Influence of the electrical double-layer on electroosmotic flow in capillary electrochromatography
Influence of the electrical double-layer on electroosmotic flow in capillary electrochromatography
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DOI：
10.1016/s0021-9673(98)00865-6
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发表时间：
1999-03-19
影响因子：
4.1
通讯作者：
Myers, P
中科院分区：
文献类型：
--
作者：
Cikalo, MG;Bartle, KD;Myers, P
已在 C-18 填充柱上对毛细管电色谱中的电渗流进行了深入研究。改变电压和电解质特性时获得的线速度与毛细管电泳中发现的线速度相当。仅在低离子强度时才观察到与预期关系的偏差；这归因于颗粒孔的双层重叠和湍流弓。 Van Deemter 对 C-18 相的研究证实，线速度与颗粒尺寸无关，但并不支持当前的理论，即较小的颗粒会提高效率。颗粒孔隙率的作用仍然不明确。与 8 nm 孔材料相比，具有 30 nm 孔的 C-18 材料产生的流速较低，但二氧化硅没有表现出相同的趋势。我们的结果表明，尽管柱可能填充不良，但对 3 μm 颗粒仍可获得高效率。在较大粒径的填充良好的色谱柱上最有可能实现可重复的分离。对二氧化硅的研究凸显了色谱柱制造中的问题；重复的色谱柱给出了可比的流量，但没有给出分离参数。使用非常小的颗粒（1.5μm）的新程序是可取的。 (C) 1999 Elsevier Science B.V. 保留所有权利。
An intensive investigation into the electroosmotic flow in capillary electrochromatography has been performed on C-18 packed columns. Linear velocities obtained when varying voltage and electrolyte characteristics were comparable to those found in capillary electrophoresis. Only at low ionic strength was a deviation from the expected relationship observed; this was attributed to double-layer overlap in the particle pores and turbulent Bow. Van Deemter studies on C-18 phases confirmed that linear velocity was unrelated to particle size, but did not support current theory that smaller particles will result in improved efficiency. The role of particle porosity remains ambiguous; lower flow-rates were generated on a C-18 material with 30 nm pores compared to an 8 nm pore material, yet silica did not display the same trend. Our results suggest that high efficiencies can be obtained on 3 mu m particles although the columns may be poorly packed. Reproducible separations are most likely to be achieved on well-packed columns of larger particle size. Studies on silica highlighted problems in column manufacture; duplicate columns gave comparable flows but not separation parameters. New procedures for the use of very small particles (1.5 mu m) are desirable. (C) 1999 Elsevier Science B.V. All rights reserved.