In order to analyze the size distribution of sub-micron particles by the sedimentation field-flow fractionation, a new apparatus which includes a rotary joint consisting of a flat surface seal and a rotary column with changeable wall material and channel thickness was coustructed.
At a low ionic strength in the aqueous carrier solution, the elution time of particles in sedimentation field-flow fractionation deviates from that by Giddings' theory, resulting in underestimation of the particle size. In this case, the elution time of particles can better be estimated by considering the particle-wall interaction and the fluid force effect. In the methanol carrier solution, the behavior of particles is apparently the same as that in the aqueous carrier solution. The particle size could be estimated by Giddings' theory when the aqueous or methanol solution with a certain concentration of di-2-ethylhexyl sodium sulfosuccinate (Aerosol OT) surfactant was used as a carrier solution.
