Autumnal Chromatography:
The Magic & Science Of Changing Leaves

Yesterday I wrote about using chromatography to suss out the myriad colors that go into black markers, but it can also be used to analyze exactly what's behind autumn leaves' blaze of glory. Put on a flannel, lace up your hiking boots, and break out the acetone•

  • I first saw fall leaf chromatography mentioned on Wired's Geek Mom blog, thanks to Kathy Ceceri of Home Chemistry. She and her (heavily supervised, of course) kids covered torn green leaves with acetone, then allowed the mixture to climb up a strip of paper towel- separating the green into yellow, greens, and brownish red.
  • Raising Leafs, whose photo is shown above, used 2-3 leaves from each of 5 different trees in her yard mashed with rubbing alcohol.
  • Science Made Simple has an elaborate set of experiments involving fall leaves, perfect for older &/or more science-inclined kids.

The examples above used green leaves in an attempt to predict what color the leaves would turn in the fall, but it appears the most satisfying experiments used green as well as already-changed leaves, showing the colors that make up the yellow, red, orange, burgundy, brown, and purple of fall foliage. Science Made Fun tried that approach (it just takes longer than with green leaves), as did Michigan Technological Institute (this one involves words like "carotenoids" and "xanthophyll", if you're into that).

Happy fall, aspiring scientists!

(Image: Raising Leafs)