Visualising the onset of viscous fingering in chromatography columns

• Published in: Journal of Chromatography A Vol. 1117; no. 2; pp. 137 - 145
• Main Authors: Catchpoole, Heather J., Andrew Shalliker, R., Dennis, Gary R., Guiochon, Georges
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 09.06.2006; Elsevier
• Subjects: Analytical chemistry; Band dispersion; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; COLUMN PACKING; DYES; EFFICIENCY; Exact sciences and technology; EXTRACTION COLUMNS; FLOW VISUALIZATION; FLUID FLOW; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LIQUID COLUMN CHROMATOGRAPHY; Onset of viscous fingering; Other chromatographic methods; OTHER INSTRUMENTATION; VISCOSITY; Viscosity contrast; Viscous fingering; Onset of viscous fingering; Viscous fingering; Band dispersion; Viscosity contrast; Viscosity; Visualization; Peak resolution; Line shape; Phase composition; Property composition relationship; HPLC chromatography; Mobile phase; Transport process; Image analysis; Column packing; Stationary phase; Rheological properties
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2006.03.074

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.