I'm a high school chemistry teacher. Students, year-after-year, enjoy the chromatography lab where we analyze ink stains. The technique is so important and so powerful that I want to add a few more simple labs or demonstrations of the analytical power of chromatography. I will probably be limited to paper, thin-layer and/or column adsorbtion methods, using simple equipment and supplies available to high schools. Any suggestions from you professionals? Any good references that you use/used during college or currently? I'd like to hear from you.

one I have used may be too similar to what you are already doing. I get the water soluble markers from different companies and chromatograph these water soluble inks. the eluent is 1% acetic acid in water and the chromatography is done on bloter paper. Be careful to spot only a small amount of ink. The colors that are single component are done first and then the mixed colors, eg brown. Often different compounds are used by different companies. I have a brown where the yellow migrates fastest and another brown where it is slowest. Surprisingly, few students figure out the yellows are different compounds, but when they do it is a good illustration of how chromatography is used.

I hope some other add to this discussion. I am looking for additional demos myself.

Thanks, Bill. Yes, I have used this lab before. Matter of fact, it generally piques the interest of my students, and I always wish I could go further. I am hoping to do some "forensic investigations" of "crime scenes". Possibly grass or plant pigment stains, bark from various trees. I'm looking for anything that I could make a part of a so-called crime scene to lend some mystery and reality to the whole thing! If you hear of others, or think of anything, toss it in my direction. If you wish to give me your e-mail, I'd be glad to send things your way when I get something?

Jim Nigrelli

You should check out the Journal of Chemical Education. It often has simple chromatography experiments that are useful to educators such as yourself.