Extraction methods

1. EXTRACTION METHODS
BY
A.JEEVARATHINAM

2. INTRODUCTION
The basic knowledge about the phytoconsttuents nature and
their characteristics is essential to select the method and solvent
for extraction.
Extraction - the separation of medicinally active compounds of plant or animal
tissues from the inactive or inert components (desired and undesired) by using
selective solvents in standard extraction procedures

3. SELECTION OF EXTRACTION METHOD
1. Nature of component – not lost, distorted or
destroyed preparing the extract.
2. Nature of material to be used - bulk collection,
pre-washing, crushing and grinding the plant
material homogeneous and uniform sample of
extraction and increases the contact surface with
the solvent.
3. Solvent system available - polar solvents such as
water, methanol, and ethanol are used in extraction
of polar compound, whereas nonpolar solvents
such as hexane and dichloromethane are used in
extraction of nonpolar compounds

4. EXTRACTION METHODS
• Conventional Methods
Decoction
Infusion
Soxhlet extraction
Maceration and Hydrodistillation
• Non conventional methods
Ultrasound assisted extraction (UAE)
Microwave assisted extraction (MAE)

5. DECOCTION

6. MACERATION
Maceration is one of the
conventional methods of
extraction that is very
simple and the cheapest
because it only requires a
simple container as the place
for extraction, but this
method requires a long time
for the extraction process.
The maceration method can
be done anywhere and this
method is most often used in
extracting active compounds

7. INFUSION
In this method, extraction consist in soaking the solids plants powder either
cold or boiling water for a short period of time. The plant material is grinded
into the powder, and then placed inside a clean container. The extraction
solvent hot or cold is then poured on top of the material, soaked, and kept for a
short period of time. This method is suitable for extraction bioactive
constituents that are readily soluble Infusions are generally prepared for
immediate use, as preservatives are absent.

8. SOXHLET EXTRACTION
This tool consists of
several parts including a heat source,
round bottom flask, soxhlet extractor,
and condenser. The solid material which
is to be extracted is placed in thimble .
and placed in an extractor. The bottom
end of the extractor is connected to a
round bottom flask containing a solvent,
and is connected to a reflux condenser.
The bottom flask is heated to boil the
solvent, the vapor rises through the
branch pipe of the extractor, is
condensed and drops into the thimble
and the solvent is contacted with the
solid for extraction. When the solvent
surface exceeds the highest point of the
siphon, the solvent containing the
extract is return back to the round
bottom falsk. This cycle is repeated until
the all the material extracted from the
solid sample.

9. SOXHLET EXTRACTION
• Small amount of solvent is
reused to perform an
extraction many times. This
means that much less solvent is
used in a Soxhlet extraction,
making it more time and cost
effective.
• Also, the Soxhlet extractor can
run continuously without any
further operation, making it an
excellent choice for extracting
compounds over hours or even
days.
• Filtration is not required So it
save lot of time, energy and
financial inputs.

10. DISTILLATION
• Simply, distillation is the process in which a
liquid is vaporized (turned to steam),
recondensed (turned back into a liquid) and
collected in a container.
• Distillation has been used widely to separate
volatile components from nonvolatile
compounds.

11. TYPES OF DISTILLATION
There are several methods of distillation
depending on the procedure and the
instrument setup. Each distillation type is used
for purification of compounds having different
properties.

12. SIMPLE DISTILLATION
• Simple distillation is practiced
for a mixture in which the
boiling point of the
components differ by at least
70° C.
• It is also followed for the
mixtures contaminated with
nonvolatile particles (solid or
oil) and those that are nearly
pure with less than 10 percent
contamination.
• Double distillation is the
process of repeating distillation
on the collected liquid in order
to enhance the purity of the
separated compounds.

13. FRACTIONAL DISTILLATION
• Those mixtures, in which the
volatility of the components is nearly
similar or differs by 25° C (at 1
atmosphere pressure), cannot be
separated by simple distillation.
• In such cases, fractional distillation is
used whereby the constituents are
separated by a fractionating column.
• In the fractionating column, the
plates are arranged and the
compound with the least boiling
point are collected at the top while
those with higher boiling point are
present at the bottom.
• A series of compounds are separated
simultaneously one after another.
Fractional distillation is used for the
alcohol purification and gasoline
purification in petroleum refining
industries.

14. HYDRODISTILLATION
Hydro-distillation is a common traditional extraction method. It is
used to isolate aromatic compounds and volatile compounds from
the plant via boiling water and plants or using steam.
Hydrodiffusion - Diffusion of essential oils and hot water through
plant membranes is known as hydrodiffusion. Membranes of plant
cells are almost impermeable to volatile oils. Therefore, at the
temperature of boiling water, a part of volatile oil dissolves in the
water present within the glands, and this oil-water solution
permeates, by osmosis, the swollen membranes and finally reaches
the outer surface, where the oil is vaporized by passing steam.
Hydrolysis - Hydrolysis in the present context is defined as a
chemical reaction between water and certain constituents of
essential oils.
Decomposition by heat - Almost all constituents of essential oils
are unstable at high temperature. To obtain the
best quality oil, distillation must be done at low temperatures.

15. • The plant material is soaked in the water that is placed over a
container over heat.
• Due to the effect of hot water or steam, the essential oils are
separated from the oil glands, which are present in the plant tissue.
• Separated water and oil (vapor mixture) go to the condenser for
conversion to liquid and then is transferred to the separator for
separating essential oil from water.
• The final product hence obtained in the receiving flask contains
only the distillate.

16. MICROWAVE ASSISTED EXTRACTION (MAE)
Electromagnetic waves are absorbed by the material and converted to heat energy. This
is a microwave Energy. Microwaves penetrate into biomaterials and generate heat by
interacting with polar molecules such as water inside the materials. This leads to
production of heat and cell structure disruption. This action, created the diffusion of
bioactive compound from the plant matrix .
2450 MHz (2.45 GHz) is the
most commonly used
frequency for commercial
microwave instruments,
which has an energy output
of 600-700 W.

17. ULTRASOUND-ASSISTED EXTRACTION
(UAE) OR SONICATION EXTRACTION
Ultrasonic is a kind of elastic
mechanical vibration wave,
essentially different from the
electromagnetic wave.
Ultrasonic extraction is the use of
ultrasonic radiation pressure
produced the penetration of solvent
into the plant materials and
increasing the target component
into the solvent promote extraction.
UAE uses ultrasound with
frequencies ranging from 20 kHz
to2000 kHz.

18. ULTRASOUND-ASSISTED EXTRACTION
UAE uses acoustic waves in the kilohertz range that travel through the solvent
producing cavitation bubbles . When the cavitation bubbles burst at the surface of
the plant sample matrix, a shockwave-induced damage to plant cell wall enhances
the mass transfer of compounds across cellular membranes into solution .

19. Compounds Plant Activity
Essential Oil Based Terpene
Compounds (Diallyldisulfide,
Diallyltrisulfide, Eugenol, Methyl
Eugenol, Carvone, Limonene,
Eucalyptol, Eudesmol, α- pinene)
Mentha piperita, Ocimum
sanctum, Eucalyptus maculata,
Allium sativum and Callistemon
linearis
Larvicidal and Adulticidal
Agent against Aedes aegypti
Phytochemicals(Alkaloids,
glycosides, tannin, etc)
Stem Bark Extracts of Euphorbia
Balsamifera
Mosquito Repellent Activity
Azadirachtin (limnoid group) Neem (seeds, leaves, and other
parts of the tree)
anti-feedant, ovipositional
deterrence, repellency,
growthdisruption, sterility
and larvicidal action against
insect
arbazole alkaloids, mahanimbine,
murrayanol, and mahanine
Murraya koengii Larvicidal activity
Limonenenanoemulsions
(Monoterephene)
Citrus sinensis essential oil Larvicidal activity
PHYTOCHEMICALS IN MOSQUITO CONTROL

20. CONCLUSION
• Extraction is not a universal one it vary
depend on the plant material which is depend
on the factors such as compound,
temperature, concentration. So the method of
selection should be selected very carefully and
then only can extract the target compound
easily.

21. STEAM DISTILLATION
Steam distillation is used for the purification of
mixtures, in which the components are
temperature or heat sensitive; for example,
organic compounds.
In the instrument setup, steam is introduced by
heating water, which allows the compounds to
boil at a lower temperature.
This way, the temperature sensitive compounds
are separated before decomposition.
The vapors are collected and condensed in the
same way as other distillation types.
The resultant liquid consists of two phases, water
and compound, which is then purified by using
simple distillation.
Steam distillation is practiced for the large-scale
separation of essential oils and perfumes.
•

22. THANK YOU