Lexikon
in other name accelerated solvent extraction, abbreviated as ASE, a sample preparation technique in determination of POP (Persistent Orcanic Pollutants) that combines elevated temperature and pressure with solvents to achieve fast and efficient removal of components of interest from any solid sample (soil, sediment, food, textile, waste, biological sample, ash, etc.). The solubility of compounds is enhanced at elevated temperature, e.g. rising the temperature from 50 °C to 150 °C the solubility of anthracene is increased 13 fold resulting in enhanced diffusion as well. The high pressure makes it possible to work on temperatures above the boiling point of the solvent and helps to the solvent to enter into the pores of the sample. ASE has been demonstrated to be equivalent to existing extraction methodologies, such as Soxhlet extraction. (Source: MOKKA database, sheet No. 582)
chlorinated solvents are chloride containing organic liquids which have the power to dissolve organic substances and materials.Trichloroethylene, tetrachloroethylene (also known as perchloroethylene), and methylene chloride are the main solvents in this group. Due to their non-flammability, these compounds have been widely used for cleaning metals in the electronics industry and for dry cleaning of clothes. The use of 1,1,1-trichloroethane was phased out at the end of 1995 under the Montreal Protocol.
solvent extraction uses an organic solvent as an extractant to separate organic and metal contaminants from soil. The organic solvent is mixed with contaminated soil in an extraction unit. The extracted solution then is passed through a separator, where the contaminants and extractant are separated from the soil. Organically bound metals may be extracted along with the target organic contaminants.
solvent extraction from soil uses an organic solvent as an extractant to separate organic and metal contaminants from soil. The organic solvent is mixed with contaminated soil in an extraction unit. The extracted solution then is passed through a separator, where the contaminants and extractant are separated from the soil. Organically bound metals may be extracted along with the target organic contaminants.
A solvent is a liquid or gas that dissolves a solid, liquid, or gaseoussolute, resulting in a solution.To distinguish between solutes and solvents, solvents are usually present in the greater amount.
The most common solvent in everyday life is water.
Commonly-used solvents are the organic solvents, which usually have low boiling point, can easily be removed by destillation or evaporation. solvents are usually clear and colorless liquids and many have a characteristic odor.
Common uses for organic solvents are in dry cleaning (tetrachloroethylene), as paint thinners, as nail polish removers and glue solvents (acetone, methyl acetate, ethyl acetate), in spot removers (e.g. hexane, petrol-ether), etc. In 2005, the worldwide market for solvents had a total volume of around 17.9 million tons, which led to a turnover of about 8 billion Euro.