Skittles or M&Ms are beloved candies! Some people even sort them by color, eating all of the yellows, then the reds, etc. What if I told you that the colors of the candy you see are made of several colors? And that those dyes can be broken down into their individual components?

What Is Chromatography?

Chromatography is a technique used to separate the different, individual components of a substance. You can think of it like a backwards recipe. If you’ve ever made cookies, you likely remember the ingredients used. But if someone handed you a freshly baked cookie you’d never made, you might want to know what ingredients the baker used. You could analyze the cookie to see its different components.

Scientists can do the same thing with a dye or solution. This allows them to see what components make up that substance. The word chromatography is composed of two pieces: chromo meaning color and graph meaning picture. It’s a picture of a color breakdown. You probably know that the colors blue and yellow mixed together make green. Blue dye and yellow dye are components of green dye.

Scientists can break down a solution (or in this case, a dye) to see what it’s made of by watching how its different components travel. We can perform a simple experiment to see what dyes are used in certain candies.

Let’s try it! Download the lab instructions & handout to get started.

What Happened?

Water travels the filter paper like water moves up a stem to nourish its flower. As the water moves, it pulls the colors from the dye along with it. This is called the mobile phase. Different colors are attracted to the stationary paper in different ways, making them travel at different speeds like runners in a race. The result should be a picture of the colors! Voila! Chromatography!

Scientists use chromatography in many ways. By pulling apart the different components of the substance, scientists can analyze various diseases and viruses to help create vaccinations. Environmental scientists can analyze soil samples or test for pollutants. Scientists in medical labs can detect what components are in your blood. Manufacturers use chromatography to make sure that every single piece of their product is consistent. And it’s what makes your candy taste the same every time.

Most of the dyes you see in foods or in fabrics are not just a single dye but a mixture. It makes you wonder what things you see around you are not quite as simple as they seem.

Even these substances follow consistent rules that God made. Science is not just a set of facts, but an understanding of the rules substances follow. So your red M&M’s may not be completely what they seem!