How to Test Electrolyte Levels in Sports Drinks

Compare the electrolyte levels in different brands of sports drinks by using gold colloid.

Find out which sports drink quenches your thirst and best replenishes lost electrolytes with gold. Gold nanoparticles in a colloid appear red or purple in their liquid state, but these react with electrolytes by clumping together, causing a color change, according to the University of Wisconsin-Madison Nanoscale Science and Engineering center. Look for gold colloid through chemistry supply outlets or create your own for this experiment using a procedure from the University of Wisconsin-Madison Nanoscale Science and Engineering center. (See Resources.)

Things You'll Need

• 20 ml gold colloid
• 3 disposable pipettes
• 2 different brands of sports drinks
• 3 glass vials (1 dram capacity)

Instructions

1. Use a disposable pipette to deposit seven to eight drops of gold colloid into each vial.

2. Drop one drop of the first sports drink brand into one of the vials with a clean pipette, and swirl the vial to mix.

3. Continue to drop the sports drink, mixing after each addition until the color changes.

4. Note the number of drops required for the color change to occur. Use one of the vials with gold colloid as a base sample for comparison to detect a change in color.

5. Repeat the test using the second sports drink brand, a clean pipette and the second test vial. Note the number of drops before the color in the second vial changed.

6. Drinks with the highest electrolyte levels will change color with the fewest addition of drops.

References

• University of Wisconsin-Madison Nanoscale Science and Engineering Center: Nanogold Sensors to Test Electrolyte Levels

Resources

• University of Wisconsin-Madison Nanoscale Science and Engineering Center: Synthesize Gold Colloid