MATERIALS AND METHODS

MATERIALS REAGENTS

Distilling flask (250ml)

Erlenmeyer flask (250ml)

Graduated cylinder (50ml)

Separatory funnel (250ml)

Test tubes

Clamps

Rubber tubing

Adaptor

Condenser

Filtration funnel

Watch glass

Red litmus paper

Ice bath

Filter paper

Iron ring

Spatula

Ground cloves

Distilled water

Hexane

NaOH (10% w/v)

HCl (6.00 M)

Anhydrous Na2SO4

NaCl

1% FeCl3

Bayer’s Reagent

Table 1. List of materials and reagents used

Part I: Distillation of Cloves

A 5.00g sample of ground cloves weighed on an analytical balance was wrapped in a filter paper tied to a

string about 10 inches long, similar to a tea bag. The filter paper with ground cloves was immersed in a distilling flask

with 75.0ml of distilled water. A distillation set-up was assembled as shown in Figure 1 below.

Figure 1. Distillation set-up

After turning on the water supply, the water was allowed to boil. 50.00 ml of distillate was collected from the

steam distillation process. The temperature of the steam was noted every after 5.00ml of collected distillate.

thermometer

water out

water in

graduated cylinder

Bunsen burner

condenser

adapter

distilling flask w/ cloves

Iron stand

Iron clamp

clamp here

Part II: Active Solvent Extraction and Characterization

The collected 50.00 ml of distillate was transferred into a 250-ml Erlenmeyer flask to which 3.0g of NaCl was

added to, and was swirled until dissolved. The distillate with NaCl was cooled in an ice bath before transferring in a

250-ml separatory funnel.

25.0 ml of Hexane was added in the separatory funnel. The funnel was shook with occasional venting in

order to release pressure build-up. After 5 minutes of shaking, there were two layers formed. A set-up for the

separation of layers was prepared and is shown in Figure 2 below. The bottom aqueous layer was discarded, having

only the upper organic layer left inside the funnel.

Figure 2. Separation set-up

Afterwards, 25.0ml of 10% NaOH was added, repeating the same shaking and venting process for five

minutes. This time, the bottom aqueous layer was separated to a 250-ml Erlenmeyer flask, discarding the upper

organic layer.

The aqueous layer was cooled in an ice bath and acidified using enough 6.00 M of HCl. The acidity was

tested using a red litmus paper. The acidified aqueous layer was placed back in the separatory funnel.

25.0 ml of Hexane was added, repeating the same shaking and venting process for five minutes. The bottom

aqueous layer was discarded, and the upper organic layer was transferred to a 250-ml Erlenmeyer flask.

A small amount of anhydrous Na2SO4 was added to the obtained upper organic layer. The hexane extract

was filtered.

Separatory funnel

iron ring

RESULTS AND DISCUSSION

The steam’s temperature was recorded every 5.00ml of distillate was obtained in the distillation process.

After 50.0ml of collected distillate, the temperature every 5.00ml of collected distillate is summarized in Figure 3.

Figure 3. The temperature of steam every 5.00ml of collected distillate

Figure 3 shows that after collecting 50.00ml of sample, the temperature remains constant at 98°C every 5.00mL

of collected distillate.

The collected eugenol underwent two qualitative tests. In reaction to potassium permanganate, the eugenol was

observed to have a purple discoloration and slowly turning into brown. This indicates the presence of an

alkyne/double bond structure in the collected eugenol sample. (Jason)

FOLLOW-UP QUESTIONS AND APPLICATIONS

1. Draw the structures of eugenol, eugenol acetate, and caryopyllene and explain the basis of separation of

eugenol from the other components in clove oil.

Eugenol Eugenol acetate Caryopyllene

Figure 4. structures of eugenol, eugenol acetate and caryopyllene (Jeffers, J.)

Tem

pera

ture

in °

C

Volume of distillate collected in ml

2. What is the temperature of volatilization of eugenol? Is this higher or lower than the actual boiling point of

eugenol and why?

The temperature of volatilization of eugenol is almost but not higher than 100°C. The actual boiling point of

eugenol is 254°C, making the temperature of volatilization much lower than its boiling point. Volitile compounds such

as eugenol decompose at very high temperatures. Steam distillation avoids very high temperatures to distill eugenol

at its temperature of volatilization, which is 98°C in this experiment. (Cebrian, p.19), (Jeffers, para. 3)

3. What are the biological and pharmacological properties of eugenol?

Eugenol is used as an insect attractant, UV absorber, analgesic, biocide, and antiseptic. It is also used as a

surgical dressing when mixed with zinc oxide. In dentistry, eugenol is used in making filling materials, dental cements,

and sealers. (Primary info, n.d.)

4. Illustrate the reaction between eugenol and FeCl3. What is the implication of this reaction?

Figure 5. Reaction of Eugenol to Ferric chloride (FeCl3)

The ferric chloride test is used to determine the presence of a phenol structure in a compound. Change in

colorations such as turning blue, red, green, or purple shows that phenol is present. (Cebrian, p. 20)

5. Illustrate the reaction between eugenol and Bayer’s reagent. What is the implication of this reaction?

Figure 6. Reaction of Eugenol to Potassium permanganate (KMnO4)

Bayer’s test using Bayer’s reagent or potassium permanganate (KMnO4) is used to test unsaturation or the

presence of alkyne structures or double bonds. (Jason, 2007)

REFERENCES

Cebrian, T. (2007). Isolating Clove Oil from Cloves Using Steam Distillation. Chemistry Lab Experiment Packet.

Retrieved from University of California Santa Cruz website on December 8, 2012 in

http://seattlecentral.edu/faculty/ptran/bastyr/Summer%2008/organic/packet%20org%20chem.pdf

Jason. (2007). What is Baeyer’s test?. Message posted on October 22, 2007. Retrieved from University of Illinois

Department of Physics website on December 8, 2012 in http://van.physics.illinois.edu/qa/listing.php?id=505

Jeffers, J. (n.d.). Isolation of Clove Oil from Cloves, a Natural Product Extraction. CHM220 Steam Distillation and

Extraction Lab. The Modular Laboratory Program in Chemistry, Tech 722. Retrieved from Kalamazoo Valley

Community College website on December 8, 2012 in

http://classes.kvcc.edu/chm220/Clove_Oil_Extraction/prelab/introduction.htm

Primary Info. (n.d.). Eugenol: Information @ a Glance. Retrieved from Primary Information Services website on

December 8, 2012 in http://www.primaryinfo.com/scope/eugenol.htm