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Chemistry · Glossary

What is Selectivity and resolution?

Also known as: selectivity factor · resolution

Definition 31.8 University Chemistry — Year 2 · Chapter 31 — Chromatography

For two neighbouring peaks with k2>k1k_2 > k_1, the selectivity factor is α=k2/k1\alpha = k_2/k_1, and the resolution is

Rs=2(tR2−tR1)w1+w2,R_s = \frac{2(t_{R2} - t_{R1})}{w_1 + w_2},

the distance between the peaks divided by their mean base width.

Two Gaussian peaks of equal size at three resolutions (model). At 0.75 they merge into a doublet; at 1.0 the valley is still at a quarter of the height; at 1.5 the signal is back at the baseline. Two Gaussian peaks of equal size at three resolutions (model). At 0.75 they merge into a doublet; at 1.0 the valley is still at a quarter of the height; at 1.5 the signal is back at the baseline. Two Gaussian peaks of equal size at three resolutions (model). At 0.75 they merge into a doublet; at 1.0 the valley is still at a quarter of the height; at 1.5 the signal is back at the baseline.
Two Gaussian peaks of equal size at three resolutions (model). At 0.75 they merge into a doublet; at 1.0 the valley is still at a quarter of the height; at 1.5 the signal is back at the baseline.
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