8/10/2019 Single Extraction

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SINGLE EXTRACTION

Hannah Marie G. Herrella, Isabelle Louise F. Ilagan, Myzhel S. Inumerable,

Natasha R. Jain and Tactto B. Kobayashi

Group 5 2C Pharmacy Organic Chemistry Laboratory

ABSTRACT

Extraction is a separation method in which an organic compound is isolated from a mixture of compounds.

There are two main types; liquid-liquid extraction and solid-liquid extraction. Caffeine was extracted fromdried tea leaves using single extraction method. 10 grams of Lipton Tea leaves was boiled in a solution of

anhydrous sodium carbonate and 100 ml distilled water. From the solution, caffeine was extracted using 60 ml

of dichloromethane. The mixture was then decanted to collect the residue. The residue was placed in the hood

to allow the dichloromethane to evaporate. Afterwards, a perforated filter paper was used to cover the

evaporating dish so that everything in the mixture can evaporate except for the caffeine. The percentage yield

was computed by getting the ratio of the weight of the caffeine and weight of the tea leaves used. The

percentage yield is 23.71%.

INTRODUCTION

Extraction is a process of separating an

organic compound from a mixture of

compounds. The theory of extraction lies in

the concept of immiscibility of two phases to

separate a solute from the other phase. There

are two main types; liquid-liquid extraction

(also known as solvent extraction) and solid-

liquid extraction.

In this experiment, groups are expected to

meet the following objectives: (1) compare

single and multiple Extractions of caffeine

from dried tea leaves, and (2) calculate the

percentage yield of caffeine for single

extraction procedure.

EXPERIMENTAL

A.

Compounds tested

Sample: Tea leaves

Brand: Lipton

Amount of caffeine: 55 mg

B.

Procedure

A solution of 4.4g of anhydrous sodium

bicarbonate and 100 ml of distilled water was

placed in a 250 ml beaker was heated by a

water bath until the solid dissolved. Ten

grams of tea leaves in tea bags was then

placed in the mixture and then boiled for 10

minutes. After boiling, the tea bags were

removed.

The tea bags afterwards were squeezed to get

the liquid in them.

The solution was extracted with 60 ml

dichloromethane in a separatory funnel. It

was swirled for 10 minutes for better

separation. After swirling, the mixture was

left to stand to clearly see the visible

separation between the two layers. The

organic layer was decanted into a beaker and

the aqueous layer was discarded.

The solution was then placed in a pre-

weighed evaporating dish. It was covered

with a perforated filter paper and afterwards

was placed in the fume hood. It was

evaporated to dryness until the residue is

completely in powder form and then it was

weighed using the triple beam balance.

Results were gathered and percentage yield

was calculated.

RESULTS AND DISCUSSION

Based on the set-up, the difference from a

single extraction and multiple extractions is

that there is repeated extraction in the latter

one. It is more efficient than single extraction

because it allows more of the caffeine to be

extracted from the mixture.