Photographed at an exhibit at the University of Wisconsin Arboretum yesterday. I need to learn about this, but haven't yet found a concise source (written for adults) to read and cite. Suggestions?
Scientific American has detailed instructions for undertaking the procedure and interpreting the results:
What are the different bands of color on the test strips? These are the different pigments in the leaves. The ones you may see on your paper towel strips are: green chlorophylls, yellow xanthophylls, orange carotenoids and red anthocyanins. Pigments with larger molecules generally stay near the bottom of the strip, where the solution was first "painted" onto the pencil line, because it is harder for them to travel up through the paper towel's woven fiber. Smaller pigments can more easily traverse the paper towel and, consequently, they usually travel farther up the strip.
I remember doing that experiment a long, long time ago. Here's a description of the experiment: http://www.rsc.org/learn-chemistry/resource/res00000389/chromatography-of-leaves?cmpid=CMP00004978
ReplyDeleteBasically, the propanone dissolves the various components and they begin to rise up the paper (due to capillary action?). The various compounds go to certain heights based on the solubility in propanone and adsorbing to the paper.
Propanone is more commonly known as the household chemical Acetone, so if you wanted to have a go at this at home, you could.
Deletehttps://www.scientificamerican.com/article/bring-science-home-leaf-colors/
ReplyDeleteAdded to the text. Thanks, anon.
DeleteThe excellent BBC In Our Time podcast did an episode on chromatography: https://www.bbc.co.uk/programmes/b06z4w7p
ReplyDeleteI have about a hundred of the In Our Time podcasts saved in iTunes. I'll listen to that one next. Tx.
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