Ink Chromatography

Ink Chromography

How to we separate a drop of ink ?

Use the process of paper chromatography to separate the pigments in various markers and then determine the R_f value for each color on your chromatogram.

Materials needed : 

1. Plastic vials
2. Paper clips 
3. Markers in assorted colors 
4. Chromatography paper 
5. Scissors 
6. Pencil

Procedure :

1. Obtain chromatography vials and chromatography strips, and different color markers so that each person in the group will have two chromatograms.
2. Cut one end of the chromatography strip to a point. The bottom of the point will mark the starting point for movement of the solvent (H₂O).
3. About 2.0 centimeters from the bottom of the strip, draw a faint horizontal line with pencil. This will mark the starting point for measuring the migration distance of each color.
4. Using a different color marker for each strip, drop a dot of ink on the center of the horizontal pencil line.  Let this dry a moment & then add more ink to the dot.
5. Add a small amount of water to the bottom of the chromatography chamber. (The ink dot should be ABOVE the surface of the water.)
6. Straighten a paper clip and poke a hole through the top of your chromatography strip
7. Use the paper clip to hang the strip in your chamber. (The straighten paper clip will lay across the top of the chamber.)
8. MAKE SURE THE TIP OF THE STRIP BUT NOT THE INK IS IMMERSED IN THE WATER!
9. Notice the separation of the ink as both the solvent and ink travel up the chromatography strip.
10. Once the solvent front has neared the top of the strip, remove the strip from the chamber and lay it on a piece of paper towel.
11. Immediately mark the solvent front with a faint pencil line.
12. Immediately mark the leading edge of each color with an "x".
13. Measure, in millimeters, the distance the solvent migrated from the tip of the strip to your solvent front pencil line.
14. Measure, in millimeters, the distance each color migrated from the point of origin (pencil line where the ink dot was placed) to the leading edge of the color (marked with an "x".
15. Record all data in Data table 1.
16. Calculate and record the R_f value for each color using the formula below.

R_f = distance traveled by the compound / distance traveled by the solven

Adopted from : http://www.biologyjunction.com/ink_chromatography.htm


I tried out this experiment at my school science lab . I've uploaded them onto this blog . Check it out people ! Thanks .