Lab #11: Determination of the Dye Concentrations in Sports Drinks Objective: The objective of this lab is to determine the concentration of added food dye in sports drinks. To determine this, we will be performing a chemical analysis that measures the absorbance of visual light at an appropriate wavelength by a blue or red sports drink. Procedure: To begin this experiment, we filled up two cuvettes halfway with either water or stick dye solution and we blanked the spectrometer with the cuvette filled with water and then placed the cuvette with the stock dye solution in the spectrophotometer and measured the wavelength of this solution. Next, we placed about 75 mL of the stock solution in the buret and we diluted 5 samples of the stock solution which resulted in measured wavelengths between 0.1 and 1.0. Using this data, we made a calibration curve according to the concentration of the various solutions and their corresponding wavelengths. Then, we obtained a sample of the red-40 drink and diluted it so that the measured wavelength would lie on the middle of the calibration curve and determined the concentration of this dye in the sports drink according to our calculated data. We also calculated the 95% Confidence Interval based on the class data. Results: In this lab, we determined the concentration of various dyes in various sports drinks. The class average for the concentration of B-1 dye in Blue Gatorade was 1.36 X M or 10.77 ppm. The class average for the concentration of B-1 Dye in Purple Gatorade was 2.19 X M or 1.74 ppm.
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- Summer '14
- Chemistry, Gatorade, Dye, Food coloring, Red-40 Dye, b-1 dye