1. Paper Chromatography

2. Chromatography
Used to separate mixtures of substances into their components
All forms of chromatography work on the same principle

3. Chromatography Stationary Phase Mobile phase Sample (mixture)
Stays still—solid, liquid or gas
Mobile phase
Moves—liquid or gas
Sample (mixture)
The mixture that you are trying to separate into its components
The mobile phase flows through the stationary phase and carries the components of the mixture with it.

4. Chromatography
Solution = a mixture of two or more substances in which the molecules of the substances are evenly distributed (ex., salt water).
Solvent = a substance in which a solute is dissolved (i.e., water).
Solute = the substance that is dissolved in a solvent (i.e., salt).

5. Chromatography In paper chromatography, the stationary phase is:
The paper!!!
The mobile phase is:
A suitable liquid solvent or mixture of solvents

6. Chromatography

7. Chromatography
What do you notice about our pigments after going through the chromatography?
Why does this happen?

8. Chromatography Imagine a river…the Bark River!!
Now…imagine that YOU (being an enthusiastic biology student) are standing in the Bark River.

9. Chromatography Imagine a river…the Bark River!!
Now…imagine that YOU (being an enthusiastic biology student) are standing in the Bark River.
You have a 5-gallon bucket filled with 3 large rocks, gravel, sand, and clay dust

10. Chromatography Imagine a river…the Bark River!!
Now…imagine that YOU (being an enthusiastic biology student) are standing in the Bark River.
You have a 5-gallon bucket filled with 3 large rocks, gravel, sand, and clay dust
And you dump that bucket into the river
in front of you!!!

11. Chromatography Imagine a river…the Bark River!!
Now…imagine that YOU (being an enthusiastic biology student) are standing in the Bark River.
You have a 5-gallon bucket filled with 3 large rocks, gravel, sand, and clay dust
And you dump that bucket into the river
in front of you!!!
…and drop a rock on your foot…

12. Chromatography Imagine a river…the Bark River!!
Now…imagine that YOU (being an enthusiastic biology student) are standing in the Bark River.
You have a 5-gallon bucket filled with 3 large rocks, gravel, sand, and clay dust
And you dump that bucket into the river
in front of you!!!
…and drop a rock on your foot…
The point is…what happened to the rocks and gravel and sand and clay??????

13. Chromatography
As the solvent travels up the paper, the different components travel at different rates and the mixtures are separated.
Some compounds (chemicals) travel almost as far as the solvent while others stay close to the baseline.
The distance travelled is a constant for a chemical as long as the type of paper and type of solvent remain the same.

14. Chromatography
The distance travelled relative to the solvent is called the Rf value.
Rf =
distance travelled by compound
distance travelled by solvent

15. Chromatography Solvent = 0.1% NaCl sol’n and methanol