Page 134 - Tandem Techniques
P. 134
Page 116
It is also clear that the microbore column gives peaks of much smaller volume, and thus extra column
dispersion would be far more damaging to any separation from such columns. It is now interesting to
examine the contribution to the peak dispersion made by connecting tubes.
The flow rate, (Qo(opt)) leaving the column will be given by,
The factor, 0.6, takes into account that 40% of the cross-sectional area of a packed column is occupied
by the solid packing and not available for flow of mobile phase. Thus the velocity of the mobile phase
(ut) flowing through a connecting tube of radius (rt) will be given by
Consequently, from equation (3.2) the variance per unit length, or height of the theoretical plate (Ht) of
the uncoated connecting tube will be.
