# Preparative Chromatography – The Loading Capacity of a Column > Page 3

From the Plate Theory (see The Plate Theory and Extensions ), , where (V_{m}) is the total volume of mobile phase in the column or the column dead volume.

Thus:

Now:

where (r) | is the radius of the column, |

(L) | is the length of the column, |

(e) | is the fraction of the column containing solvent. |

Thus:

Now (e) can be taken as approximately 0.6:

Thus,

and: (1)

The magnitude of (A_{v}) will be determined by the nature of the separation, and (A_{m}) will be defined by the loading capacity of the stationary phase and, to some extent, by the shape of the adsorption isotherm.