## mass distribution ratio

in chromatography
https://doi.org/10.1351/goldbook.M03718
The fraction ($$1 - R$$) of a component in the stationary phase divided by the fraction ($$R$$) in the mobile phase: $D_{\text{m}}=\frac{\text{amount of substance in the stationary phase}}{\text{amount of component in the mobile phase}}$ This term is recommended in preference to the term capacity factor frequently used in the chromatographic literature.