Ps. Williams, PARTICLE TRAJECTORIES IN FIELD-FLOW FRACTIONATION AND SPLITT FRACTIONATION CHANNELS, Separation science and technology, 29(1), 1994, pp. 11-45
The need for particle trajectory determination within field-flow fract
ionation and SPLITT fractionation channels is discussed. In the case o
f steric or steric/hyperlayer FFF, the trajectory followed by a partic
le determines its elution time. With hydrodynamic relaxation, the dete
rmination of a representative set of trajectories can also provide inf
ormation on the band spreading inherent to the technique. In the simpl
est case of SPLITT fractionation where a binary separation is the obje
ctive, the trajectories determine the point at which a separative cut
is made, as well as the sharpness of the cut. The influence of hydrody
namic lift forces, applied transverse and longitudinal fields, and sec
ondary crossflow on particle migration are discussed, as well as the p
erturbing influence of the presence of the channel walls. Finally, a c
omputer program is used to generate sets of particle trajectories to i
llustrate certain aspects of the preceding discussion.