TABLE OF CONTENTS In this chapter the mass and fluid transfer processes that dominate as a solvent passes over particles in a packed column bed are summarized in both physical and philosophical terms. To introduce some basic terminology and to put us on common ground, the liquid passing through column is referred to as the mobile phase whilst, in most cases, the solid particle is called the stationary phase.
It will become apparent as an understanding of the philosophy is developed that in one particular mode of chromatography the stationary phase is not the solid particle.
Complex mathematical formulae will be minimized here for the purpose of simplicity since there are numerous texts that deal with detailed theory of mass transport in chromatography [2.1] , [2.2]. The flow of mobile phase through a packed column bed is shown schematically in Figure 2.1. There are two transport mechanisms in progress. Firstly, the convectional flow around the particles; and secondly, the diffusion in and out of the pores of the stationary phase.
In order to describe mass transport effects it is necessary to have an understanding of the measurements used to quantify the efficiency of a chromatographic separation. Traditionally the term number of theoretical plates is used to define the efficiency of the packed column bed. The mathematical derivations for plate theory were initially developed by Martin and Synge [2.3] and published in 1941.
This term actually originated in the petrochemicals industry and is derived from...
