
Figure 23 Resistance to Mass Transfer in the Stationary Phase
All four molecules will continue moving down he column, while molecules 5 and 6 diffuse to the interface. By the time molecules 5 and 6 enter the mobile phase, the other four molecules will have been smeared along the column and the original 6 molecules will be dispersed.
Van Deemter derived an expression for the variance
from the resistance to mass transfer in the stationary phase,
(
), which is as follows:
(7)
