resolution as function of k'
Posted: Tue Nov 27, 2007 5:02 pm
why does resolution level off with increasing k'?
The equation is:
Rs ≈ (1/4) * (N^0.5) * (α -1) * [k'/(1+k')]
As k' get's large, the [k'/(1+k')] term asymptotically approaches 1.
As to where that equation comes from, the definitions are:
k' = (tR - t0)/t0
α = k'2 / k'1
N = 16 * (tR/W)^2
Rs = (tR2 - tR1) / [0.5 *(W1 + W2)]
If you assume that the width of the first peak is close to that of the second and that the retention time of the first peak is close to the average retention time of the pair (i.e., W ≈ W1 and tR ≈ tR1), then you can do some basic algebra to combine those definitions and get that first equation ("proof is left to the student as an exercise").