mobile-phase volume

in counter-current chromatography
symbol: $V_{\rm{M}}$
https://doi.org/10.1351/goldbook.09945

Volume of the liquid mobile phase contained in the column in counter-current chromatography \[V_{\rm{M}} = V_{\rm{C}} - V_{\rm{S}}\] where \(V_{\rm{C}}\) is the total volume of the column and \(V_{\rm{S}}\) is the volume of the liquid stationary phase in the column.

Source:
PAC, 2017, 90, 181. (Terminology of separation methods (IUPAC Recommendations 2017)) on page 204 [Terms] [Paper]