Spectrophotometric Determination of Dye Content in Beverages Rebecca Nagurney and Jillian Grudzinski Advisor: Dr. Pham. Materials and Methods. Results. Abstract.
Spectrophotometric Determination of Dye Content in Beverages
Rebecca Nagurney and Jillian Grudzinski
Advisor: Dr. Pham
Materials and Methods
In this work we determined the amount of dyes in some commercial food products using spectrophotometric methods. We tested red and yellow Powerade drinks which according to the manufacturer contain red #40 and yellow #6 respectively. By applying Beer’s law, we found that the red Powerade contained 0.051 grams of dye and the yellow Powerade contained 0.059 grams of dye per bottle. These amounts may not seem like much; however, because most food products contain dyes the amount of dyes we consume in our diet per year could be rather large. An individual consuming one bottle of Powerade a day is consuming more than 18 g/yr.
The results obtained show that there is a substantial amount of dye in each .946 L bottle of powerade. The amount of dye calculated for the red powerade was 0.051 grams and the amount of dye calculated for the yellow powerade was 0.059 grams.
To test the amount of red and yellow dye in each drink, stock solutions of the red #40 and yellow #5 dyes were made. The stock solution of Red #40 had a concentration of 5.4 x 10-5 , and the Yellow #5 stock solution had a concentration of 5.8 x 10-5. To determine the wavelength that had the highest absorbance level for each dye, a spectrophotometer was used and the dyes were tested across the visible wavelength spectra of 375nm to 700nm. The absorbance values obtained for the stock solutions were plotted on a graph to easily show the lambda max values. Three additional solutions were made for each dye and were tested at the lambda max values obtained from the stock solutions. The absorbance level readings for the four red #40 and yellow #5 dye solutions were plotted on graphs to form the standard curves. The slope of the line of the standard curve was used to find the concentration of the dye in each drink. The powerade drink was the diluted and its absorbance level was measured. The concentrations were then used to find the amount of dye in grams in each bottle of powerade. This was done by using to formula:
(dye concentration (mol/L)) X (L of solution) X (Molecular Mass of dye (g/mol)) X
(L of powerade/L of powerade in the solution) = Grams of Dye
Food dye is included in almost everything we eat. Even food and drinks that claim they are “100 percent natural” contain dye. Artificial food dyes such as Red #40 and Yellow #5 are approved by the FDA; however, some studies prove that these dyes have carcinogenic effects and can cause hyperactivity in children. Dyes are also included in medicine and are used as a way to identify and classify ourselves with familiar items. Other countries besides the United States use all natural resources as food dyes. The coloring that naturally occur in many different fruits, vegetables, and flowers are extracted and used instead of artificial dyes. In this experiment, we obtained the amount of dye in Powerade by using spectrophotometric methods. Different dilutions of red and yellow dye solutions were made and absorbance levels were obtained from 375nm to 700nm wavelengths with 25nm increments.
Most foods we eat contain artificial dyes, but do we really know how much dye we are consuming per year? If a person consumes one bottle of powerade per day for a whole year, that person will be consuming over 18 grams of dye per year just from the powerade. Because most foods that a person eats on a daily basis contains dye , the amount of dye that a person would consume per year is be quite large. Red #40 has a MSDS heath rating of 1 and Yellow #5 has a health rating of 2. If the MSDS health hazard level is that high for handling, how could it be safe to consume even in small amounts? Tests have been conducted on rats that have consumed dye in their water, and each test showed the dye had a negative effect on the rat’s health. Other tests showed that the dyes may have been a cause of cancer and infertility in the rats tested. Soon, food and drink items that contain Red #40 dye will have to place a warning on the label because of the adverse effects the dye can do to a person’s health.
“Material Safety Data Sheet FD&C Red 40 MSDS.” Science Lab. Web. 11 April 2012.
“Material Safety Data Sheet FD&C Yellow 5 MSDS.” Science Lab. Web. 11 April 2012.
Vorhees, Charles V., et al. “Developmental Toxicity and Psychotoxicity of FD and C Red Dye # 40 (Allura Red AC) in Rats.” Toxicology 28.3 (2003): 207-217. Web. 11 April 2012.