Chromatography

Are the food colorings used in colored candy the same as the the FD&C approved chemicals?

How many colored spots do you expect to see for each reference standard?

  1. Obtain a 25 cm square piece of chromatography paper that will fit into the beaker that will serve as the chromatography chamber.
  2. Draw a pencil line across the lower end of the chromatography paper about 2 cm from the bottom.
  3. Draw additional vertical tick marks along this line every 2 cm
  4. Place colored candy in a flask with 2 ml ethanol until the color dissolves into the solution
  5. Using an applicator, create a very small spot on a tick mark and allow to dry
  6. repeat application on the spot to make a very small and dark spot
  7. Continue to spot reference standards along other tick marks. These reference standards are food coloring.
    • chromatography_setup
  8. place approximately 1 cm of mobile phase solution (a very polar salt water solution) into the beaker
  9. roll the filter paper into a cylinder and fix with staples
    • chromatography_cylinder
  10. place cylinder into the beaker and cover for 20 minutes or until the mobile phase reaches 2 cm from the top of the paper.
    • chromotagraphy_beaker
  11. Mark the final distance of the mobile phase and dry the filter
  12. Measure the distance of each spot from the starting point
    1. Each spot is a separate analyte.
    2. Some spots separate into multiple analytes.
    3. Measure EACH one
  13. Measure the distance from the starting point to the final point that the solvent reached.
  14. Calculate Rf values and tabulate results.
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