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Title: Decrappeinate It

Authors: Matthew Leets, Julie McElhaney and Denise Wilkinson


Background:
The process of decaffeinating foods uses a variety of chemicals that leave trace amounts in the food product while leaving a tremendous amount of toxic waste that needs to be disposed of. The current lab gives awareness to students that consume decaffeinated products of their chemical consumption as well as the environmental hazards. By greening the lab we are able to reduce the hazardous exposure to the students and the environment.
Economic and technological concerns have kept these hazardous methods in use. Applying green chemistry, a safer, healthier and more profitable process may be implemented. Through this project we hope to achieve a method that meets these criteria.


A: Replacing chloroform from current decaffeination experiment with ethyl acetate

B: Swiss Water Method of Decaffeination
This uses only water and no chemicals to extract caffeine. This procedure is very long and tedious.

C: CO2 extraction, limonene experiment

A. supply list:

- 3g of food to be decaffeinated
- separatory funnel
- 30ml ethyl acetate per food product tested
- 1.5ml 6M NH3 per food product tested
- 1.5ml distilled water per food product tested
- 1 evaporating dish per food product tested
- 2.5ml .2M H2SO4 per food product tested
- filter paper and filter for gravitational filter per food product tested
- 10 drops iodine test solution per food product tested

B. supply list:

C. supply list:




12 principles to be addressed in this lab:
1- Prevent waste
2- Design chemical products that are safer
3- Less hazardous chemical synthesis
4- CO2 is reusable
6- Avoid chemical derivatives
8- Safer solvents
11- Eliminating formation of by products
12- Decrease severity of potential accidents


Progress:

- 10/28/08 – Caffeine extraction experiment was attempted. The food products were mixed with ethyl acetate and ammonia then placed in a separatory funnel and left for 24 hours.

- 10/29/08 – The samples were drawn from solutions and placed in drying dishes to allow for the evaporation of ethyl acetate and ammonia leaving behind caffeine.

- 10/31/08 – The final steps including the addition of H2SO4 and iodine test solution along with spectroscopic analysis were done. The experiment was completed. The process of replacing the chloroform with ethyl acetate for the purpose of decaffeination was successful. The experiment was successful with a variety of food products. Food products used were cola, baking chocolate powder, ground coffee and tea leaves. It was unsuccessful at determining the exact concentrations of caffeine extracted. It was determined that chocolate and soda produced the greatest yield of caffeine while the tea produced the least amount of caffeine yield.








Current High School Lab that we are greening:
testing for caffeine in coffee

day 1-perform this experiment in the ventilation hood
1. weigh 3 g of freshly ground coffee. Place into 125 ml separatory funnel.

2. in the ventilation hood, add 30 cm3 of chloroform to the separatory funnel. Caution, avoid inhaling the chloroform vapors. After handling, wash hands thoroughly. Stopper the funnel and let stand for 3-5 minutes (vent occasionally).

3. add 1.5cm3 of 6M NH3 and 1.5 cm3 de-ionized water to the separatory funnel.

4. shake the separatory funnel under the ventilation hood for a total of 20 minutes. Vent as needed. (hold the funnel in such a way as to have the stopper between two fingers. You can feel the pressure building as the chloroform vaporizes. Don’t wait too long to crack the seal on the stopper (“venting it”) to relieve the pressure.) Avoid breathing the chloroform vapors. After 20 minutes of shaking suspend the separatory funnel in an iron ring clamped to a ring stand. let stand over night in the ventilation hood. Angle the stopper in the funnel so that it is not sealed.

day 2-perform this experiment in the ventilation hood
5. shake again for 20 minutes venting as needed. Separate about 20 cm3 of chloroform solution into a small beaker or evaporating dish and allow the chloroform to evaporate overnight.

day 3-perform this experiment in the ventilation hood
6. treat the residue with 2.5 cm3 of .2M H2SO4 stirring continuously. Use a hot plate and heat gently. The caffeine solution should not become warmer than 50oC. allow the caffeine solution to cool to room temperature then filter. Finish with either a. or b. below
a. 10 drops of iodine test solution added to the cooled solution should result in a brown precipitate indicating the presence of caffeine…or

b. evaporating the caffeine solution should result in the formation of caffeine crystals which can be further analyzed spectroscopically


MSDS:
ethyl acetate: http://www.jtbaker.com/msds/englishhtml/e2850.htm
.2M H2SO4: http://www.jtbaker.com/msds/englishhtml/s8231.htm
NH3: http://www.jtbaker.com/msds/englishhtml/A5916.htm
Iodine test solution (lugol's solution): http://www.jcrows.com/lugolsmsds.html


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