New concept in focusing field-flow fractionation and thin layer isopycnic focusing: Coupling of primary electric field with secondary gravitational force

A new concept of isopycnic focusing exploiting the simultaneous action of coupled electric and gravitational fields is described. Experimental implementation of this concept is demonstrated under conditions of focusing field-flow fractionation and of newly proposed thin layer isopycnic focusing. Both methods are aimed for particle separations. Although the demonstration was performed by using model cross-linked polymer and latex particles, the most important field of potential applications is intended for analytical and preparative separations of biological particles.