SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
TITLE EXPERIMENT 2 EXTRACTION OF CAFFEINE FROM BEVERAGES
OBJECTIVE
1. To extract caffeine from beverages using liquid–liquid extraction technique.
2. To determine amount of caffeine present in beverages.
3. To determine the KD of caffeine between water and dichloromethane solvent.
INTRODUCTION
Caffeine is a stimulant commonly found in many foods, drinks and has a mild addictive effect on
the body. Caffeine can stimulates both the central nervous system and skeletal muscles. This
stimulation will results in increased alertness that is making human concentration ability to
increases in a short time. This then can increases the human ability to stay awake when tired. The
bad side of this effect is that excessive intake of caffeine may result in restlessness, insomnia,
and irritability. Heavy caffeine use can lead to both a tolerance to and a dependence on the
consumption of caffeine.
Figure 1 Caffeine Molecular Structure
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
In this experiment we will use the extraction method. Extractions can be either solid-liquid, or
liquid-liquid, depending the compound that we will conduct the experiment. A liquid solvent is
used to isolate the compound in both types of the extraction. Scientists often perform extractions
of organic material, using an inorganic solvent in order to separate the organic compound from
the typical byproducts and starting materials. In these types of liquid-liquid extractions it is
important to choose an ideal solvent that will not dissolve in water, have a low boiling point so it
can be easily removed so that it should not react with the solute or other solvent. Ideally, a well-
chosen organic solvent when mixed with the mixture containing the liquid compound, will create
two immiscible layers which is one containing the extraneous materials in the aqueous layer, and
the compound to be extracted in the organic layer.
CHEMICALS AND MATERIALS
• Distilled water
• Beverages sample
• Dichloromethane
• Anhydrous sodium carbonate (Na2CO3)
• Boiling chip
• Sodium sulfate (Na2SO4)
APPARATUS
• Beaker (50 and 150 mL)
• Separatory funnel
• Ring and retort stand
• Glass rod
• Spatula
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
PROCEDURE
1. 30 mL of liquid sample was measured and each sample was transferred to 150 mL beaker.
2. Add 2.0 g of anhydrous sodium carbonate was added into the beaker.
3. A few boiling chip was added in the beaker then the solution was boiled gently for about 10
minutes using a hot plate.
4. The solution was filtered and it was boiled again until the volume of solution decreases to
approximately 5 mL.
5. The sample solution was cooled down to room temperature and was transferred to separatory
funnel which is supported by a ring attached to retort stand. Make sure to properly conducted the
separatory funnel before use.
6. 20 mL of dichloromethane was added into the separatory funnel (you may use a part of this
organic solvent to rinse the beaker for quantitatively transfer the sample).
7. The separatory was closed funnel with stopper and was shaken gently to allow intimate mixing
of the solutions (Caution: When shaking, the mixture may develop pressure; be sure to vent it
periodically).
8. The stopper was hold and the funnel was inverted as shown in Figure 2. The stopcock was
open slowly to release any built up pressure, then reclose the stopcock.
Figure 2: Shaking and venting the separatory funnel
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
9. The contents in the funnel was allowed to settle. There should be two distinct layers formed. If
there is an emulsion (cloudy) layer formed between two layers, it is possible broken by stirring
using a glass rod.
10. The bottom layer was carefully drained (the organic layer of dichloromethane) into a beaker.
Try do not include any of aqueous (upper) layer into the beaker.
11. Approximately half spatula of Na2SO4 was added into the organic solution.
12. The solution was filtered and transferred to weigh petri dish, then it was left for overnight at
room temperature to form white crystals.
13. The white crystals was collected, the yield was weighted and attached one of the sample to
lab report.
14. The percentage of caffeine in the beverage was calculated.
15. The melting point of your caffeine was determined and it was compared to the actual value.
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
TITLE EXPERIMENT 2 EXTRACTION OF CAFFEINE FROM BEVERAGES
OBJECTIVE
1. To extract caffeine from beverages using liquid–liquid extraction technique.
2. To determine amount of caffeine present in beverages.
3. To determine the KD of caffeine between water and dichloromethane solvent.
INTRODUCTION
Caffeine is a stimulant commonly found in many foods, drinks and has a mild addictive effect on
the body. Caffeine can stimulates both the central nervous system and skeletal muscles. This
stimulation will results in increased alertness that is making human concentration ability to
increases in a short time. This then can increases the human ability to stay awake when tired. The
bad side of this effect is that excessive intake of caffeine may result in restlessness, insomnia,
and irritability. Heavy caffeine use can lead to both a tolerance to and a dependence on the
consumption of caffeine.
Figure 1 Caffeine Molecular Structure
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
In this experiment we will use the extraction method. Extractions can be either solid-liquid, or
liquid-liquid, depending the compound that we will conduct the experiment. A liquid solvent is
used to isolate the compound in both types of the extraction. Scientists often perform extractions
of organic material, using an inorganic solvent in order to separate the organic compound from
the typical byproducts and starting materials. In these types of liquid-liquid extractions it is
important to choose an ideal solvent that will not dissolve in water, have a low boiling point so it
can be easily removed so that it should not react with the solute or other solvent. Ideally, a well-
chosen organic solvent when mixed with the mixture containing the liquid compound, will create
two immiscible layers which is one containing the extraneous materials in the aqueous layer, and
the compound to be extracted in the organic layer.
CHEMICALS AND MATERIALS
• Distilled water
• Beverages sample
• Dichloromethane
• Anhydrous sodium carbonate (Na2CO3)
• Boiling chip
• Sodium sulfate (Na2SO4)
APPARATUS
• Beaker (50 and 150 mL)
• Separatory funnel
• Ring and retort stand
• Glass rod
• Spatula
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
PROCEDURE
1. 30 mL of liquid sample was measured and each sample was transferred to 150 mL beaker.
2. Add 2.0 g of anhydrous sodium carbonate was added into the beaker.
3. A few boiling chip was added in the beaker then the solution was boiled gently for about 10
minutes using a hot plate.
4. The solution was filtered and it was boiled again until the volume of solution decreases to
approximately 5 mL.
5. The sample solution was cooled down to room temperature and was transferred to separatory
funnel which is supported by a ring attached to retort stand. Make sure to properly conducted the
separatory funnel before use.
6. 20 mL of dichloromethane was added into the separatory funnel (you may use a part of this
organic solvent to rinse the beaker for quantitatively transfer the sample).
7. The separatory was closed funnel with stopper and was shaken gently to allow intimate mixing
of the solutions (Caution: When shaking, the mixture may develop pressure; be sure to vent it
periodically).
8. The stopper was hold and the funnel was inverted as shown in Figure 2. The stopcock was
open slowly to release any built up pressure, then reclose the stopcock.
Figure 2: Shaking and venting the separatory funnel
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
, SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
9. The contents in the funnel was allowed to settle. There should be two distinct layers formed. If
there is an emulsion (cloudy) layer formed between two layers, it is possible broken by stirring
using a glass rod.
10. The bottom layer was carefully drained (the organic layer of dichloromethane) into a beaker.
Try do not include any of aqueous (upper) layer into the beaker.
11. Approximately half spatula of Na2SO4 was added into the organic solution.
12. The solution was filtered and transferred to weigh petri dish, then it was left for overnight at
room temperature to form white crystals.
13. The white crystals was collected, the yield was weighted and attached one of the sample to
lab report.
14. The percentage of caffeine in the beverage was calculated.
15. The melting point of your caffeine was determined and it was compared to the actual value.
SKA3013 LAB REPORT|ANALYTICAL CHEMISTRY
EXPERIMENT 2- EXTRACTION OF CAFFEINE FROM
BEVERAGES STUDY GUIDE 2022/2023
