Countercurrent distribution studies on fat soluble plant pigments

Summary

Chlorophyll-a, chlorophyll-b, and carotene have been used to study the operation of countercurrent distribution apparatus. An incomplete separation of the chlorophylls was obtained by the use of the 25-tube Craig apparatus, but nearly complete separation of the chlorophyll and carotene pigments resulted. Degree of separation can be estimated by the modification of the equation of Martin and Synge which follows:

$$t = \sqrt n \frac{{R - 1}}{{R + 1}} = \sqrt n \frac{{K_b - K_a }}{{K_a + K_b + 2K_a K_b }}$$

Comparisons were made between the degree of separation predicted by these formulae and that calculated by the use of the binomial expansion. The utility of such predictions is illustrated by the problem of separating plant pigments. A nomographic solution of these equations is presented to facilitate their application.