Wang Na, Liao Yuan, Wang Jiamin, Tang Sheng, Shao Shijun
Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, P. R. China.
University of Chinese Academy of Sciences, Beijing, P. R. China.
J Sep Sci. 2015 Dec;38(23):4111-8. doi: 10.1002/jssc.201500913. Epub 2015 Nov 3.
A novel bis(indolyl)methane-modified silica reinforced with multiwalled carbon nanotubes sorbent for solid-phase extraction was designed and synthesized by chemical immobilization of nitro-substituted 3,3'-bis(indolyl)methane on silica modified with multiwalled carbon nanotubes. Coupled with high-performance liquid chromatography analysis, the extraction properties of the sorbent were evaluated for flavonoids and aromatic organic acid compounds. Under optimum conditions, the sorbent can simultaneously extract five flavonoids and two aromatic organic acid preservatives in aqueous solutions in a single-step solid-phase extraction procedure. Wide linear ranges were obtained with correlation coefficients (R(2) ) ranging from 0.9843 to 0.9976, and the limits of detection were in the range of 0.5-5 μg/L for the compounds tested. Compared with the silica modified with multiwalled carbon nanotubes sorbent and the nitro-substituted 3,3'-bis(indolyl)methane-modified silica sorbent, the developed sorbent exhibited higher extraction efficiency toward the selected analytes. The synergistic effect of nitro-substituted 3,3'-bis(indolyl)methane and multiwalled carbon nanotubes not only improved the surface-to-volume ratio but also enhanced multiple intermolecular interactions, such as hydrogen bonds, π-π, and hydrophobic interactions, between the new sorbent and the selected analytes. The as-established solid-phase extraction with high-performance liquid chromatography and diode array detection method was successfully applied to the simultaneous determination of flavonoids and aromatic organic acid preservatives in grape juices with recoveries ranging from 83.9 to 112% for all the selected analytes.
通过将硝基取代的3,3'-双(吲哚基)甲烷化学固定在多壁碳纳米管修饰的二氧化硅上，设计并合成了一种新型的多壁碳纳米管增强的双(吲哚基)甲烷修饰的二氧化硅固相萃取吸附剂。结合高效液相色谱分析，评估了该吸附剂对黄酮类化合物和芳香族有机酸化合物的萃取性能。在最佳条件下，该吸附剂能够在一步固相萃取过程中同时萃取水溶液中的五种黄酮类化合物和两种芳香族有机酸防腐剂。获得了较宽的线性范围，相关系数（R(2)）在0.9843至0.9976之间，所测试化合物的检测限在0.5 - 5 μg/L范围内。与多壁碳纳米管修饰的二氧化硅吸附剂和硝基取代的3,3'-双(吲哚基)甲烷修饰的二氧化硅吸附剂相比，所开发的吸附剂对选定分析物表现出更高的萃取效率。硝基取代的3,3'-双(吲哚基)甲烷和多壁碳纳米管的协同作用不仅提高了比表面积，还增强了新型吸附剂与选定分析物之间的多种分子间相互作用，如氢键、π-π相互作用和疏水相互作用。所建立的高效液相色谱-二极管阵列检测固相萃取方法成功应用于葡萄汁中黄酮类化合物和芳香族有机酸防腐剂的同时测定，所有选定分析物的回收率在83.9%至112%之间。
