The need for increasingly faster and more efficient separations continues to strain the limits of separation power in liquid chromatography. A very promising technique is supercritical fluid chromatography (SFC), which uses supercritical CO2 mixed with organic modifiers as a mobile phase. The very low viscosity (20 times lower than water) and the resulting small pressure drops allow the use of longer separation columns operated at higher flow rates, resulting in faster and more efficient separations. In addition, the much higher diffusion coefficients in this mobile phase enhances the mass-transfer inside the mobile and stationary phase, limiting their contribution to axial dispersion. Although the principles of the technique are already known for more than four decades, theoretical knowledge of the underlying behavior of the supercritical mobile phase in the column is still limited. The high compressibility not only influences the elution speed (volumetric flow rate) inside the column, but also has a large effect on the retention behavior of the components (phase equilibrium). The goal of this project is to systematically investigate the most important contributions to retention and band broadening in SFC, using experimental and numerical techniques. Considering the high compressibility of CO2 and much more limited compressibility of the added organic modifiers, the importance of mass flow rates vs. the more commonly used volumetric flow rates will be investigated in detail.
|Effective start/end date||1/01/15 → 31/12/15|
- Applied Biology
Flemish discipline codes
- Biological sciences