May 14 - Happy Birthday, Mikhail Tsvett

Posted on May 14, 2021

Key Points

This is an update of my post published on May 14, 2010:

This Russian botanist (plant scientist), born on this day in 1872, discovered chromatography. He was trying to separate a mixture of plant pigments that were very similar to each other. One method he tried was trickling the mixture through a glass tube packed with calcium carbonate powder. As the liquid trickled down through the powder, each kind of pigment stuck to the powder with its own unique amount of strength. This created a series of bands (or stripes), and each band was a different pigment.
Using his new technique, Tsvett discovered several new plant pigments. He named the technique chromatography, he called the resulting bands a chromatograph, and he called the new pigments carotenoids.

Although Western scientists did not discover Tsvett’s work for 30 years, his technique is now used all over the world.

Felt Pen Chromatography

This will work with any water-based felt-tipped pen, but it’s most fun to use a bunch of different brands of black markers. (Again, remember, they have to be water-based markers! Don’t use Sharpies or other permanent markers!)

I did a similar experiment several times using coffee filters rather than blotting paper.

Chalk Chromatography

Test red, yellow, green and blue food coloring to see if they are made of various substances. Instead of using coffee filters or blotter paper, use white chalk. At the end of the experiment, you will have cool-looking chalk with a colorful outer decoration.

Get instructions here.

Leaf Chromatography

Squeeze some “leaf juice” onto the coffee filter to test for pigments in plant leaves. This experiment is more like Tsvett’s original research. Get instructions here.

T-Shirt Chromatography

Get an old (or cheap-and-new) white T-shirt for this activity. This time, use alcohol rather than water, and permanent markers rather than water-based ones. Follow the instructions carefully to make a unique Tee to wear.

Chromatography as Art

Did You Know…?

Forensic science (crime-scene investigation) can involve chromatography to see what type of pen was used in a crucial piece of evidence. Unfortunately, the test would tend to destroy the evidence—so I’m sure that CSI scientists test only part of a small part of the message, letter, or other ink sample.