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How Much Food Dye is in a Sports Drink?Lab 4: Jamie Caylor, Grace Michel, Riley Tracy, and Makena WintonTA Jonathan BelnapWednesday, October 23rd 2019, 4:30PMIntroduction:
As production of food dye has increased in recent years, they are found in many everydayfoods, but they are most abundantly found in various sodas and energy/sports drinks. The most common dyes used in these beverages are Red #40, Blue #1, Yellow #5, and Yellow #6. In this experiment, it was determined what the unknown concentration of the dye in a sports drink was by generating a calibration curve from solutions with known amounts of dye, which was achieved by using a combination of various techniques in the lab. Spectroscopy, which is the focus of how matter interacts with electromagnetic radiation, when related to spectrophotometry, measures how much light a colored sample absorbed, thus becoming possible to identify the concentrations of a mixture with two components. This is identified by the colorimeter, which measures the concentration of any colored substance in a solution by measuring the amount of light that is able to pass through it. Light is a way of measuring how concentrated or pigmented asolution is because as it becomes more concentrated, more light will be absorbed and less light will be transmitted for the colorimeter to measure. Thus, in order to obtain the most accurate results, the best wavelength to measure each dye sample must be determined. This is done by using the colorimeter to find at which wavelength there is maximum absorbance or minimum transmittance. Along with these techniques, the Beer-Lambert Law was fundamental in allowing for the concentration of dye in the solution to be known. This law is shown by the equation A=Elc, where A is the amount of light absorbed by a colored sample, E is the molar absorptivity constant (L/mol*cm), l is the length of the path (cm) or the distance of the solution that light must pass through, and c is the concentration of the solution (mol/L). This law’s equation relates to the experiment because when comparing a series of known concentration solutions to a samplewith an unknown concentration, the law states that the amount of light absorbed by a substance that is dissolved in a solvent is directly proportional to the concentration of said substance and
the path length of the light in the solution. After obtaining the data measured by a colorimeter, and the concentration of all the standard solutions have been determined by using the appropriatewavelength, then the Beer-Lambert Law is applied.When graphing the data of this experiment, it is labeled as the absorbance vs. concentration of each solution. When graphed this way and the equation of the line (y=mx+b) is related to the Beer-Lambert equation, a calibration curve is created. Once the calibration curve is made, it is then used to determine the unknown concentration of the sports drink sample by comparing this curve to that of standard solutions.