From Column Column

Figure 1. The steps of chromatographic separation are: addition of the mixed solutes to the column, elution to effect separations, and removal of the separated solutes.

Resin Bead

Figure 2. Representation of the three phases involved in chromatographic separation.

Resin Bead

Interstitial Liquid

1qu1d 1n Resin

Figure 2. Representation of the three phases involved in chromatographic separation.

The ratio of individual distribution coefficients is often used as a measure of the possibility of separating two solutes and is called the separation factor, a, or relative retention factor.

From Table 1, the separation factors for acetone-formaldehyde separability are 0.49, 0.98 and 1.54 for Dowex 50WX8 (H+), Dowex 1X8(C1) and Dowex 1X8(S04"2) resins, respectively. For comparison purposes, it may be necessary to use the inverse of a, so that the values would be 2.03 and 1.02 for Dowex 50WX8(H+) and Dowex 1X8(C1"), respectively. When a is less than l,thesoluteinthenumeratorwillexitthecolumnfirst. When a is greater than 1, the solute in the denominator will exit the column first.

Table 1 Distribution Coefficients'171

Solute

Resin

Kd

Ethylene Glycol

Dowex 50-X8, H+

Was this article helpful?

0 0

Post a comment