Centrifugal Partition Chromatography. vi. Temperature Effects

Temperature changes induce numerous physico-chemical changes in liquids. Vapor pressure, density, refractive index, viscosity and surface tension are such temperature dependent parameters. The mutual solubilities of the stationary and mobile phase liquids are also temperature dependent. The ternary diagram of the water-methanol-hexane system is presented for two temperatures, 20° and 40°C. It is shown that a flow behavior change, as determined by an efficiency study, is temperature dependent because the viscosities of the liquids are modified by the temperature. A solute's partition coefficient is also dependent upon temperature. Using Van't Hoff plots, it is possible to determine the enthalpy of transfer of the solute from the mobile phase to the stationary phase. In the last part of this study, additional problems resulting from temperature changes in CPC are discussed.