School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China.
School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, China.
J Chromatogr A. 2021 Jan 4;1635:461704. doi: 10.1016/j.chroma.2020.461704. Epub 2020 Nov 13.
In this study, porous covalent organic frameworks (COFs, named as COFs-SWMU) were synthesized for the first time via a facile approach by using 4,4',4''-methylidynetri-anilin and 2,5-dihydroxy-1,4-benzenedicarboxaldehyde as precursors under ambient temperature. The COFs-SWMU were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, thermogravimetric analysis, etc. The COFs-SWMU exhibited a relatively high specific surface area and desirable thermal stability. The adsorption performance of COFs-SWMU towards fluoronitrobenzenes (FNBs, including 1-fluoro-2-nitrobenzene, 1-fluoro-3-nitrobenzene, 1-fluoro-4-nitrobenzene, 2,4-difluoronitrobenzene, 3,4-difluoronitrobenzene, and 3,4-dinitrofluorobenzene) was investigated on the basis of adsorption capacity and partition coefficient (PC). The adsorption kinetics and isotherm of COFs-SWMU for FNBs were studied in detail. Further, a simple, fast and sensitive method which combined COFs-SWMU based extraction with high-performance liquid chromatography-diode array detection, was proposed for the analysis of FNBs in environmental samples. Desirable linearity (R>0.9998) in the range of 0.1-100 μg•mL, low limits of detection (LODs; 0.1‒0.15 μg•mL), low limits of quantitation (LOQs; 0.28‒0.40 μg•mL), and desirable precision (RSDs, 0.24-2.83% for intraday and 1.13-6.92% for interday) are obtained. Finally, the COFs-SWMU were applied to the effective extraction of FNBs from environmental samples, and desirable recovery results were obtained.
在这项研究中，首次通过简便的方法，在环境温度下，以 4,4',4''-亚甲基三苯胺和 2,5-二羟基-1,4-苯二甲醛为前体，合成了多孔共价有机骨架（COFs，命名为 COFs-SWMU）。COFs-SWMU 通过扫描电子显微镜、傅里叶变换红外光谱、X 射线衍射和 X 射线光电子能谱、热重分析等进行了表征。COFs-SWMU 表现出相对较高的比表面积和理想的热稳定性。基于吸附容量和分配系数（PC），研究了 COFs-SWMU 对氟硝基苯（FNBs，包括 1-氟-2-硝基苯、1-氟-3-硝基苯、1-氟-4-硝基苯、2,4-二氟硝基苯、3,4-二氟硝基苯和 3,4-二硝基氟苯）的吸附性能。详细研究了 COFs-SWMU 对 FNBs 的吸附动力学和等温线。此外，提出了一种简单、快速、灵敏的方法，该方法将 COFs-SWMU 萃取与高效液相色谱-二极管阵列检测相结合，用于分析环境样品中的 FNBs。在 0.1-100 μg·mL 的范围内获得了良好的线性（R>0.9998）、低检测限（LOD；0.1‒0.15 μg·mL）、低定量限（LOQ；0.28‒0.40 μg·mL）和良好的精密度（RSDs，日内为 0.24-2.83%，日间为 1.13-6.92%）。最后，将 COFs-SWMU 用于从环境样品中有效提取 FNBs，得到了令人满意的回收结果。
