You'll need:
As the solvent travels up the paper, it will bring the ink with it. If the ink is made of multiple components, these will separate.
Chromatography is used to help separate something into components. For example, if you have a sample of ink from a message, you can use chromatography to compare it to other inks to figure out which type of pen wrote the message.There are many types (gas, liquid, thin layer, and paper) but this technique is paper chromatography.
The paper is called the stationary phase, and the solvent is called the mobile phase. The substances affinity to each phase is what determines how far up the page the compound moves. Since "how far up the page is relative" - you could let the ink sit a long time in the solvent so the ink has more opportunity to be in the mobile phase - a better way to compare is needed. This is called the Rf value. The formula is Rf = [distance traveled by compound]/[distance traveled by solvent]. Comparing Rf values allows you to compare different substances. If two substances have different Rf values then they are obviously different. However, just because the Rf values are the same doesn't mean the substances are.
One compound will have different values in different solvents. To verify two inks are the same, do chromatography with more than one solvent.
- absorbent paper (paper towels will work)
- a solvent (water, rubbing alcohol, or vinegar)
- pens/markers - these depend on what solvent you're using. For example, Sharpies are alcohol based, so this won't work if you are using water. Common water soluble brands are Pilot, Foray, and Uni, but there are many more. Washable markers tend to be water soluble.
As the solvent travels up the paper, it will bring the ink with it. If the ink is made of multiple components, these will separate.
Chromatography is used to help separate something into components. For example, if you have a sample of ink from a message, you can use chromatography to compare it to other inks to figure out which type of pen wrote the message.There are many types (gas, liquid, thin layer, and paper) but this technique is paper chromatography.
The paper is called the stationary phase, and the solvent is called the mobile phase. The substances affinity to each phase is what determines how far up the page the compound moves. Since "how far up the page is relative" - you could let the ink sit a long time in the solvent so the ink has more opportunity to be in the mobile phase - a better way to compare is needed. This is called the Rf value. The formula is Rf = [distance traveled by compound]/[distance traveled by solvent]. Comparing Rf values allows you to compare different substances. If two substances have different Rf values then they are obviously different. However, just because the Rf values are the same doesn't mean the substances are.
One compound will have different values in different solvents. To verify two inks are the same, do chromatography with more than one solvent.
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