Resolution (chromatography)

{{About|the quantity used in chromatography|other uses|Resolution (disambiguation)}}

In chromatography, resolution is a measure of the separation of two peaks of different retention time t in a chromatogram.{{GoldBookRef|title=Peak Resolution Rs in chromatography|file=P04465}}{{GoldBookRef|title=Peak Resolution in gas chromatography|file=R05317}}{{cite journal |last1=Maryutina |first1=Tatiana A. |last2=Savonina |first2=Elena Yu. |last3=Fedotov |first3=Petr S. |last4=Smith |first4=Roger M. |last5=Siren |first5=Heli |last6=Hibbert |first6=D. Brynn |title=Terminology of separation methods (IUPAC Recommendations 2017) |journal=Pure and Applied Chemistry |date=2018 |volume=90 |issue=1 |pages=181–231 |doi=10.1515/pac-2017-0111 |issn=0033-4545|doi-access=free }}{{cite journal|last1=Ettre|first1=L. S.|title=Nomenclature for chromatography (IUPAC Recommendations 1993)|journal=Pure and Applied Chemistry|volume=65|issue=4|year=1993|pages=819–872|issn=1365-3075|doi=10.1351/pac199365040819|doi-access=free}}

Expression

Chromatographic peak resolution is given by

: $R_s = 2\cfrac{t_{R2}-t_{R1}}{w_{b1}+w_{b2}}$

where t_R is the retention time and w_b is the peak width at baseline. 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

: $R_s = \cfrac{t_{R2}-t_{R1}}{w_b}$ .

Plate number

File:Rt 5 15.png

The theoretical plate height is given by

: $H = \frac{L}{N}$

where L is the column length and N the number of theoretical plates.{{GoldBookRef | title = plate number, N | file = P04694}} The relation between plate number and peak width at the base is given by

: $N = 16 \cdot \left(\frac{t_R}{W_b}\right)^2 \,$ .

References

External links

[http://www.iupac.org/publications/pac/1993/pdf/6504x0819.pdf IUPAC Nomenclature for Chromatography]

Resolution (chromatography)

Expression

Plate number

See also

References

External links