# Plate Theory and Extensions - The Peak Capacity of a Chromatographic Column > Page 98

Now, the
effect of sample volume on peak width will be most significant for the early
peaks (the most narrow peaks). In addition, the degrading effect of sample
volume will progressively decrease as the capacity ratio of the peak becomes
larger. Nevertheless, the resolution of both late and early peaks are equally
important and, consequently, the limiting sample volume will be taken as that
which restrains the dispersion of the *first* peak to 5% or less.

Thus, for an unretained peak,

Consequently, if the solute concentration
in the sample is (X_{i}),

(79)

Equating equations (31) and (32),

Dividing both
sides by (v_{m}), noting
that (_{}), and simplifying,

and thus . (80)