新型二元致孔剂Pluronic F127/十二胺用于辛基杂化整体柱的合成与色谱性能评价

Improvement of Chromatographic Performances of C8 Hybrid Monoliths by Using a Novel Binary Porogenic Agent of Pluronic F127/Dodecylamine

采用新型二元致孔剂Pluronic F127/十二胺,通过两步溶胶-凝胶法合成了辛基杂化整体柱,并用于稠环物质、苯系物以及水体中8种生物毒素的毛细管液相色谱分离分析。在整体柱的形貌方面,F127的加入使材料由聚集球状结构转变成双连续孔结构,并实现了对材料通孔、骨架以及骨架上介孔的尺寸调节,得到了更适于小分子分离的结构。此外,通过减少十二胺用量使凝胶化时间延长,显著降低了灌柱的难度以及灌柱时可能引起的材料不均匀和重复性差的问题。优化后的辛基杂化整体柱保持了良好的机械稳定性和高渗透性,塔板数为49 000/m,与传统的制备方法相比柱效明显提高。在对稠环物质、苯系物等典型小分子的测试中均得到了良好的分离效果。新型二元致孔剂的辛基杂化整体柱制备更容易,形貌控制简单,稳定性好,实用性显著增强。

A novel binary porogenic agent of Pluronic F127/dodecylamine was used in the fabrication of C8 hybrid monoliths by the two-step acid/base sol-gel transition.Scanning electron microscope images showed that the morphology varied from particle aggregates to co-continuous structure and the sizes of macropore and skeleton decreased when F127 was added.In the meantime,F127 was also helpful for the regulation of the mesopore of the monoliths.As a result,a more fine morphology with a higher surface area was obtained which was more beneficial for small molecules analysis.In addition,the time of sol-gel transition was prolonged about 10 min when reducing the amount of dodecylamine,which provided enough time for filling step and improved the column-to-column reproducibility.The permeability of the C8 hybrid monolithic columns was calculated to be 2.53×10-13 m2 which was still satisfactory compared to the other kinds of monolithic columns.Pressure test was passed in a wide range of flow rate of mobile phase and the van Deemter curves for benzene and toluene were acceptable.The C8 hybrid monolith of the binary porogenic agent had a plate number of 49 000/m which was much higher than that of C8 monolith fabricated by traditional method without Pluronic F127.The performance of the C8 hybrid monoliths was investigated in nanoliquid chromatography-ultraviolet/mass spectrometry（nanoLC-UV/MS） mode.Good peak shapes were obtained in the analysis of polycyclic aromatic hydrocarbons and alkylbenzens.Seven kinds of microcystins and Nod-R were also separated by the C8 hybrid monoliths.As a conclusion,the new C8 hybrid monolithic columns were easier in preparation,more convenient in the control of morphology,higher in column efficiency,and more useful in analysis of small molecules.