The thermodynamic limit of linear gradient chromatography.

The thermodynamic limit of the elution profile for solutes in linear gradient chromatography is obtained from the analytical solution of the equation for the ideal model of chromatography, Eq. (12). This limit is of great interest in both preparative and analytical chromatographies because it specifies the maximum possible concentration profile that can be achieved at elution. Elution profiles that are obtained from simulated experiments of the equilibrium dispersive model, Eq. (8), are compared with predictions made by the presented theory as well as the theory by Poppe [11]. It is found that for short injection times the simulated experimental peak is Gaussian like and its width agrees very well with the theory of Poppe. When the injection time increases, the experimental elution profile gradually approaches the profile that is obtained as the thermodynamic limit.