Dispersion in Chromatography Columns - The Random Walk Model > Page 8

                   Lateral Movement/Particle =

It follows, that the average lateral step will be, 

Employing the random walk function, the radial variance will be given by:-                   (2)

 

Now assuming one lateral step is taken by a molecule for every distance (jdp) that it moves axially, then, (n) the number of steps is given by:-                                                                             

where (l) is the distance traveled axially by the solute band.

Thus, substituting for (n) in equation (2),