Resolution (chromatography)

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Example chromatogram showing signal as a function of retention time Chromatogram in English.svg
Example chromatogram showing signal as a function of retention time

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

Contents

Expression

Chromatographic peak resolution is given by

where tR is the retention time and wb is the peak width at baseline. The bigger the time-difference and/or the smaller the bandwidths, the better the resolution of the compounds. Here compound 1 elutes before compound 2.

If the peaks have the same width

.

Plate number

Two resolved peaks in a chromatogram Rt 5 15.png
Two resolved peaks in a chromatogram

The theoretical plate height is given by

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

.

See also

References

  1. IUPAC , Compendium of Chemical Terminology , 5th ed. (the "Gold Book") (2025). Online version: (2006) " Peak Resolution Rs in chromatography ". doi : 10.1351/goldbook.P04465
  2. IUPAC , Compendium of Chemical Terminology , 5th ed. (the "Gold Book") (2025). Online version: (2006) " Peak Resolution in gas chromatography ". doi : 10.1351/goldbook.R05317
  3. Maryutina, Tatiana A.; Savonina, Elena Yu.; Fedotov, Petr S.; Smith, Roger M.; Siren, Heli; Hibbert, D. Brynn (2018). "Terminology of separation methods (IUPAC Recommendations 2017)". Pure and Applied Chemistry. 90 (1): 181–231. doi: 10.1515/pac-2017-0111 . ISSN   0033-4545.
  4. Ettre, L. S. (1993). "Nomenclature for chromatography (IUPAC Recommendations 1993)". Pure and Applied Chemistry. 65 (4): 819–872. doi: 10.1351/pac199365040819 . ISSN   1365-3075.
  5. IUPAC , Compendium of Chemical Terminology , 5th ed. (the "Gold Book") (2025). Online version: (2006) " plate number, N ". doi : 10.1351/goldbook.P04694