The extraction process (extraction) is the extraction of substances from various materials using solvents (extract) in special devices called extractors. Extraction is used for the extraction of medicinal substances from raw materials of vegetable and animal origin, and also in chemical-Toxicological and biochemical analyses.

The extraction process (extraction; from lat. extrahere extrude, extract)is the process of extracting substances solvent cleaning of the solutions or solid (plant, animal, mineral materials. Extraction is connected with diffusion, dissolution, and for biological objects and with dialysis. Extraction of liquids based on the distribution law, according to which
extraction distribution law
where: m0 - number of extractable substances contained in the volume of solvent VA to extraction; mn - quantity of that substance remaining in the same amount after the n-fold extraction; VB - the amount of solvent (solvent), which every time is extraction; - the distribution coefficient of the extracted substance between two solvents. Extractant should not be mixed with the solvent, well dissolve recoverable and bad dissolve related compounds, have a low viscosity and good to diffuse. It is desirable that the extractant prevented the development of microflora and was not harmful to the body. The most common extractive agents: water, alcohol, ether, glycerol, oil, chloroform and other Sometimes extraction spend several solvents sequentially or in a mixture. For a quick and complete extraction increase the surface of contact of phases, crushing and mixing the material; create a greater difference of concentrations, increasing the number of extractive agent, frequently changing his or using the counterflow principle, raise temperature, increase the time of extraction add electrolytes. Removing the material data: volume of extractant will be more complete if this volume is divided into several portions and extraction to produce multiple times, but not once the entire volume of the extractant. The extraction process is usually conducted in the separating funnel or in extraction devices.
the to conventional Soxhlet extractions for extraction
In Fig. 1 shows the to conventional Soxhlet extractions for extraction of solid substances (1 - refrigerator; 2 - cylindrical part of the device; 3 - siphon; 4 - flask solvent). In Fig. 2 - the device for the automatic extraction of liquid (1 - refrigerator; 2 - a separating funnel; 3 and 6 - heaters; 4 - extraction chamber; 5 - siphon; 7 - flask to collect extract).
Extraction produce, shaking extractant with a liquid or solid material (periodic extraction) or permanently flowing extractant through them (continuous extraction). A solution containing the extracted substance (extract), separated from the rest of filtration, centrifugation or by merging after settling (by decantation). Extraction is widely used in biology, medicine, pharmacy, industry for recovery and separation of proteins, fats, vitamins, hormones, antibiotics, isotopes, and the production of synthetic rubber, caprolactam, for sewage treatment, in manufacture galenovyh preparations, tinctures, etc. are Widely used in the food industry (meat, fruit, malt), tanning, medicinal and other extracts.