Hexane Extraction Write Up

Hexane Extraction

Purpose: To determine the percentage of diesel fuel within the water sample from Goldstream Provincial Park.

Materials:

- Three water samples

- Hexane

- Separating Funnel

- Test tube (mL)

- Water from the tap

- Scale

Procedure:

Sample 1

1) Weigh the water sample in the test tube

2) Add 100 mL of water to the separating funnel.

3) Add 5 mL of hexane to the separating funnel.

4) Add water sample.

5) Shake the funnel so the liquids mix together.

6) Let the hexane and the fuel with the water sample bond together and give time to let them separate from the water.

7) Drain the water through the funnel into a glass beaker.

8) Put the hexane mixed with the fuel into its original test tube and weigh it.

9) Leave the cap off the test tube in order for the hexane to evaporate.

10) Check on the samples within two days.

11) Weigh what is left of the samples in order to get a percentage of the amount of fuel contained in the water.

Sample 2

Repeat the process outlined for sample 1.

Sample 3

Repeat the process outlined for sample 1.

Conclusion:

The results of this experiment were unsuccessful. Although all the right steps were carried out, the result of the amount of gasoline present after the hexane evaporated was actually a negative value, and, therefore, no percentage of gasoline was found in the water samples we used. One source of error encountered during this experiment was the fact that there was no way to determine when exactly the hexane would have evaporated in order for us to weigh the contents of the flasks before they evaporated as well. Another reason concluded from our value of 0% gasoline content is the fact that the truck had spilled 700L of gasoline and 300L of biodiesel, which was claimed to have evaporated immediately. The trip we took to Goldstream was at least three weeks after the spill had taken place, and therefore, most of what was spilled into the river was likely to have evaporated before we took our samples. Our experiment could lead us to the conclusion that the cleanup (use of booms in the river, etc.) before we arrived on site was actually going quite well. Although it is not easily estimated what the long term effects on the ecosystem will be, based on our results, one may conclude that the ecosystem is looking towards a quick recovery in some aspects.