In chromatography, resolution is a measure of the separation of two peaks of different retention time t in a chromatogram.^[1][2][3][4]

Expression

Chromatographic peak resolution is given by

${\displaystyle R_{s}=2{\cfrac {t_{R2}-t_{R1)){w_{b1}+w_{b2))))$

where t_R is the retention time and w_b is the peak width at baseline. Here compound 1 elutes before compound 2.

If the peaks have the same width

${\displaystyle R_{s}={\cfrac {t_{R2}-t_{R1)){w_{b))))$.

Plate number

The theoretical plate height is given by

${\displaystyle H={\frac {L}{N))}$

where L is the column length and N the number of theoretical plates.^[5] The relation between plate number and peak width at the base is given by

${\displaystyle N=16\cdot \left({\frac {t_{R)){W_{b))}\right)^{2}\,}$.