Capacity factor factors affecting elution time

As the solvents used will affect both the capacity factors and the selectivity of the system, the mobile phase is selected on its ability to elute the solutes in an acceptably short time with a reasonable resolution between each one. The choice of mobile phase components may also be influenced by the desire to suppress the ionisation of one or more of the analytes or to reduce peak tailing. These considerations, whilst very important are generally viewed separately from the factors which affect the k and a values. 

As shown by Eq. 1 the resolution of components in a Uquid chromatographic separation is dependent on (1) their relative retention on a particular chromatographic system, and (2) their peak widths. To optimize these parameters for maximum resolution, a clear understanding of their nature and the factors that affect them is necessary. Although the retention time of a component adequately describes the amount of time a particular solute takes to elute from a chromatographic system, a more usefid parameter describing chromatographic retention is the capacity factor k. This parameter is defined as the ratio of time spent by a solute in the stationary phase to the time it spends in the mobile phase. It can be calculated by Eq. 2, where Tr is... 

Among the factors which influence the adsorption of fission product gases from a dynamic system are (1) adsorptive capacity of adsorber material, (2) temperature of adsorber material, (3) volume flow rate of gas stream, (4) adsorbed moisture content of adsorber material, (5) composition and moisture content of gas stream, (6) geometry of adsorber system, and (7) particle size of adsorber material. The average time required for the fission product gas to pass through an adsorber system, tmax, is influenced by the first five of the above factors. The shape of the experimental elution curve is affected by the last two. 

---