Question

State briefly how would you separate the dyes present in black ink.

Answer 1

Part 1: Paper Chromatography

The dyes present in black ink can be separated by the paper chromatography technique.

Two phases of Paper chromatography:

Stationary phase: porous filter paper known as chromatography paper.

Mobile phase: solvent (alcohol-water mixture).

Principle: the separation occurs due to the solubility difference of the analyte (a substance to be separated).

Part 2: Mechanism:

• The analyte is applied to the bottom of the filter paper strip (chromatography paper) then this paper strip is placed inside the glass vessel having the solvent in such a way that the testing sample should be in contact with the solvent.
• Now solvent is allowed to move through the stationary phase.
• In this process, the components of the mixture are carried away by the solvent to different heights according to their absorption forces in the stationary phase thereby separating the substances.
• The stronger the absorption between the stationary phase and components of the mixture least distance it travels and the least the absorption distance is traveled by the analyte as it is more soluble insolvent.

As the component of black ink are colored then colored spots appear on the filter paper.