Pharmaceutical Physical Chemistry: Theory and Practices

Experiment 18

OBJECT

To separate Cu²⁺ and Cd²⁺ ions present in a given mixture using paper chromatography and to determine the R_f values.

THEORY

Paper chromatography is a special case of partition chromatography. In this case, the stationary phase is the paper, which contains about 22% water absorbed on 78% of the cellulose. Thus, the stationary phase is water adsorbed on cellulose which provides an inert support. The solvent used for developing is called the irrigent and is the mobile phase. The irrigent is usually solvent or a mixture of solvents.

The separation of the mixtures into its components takes place by partitioning of the components between stationary phase containing water and the mobile phase (irrigent). The mobile phase travels ...