how would you separate dyes in black-black ink using chromatography
The black ink is basically a mixture of two dyes - blue and red. These two dyes can be easily separated with the help of chromatography. Chromatography is usually carried out with the help of a special type of filter paper, called the Whatman's filter paper.
1) Take a thins strip of whatman's filter paper.
2) Draw a line on it using a pencil, approximately 3 cm above the lower edge.
3) Put a small drop of ink either from a sketch pen or fountain pen at the centre of the line. Allow it to dry.
4) Lower the filter paper into a glass jar containing water so that the drop of ink on the paper is just above the water level. Carefully, cover the mouth of the jar with a lid and leave it undisturbed.
5) As the water rises up on the filter paper, the components of black ink are separated.
Remove the filter paper after some time. Let it dry. You will see three different spots on the filter paper - one for the pure solvent that is water, one for blue dye and one for red dye.