Title: separation number
Long Title: IUPAC Gold Book - separation number
DOI: 10.1351/goldbook.S05616
Status: current
Index: quantity

Definition
This expresses the number of peaks which can be resolved in a given part of the chromatogram between the peaks of two consecutive n-alkanes with \(z\) and (\(z+1\)) carbon atoms in their molecules: \[\rm{SN} = \frac{t_{\rm{R}\left(z\,+\,1\right)}- t_{\rm{R}z}}{w_{\rm{h}z}\,+\,w_{\rm{h}\left(z+1\right)}} - 1\] In the German literature the symbol \(\rm{TZ}\) (trennzahl) is commonly used to express the separation number. As the separation number depends on the n-alkanes used for the calculation, they always must be specified with any given \(\rm{SN}\) value.

Related Terms
- alkanes: https://goldbook.iupac.org//terms/view/A00222
- chromatogram: https://goldbook.iupac.org//terms/view/C01071

Source
- PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 847 (https://doi.org/10.1351/pac199365040819)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/S05616/html
- json: https://goldbook.iupac.org/terms/view/S05616/json
- xml: https://goldbook.iupac.org/terms/view/S05616/xml

Citation: Citation: 'separation number' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.S05616
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Accessed: 2026-05-12T11:58:06+00:00