## relative retention, $$r$$

in column chromatography
https://doi.org/10.1351/goldbook.R05277
The ratio of the adjusted or net retention volume (time) or retention factor of a component relative to that of a standard, obtained under identical conditions: $r=\frac{V_{\text{R}i}^{'}}{V_{\text{R}\left(\text{st}\right)}^{'}}=\frac{V_{\text{N}i}}{V_{\text{N}\left(\text{st}\right)}}=\frac{t_{\text{R}i}^{'}}{t_{\text{R}\left(\text{st}\right)}^{'}}=\frac{k_{i}}{k_{\text{st}}}$ Depending on the relative position of the peak corresponding to the standard compound in the @C01071@, the value of $$r$$ may be smaller, larger or identical to unity.
Sources:
Orange Book, 2nd ed., p. 105 [Terms] [Book]
PAC, 1993, 65, 819. (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 843 [Terms] [Paper]