Chromatography is used to separate 2 or more dissolved solids in a solution, but these dissolved solids are in very small quantities . Example - Different Dyes from Blank Ink
What is chromatography?
It is a technique used to separate different solutes that dissolve in the same solvent.
This technique is used for separation of different colors .
Example
- It is used to separate different colors of dye.
- It is used to separate drugs from blood
- It is used to separate different colours from pigments
Central Idea behind Chromatography
Different solutes have different solubilities in a solvent. And these solutes are separated using Chromatography
Let's look at a Case where Chromatography is used
Separating Different Colors of Dye
Ink has water as solvent and dye is soluble(solute) in it.
Is DYE made of Single color?
- No
- Dye in ink is made up of different colors mixed together.
How to Separate Different Colors of Dye
- Take a small strip of filter paper
- Draw a line on it (around 3 cm from bottom)
- Put a small drop of ink at the center of the line using a sketch pen.
- Let it dry
- Now take a beaker filled with some water
- Lower the filter paper in the beaker
- Lower end of filter paper should dip in water but ink spot should be just above the water
- After some times, we see water rise up over the filter paper
- Different colors of ink are also visible at different heights
Reason :
When water rises up on filter paper, it takes the dye of ink along with it.
- The component which is more soluble in water rises faster and is seen at higher position
- The component which is less soluble is seen below at lower position
