mass distribution ratio

in chromatography
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.
See also: extraction factor
Orange Book, 2nd ed., p. 107 (
PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2384 (