https://doi.org/10.1351/goldbook.L03587
This term may be used in place of liquid-liquid distribution when the emphasis is on the analyte(s) being distributed (or extracted).
Note:
The distinction between the @D01813@ (\(K_{\text{D}}\)) and the @P04438@ (\(K_{\text{D}}^{\text{o}}\)) or the concentration distribution ratio  (\(D_{\text{c}}\)) is reaffirmed and it is recommended that the terms @P04438@, @P04437@ and @E02293@ constant should not be used as synonyms for the (analytical) @D01817@, \(D_{\text{c}}\). A distinction is drawn between the terms solvent and diluent, and the term @E02299@ is now restricted to the active substance in the solvent (i.e. the homogeneous 'organic phase' which comprises the @E02299@, the diluent and/or the modifier) which is primarily responsible for the transfer of solute from the 'aqueous' to the 'organic' phase.
Source:
Orange Book, 2nd ed., p. 88 [Terms] [Book]