Real World Lab: Extraction of Essential Oils from Soap
Matthew Marthaler
Introduction:
Essential oils are organic molecules that basically give soap its smell. There are only about four
to five drops that are added to the soap during the soap’s creation, so there is only a minute quantity of
essential oils. There are many different essential oils and they should be able to be extracted. We used
four brands of soap for this experiment: Dove Men + Care, Dove (regular brand), Zest, and Yardley
London Oatmeal and Almond.
In this experiment the essential oils from soap will be extracted. The instruments that will be
used are the SFE and IR. Organic steam distillation will also be used. Through this experiment it will be
determined if essential oils can be extracted from soap, what the best method of extraction is, and the
quantity of essential oils in various soaps. Steam distillation is a commonly used technique to extract
essential oils from samples such as cinnamon or spearmint, so we decided to test steam to see if it can
work with a bar of soap. After this, we will move on to the SFE. While searching for information, I could
not find any information on extracting essential oils from soap with the SFE, so the settings will be based
upon educated guesses and checking to see if they need to be re-adjusted for the other samples. The IR
will be used to determine if we have extracted essential oils from our samples. We looked for aromatic
rings, esters, aldehydes, or carboxylic acid peaks present in the IR spectra. We looked for these, because
essential oils can contain these and a presence of these organic groups can tell us if we have extracted
essential oils. This is an experiment that could be hit or miss. Because of time constraints, we only have
a few chances with the SFE to get the settings right, so we could end up not being able to extract the
essential oils entirely.
For The settings of SFE, I did however find some information regarding how to extract essential
oils from food. The best settings for peanuts and spearmint were around 40-100°C with 100-350 bar.
The higher the bar and temperature in the SFE, the more wax that was extracted. From this, I decided to
start off with the lowest settings and work up if necessary (because I wanted to get oil with no wax).
Purpose:
The purpose of this lab is to be able to work by ourselves in a lab setting and develop a
technique that uses instruments to accomplish a goal. For my personal experiment, I will be working
with bar soaps and trying to extract essential oils using steam distillation and the SFE. I will then run the
oils on IR to determine if they are actually the essential oils. This will help me learn how to work on my
own and help me develop more confidence in my lab abilities.
Method:
For Day One, We Ran a Steam Distillation:
1) 0.9953g of Dove Men + Care soap was placed in a 100mL round bottom flask with
35mL water and a stir bar. This was put in a Thermowell, surrounded by sand.
2) The steam distillation apparatus was set up. The Thermowell was set to 40. This was
supposed to cause the sample essential oils to vaporize up the column and dissolve
back to oil as they went through the de-ionized water column.
3) Soap bubbles began to form in the 100mL RBF as soon as steam distillate could be
detected (around 30 minutes). Water was first used to clear away the bubbles. This
went on for about ten minutes of pouring in water every time bubbles filled the
column. Seeing that this was not working, we then put glass wool was into the
column. This also did not help as the bubbles went past the wool and the sample
vapor would get caught in the bubbles and would not travel up the column.
4) We could not stop the bubbles from traveling up the column no matter what we did
and we did not want water (from the bubbles) getting into our product, so we stopped
the distillation after we got around 1 ml of collected distillate.
5) Methylene Chloride was then used to extract the distillate in a seperatory funnel. This
was repeated twice to completely separate the distillate and any constituents collected
during our procedure.
6) A rotary evaporator was used and the sample was tested on the IR. To determine if
essential oils were extracted, there should be aromatic rings, esters, aldehydes, or
carboxylic acid peaks present in the IR spectra. Our spectrum was awful and was just
a spectrum of water.
For Dove Men + Care SFE:
1) First, melting points for each of the soaps were determined using Mel-Temps to
obtain the maximum temperature to be used in the SFE.
2) For Dove Men + Care, we determined its melting point was around 110-140°C.
3) 2.2383g of Dove Men+Care was placed in the SFE column.
4) We used a 25mL volumetric flask filled with 10 mL of methanol to bubble the sample
into (44.9150 g).
5) We made the SFE settings:
Pressure-120 bar
Temperature-40°C
Valve Temp-80°C
Running Time-40 minutes
6) After running for 40 minutes, we took an IR of the sample and determined percent
composition based off the sample’s final mass.
For Yardley London Oatmeal and Almond SFE:
1) First, melting points for each of the soaps were determined using Mel-Temps to
obtain the maximum temperature to be used in the SFE.
2) For Yardley, we determined its melting point was around 145-200°C.
3) 2.990g Yardley London soap was placed in the SFE column.
4) Essential oil was extracted into a 25mL flask with no solvent (mass: 29.7397g). We
decided not to bubble samples into solvent, due to the solvent evaporating and a loss
of mass.
5) We made the SFE settings:
Pressure-250 bar
Temperature-110°C
Valve Temp-120°C
Running Time-20 minutes
6) After running for twenty minutes, we took an IR of the sample with added hexane as
a solvent and determined percent composition based off the sample’s final mass.
For Dove Beauty Soap:
1) First, melting points for each of the soaps were determined using Mel-Temps to
obtain the maximum temperature to be used in the SFE.
2) For Dove, we determined its melting point was around 110-140°C.
3) 2.9970g Dove soap was placed in the SFE column.
4) Essential oil was extracted into a 25mL flask with no solvent (mass: 24.923g).
5) We made the SFE settings:
Pressure-250 bar
Temperature-100°C
Valve Temp-120°C
Running Time-30 minutes
6) After running for thirty minutes, we took an IR of the sample with added methanol as
a solvent and determined percent composition based off the sample’s final mass.
For Zest Soap:
1) First, melting points for each of the soaps were determined using Mel-Temps to
obtain the maximum temperature to be used in the SFE.
2) For Zest, we determined its melting point was around 180-250°C.
3) 3.0086g Zest soap was placed in the SFE column.
4) Essential oil was extracted into a 25mL flask with no solvent (mass: 38.5932g).
5) We made the SFE settings:
Pressure-250 bar
Temperature-100°C
Valve Temp-120°C
7) After running for twenty minutes, we took an IR of the sample with added hexane as
a solvent and determined percent composition based off the sample’s final mass.
Results:
(Note: All other results and original IR data can be found in lab notebook)
Melting Temperatures of Soaps
Soap
Trial 1
Trial 2
Dove Men+Care
95-127°C
111.2-139.9°C
Dove
107-115°C
110-137°C
Zest
160.1-238.8°C
189.3-248.0°C
Yardley London Oatmeal and
Almond
159.3-205.9°C
145.7-197.5°C
Steam Distillation of Dove Men+Care Soap
IR of Dove Men+Care Soap
Steam Distillation Data
Soap
Essential Oil Mass
Percent Composition
of Essential Oil
Dove Men+Care
0.5911g
59.39%
SFE Dove Men+Care IR
Methanol IR (done as a background)
Methanol and Dove Men+Care Extracted Sample
SFE Yardley London Oatmeal and Almond IR
Hexane (done as a background)
Hexane and Pure Almond Oil Standard
Hexane and Yardley London Soap Extracted Sample
SFE Dove Soap
Methanol (done as a background)
Methanol and Dove Extracted Sample
SFE Zest Soap
Hexane (done as background):
Hexane and Zest Extracted Sample:
SFE Data
Soap
Essential Oil Mass
Percent Composition of
Essential Oil
Dove Men+Care
-2.046g
-91.41%
Yardley London
0.3247g
10.86%
Dove
0.2626g
8.76%
Zest
0.1285g
4.27%
Data and Calculations:

Determining Percent Composition:
(Mass of Essential Oil Extracted/ Mass Soap Sample)X 100%= Percent Composition
Example: (Zest Soap)
(0.1285g/3.0086g)X 100%= 4.27% Mass of Essential Oil Extracted
Conclusion:
In conclusion, our experiment was quasi-successful. We were able to extract essential oils from
soaps, which can be seen by the IR spectrum. We discovered steam distillation is not the best way to
extract essential oils from soap and the SFE worked much better. We determined the best settings for
extraction using the SFE and what solvent to use for the IR. Due to time constraints and other students
using the instruments, we were not able to use the HPLC and the GC-MS. Our quantitative data could be
improved using the knowledge that we have now.
The quantitative data for the steam distillation could be better by6 making a lot of changes.
While we were running the distillation, the bubbles began to rise up the column into our extract (the
glass wool did not prevent this). A longer column could have been used to prevent this because a threeway adaptor is not necessary for this extraction. The extract also had a lot of water in it, which yielded
bad IR results. This could be countered by using anhydrous sulfide to dry our extract. Finally, a small
amount of sample was collected, so letting the distillation go for a longer period of time instead of an
hour could give more product.
The quantitative data for the SFE could be greatly improved as well. With the Dove Men+Care
extraction, the oils were bubbled into methanol. The methanol evaporated during the extraction, which
disrupted the original mass from before the oils were present. This is responsible for the negative
percent composition. We stopped bubbling sample into solvents after this. Methanol solvent was also
added to the Dove Men+Care and the Dove soap extracted oils. This produced poor IR spectra.
Methanol was used because we wanted to run the sample on the GC-MS. Another problem was that all
of the samples except Zest (our last sample) were run on the SFE for too long and yielded oil and other
products. This is why our percent compositions were high as they should be around 1-5%. We should
run our samples around 10-20 minutes like we did with Zest from now on. Finally, in the last IR’s run (for
Dove regular and zest soap), there was something wrong with the IR and our spectra was
incomprehensible. We could try to take an IR of oil without solvents in the future to prevent an IR of an
evaporating solvent (which is what we got).
I believe I learned a lot from this lab experience and I feel confident to use the instruments if
ever called upon in a job. I gained crucial experience with the SFE and IR that I will carry on with in my
life and brag to my friends about. Overall, I believed Alexa and I chose a challenging enough topic to
push us and we were able to accomplish many goals.