Catchpoole Heather J, Andrew Shalliker R, Dennis Gary R, Guiochon Georges
Nanoscale Organisation and Dynamics Group, University of Western Sydney, NSW, Australia.
J Chromatogr A. 2006 Jun 9;1117(2):137-45. doi: 10.1016/j.chroma.2006.03.074. Epub 2006 Apr 18.
Viscous fingering is an important fluid transport phenomenon that manifests itself when two fluids having different viscosities move in the same direction. Their interface is unstable and a complex fingering pattern may arise. This phenomenon is important in chromatography because it may lead to a decrease or even a failure in separations. The onset of viscous fingering was visually observed by packing a glass column with particles having the same refractive index as the mobile phase and injecting plugs of dye solutions having viscosities different from that of the mobile phase. Severe fingering effects are observed if the viscosity difference exceeds 0.17 cP. However, for smaller viscosity differences, band distortions are observed that may affect retention data, band efficiency, and band resolution. Careful attention should be paid to matching the mobile phase viscosity and that of the injection plug when accurate chromatographic information is required.
粘性指进是一种重要的流体传输现象，当两种具有不同粘度的流体同向流动时就会出现这种现象。它们的界面不稳定，可能会出现复杂的指进图案。这种现象在色谱分析中很重要，因为它可能导致分离效果下降甚至分离失败。通过用与流动相具有相同折射率的颗粒填充玻璃柱，并注入粘度与流动相不同的染料溶液塞，从视觉上观察到了粘性指进的起始。如果粘度差超过0.17厘泊，就会观察到严重的指进效应。然而，对于较小的粘度差，会观察到谱带畸变，这可能会影响保留数据、谱带效率和谱带分辨率。当需要准确的色谱信息时，应特别注意使流动相粘度与进样塞粘度相匹配。
