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.