Chromatography is a method of separating out materials from a mixture. Ink is a mixture of several dyes and therefore we can separate those colors from one another using chromatography. When ink is exposed to certain solvent the colors dissolve and can be separated out. When we expose a piece of paper with ink on it to a solvent, the ink spreads out across the paper when the ink dissolves. Some inks are water soluble, so you can use the water as the solvent. Inks which are not water soluble are often alcohol soluble and you can use Isopropyl alcohol as the solvent to create your chromatograph. Different ink pens use different types of ink and this is obvious when you expose him to a solvent. A banding pattern of the components of the ink mixture is called a chromatograph. Follow the instructions below to discover which pen was used to write a note. PREPARATION
1.Gather several black or blue pants
2. Obtain a sample of evidence (have someone use one of the pens to write a note – your job is to figure out which pen they used)
3. Cut several coffee filters into 1/2” strips
4. Set up your chromatograph apparatus. Place a skewer or another long object across two supports. Place a pan underneath the skewer and fill it about 1/2” deep with the solvent (water or alcohol)
PROCEDURE
1. Using a long 1/2” wide strip of your evidence and hang it from the skewer so the end just touches the solvent. Don’t let the ant get wet.
2. Use each of your suspect pens to place a dark spot of ink around 1/4” - 1/2” from the end of each coffee filter strip.
3. Hang these strips from the skewer so that the tips of the strips just touch the solvent.
4. Allow the inks to separate for about 15 minutes
5. Examine the banding patterns and determine which of your known suspect pens is the pain used to write the note.

Questions:
-What do you observe on the filter paper strip after 2-3 hours?
-what conclusion can you draw from this experiment about the components of the black ink?