Samantha Sequito and Anna Steenland
Lab Performed: December 3, 2013
Lab Due: December 13, 2013
Different amounts of FD&C Blue I were diluted with water to make eight differently concentrated 10 mL solutions. Samples were placed in the spectrophotometer to determine the percent transmittance of FD&C Blue 1. All of the data was summarized in graphs to predict the concentration of FD&C Blue I in a sample of Gatorade.
FD&C Blue 1 stock solution, 50-mL
Sample of consumer sports drink, 10-mL
Water, distilled or deionized
Beakers, 50-mL, 2-3
Cuvets or test tubes, 13 x 100 mm, 3-8
Kimwipes or lens tissues
Pipet, serological, 10-mL
Pipet bulb or pipet filler
Spectrophotometer or colorimeter
Test tube rack
1) Turn the spectrophotometer on allow to warm up for 15-20 minutes.
2) Based on maximum absorbance of the dye tested, select the appropriate wavelength on spectrometer.
3) Read the entire procedure. Construct an appropriate data table to record measurements and the results of calculations. Note: As part of a cooperative lab activity, your instructor may assign different groups to prepare and analyze different solutions, and to graph the results. Each group will need analyze the results for all solutions in order to complete the guided-inquiry activity.
4) Obtain approximately 50 mL of stock solution containing FD&C Blue 1 dye.
5) Using a serological pipet for accurate volume measurements, dilute the stock solution as indicated in the following table to prepare 10 mL each of a series of standard solutions, B-H. Thoroughly mix each solution. Hint: To avoid contaminating the stock solution, and then measure and add the required amount of stock solution to each test tube.
6) Measure and record the percent transmittance (%T) of the stock solution and each standard solution (B-H) at the optimum wavelength.
7) Convert %T to