<p>Name: Paper Chromatography of Food Dyes</p><p>Purpose – To use paper chromatography to separate and identify food dyes in various samples.</p><p>Procedure: 1. Take a strip of chromatography paper and label it with pencil, NOT PEN, as shown below.</p><p>2. Use a different toothpick to place a spot of each of the four food colors on the Xs on your chromatography paper.</p><p>3. Allow the dots to dry for a few minutes.</p><p>4. Pour enough 0.1% NaCl solution into your beaker to just cover the bottom of the beaker.</p><p>5. Roll or fold your chromatography paper so that it will stand on its own. Place your paper in the beaker with the color-spotted end down.</p><p>6. As the solvent “climbs” the paper you should see separation of the dyes. When your solvent reaches almost to the top, remove it from the beaker and allow it to lie flat on the lab table and dry.</p><p>7. Sketch a picture of your results in the space provided.</p><p>8. If you have time, repeat the procedure using black, blue, red, and green Vis-à-vis markers.</p><p>Results: Example Results</p><p>X X X X Red Yellow Green Blue Analysis:</p><p>1. If a food color sample yields a single streak or spot, it is usually a pure compound.</p><p> a. Which food colors consist of pure compounds? ______</p><p> b. Which food colors are mixtures of compounds? ______</p><p>2. On your sketch of your chromatography paper, label each spot or streak with the appropriate color dye.</p><p>3. Paper Chromatography separates polar compounds based on their relative polarities. The most polar dyes migrate the fastest and appear at the top of the paper.</p><p> a. Which dye is the most polar? ______</p><p> b. Which dye is the least polar? ______</p><p>Vis-à-vis Markers</p><p>1. Which Vis-à-vis markers consist of pure compounds? ______</p><p>2. Which Vis-à-vis markers are mixtures of compounds? ______</p><p>3. Which dye in the markers is the most polar? ______</p><p>4. Which dye in the markers is the least polar? ______</p>