Plate Theory and Extensions - Resolving Power of a Column > Page 61
Equation (55), developed by Purnell (13) in 1959 can be used to calculate the efficiency needed to separate a given solute pair from the capacity factor of the first eluted peak and their separation ratio. It is very useful in column design. This derivation utilizes, (kA), the capacity ratio of the first eluted peak but A similar equation which takes a slightly different form, can be derived using (kB), the capacity ratio of the second peak. Both equations give the same numerical result.
Figure 18. Graph of Log Efficiency against Capacity Factor for Solute Pairs Having Different Separation Ratios