By: Avani Reddy
Ever wondered why candies are different colors? Ever wondered why candies are different colors? Many candies contain colored dyes. Bags of M&Ms or Skittles contain candies of various colors. The labels tell us the names of the dyes used in the candies. But which dyes are used in which candies? We can answer this by dissolving the dyes out of the candies and separating them using a method called chromatography.
Candy Chromatography is the method of analysis of separating and comparing dyes used in candies and food coloring. It is also a proven method to analyze candy and its complex structure, without having to taste it. These complex mixtures can be separated back into pure substances. To find out the ingredients of a favorite candy, chromatography would help to define every ingredient found in the candy sample. The word chromatography is derived from the two Greek words, “Chroma” meaning color and “graphic” meaning to write. Paper chromatography is the best method of separation used in candy chromatography. Paper chromatography is a technique that involves placing a small dot or line of sample solution onto a strip of chromatography paper.. The paper is placed in a jar containing a shallow layer of solvent and sealed. As the solvent rises through the paper, it meets the sample mixture, which starts to travel up the paper with the solvent. This paper is made of cellulose, a polar substance, and the compounds within the mixture travel farther if they are non-polar. More polar substances bond with the cellulose paper more quickly, and therefore do not travel as far. Hypothesis
The same color candies will have the same colored dyes which are used in making the candy. For example, the green skittle will have a green colored dye used in order to make the skittle.
1. M&M or Skittle Candies (1 of each color)
2. Coffee filter paper
3. A tall glass
5. Table salt
6. A pencil
8. A ruler
9. 6 toothpicks
10. Aluminum foil
11. An empty 2 liter bottle with the cap
1. Amount of water
2. Amount of table salt
Independent: Type of dye used
Dependent: Color of the candy
Compare the dyes between the skittles and M&M
1. Cut the coffee filter paper into a 3 inch by 3 inch square. Make six dots with the pencil equally spaced along the line. Below the line, use the pencil to label each dot for the different colors of candy that you have. 2. Next we’ll make solutions of the colors in each candy. Take an 8 inch by 4 inch piece of aluminum foil and lay it flat on a table. Place six drops of water spaced evenly along the foil. Place one color of candy on each drop. Wait about a minute for the color to come off the candy and dissolve in the water. Remove and dispose of the candies. 3. Next we’ll “spot” the colors onto the filter paper. Dampen the tip of one of the toothpicks in one of the colored solutions and lightly touch it to the corresponding labeled dot on your coffee filter paper. Then using a different toothpick for each color, similarly place a different color solution on each of the other five dots. Repeat this process three times, waiting for the spots to dry each time. 4. When the paper is dry, fold it in half so that it stands up on its own, with the fold standing vertically and the dots on the bottom. 5. Next we will make what is called a developing solution. Add ⅛ teaspoon of salt and three cups of water to your 2-liter bottle. Then screw the cap on tightly and shake the contents until all of the salt is dissolved in the water. You have just made a 1% salt solution. 6. Now pour the salt solution into the tall glass to a depth of about ¼ inch. The level of the solution should be low enough so that when you put the filter paper in, the dots...