaction as well as potential hydrophobic effect. The optimal extraction conditions are sample pH at 6.0, adsorbent dosage of 3 mg, eluent of 1.0 mL methanol solution containing 7.5% ammonia, and extraction/desorption time of 30 min. Under the optimized conditions, the FeO@iCOF-COOH was used as an adsorbent for MSPE of FQs in milk, an analytical method was established by combining with high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The limits of detection (LODs) and limit of quantification (LOQs) were 1.24-4.58 ng⋅mL and 4.12-15.3 ng⋅mL, respectively. The recoveries of target FQs in spiked milk were 68.4-105%. This work provides a new way to prepare covalent organic framework based adsorbents for solid phase extraction, and can be readily extended to other type of adsorbents.
在这里，我们通过结合多元合成策略和后合成修饰，制备了一种羧基功能化的磁性共价有机骨架（FeO@iCOF-COOH）。它被用作六种氟喹诺酮（FQs）的磁性固相萃取（MSPE）的吸附剂，在中性 pH 下表现出良好的吸附性能。羧基基团对于氟喹诺酮的吸附至关重要。吸附机制主要归因于强氢键、π-π相互作用以及潜在的疏水效应。最佳萃取条件为样品 pH 值为 6.0，吸附剂用量为 3 mg，洗脱液为 1.0 mL 含 7.5%氨的甲醇溶液，萃取/解吸时间为 30 min。在优化条件下，FeO@iCOF-COOH 被用作牛奶中 FQs 的 MSPE 吸附剂，通过与高效液相色谱-紫外检测（HPLC-UV）相结合建立了分析方法。目标 FQs 的检测限（LODs）和定量限（LOQs）分别为 1.24-4.58 ng⋅mL 和 4.12-15.3 ng⋅mL。目标 FQs 在牛奶中的加标回收率为 68.4-105%。这项工作为制备基于共价有机骨架的固相萃取吸附剂提供了一种新方法，并且可以很容易地扩展到其他类型的吸附剂。
