Forensic Chromatography of American Junk Food Dyes

The Lore / Historical Context

Look at the vibrant colors of American sports drinks, candies, and cereals. These striking colors are rarely natural; they are created using complex, homogeneous mixtures of synthetic petroleum-based dyes like FD&C Red 40, Yellow 5, and Blue 1. Because some synthetic dyes have been linked to health concerns, the FDA strictly regulates exactly which dyes can be consumed.

However, international supply chains are messy, and sometimes illegal or toxic dyes (like Rhodamine B) are secretly mixed into imported foods. Food chemists act as detectives, using a physical separation technique called chromatography to tear these mixtures apart.

By forcing the dyes to race across a specialized material, chemists can isolate and identify every single hidden molecule based on its chemical polarity.
Inquiry Challenge: Separate the mystery candy mixture and mathematically calculate the Retention Factor (R_f) for each color band (R_f = distance of dye / distance of solvent). Compare your calculated R_f values against an FDA database to prove whether the candy contains illegal, unapproved food dyes.