ABSTRACT
The emphasis on kinetics stems from the fact that this is the most important and challenging aspect of chromatographic dynamics. The ratio in equation is composed of equilibrium or thermo-dynamic parameter and a dynamic zone spreading parameter. In some cases specific interactions can be employed to yield widely different migration rates, and the control of zone spreading is of secondary importance. It is difficult to generalize regarding the relative importance of controlling migration rate differences and zone spreading. There is one important class of separations in which the control of zone spreading may be regarded as the paramount requirement. Some of the physical processes leading to zone spreading are present in all forms of chromatography. The development of concepts and mathematical expressions for zone spreading has been one of the major theoretical and practical challenges of chromatography. The theoretical plate model has maintained a widespread popularity in the description of chromatographic zone spreading.
