DFGF Simulations

Dynamic field gradient focusing (DFGF) has been realized at various scales, providing a new exciting technique for resolving individual components from complex mixtures.  As Protasis moves forward to bring this revolutionary technology to the laboratory, numerical simulations of DFGF separations have been created to better understand the underpinnings of the technique (i.e., fluid mechanics, heat transfer, and electrophoretic processes) and guide instrument designs.

(~ 1 MB)

In Simulation One, a cocktail of R-phycocyanin, R-phycoerythrin, and myoglobin have been injected into the separation chamber as a dilute solution, and completely fills the column volume.  Upon initiation of the trial, a linear electric field, shown in the field gradient plot window, is applied to the column resulting in the formation of individual bands.  The separation reaches pseudo-steady state in about 9 minutes.  From top to bottom, the bands represent R-phycoerythrin, R-phycocyanin, and Myoglobin, respectively.  At this time, the magnitude of the linear field is reduced to shift the band focal points toward the exit of the separation chamber.  At 23 minutes, the field is reduced further to elute myoglobin from the chamber.  At 33 minutes, a high field is again applied to shift the band focal points up and demonstrate that products bands can be manipulated within the chamber with adjustment of field gradient.  At 50 minutes, the field is again lowered to elute R-phycocyanin, while R-phycoerythrin is still held in the column.  After the complete elution of R-phycocyanin, R-phycoerythrin is eluted.  A point UV-Vis detector monitoring column eluent records a chromatograph of the separation, and results charted in the line plot to the right.

The simulation demonstrates that band positions, as well as elution time of individual bands, are controllable by adjustment of the field gradient applied to the column.  In addition to the high resolution of DFGF, this unique feature greatly increased the flexibility to operate an electrochromatographic column.