Wednesday, October 15, 2008

Science!

One more side road before I finish up my Spain pictures, which I've been meaning to do... but you know... work n' stuff.

Last night my friend Becky asked me a chemistry question, as she is want to do from time to time. She is a teacher at a science camp in Palo Alto and often calls upon my doctor of science abilities to help her figure out how to teach kids science things.

Apparently Becky wants to do chromatography of leaves, I assume to look at chlorophyll and other various leaf pigments as they start to change colors. The problem was that the teacher she was working with wanted to use ether to do the pigment extraction. Why is this a problem? Well, sometimes ether goes Boom-y Boom, also, they're little kids, and huffing ether is an adult past-time.

So, the question to me was: "Why can't I use rubbing alcohol?"

Well, I think rubbing alcohol would be fine, you really just need something relatively (relative to water that is) non-polar. Ether would work great, but dag, that's a tad rough on the wee ones. I didn't, however, know for sure that this would work, so I decided to try it myself. Here is my home-brew thin layer chromatography, just for Becky.

Mission #1, find some leaves. Luckily there are trees outside, and trees have leaves... at least for the time being. Mission complete:


Once I had the leaves I needed to cut them up small so it would be easy to extract all their juicy insides with the isopropyl (rubbing) alcohol. I just rolled a bunch of leaves up and cut them up with scissors. I got something like this:



And a bowl of things like this:


Once I had this I added some isopropyl alcohol (70%, just your standard rubbing stuff from longs), a spoon, and mixed a bit.


I did this twice, once I just mashed the leaves with the spoon for a while and it seemed to take a very long time for anything to leach out into the alcohol. In order to speed things up I put the whole shebang (minus the spoon of course) into a microwave for 10 seconds. This worked like a charm. I had a nice yellow alcohol and all was good.


Then the question is what to use as my chromatography plate... well, simple is good so I wanted a thick paper substrate. I had just the thing.


I hope that isn't illegal. If it is, I guess I'll just take one for science. This went into the "liquor" of my leaf, alcohol mixture and guess what. Things started happening:


Bands of color are even showing up!

I'm guessing this would probably work better with leaves that are more fully red, at least in terms of the number of colors you would see in the chromatography, but it's still pretty awesome... at least to me. I wasn't too happy with the intensity of the bands, so I let it sit in the liquid over night (8ish hours) and check it out:

That is totally sweet. Science in action. Home-brew style.

1 comment:

Becky Swanson said...

You are awesome and very entertaining. I think you missed your true calling as a science teacher and I thank you mightily for helping me make science fun!