CLAW At-Home Experiment: Paper Chromatography of Food Dyes and Ink
At a Glance
Discipline
- Chemistry
- STEM
Instructional Level
- College & CEGEP
- University
Course
- Organic Chemistry 1
Tasks in Workflow
Social Plane(s)
- Individual
Type of Tasks
- Analyzing
- Writing
- Experimenting & conducting inquiry
Technical Details
Useful Technologies
- Equipment (e.g., chromatography paper, commercial food colouring)
Class size
- Medium (50-99)
Time
- Single class period (< 90 mins)
Instructional Purpose
- Exploration & inquiry
Overview
In this CLAW (Chemistry Laboratory Alternative Work) At-Home experiment, students will perform an experiment using household chemicals and materials. It was designed as a substitute for in-person laboratories, usually performed at the college level, during the COVID-19 pandemic. However, it may also be used as an experiment that students can carry out in the lab or for student projects.
Instructional Objectives
The objective of this at-home experiment is to identify the food, drug, and cosmetic (FD&C) dyes found in food/beverage samples (such as Kool-aid, Gatorade, popsicles) or water-soluble markers, using the paper chromatography technique. Determination of the retention factor (Rf) values of the dyes found in the samples and comparison with those of known commercial sources will be carried out in this at-home experiment.
Workflow & Materials
Activity Workflow
Contributor's Notes
Benefits
Challenges
Tips
Benefits
- This hands-on home experiment is an engaging way to manipulate and measure chemical compounds outside an official laboratory set-up;
- Experimental data recorded by the students can be analyzed to perform calculations and write a complete lab report.
Challenges
- It may be difficult to estimate the time needed for students to complete this activity at home.
- Gathering of chemicals and material usually carried out by a technician must be done by each student;
- It may be difficult for students to find chromatography paper, so consider having the college provide one sheet to each student.
Tips
- The list of chemicals and material necessary for the experiment should be given to students as soon as possible to make sure they have the time to purchase and gather the needed items;
- Use the commercial “Club House” dyes of the regular colours or the neon dyes. If a different brand is used, contact the company to ask them which FD&C compounds are present in their food colourings;
- After the chromatography paper has been removed from the developing chamber, dry it until it is slightly damp using a hair dryer (do not use a flame), then allow to air dry overnight. If the chromatogram is not dry, it is possible that the solvent may continue to migrate. If this happens, the solvent front must be re-traced as it has moved from its original spot;
- If a ¼ teaspoon measuring spoon is not available, use a ½ teaspoon or full teaspoon, but the volume of water used should be adjusted for the proper dilution.
Additional Contributors
- Yann Brouillette, Dawson College
- Nadia Schoonhoven, Dawson College
Applied Strategies
Published: 16/07/2020
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