Tlc Lab Report Essay

1673 Words Nov 26th, 2012 7 Pages
Separating Substances:
Identifying Food Dyes with TLC

Background

The color of food is an integral part of our culture and enjoyment of life. Who would deny the mouth-watering appeal of a deep-pink strawberry ice cream on a hot summer's day or a golden Thanksgiving turkey garnished with fresh green parsley? Even early civilizations such as the Romans recognized that people "eat with their eyes" as well as their palates. Saffron and other spices were often used to provide a rich yellow color to various foods. Butter has been colored yellow as far back as the 1300s. Food color additives are dyes, pigments or substances that impart color when applied to a food, drug, cosmetic, or the human body. The Food and Drug Administration
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Then, if the wool is placed in a solution of 1M ammonia, the ammonia supplies sufficient OH( to reduce the concentration of the H+ and shift the equilibrium to the left, which releases the dyes.

WOOL + DYE + H+ ( DYED WOOL+

Objectives
By preparing for and performing this experiment, you will: • Isolate they FD&C dyes present in the coating of M&M candy; • Use thin layer chromatography to separate dyes from each other; • Investigate the relationship between molecular structure and retention factor; • Compare your samples to standards; • Identify the dyes present in the various colors of M&Ms.

Red 40 and other dyes are listed on the ingredients of M&Ms candy. In this experiment, you will study samples of M&Ms to determine which dyes are in each colored candy. You will first use acid, wool, and ammonia to extract and isolate the dyes, and then you will run TLC to separate the dyes. If samples containing known FD&C dyes are run as standards, it is possible to identify the dyes used in the candy coatings.

Purpose: Which food dyes are present in the candy coating of M&M candies?

Note: Each student should be responsible for one color. Every color needs to be done by at least two students in each section so there is data to compare. TAs should collect data on the computer or board, and students must have a full set

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