electrophoretic velocity, νep 

https://doi.org/10.1351/goldbook.ET06925
The velocity of a charged analyte under the influence of an electric field relative to the background electrolyte. Also called rate of migration (in electrophoresis).
Source:
PAC, 2004, 76, 443. (Terminology for analytical capillary electromigration techniques (IUPAC Recommendations 2003)) on page 448 [Terms] [Paper]