The Thermodynamics of Chromatography - Other Thermodynamic Methods that are Used for Studying Chromatographic Systems > Optimum Operating Conditions for Chiral Separations in Liquid Chromatography > The Effect of Temperature and Solvent Composition on the Capacity Ratio > Page 75

   

 

The Effect of Temperature and Solvent Composition on the Capacity Ratio

Curves showing the change in capacity factor of the (R) isomer (the first eluted isomer) with temperature and solvent composition are shown in figure 20. It is  confirmed that an increase in temperature and an increase in ethanol content reduces the capacity factor of the solute in the expected manner. The effect of ethanol content on retention is seen to be much greater than that of temperature. Increasing the temperature from 5˚C to 50˚C halves the capacity factor whilst increasing the ethanol content from 5%v/v to 50%v/v reduces it by tenfold or more.

Figure 20. Curves Demonstrating the Change in Capacity Factor of the (R) Isomer with Temperature and Solvent Composition