Introduction Eugenol is a naturally occurring chemical that has medical applications such as its use as a natural dental anesthetic. It can be extracted from cloves by using the method of steam distillation. The extracted compound will then be separated from the water using methyl chloride, which will then be evaporated using a rotary evaporator leaving only the essential oil, Eugenol. IR spectroscopy will be used to determine the structure of the extracted compound. Results and Discussion Four samples of Eugenol were combined to be analyzed for the final product.
A lower percent recovery, as indicated by Table 1 could be due to the fact that much of the weight of the cloves was not actually eugenol. Cloves Used| Eugenol Recovered | Percent Recovery| 10 g| 7. 304 | (7. 304/40) x 100% = 18. 26%| Table 1: Calculations of the percent recovery of Eugenol. Figure 1: The structure of Eugenol. The IR spectroscopy run on the sample gave results as shown in Table 2. The –OH stretch accounts for the hydroxyl group on the aromatic ring as shown in Figure 1.
The C-H peaks are from the mexthoxy group on the aromatic ring. The C=C-H are a result of the hydrogen’s bonded to the carbons of the aromatic ring. The peak from the C=O stretch is not from the compound, but may be a result of product contamination. Absorbance | Shape| Intensity| Group-motion| 3512. 21| Broad| Weak| H2O or –OH stretch| 3072. 52| Sharp| Medium| C=C-H stretch| 2948. 85| Broad| Strong| C-H stretch| 2845. 80| Sharp| Medium| C-H stretch| 1767. 18| Sharp| Weak| C=O stretch| Table 2: IR Table of sample taken.
Experimental Extraction of Eugenol began by taking 10 grams of cloves and placing them in a 250mL round bottom flask. This flask was then attached to a steam distillation apparatus and heated to the boiling point of about 100°C. The steam was condensed and collected in a graduated cylinder. This collected material consisted of water and the eugenol contained in the cloves. 100mL of the product was collected and placed into a separatory funnel. The eugenol now had to be removed from the water by adding 15mL of CH2Cl2 and shaken.
The layers were allowed to separate. The CH2Cl2 layer was more dense than water and sank to the bottom of the funnel. The bottom layer was collected and another 15mL of dichloromethane was added to the funnel to repeat the process. This was repeated yet again to obtain a final amount of 45mL of dichloromethane with eugenol dissolved in it. The 45mL of product was moved to a 100mL Erlenmyer flask. The next step was to dry the mixture with 0. 5g of CaSO4 to remove any excess water in the mixture.
The flask was swirled to allow for the CaSO4 to collect any water. The product was then allowed to rest and was put through a filter to remove the CaSO4. Once filtered, four different samples were collected in a single 500mL round bottom flask. This product was then placed onto a rotary evaporator to evaporate away all of the dichloromethane and leave behind only eugenol. This was achieved because the boiling point of the dichloromethane was much lower than that of eugenol. The final product was then analyzed by IR spectroscopy.