An analytic description of electrodynamic dispersion in free-flow zone electrophoresis.

摘要: The present work analyzes the electrodynamic dispersion of sample streams in a free-flow zone electrophoresis (FFZE) chamber resulting due to partial or complete blockage electroosmotic flow (EOF) across channel width by sidewalls conduit. This EOF has been assumed generate pressure-driven backflow transverse direction for maintaining balance system. A parallel-plate based FFZE device with analyte stream located far away from side regions considered simplify current analysis. Applying method-of-moments formulation, an analytic expression was derived variance at steady state as function its position separation under these conditions. It shown that increase broadening phenomenon is additive contributions molecular diffusion and injection, simply modifies coefficient hydrodynamic term fixed lateral migration distance stream. Moreover, this mechanism can dominate overall spatial zones when significant fraction blocked sidewalls. analysis also shows do not undergo any unwanted cross-flows absence electric field. noted results have validated using Monte Carlo simulations which further demonstrate while concentration profile outlet approaches Gaussian distribution only chambers substantially longer than product axial velocity characteristic time system, exiting well described Taylor-Aris limit even ducts much shorter length scale.