FLOW PROGRAMMED FIELD-FLOW FRACTIONATION

The concept of flow programming in field-flow fractionation (FFF) is introduced and justified. It is shown that the method can preserve or improve the resolution of early peaks and at the same time significantly hasten the elution of late peaks, thus increasing analysis speed. Flow programming is compared briefly to the related options, field-strength and solvent programming. The background theory is then presented, and is used to show that very abrupt velocity programs can be employed without undue degradation of resolution for late peaks. Finally, the utility of flow programming is illustrated using three sizes of polystyrene latex beads in a sedimentation FFF system. © 1979, American Chemical Society. All rights reserved.