Plate Theory and Extensions - The Compressibility of the Mobile Phase > Page 25


Now, if the retention volume of a solute at the outlet pressure (Po) is (Vr(o)) and the true retention volume is (Vr) measured at the mean column pressure (Pr), then


                                     PrVr  = PoVr(o)

Thus,                                                                  (24)

It is now necessary to derive an expression for (Pr) and then the correction factor  can be evaluated. The average pressure in the column (Pr) is defined as,          .


Now it has been shown that