Virtual migration distances

Rathore, A. S., and Horvath, C. S. (1996). Separation parameters via virtual migration distances in high-performance liquid chromatography, capillary zone electrophoresis and electrokinetic chromatography /. Chromatogr. A 743, 231-246. 

The virtual migration distance, /q, arising from EOF is expressed as the product of the migration time of the analyte (O and the electroosmotic mobility (fieof) ... 

In terms of virtual migration distance, the electromigration factor is the dimensionless virtual distance of separative migration that measures the separative fraction of the total column length. Table 6.2 summarizes the fundamental migration parameters of CZE expressed according to the conventional formalism and to the concept of virtual migration distances. 

Separation Parameters in CZE According to (A) Conventional and (B) Virtual Migration Distance Formalism... 

An additivity relationship for the separative and nonseparative parts of the overall migration process that is equally applicable to HPLC and CZE arises naturally upon introduction of virtual migration distances, which represent the... 

Mode Velocity factor, /r Virtual migration distances Sample electropherogram... 

Here uh is the migration velocity of the eluite band and u is the velocity of an inert tracer. In HPLC both virtual lengths,, and i are positive quantities, and therefore neither of them can be greater than the total migration distance. 

During gel electrophoresis, the migration of macromolecules is obstructed by the polymer matrix, and thus depends on the molecular weight as well as the frictional coefficient with the matrix. In the reptation model, DNA is assumed to move in a worm-like fashion through virtual tubes in the gel polymer matrix (Fig. 9.1A). The central result is that the electrophoretic mobility depends on the mean-square end-to-end distance of the macromolecule, and inversely on length (L) or molecular weight. The electrophoretic mobility is expressed as... 

In HPLC, the virtual distance, representing separative migration, is defined as [1]... 

Although sewers can have methane in them, it is virtually impossible for it to travel any distance through the ground outside the sewer (except in the backfill) because sufficient pressure cannot be generated to cause migration (it would cause other problems within the system before migration in the ground occurred). 

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