This week's memo arrives courtesy Dr. Katherine O’Brien, a postdoctoral fellow at OSU and the community outreach specialist for the Museum of Biological Diversity.
In the stretch between Halloween and Thanksgiving, fall is in full swing. Despite the characteristically grey weather this is my favorite time of year watching chemistry play out on leaves all across the city. As leaves stop producing chlorophyll as the days have been getting shorter, this shows the other pigments in a leaf like yellow (xanthophyll), orange (carotene), and red (anthocyanin).
If you want to see these underlying colors in leaves that have not changed, you can! All you need are some leaves (spinach works great), rubbing alcohol, a white coffee filter, a pie plate, pencil, a glass, and some plastic wrap. Okay, ready for some home science?!?
1) Tear up the leaf and place it in the glass with enough rubbing alcohol to cover the leaves.
2) Cover the glass with the plastic wrap - this keeps the alcohol from evaporating.
3) Fill the pie plate with warm water and place the glass in the water for 30 minutes so that the alcohol becomes green.
4) Cut the paper filter into strips and tape them to your pencil.
5) Suspend the filter so it is just touching the liquid- set aside for 30-90 min.
What you will see are the pigments that are inside the leaf being masked by the green (chlorophyll) and a large strip of green pigment.