Plate Theory and Extensions - Introduction > Page 1

Introduction

The first and most important aspect of chromatography theory that needs to be initially understood is summed up as follows.

The dynamic and thermodynamic effects that result in a chromatographic separation are straightforward and easy to understand.

                          "first order effects are simple".

Only when second order effects are considered does the theory and accompanying mathematics become more complex.

In addition, the vocabulary employed to describe the various physical chemical processes need not be confusing or difficult to comprehend.

To quote from a lecture given in the early 1940s at the University of London by a physicist, G. W. Poole,

 

 "those who really know, speak in words that everyone can understand"

With these comments in mind the Plate Theory will be developed.

In the definition of chromatography it is stated that the solutes will elute in order of their increasing distribution coefficients with respect to the stationary phase.  It follows, that the relative retention of a pair of solutes (the time interval between their elution) will determine how well they are resolved.  It follows, that an algebraic expression for the retention volume of a solute will disclose those factors that control retention, how the retention can be increased, and how the separation can be improved.