Nordhoff High School Site
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Chromatography Lab Write up
- Heading (Title, name, partner, date)
- Objective: Use a paper chromatography technique to separate and identify the pigments in spinach leaves.
- Results: Your chromatography strip taped to your paper with the solvent front, pigment 1, 2, 3, 4 clearly labeled. For each labeled part, the distance traveled is given. For each pigment, the rf value is calculated. For each pigment the name of the pigment is written.
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| solvent front |
d=___ |
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| pigment 1 |
d=___ |
rf=_____ |
name =___________ |
| pigment 2 |
d=___ |
rf=_____ |
name =___________ |
| pigment 3 |
d=___ |
rf=_____ |
name =___________ |
| pigment 4 |
d=___ |
rf=_____ |
name =___________ |
- In a well developed chromatogram, a band of yellow pigment will be found close to the solvent front. It will have an rf value close to 1. these are the carotenes.
- Further down the paper, with an rf around .4 - .6, will be another yellow band (sometimes two separate bands). These are the xanthophylls.
- Chlorophyll B tends to be yellowish green while chlorophyll A is more bluish green.
- Conclusion What makes chromatography work and what did it tell you about the pigments in plants?
- Use the following prompts to help you create a conclusion in paragraphs. Do not simply write answers to these questions item by item. Use them and information you gained during the lab to help you develop a working conclusion communicating your understanding.
- What colors did you see in your chromatogram?
- Why is it that all of those colors weren't visible on the leaf?
- Suggest a possible explanation as to what happens to cause the color change that happens in some leaves in the autumn.
- Were all of the pigments soluble in the solvents used? How do you know? Which might be more soluble?
- Did all of the pigments start at the same point on the chromatography paper?
- Did all pigments travel for the same amount of time?
- What characteristics of these pigments would explain their different positions at the end of the lab?
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