Development for Displacement Chromatography

Methods development for displacement chromatography has been previously described for a Langmuirian system using a graphical approach which employs the adsorption isotherms for the displacer and the various components 

The steric mass action (SMA) model has been shown to successfully predict nonlinear, multicomponent behavior in ion-exchange systems over a range of mobile phase salt concentrations.71-75 It has also been widely employed as a methods development tool for displacement separations.42,45,50 In this section, we will describe several graphical techniques derived this theory which can facilitate methods development in ion-exchange displacement systems. 

Isocratic elution under linear conditions at various mobile phase salt concentrations can be employed to determine v and K26 by the following expression  

Linear gradient experiments can also be employed to determine K and v.52 Equation (3) relates a solute retention volume (Vg) to initial and final carrier salt concentrations (x xf), the gradient volume (Vg), the column 

This expression can be employed with two or more gradient experiments to determine v and K (using a least-squares fit). The gradient technique is better suited for simultaneously determining parameters for several components of a complex mixture. 

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