Field flow description

A laminar horizontal flow is used as a force to push the analytes forward. It is slow near the walls and faster far away. At the same time, a vertical force is pushing the analytes down. By combining the horizontal laminar flow with the vertical force, separation can be obtained. The key to separation is that the analytes react differently to the vertical force, here a flow.

Field flow fractionation (FFF) focusing, followed by separation

While being pushed forward horizontally by a laminar flow, the analytes are also pushed down by a vertical force. Differences in random movement due to dependencies between the analyte and the vertical force will influencing the average vertical positions of the analytes. If the analytes respond differently to the vertical force, they will exit at different times, because the laminar flow is slow near the walls and faster far away from the wall. The below examples were simulated using MATLAB scripts.

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