Yang Yuanzhong, Boysen Reinhard I, Hearn Milton T W
Australian Research Council Special Research Centre for Green Chemistry, Australian Centre for Research on Separation Science, Monash University, Clayton, Vic, Australia.
J Chromatogr A. 2004 Jul 16;1043(1):81-9. doi: 10.1016/j.chroma.2004.04.046.
The effect of variations in the concentrations of different organic solvents, including acetonitrile, methanol, ethanol, propanol and isopropanol, with aqueous buffer electrolytes of defined composition and pH on the electroosmotic flow velocity, v(EOF), of uncoated fused silica capillaries and on the electrophoretic mobility, mu(e), of synthetic peptides in high-performance capillary electrophoresis (HPCE) has been systematically investigated. In these experiments, the volume fractions of the organic solvent in the aqueous buffer electrolyte were changed from psi = 0.0 to 0.80. The addition of these organic solvents to the aqueous buffer electrolyte reduced the electroosmotic flow (EOF) of the system, but to significantly different extents. For the protic solvents as the alkyl chain of the alcohol increased, at the same volume fraction the greater was the influence on the electroosmotic flow. However, for the aprotic solvent, acetonitrile, the EOF did not change substantially as the volume fraction was varied. The electrophoretic mobility of synthetic peptides under the different buffer electrolyte conditions showed similar trends, confirming that the content and type of the organic modifier can be rationally employed to subtly manipulate the separation selectivity of synthetic peptides. These results, therefore, provide fundamental insight into the experimental options that can be used to maximise resolution of synthetic peptides in HPCE with aqueous buffer-organic solvent mixtures as well as a basis to select optimal binary or ternary buffer electrolyte compositions for the analysis of peptides when hyphenated techniques, such as HPCE-electrospray ionisation mass spectrometry (ESI-MS), are contemplated for the analysis of peptide samples of low abundance as can often be experienced in proteomic investigations.
系统研究了不同有机溶剂（包括乙腈、甲醇、乙醇、丙醇和异丙醇）与特定组成和pH值的水性缓冲电解质混合后，对未涂层熔融石英毛细管的电渗流速度v(EOF)以及高效毛细管电泳（HPCE）中合成肽的电泳迁移率μ(e)的影响。在这些实验中，水性缓冲电解质中有机溶剂的体积分数从ψ = 0.0变化到0.80。向水性缓冲电解质中添加这些有机溶剂会降低系统的电渗流（EOF），但程度差异显著。对于质子性溶剂，随着醇的烷基链增长，在相同体积分数下，对电渗流的影响越大。然而，对于非质子性溶剂乙腈，随着体积分数的变化，EOF基本不变。不同缓冲电解质条件下合成肽的电泳迁移率呈现相似趋势，这证实了有机改性剂的含量和类型可合理用于巧妙调节合成肽的分离选择性。因此，这些结果为深入了解可用于在HPCE中使用水性缓冲液 - 有机溶剂混合物最大化合成肽分辨率的实验选项提供了基础，同时也为在考虑使用如HPCE - 电喷雾电离质谱（ESI - MS）等联用技术分析蛋白质组研究中常见的低丰度肽样品时选择最佳二元或三元缓冲电解质组成提供了依据。
