Method of Visual Color Inspection Equipment  8 3-oz paper cups  60-mL syringe

Method of Visual Color Inspection
Equipment
 8 3-oz paper cups
 60-mL syringe
 Measuring cup (Preferably 1 cup total size but 2 cup will also work.)
 Large container (Ideally one that can hold slightly more than 2 quarts of liquid.)
 Strawberry Kool-Aid packet
 Red-Colored Beverage (e.g. Gatorade)
 Spoon or fork
 Paper towels
 Distilled water (Tap water is also okay)
Safety Notes
 Distilled water is a health hazard if consumed in large quantities because it can throw
off your body’s electrolyte balance. Do not consume it as you would regular water.
 Red 40 is an FDA approved food-additive, however, some individuals may exhibit
sensitivity to Red 40 if it is consumed. As with all experimental materials, avoid
consuming it and dispose of unused stock promptly. Red #40 can also stain clothing and
skin, avoid contact to reduce the risk of staining.
Disposal
Red 40 standard solutions and beverage samples can be disposed of down any sink drain. Be
sure to maintain good chemical hygiene- do not dispose of ANY waste materials by consuming
them.
Procedure
Cleaning the Syringe
1. Fill a clean, dry 5-oz paper cup with distilled water. (This is your water reservoir for the
experiment, refill this as needed.)
2. Use the water to rinse your syringe by pulling water up into the syringe and then
emptying the syringe. Repeat this 3-5 times.
Creating 100 ppm Dye Stock Solution
1. Empty the entire packet of red Kool-Aid into a 1 or 2 cup measuring cup.
2. Add water to a final volume of 1 cup. Mix thoroughly with a spoon or fork.
3. Use your syringe to draw up 5.0 mL of the concentrated solution you just made (i.e. 1
packet red Kool-Aid in 1 cup water) and dispense it into a 3.0 oz cup. Add an additional
35.0 mL of water to make a total volume of 40 mL of solution. This is your 100 ppm
stock solution.
Creating Visual Standard Solutions
1. Set out and label separate 5-oz cups for each standard solution (2 ppm, 4 ppm, 6 ppm, 8
ppm).
2. Fill the 60-mL syringe with the 100 ppm Kool-Aid standard.
3. Use the syringe to carefully drip in Kool-Aid standard to your 10-mL graduated cylinder
until the liquid is at the 1.0 mL mark on the cylinder.
4. Slowly add distilled water to the same 10-mL graduated cylinder until the total volume is
10-mL.
5. Pour the contents of the 10-mL graduated cylinder into the cup labeled 2 ppm.
6. Use your 50-mL graduated cylinder to add an additional 40 mL of water to the cup.
(Now you’ve got 50 mL total volume in the cup.)
7. Repeat steps 8-11 three more times but replace the 1.0 mL of Kool-Aid standard with
2.0 mL, 3.0 mL or 4.0 mL of the sample to make the 4 ppm, 6 ppm and 8 ppm standards
respectively.
Preparing Sample Solution
1. Label 3 5-oz cups with the name of the beverage you are testing.
2. Wash the syringe and 10-mL graduated cylinder by filling them completely full of
distilled water and then emptying them. Repeat this step three times. [Shake to dry, just
get the major droplets off, don’t worry about the tiny bits of water left over.]
3. Fill the 60-mL syringe with the red beverage you’re testing.
4. Add 2.5 mL of your chosen red drink to the 10-mL graduated cylinder.
5. Slowly add distilled water to the same 10-mL graduated cylinder until the total volume is
10 mL
6. Pour the contents of the 10-mL graduated cylinder into the cup labeled with your drink
sample name.
7. Use your 50-mL graduated cylinder to add an additional 40 mL of water to the cup.
(Now you’ve got 50 mL total volume in the cup.)
8. Repeat steps 4-7 until you have three samples to test.
Visual Comparison of Sample to Standards
1. Place the first cup containing your diluted drink between the 2 ppm and 4 ppm
standard. Note if the sample is darker or lighter than each standard.
2. Repeat this process by placing the sample between the 4 ppm and 6 ppm sample and
the 6 ppm and 8 ppm sample. Note if the sample is darker or lighter than each standard.
3. The concentration of your diluted sample is between the last sample it is darker than
and the first sample it is lighter than. Record which solutions these are.
4. Repeat steps 1-3 for your other 2 replicates.
5. Because you diluted your drink sample, we have to correct for the dilution when
reporting values. The true concentration is 20-times larger than the diluted sample. To
correct for the dilution, just multiply the high and low concentration values by 20. (For
example, if your low standard was 2 ppm and high standard was 4 ppm, your sports
drink originally had between 40-80 ppm of dye before you diluted it.)
Cleanup
1. Wash the syringe and graduated cylinders by filling them completely full of tap water
and then emptying it. Repeat this step three times.
2. Repeat the washing process with distilled water another three times. (This will prevent
hard water deposits.)
3. Carefully remove the plunger from the syringe and rinse it with distilled water.
4. Allow the syringe and gradated cylinders to dry on a paper towel.
5. Once they are dry, store equipment in a safe location for future experiments