Chromatography of Food Dyes
Peter Jeschofnig, Ph.D. Version 42-0148-00-01
Lab Report Assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.
Observations
Enter data tables, observation questions from the Procedures and descriptions of diagrams to be drawn or pictures to be included here, one per text box.
Data Table Sheet 1: FD&C Food Colors
ColorBlue1Blue2Red3Red40Yellow5Yellow6Solvent
Distance (mm)
Rf
Data Table Sheet 1: Drink Mixes
SubstanceKool-Aid® GrapeKool-Aid® StrawberrySolvent
Distance (mm)
Distance (mm)
Rf
Data Table Sheet 2: Store Food Colors
SubstanceStore RedStore YellowStore GreenStore BlueSolvent
Distance (mm)
Rf
Data Table Sheet 2: Candy Colors
SubstanceM&M GreenM&M YellowM&M BlueM&M RedSolvent
Distance (mm)
Rf
Questions
A. Why can’t a pen be used to draw the baseline on the chromatography paper?
B. Why is it important to stop the chromatograph before the solvent reaches the top of the paper?
C. Why is it important to keep the dye spots above the solvent level?
D. Why is it important to mark the solvent level on the chromatography paper when you remove it from the petri dish?
Extra credit and/or extra fun possibilities: Experiment with different solvents such as pure water, rubbing alcohol, or a mixture of alcohol and water. Do not use flammable solvents to experiment! There are often interesting dyes making up the colors of marker pens (especially black). If you want to experiment with marking pens remember not to use permanent ink markers for this experiment.
