Extra Column Dispersion - Dispersion Due to Detector Electronics Response Time > Page 48

It is seen from figure 23 that the a.c. noise from the lamp has virtually been eliminated. From the expanded log curve the time constant of the photo multiplier was found to be about 40 msec. Such small time constants are quite adequate for the majority of high speed chromatography separation.

An example of the use of the use of a carefully designed system having low extra column dispersion and a sensor with a fast response is shown in figure 24. The figure shows the separation of the five component mixture in just over 3 seconds.

J. Chromatogr.,253(1982)159

 

Column length 2.5 cm, column I.D. 2.6 mm, column packing, silica gel, particle size 3 mm, mobile phase 2.2% w/w methyl acetate in n-pentane, linear velocity 3.3 cm/sec (equivalent to 13 ml/min.), inlet pressure 5300 psi.

Figure 24. Rapid Separation of a Five Component Mixture