In the Pharmaceuticals many extractions are performed.
The definition of an extraction needs additional features, so there is the definition of chemical extration:
Extract in chemistry - Definition
- Extraction is a process whose name was formed from the Latin word "extrahere" = "pull". Accordingly, extraction is generally called each separating method in which a separable mixture is separated into single substances.
- The mixture to be separated is called extraction, it may be made of liquid or solid gaseous individual substances exist.
- The agent which is used for extracting this substance, may also be liquid, solid or gaseous, it is referred to as extraction agent.
- The extract is what extracting yields as a result, even if the extracted material is extracted in a liquid, so a solution is formed.
- When the extracted material is not changed by the extraction, that is z. B. is adsorbed only by a different material or is dissolved in a liquid, is referred to as the physical extraction. Only when the extracted material performs a chemical reaction when extracting, it is a chemical extraction. A chemical reaction makes the extract by whenever changes its chemical structure, if so give new chemical compounds.
The methods of extracting
- When extracting different methods can be distinguished, which are described by the physical state of the extraction medium, followed by the extraction of the goods:
- So there are liquid-solid extractions, here the extraction material is a mixture of solids, the extraction agent is liquid. Thus, for. Example, the brewing of coffee or tea is a liquid-solid extraction. When a solid substance is placed in a solvent in which it is extracted after a certain time, called the maceration when doing heat is applied, this is referred to as digestion. During digestion, the solid is usually mixed with the liquid active, the separation of the insoluble components is called decanting. Also, the washing or leaching is a liquid-solid extraction, z. B. is carried out to extract pollutants from the soil.
- The liquid-liquid extraction extracted a substance using a liquid extraction agent from another liquid. Then there is the liquid-gas extraction in which a gas is extracted from a mixture of gases with the aid of a liquid, the solid-liquid extraction in which a solid absorbs contained in a liquid material, and many other extractions from materials of different aggregate states, which are not labeled with specific terms. Thus, for. Example, an absorbed by a solid material to be extracted by a gas (which happens when you cook with steam espresso) also bound chemical substances can be extracted by use of gas.
- There are extractions, in which gas is extracted from the gas, those in which a solid absorbs a substance which is in a gas, and extractions "laid out firmly" if a substance diffuses from one into the other solids (eg. as plasticizers in plastic in the applied to the plastic coating).
- In the chemical industry extraction of organic substances are often made, for example, because the extraction is the most efficient way. However, it may also be that other methods such as rectification or distillation, are technically not possible. Extracting is z. B. often the best way when heat-sensitive substances are to be extracted. In inorganic region z. B. metal salts are extracted, so titania is obtained or dissolved iron hydroxide from bauxite ore.
- In the Pharmaceuticals many extractions are made with different extraction methods, for example, the active substances from medicinal plants are extracted. Also in perfumery very many fragrances are produced by extracting, such. B. Rose oil is obtained by being extracted by steam of rose petals.
- Another area take place in the very many extractions, is the food industry, are used in numerous extractions to provide our food or beverage, and there are an infinite number of fields of application, in which we ask only extractions well-to-use materials available.
The definition of extraction should always be supplemented by the reference to the procedure used, is used because the word "extract" for all other separation methods. For example, the phrase extraction is also used when it comes to pervaporation, precipitation or filtration processes comes to magnetic separation, even if all of these methods are not really extractions.