Wang Qian, Baker Gary A, Baker Sheila N, Colón Luis A
Department of Chemistry, University at Buffalo, The State University of New York, 578 NS Complex, Buffalo, New York 14260-3000, USA.
Analyst. 2006 Sep;131(9):1000-5. doi: 10.1039/b607337a. Epub 2006 Jul 21.
Trimethoxysilane "ionosilane" derivatives of room temperature ionic liquids based on alkylimidazolium bromides were synthesized for attachment to silica support material. The derivatives 1-methyl-3-(trimethoxysilylpropyl)imidazolium bromide and 1-butyl-3-(trimethoxysilylpropyl)imidazolium bromide were used to modify the surface of 3 microm diameter silica particles to act as the stationary phase for HPLC. The modified particles were characterized by thermogravimetric analysis (TGA) and (13)C and (29)Si NMR spectroscopies. The surface modification procedure rendered particles with a surface coverage of 0.84 micromol m(-2) for the alkylimidazolium bromide. The ionic liquid moiety was predominantly attached to the silica surface through two siloxane bonds of the ionosilane derivative (63%). Columns packed with the modified silica material were tested under HPLC conditions. Preliminary evaluation of the stationary phase for HPLC was performed using aromatic carboxylic acids as model compounds. The separation mechanism appears to involve multiple interactions including ion exchange, hydrophobic interaction, and other electrostatic interactions.
合成了基于烷基溴化咪唑鎓的室温离子液体的三甲氧基硅烷“离子硅烷”衍生物，用于连接到硅胶载体材料上。衍生物1-甲基-3-(三甲氧基硅丙基)溴化咪唑鎓和1-丁基-3-(三甲氧基硅丙基)溴化咪唑鎓用于修饰3微米直径的硅胶颗粒表面，以作为高效液相色谱的固定相。通过热重分析（TGA）以及¹³C和²⁹Si核磁共振光谱对改性颗粒进行了表征。表面改性过程使烷基溴化咪唑鎓在颗粒表面的覆盖度达到0.84 μmol m⁻²。离子液体部分主要通过离子硅烷衍生物的两个硅氧烷键连接到硅胶表面（63%）。在高效液相色谱条件下测试了填充有改性硅胶材料的色谱柱。使用芳香族羧酸作为模型化合物对高效液相色谱固定相进行了初步评估。分离机制似乎涉及多种相互作用，包括离子交换、疏水相互作用和其他静电相互作用。
