Apparent Dispersion from Detector Sensor Volume

It is obvious that the average concentration of solute in the mobile phase, contained in the slice representing the cell volume, will differ considerably from the instantaneous concentration of solute in the column eluent If the sensor volume is significant compared with the peak volume, the mean concentration measured by the sensor will always be less than the true instantaneous concentration of solute leaving the column. Moreover, under the same circumstances, the peak width as measured by the sensor, will always be significantly wider than the actual peak width.

The Separation of Two Solutes 4s Apart on a Microbore Column Employing Detectors Having Different Sensor Volumes. Column Length 15 cm, Column Diameter 1 mm I.D., Particle Diameter 5 mm, k' of first Eluted Peak 1.

Figure 21. The Effect of Detector Sensor Volume on the Resolution of Two Solutes