Department of Applied Chemistry, China Agricultural University, Beijing, P. R. China.
J Sep Sci. 2021 May;44(9):1931-1938. doi: 10.1002/jssc.202001153. Epub 2021 Feb 17.
Herein, a novel hyperbranched aromatic polyamide-coated magnetic sorbent was prepared by in situ polymerization on the surface of amino-functionalized Fe O nanoparticles. The magnetic sorbent was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, elemental analysis, Brunauer-Emmett-Teller measurement, and X-ray photoelectron spectroscopy, etc. The new magnetic sorbent was used in the magnetic solid-phase extraction for the detection of seven benzoylurea insecticides. Under optimum conditions, low method detection limits (0.56-1.20 ng/mL), acceptable coefficient of determination (0.9967-0.9996), wide linear ranges (2.5-500.0 ng/mL), and good repeatability (intraday: 2.0-7.3%; interday: 1.9-9.2%) were achieved. The magnetic solid-phase extraction method based on the new magnetic sorbent showed good reliability in the analysis of seven benzoylurea insecticides in real water samples, as the relative recoveries were in the range from 80.1 to 116.3% with satisfactory RSDs (0.1-9.8%). By means of density functional theory and semiempirical quantum mechanical, the binding configuration and interaction energy of hyperbranched aromatic polyamide and benzoylurea insecticides were calculated. The result of theoretical calculation revealed that the adsorption of benzoylurea insecticides by hyperbranched aromatic polyamide was derived from hydrogen bonding and π-π stacking. The contribution of π-π stacking was greater than that of hydrogen bond, which was confirmed by energy decomposition analysis.
本文通过在氨基功能化 Fe3O4纳米粒子表面原位聚合，制备了一种新型超支化芳香聚酰胺涂层磁性吸附剂。采用透射电子显微镜、傅里叶变换红外光谱、元素分析、BET 比表面积和 X 射线光电子能谱等手段对磁性吸附剂进行了表征。该新型磁性吸附剂用于检测七种苯甲酰脲类杀虫剂的磁固相萃取。在最佳条件下，该方法具有较低的检测限（0.56-1.20ng/mL）、可接受的相关系数（0.9967-0.9996）、较宽的线性范围（2.5-500.0ng/mL）和良好的重复性（日内：2.0-7.3%；日间：1.9-9.2%）。基于新型磁性吸附剂的磁固相萃取方法在实际水样中七种苯甲酰脲类杀虫剂的分析中表现出良好的可靠性，相对回收率在 80.1-116.3%之间，RSD （0.1-9.8%）令人满意。通过密度泛函理论和半经验量子力学计算，得到了超支化芳香聚酰胺与苯甲酰脲类杀虫剂的结合构象和相互作用能。理论计算结果表明，超支化芳香聚酰胺对苯甲酰脲类杀虫剂的吸附源于氢键和π-π堆积作用。π-π堆积作用的贡献大于氢键，这通过能量分解分析得到了证实。
