Date: Tue, 28 Jan 97 11:24:58 PST
Message-Id: <v01540b04af13920ce650@[192.174.2.182]>
To: pinhole@exploratorium.edu
From: karenk@exploratorium.edu (Karen Kalumuck)
Subject: Chromatography
To all interested chromatographers:
Spinach is the classic material to use for simple chromatography -
the chlorophylls separate nicely, often even revealing the two types and
the xanthophyll is always a bright yellow band near the solvent front.
I've also used seaweed quite successfully; very fleshy seaweed can
be put in a blender with a very small amount of solvent to provide a thick
homogenate. The browns are great to show that they contain both green and
yellow pigments and if a large amount of pigment extracted from reds algaes
are used, you can often see red pigment in addition to greens and yellows.
The book "The Chemistry of Food Dyes" which we have in the Explo
library, has a very interesting chapter on food dyes and additives;
students can determine which food dye is in a food by comparing "known"
dyes to pigments extracted from foods. The procedure is somewhat involved
but would be great for advanced Bio or Chemistry classes.s
Enjoy!
---Karen Kalumuck