Last Updated on December 10, 2020
Extraction is the process of separation whereby one substance is gotten out of a mixture. It is a chemical process and takes place in a series of steps with accordance to the extracts in question.
An extract is the end product of an extraction process. We have different types of extractions and extracts that include, electrolysis, propolis, maceration, ultrasound extraction, microwave assisted extraction.
Different extracts include aluminum, potassium, sodium, calcium, magnesium metals through electrolysis.
Let’s have a look at the different types of extraction.
5 Types of Extraction
Electrolysis is a separation technique in which a direct current passes through an ionic substance in molten or solution form, which would produce chemical reactions at the electrodes that separate the materials.
First of all, we need to understand that electrolysis is the most powerful type of extraction. It is an extraction method used to extract the most reactive metals from an ore; a compound of a metal mixed with impurities.
It is the most expensive since a lot of electricity is used. Electrolysis deals with the addition of electrons into the metal ions at a cathode terminal(the negative electrode). Electrolysis produces the purest metals.
What is needed during electrolysis?
- Electrolyte; a substance with free ions that is they are mobile.
- Direct current; for charging and discharging the ions in the electrolyte.
- Two electrodes; act as connectors between the electrolyte and electrical circuit.
Propolis is a mixture containing resin collected by bees from tree buds and plant resins. Bees use propolis for its antiviral and antimicrobial properties. Humans, due to its healing power use propolis for its health benefits in combating some diseases which even occur in animals; pets and cattle alike.
Since propolis is a mixture of impurities it needs to be extracted into pure form. One may make propolis extract simply by using the right solvent; oil, water, alcohol.
Maceration process of extraction deals with extraction of phytochemicals or essential oils from plants that are used medicinally in chemically manufacturing drugs. Used in most small drug manufacturing companies.
Herein flowers are soaked in hot oil to have the cell membranes rapture then the hot oil would now absorb the essence. The oil is then used to get the extract mostly through decantation process.
4. Ultrasound Extraction
It is the process of moving a substance from any matrix to an appropriate liquid phase assisted mainly by sound waves that propagate through the liquid media.
Ultrasound extraction is used in extracting food ingredients, products, nutraceuticals, cosmetics, pharmaceuticals and bioenergy applications.
5. Microwave Assisted Extraction
Microwave assisted extraction combines microwave and traditional solvent extraction methods. The microwave heats the solvent and plant tissues increasing their kinetic of extraction.
It is advantageous since it takes a shorter time, requires less solvent, it has a higher extraction rate and costs low. It is used in extraction and manufacturing of herbal drugs.
Now let us have a look at the different experimental processes of the different extraction processes.
Case study; extraction of sodium.
- Sodium chloride
- Electrodes; graphite rods may work.
- Source of direct current.
Setup the experiment as shown in the diagrams. This experiment can be repeated for various kinds of metals though with different forms of complexity with regards to the reactiveness of the metal in question.
General experimental setup
Electrolysis of sodium chloride
Heat the sodium chloride to its molten form.
- There reactions taking place at each electrode known as half equations.
- At the cathode; 2Na+ + 2e- 2Na
- At the anode; 2Cl- + 2e- Cl2
- Sodium ions gain electrons forming sodium metal.
- Chloride ions lose electrons forming chlorine gas seen as bubbles in the electrolyte.
Propolis Extraction Experiment
In propolis extraction, we are dealing with raw propolis that contains various impurities. There are three different ways employed and only different with the type of solvent in play.
Step 1: Break the propolis into smaller chunks so as to increase the surface area of contact between the propolis and the solvent in play. For very sticky propolis one may first refrigerate it to reduce the sticking effect.
Step 2: Use either of the three solvents with regards to intent or purpose of the extract. One may choose one that is easily and readily available. If the extract shall be used for human consumption then ethanol as alcohol should be used. Rubbing alcohol is used when the extract shall be used in the external application.
For an efficient collect of correct concentrations of the extract then the solvent used should not exceed 30% of the propolis used.
Step 3: Put the propolis and the alcohol in a container, seal it and shake thoroughly. Leave the mixture in a warm dark place for at least three days in which for each day you repeat the shaking procedure. After a week or so filter the contents and a clear extract shall flow out easily.
While using water as the solvent, the extract can be got through soaking the propolis in water for several days or boiling the mixture.
For oil as a solvent, mix around 20 g of propolis with 400 ml of refined food oil or 200 g of butter. Heat the mixture gently in a water bath for 10 minutes while stirring. Filter the solution and you have your extract.
Cut the plant material into pieces or grind into powder form. Place the material in a container full of menstruum and let it stand for approximately three or more days with frequent shakes within the days. Filter the solution to obtain the extract. All this occurs at room temperature.
Maceration in water for too long may cause fungal growth hence must be minimized or done in a few days. The time of extraction is dependent on the plant type and the part of the plant from which the extract is to be gotten from.
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