Chromatography Lab
Introduction:
• Background : Leaves are green because
of the chlorophyll pigment that you can
see. It is involved in the process of
photosynthesis.
– However chlorophyll is not the only pigment.
– Chromatography is the process that will
separate out all of the pigments.
• Purpose: to know that sunlight is captured
in the chloroplasts where the chlorophyll
and other pigments are found.
Hypothesis:
• I think the green (chlorophyll) from the
Spinach Leaf will move to the (top/ middle/
or bottom) of the paper because:……
• I think that the other pigments will be the
following colors:
because….
Materials: (per group)
1. Chromatography paper
2. Mortar and pestle
3. Spinach leaves
4. Ruler
5. Beaker
6. Pipette
7. crayons/ color pencils
8. Alcohol (solvent)
Procedures
• 1. Mash the spinach leaves to get the liquid out
of them.
• 2. Take the chromatography paper and draw a
dot at 5 mm (1/2 cm) from the bottom.
• 3. Take the chromatography paper and make
sure the dot is above the level of alcohol.
• 4. Then take the pipette and put a dot of spinach
juice where the dot was on the chromatography
paper.
• 5. Put the juice about 4-5 times but allow the
spot to dry each time.
More Procedures
• 6. Place the chromatography paper in the
beaker of alcohol again. Watch the solvent move
up.
• 7. Remove the paper when the solvent reaches
the top.
• 8. Draw your slide and all the colors and exactly
where they were found?
• 9.Measure the distance each pigment moved.
From the dot to where the color stops.
• 10. Find the Rf value by dividing the distance the
pigment traveled by the distance that the solvent
moved.
Substance/
Pigment
Solvent (clear)
Carotenes (yellow
and orange)
Lutein (gray)
Chlorophyll a (bluegreen)
Xantholphylls
(yellow)
Chlorophyll b
(yellow-green)
Distance Moved
Rf Value
------------
Conclusion Individual
• 1. Which pigment seems to be the most
abundant judging by the darkest?
• 2. Which pigment had the highest Rf factor
and what does this mean?
• 3. Do you think the results would be the
same if you used a different kind of green
leaf and why?
Conclusion at your tables
• Write these down after talking with your
group and I will randomly call on some
groups so be ready!!!
• 4. Why do leaves look green when there
are so many other colors in them?
• 5. Why do leaves change colors in fall?
What do you think is happening.
Download

Chromatography Lab