I. PURPOSE OF EXPERIMENT
The purpose of this Lab is to use spectroscopy create graph to determine the concentration of dye in a sport drink, by creating series of standard dilutions of an FD&C Blue 1 Stock solution and measuring the percent transmittance of each dilutions. Results in each dilutions will be use, to determine the linear function among various functions (T, T%, log T, - logT) For a Beer’s law calibration curve. The produce provides a model for guided-inquiry analysis of the concentration of food dye(s) in sports drinks and other consumer beverages.
II. MATERIAL USED
Beaker, 500-mL, 1
Pipets, serological, 10-mL, 2
Cuvets, 13 × 100 mm , 1
Sample of consumer sports drink (Gatorade Blue), 10-mL
FD&C Blue 1 stock solution, 50-mL
Distilled Water , 100 mL
Test tube rack
Logger Pro 3.8.7 Software
STEP 1. Turn on laptop and open Logger Pro 3.8.7.
STEP 2. Turn on spectrophotometer and connect it to laptop, warm up for 15 minute. STEP 3. Set up an appropriate data to record measurement and the results of calculations as shown below. Beaker
7.0 × M
4.2 × M
2.8 × M
2.1 × M
1.4 × M
0.7 × M
STEP 4. Obtain 50 mL FD&C Blue 1 stock solution in 100 mL beaker, Label it “A”. STEP 5. Place 7 small, clean, dry 100mL beakers and label them B through H. Add the amount of stock dye solution and distilled water according to table below. Use a 10mL graduated cylinder to carefully measure the prescribed volume of each stock solution. After adding the stock solution to the beaker and without rinsing the cylinder, use a wash bottle to add the volume of distilled water. Solution
STEP 6. Obtain 10 mL of Gatorade in 100 mL beaker, Label Gatorade. STEP 7. Rinse the empty cuvet with a small amount of the first sample to be measured, starting with the most dilute sample (H). Fill the cuvet 2/3 full with this solution and place it in the sample holder. Read the absorbance and record the concentration in the data table. STEP 8. Measure the absorbance of the remaining five samples in order of increasing concentration, following the procedure in step 7. STEP 9. Rinse the cuvet with small volumes Gatorade sample. Fill the cuvet 2/3 full and analyze the unknown solution as done previously. STEP 10. Fill up the data record table and graph the following table Concentration v. %T -Concentration v. T
Concentration v. logT -Concentration v. -logT
STEP 11. Determine the Linear function of graph by Calculator to find the concentration of Gatorade.
IV. DATA AND OBSERVATION
Data Table 1
Graph 1.Concentration v. %T
Graph 2.Concentration v. T
Graph 3.Concentration v. logT
Graph 4.Concentration v. –logT
V. DATA ANALYSIS
Among graph 1-4, Graph 4 Concentration v. –log T is the most likely to be Linear function
Calculate linear function by using TI-84...
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