The Optimum Capacity Ratio

Throughout the optimization procedure, the role played by the capacity ratio has not been examined, and (k ) has been treated as a constant in the equations. As a consequence, the effect of the magnitude of (k1) on chromatographic performance has not been considered, This is because, in choosing the phase system to provide the maximum separation ratio for the critical pair, the value for (k ) is automatically defined by the phase system 

Graph of Log. Analysis Time against Capacity Ratio 

It is seen from figure (8) there is no true optimum value for (k) that will produce a minimum analysis time, but the shortest times will occur when the critical pair are close to the last eluted solutes of the mixture. This situation will be rarely possible in practice. However, it is also seen from the curves in figure (8), that if the phase system is adjusted such that the value for (k ) is 2.5 or greater, then the (k ) value will not greatly effect the analysis time. This is because the curves are very flat subsequent to a (k ) 

It now possible to summarize the design equations for a packed column which are given as follows. 

---