Phytochemistry lab

1. EXTRACTION OF EUGENOL FROM CLOVE OIL
“Essential oils” are the volatile components associated with the aromas of many plants.1 In this experiment,
the essential oil eugenol (the main component of oil of cloves) will be isolated from ground cloves by steam
distillation and identified by infrared spectroscopy. The principle of steam
distillation is based on the fact that two immiscible liquids will boil at a lower
temperature than the boiling points of either pure component, because the total
vapor pressure of the Po heterogeneous mixture is simply the sum of the vapor
pressures of the individual components (i. e. PT = + A o Po P B, where Po is the
vapor pressure of the pure liquids). During the isolation of a liquid natural
product by steam distillation, water is one of the components, and the liquid
natural product being isolated (which is immiscible with water) is the other
component. The product can be steam distilled from the natural source at a
relatively low o .temperature (always less than 100 oC), thus avoiding decomposition of the product.
Steam distillation can be carried out in two ways: the direct method and the live steam method. In the direct
method, steam is generated by boiling a mixture of the source of the compound of interest and water. The live
steam method is carried out by passing steam from an external source into the distillation flask. The direct
method of steam distillation will be used in this experiment.
Methods And Materials :
Firstly for distillation of clove oil ,5g of whole clove with 50 ml distill water added in round bottom flask and it
couple of boiling chips, then distillation apparatus was collect (Figure 1)
and 100 ml Of graduated cylinder, was added to collect the distillate . After
that it heated by heating mantle until 35 ml of distillate (water + clove oil)
present in graduated cylinder.
Secondly for extraction the distillate transfer to separatoty funnel then
10ml NaCL (as drying organic solution) with 5ml of dichloromethane were
added . And they shaked until two separate layer appeared after that the
aqueous layer in the bottom drain and organic layer transfer into 50 mL
Erlenmeyer flask .Then Na2SO4 as drying agent added then it filtrate .
Finally, dichloromethane and clove oil evaporate for one week then the percentage yield measured
Isolation of eugenol from clove oil: A weighed solution of oil of clove was mix 30 mL dichloromethane in a
separating funnel and 35 mL of 5% aqueous potassium hydroxide(KOH). They shaked until two layer appear
the lower dichloromethane layer extract again in another separating funnel and 20 mL of the aqueous
potassium hydroxide were added (KOH). Then the aqueous layer was used and dichloromethane drain .
After that the two aqueous alkaline extracts the 10% hydrochloric acid (HCL)was added until the liquid is acid
by using litmus. Then the free eugenol Extract from the acidic aqueous layer with 25 mL dichloromethane for
each portions. After that the layers was separate and the lower organic phase was collected in a 100 mL
conical flask.
The water traces removed from the organic solution by shaking with about 1-2 g of anhydrous magnesium
sulphate(MgSO4) it for 10 mins . Finally, organic layer evaporated from dichloromethane (CH2Cl2) and. The
present yield measured of eugenol .
Chemical test of eugenol
To two 2 drops of the sample of eugenol, 5 mL 95% ethanol was added and then ferric chloride solution
dropwise.. the test Repeated with two 2 drops of standard eugenol and the results compared .

2. EXTRACTION OF CAFFEINE FROM TEA
Tea is one of the most commonly used caffeinated beverages in the world. The caffeine (C8H10N4O2) found in
tea is a bitter, white, crystalline methyl xanthine and a member of a class of compounds known as alkaloids .
Alkaloids are basic nitrogen containing compounds present in plants. The
structure of caffeine affects the functions it perform
In order to extract caffeine from tea, several methods are used. First, a
solid/liquid extraction must take place in order to get the solid natural product
into the liquid solvent. This can be done by using a Soxhelet extractor, or by
simply brewing a cup of tea. In order to isolate the desired reaction compounds
from the natural product, liquid/liquid extractions are used. Neutral and
acid/base are two forms of liquid/liquid extractions its used in this experiment .
Caffeine extraction from tea leaves involves an acid/base liquid/liquid extraction
.The reaction involves a homogenous mixture of an organic and aqueous layer. The ideal solvent in the
extraction should have a low boiling point,
A series of techniques were used to extract pure caffeine from tea leaves. The percent error and percent
recovery were calculated to assess how much pure caffeine was obtained, and to account for errors that may
have occurred that led to a loss of product.
Methods And Materials :
Firstly , in 50mL beaker was obtained. Two bag of Lipton tea was added to 25 mL of distilled water. After 5
minutes had passed, the tea bags were squeezed in order to remove excess water. Then it placed in an ice bath
to cool and Na2Co3 was added .The extract was then poured into a separatoty funnel and portions of 10mL
CH2Cl2 were then used to extract the caffeine from the solution. The tube was shaken gently after each portion
was added in order to mix the solvents while avoiding emulsions. One portion was added, and a transfer pipet
was used to remove the bottom layer that contained CH2Cl2 and caffeine and it placed in a 50mL beaker. This
process was repeated two more times for the two remaining portions of CH2Cl2 (dichloromethane. The
dichloromethane organic layer that contained the caffeine was transferred to another 50mL beaker and a
drying agent in the form of Na2Co3 were added. Evaporation of the solvent, dichloromethane, would leave a
crude version of caffeine. After that recrystallize done by adding ethyl alcohol then it cooled in ice bath until
the crystal appear . Finally The caffeine filtrate by vacuum filtration apparatus and then caffeine is collected on
the filter paper and let to dry
Caffeine