Question

A student researcher performed a chromatographic separation of caffeine and aspartame. The retention time for caffeine, tc,was found to be 207.6 s with a baseline peak width, wc, of 16.2 s. The retention time for aspartame, ta, was 253.7 s with a baseline peak width, wa, of 18.7 s. The retention time for the unretained solvent methanol was 40.7 s.

Calculate the average plate height, H, in micrometers for this separation, given that it was performed on a 27.3 cmlong column.

H=

μm

Calculate the resolution, R, for this separation using the widths of the peaks.

R=

Calculate the resolution if the number of theoretical plates were to increase by a factor of 2.5.

R2.5N=

Answer 1

The detailed calculation is provided below. Please note that

Resolution is directly proportional to square root of no.of theoretical plates.