A+ solution uop chm/150 chromatography of food dyes

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.