Electroosmotic flow, hydrodynamic methods

Some types of electrophoretic cells are stationary layer problem free , but in the other cells the electroosmotic flow can lead to erroneous results. The observed velocity of particles is a sum of the electroosmotic flow of the fluid and the velocity of particles with respect to the fluid. The latter is a function of the potential of the particles and the former is a function of the position in the cell cross section. Hydrodynamic calculations make it possible to find the stationary levels, i.e. the positions in the cell cross section where the electroosmotic flow equals zero. Certainly the position of stationary levels in commercial electrophoretic cells can be found in the user s manual, and there is no need to perform any calculations. The fastest method to determine the electrophoretic mobility is from the velocity at one stationary level, but such a procedure can lead to substantial errors. For example, when the cell position is adjusted at room temperature and then measurements taken... 

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