Plate Theory and Extensions - The Conditions for Chromatographic Separation > Page 15


 Vm + K(A)VS  < > Vm + K(B)VS  and Vm + K(A)VSVm + K(B)VS


i.e.,    either   K(A)VS  < >  K(B)VS  and  K(A)VS K(B)VS


Thus,  either     K(A)  < > K(B)    or     VS(A)  < > VS(B)


The separation of two solutes depends exclusively on the magnitude of their distribution coefficients (K(A)) and (K(B)) and the amount of stationary phase available to them, (V(A)) and (V(B)).


Thus, to separate two solutes, either their distribution coefficients must  be made to differ (choose appropriate phase systems), the amount of stationary phase with which they interact must be made to differ (choose a stationary phase with appropriate exclusion properties), or a shrewd combination of both.