chapter  4
16 Pages

DIFFUSION IN THE ION EXCHANGER

As described in Chap. 2, diffusion in the stationary phase, that

is, intraparticle diffusion in the ion exchanger, is also respon-

sible for dispersion of a solute in a chromatographic column.

The residence time of a solute in the ion exchanger is distributed

around an average value of t n = Rp 2/2D (Giddings, 1965), where Rp is the radius of the ion exchanger and n, the diffusion coefficient in the ion exchanger. The degree of the dispersion

in a column becomes larger with an increase in the ratio of the

residence time of a solute in the ion exchanger to the time re-

quired for passing through the interstices of a column. In this

chapter, we provide information about diffusion in ion exchangers

and a prediction method.