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Chemistry In Pictures

Chemistry in Pictures: What's in your ink

by Manny Morone
September 18, 2019


A thin-layer chromatography plate with various colorful inks spotted at its bottom streaking upward as their components are separated.
Credit: Claire Hartmann-Thompson

Claire Hartmann-Thompson is a chemist at 3M, but outside the lab, she and other 3M scientists lead demos for students in grades 1 through 6, showcasing chemistry. In this demo, Hartmann-Thompson introduced chromatography to her son’s elementary school class using a thin-layer chromatography (TLC) plate. The large spots on the plate were made by different pens in the classroom. As a liquid solvent at the bottom of this jar soaks through the TLC plate, it carries some of the pens’ inks with it, making the inks streak and travel upward. What they were seeing was the separation of some of the inks’ component chemicals, which demonstrated—to the class’s surprise—that ink is complex mixture of several substances even though on paper it looks like a pure liquid.

Submitted by Claire Hartmann-Thompson. This photo is part of our Chromatography Contest sponsored by Restek. Enter the photo contest here, or submit your chromatography photo via Instagram and Twitter using the hashtag #SeparationScene.

Do science. Take pictures. Win money. You can also enter our regular monthly photo contest here.

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