The Thermodynamics of Chromatography - The Distribution of Standard Energy Between Different Types of Molecular Interactions > The Concept of Complex Formation > Page 49

As already discussed, the complex is considered to have zero vapor pressure and is stationary in the column. Thus, there are now two parts of the denominator, () the free solute activity coefficient and (1-c) the fraction of free solute.

  

 

The thermodynamic equilibrium constant (K1) is contained in the function,

where (KEQ) is the thermodynamic equilibrium constant,
(aDA) is the activity of the complex in the stationary phase,
(aD) is the activity of the solute in the stationary phase,
(aA) is the activity of the stationary phase,
(gDA) is the activity coefficient of the complex,
(gD) is the activity coefficient of the solute,
and (gA) is the activity coefficient of the stationary phase.