Science fair project ideas – Quick and easy project #3 - Paper chromatography

Are you thinking about possible science fair project ideas? How about studying Paper Chromatography? In this project, you will study paper chromatography by analyzing ink components in permanent black markers.

The time required for this science project is typically a day or two. Plus, it does not cost a whole lot and chances are you already have what you need lying around your house.

Chromatography has great vale for many different professions and in many different investigational arenas. Police detectives use chromatography for example to recognize clues at crime scenes. A chemistry scientist will utilize chromatography in their lab to keep track of an experiment’s progress. They can readily discover when products begin to accumulate and the exact time that the reactants were used by viewing at the results on a chromatography plate. In the field of biology, scientists also use this process to identify elements that are present in plants or other samples. If you have an interest in chemistry or biology, consider this project as one of your science fair project ideas.

Everything in our universe is made from matter. Solids, liquids and gas are the various kinds of matter. It is often the combination of various substances. If a mixture combines elements that are not alike (like sand), we call the mixture heterogeneous. A mixture that has uniform parts (like milk) we call it homogeneous, and they are referred to as solutions. A cube of sugar sitting in water is an example of a heterogeneous mix. But, the mixture becomes homogeneous when the sugar dissolves into the water.  When a substance gets dissolved into another substance, we call it the solute. The solvent, on the other hand, is the part of the mixture that does the dissolving. In the sugar water example, the sugar is considered the solute whereas the water is considered the solvent. 

In this experiment, you will determine whether the ink contained in a marker is a heterogeneous or homogeneous mixture, or just one compound. You will do this by coloring a small spot of ink on a piece of paper. Then you will place the bottom edge of the paper into water and let the water soak in the paper. 

Science fair project ideas usually require that you get acquainted with basics of the subject you are studying. In this project, it’s important to know that there are two basic principles related to chromatography. There are two phases of chromatography, mobile and stationary.  In this case, the water is mobile and the paper is stationary.  Chromatography uses something called capillary action to work. The adhesion force (the fact that the water will be attracted to the paper) is stronger than the force of cohesion (the likelihood for water to attract itself). That is what makes the water travel through the paper. The ink from the marker will attract to the paper, its own self and the solvent, or water, each differently. The many components of the ink will travel differently depending on their attraction and reaction to the other various elements involved. 

Chromatography is definitely one of the more interesting science fair project ideas, especially if you are interested in detective work.  

What do I need to get going?

 Here are some terms you need to know:

•    the forces of adhesion and cohesion

•    capillary action

•    the phases of mobile and stationary

•    hydrophilic, hydrophobic

•    paper chromatography

•    solvent

•    solution

 Here are some questions you could ask for the project:

•    How come different elements of a compound will travel further than others through the paper?

•    Why is chromatography important?

 The materials and equipment you will need:

•    water

•    about 15 thin pieces of paper that are exactly the same size (5 pieces per pen) NOTE: the best kind of paper to use is chromatography paper but you can also use paper towel

•    ruler

•    pencils

•    three different brands of markers with black ink (make sure one is a permanent marker), or three various colors of ink markers (make one a permanent marker)

•    a jar with a wide mouth to put your solvent in 

What steps are involved in the experiment? 

In order to make your experiment valid, you must keep all of your materials as similar as possible except the one being tested. Everything from temperature and type of water used, the size and type of paper used as well as the location of the ink mark need to be as identical as possible for the duration of the experiment. 

1.    Cut the paper strips into 1-inch by 4-inch squares.

2.    Using a ruler and a pencil, draw a line horizontally across the bottom of one of the strips of paper exactly 2 cm up from the bottom.  This will stand as your line of origin.

3.    Pour a little bit of water into the bottom of a glass.

4.    Choose a marker to start with an d with it, draw a small dot of its ink right on the origin line.

5.    Be sure to label this strip of paper with the marker used so that you can keep track of the results.

6.    Making sure that the paper is just touching the water in the bottom of the glass, tape you strip to a pencil and let it rest on the rim of the glass.

7.    As it sits, the water will creep up the paper until it is just about at the top.

8.    At this time, remove the paper strip from the glass and make a mark to show how far the water, or solvent, has risen. Use the pencil to mark it.

9.    Analyze the various components that make up the ink by measuring the distance the solvent and ink traveled past the place they started.

10.    Repeat the experiment five more times and for all of the different brands or colors of markers you are testing.

  For a variation, test some different solvents besides water and see if different inks will separate differently. Some other solvents you could try are nail polish remover, rubbing alcohol or peroxide. Which solvent allows the ink to separate the neatest? Why? 

For more science fair project ideas, check out the links below. 

Easy Steps to Award-Winning Science Fair Projects