Lexikon

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accelerated solvent extraction

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

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.

cosolvent
extraction from soil by organic solvents

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.

extraction from soil by solvents

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.

halogenized organic solvents
membrane assisted solvent extraction
chemical extraction using polypropylene membrane filled with organic solvent and placed into the aqueous sample. Sample preparation method for chromatography based on liquid/liquid extraction procedure where the phases are separated by the membrane. It can be fully automated. Typical applications: extraction of extractable hydrocarbons (EPH), PAHs, phenols, PCBs, pesticides from water or aqueous suspensions. Suitable for analytes to be extracted from extremely dirty matrices. (Source: B. Hauser, M. Schellin, and P. Popp: Membrane-Assisted Solvent Extraction of Triazines, Organochlorine, and Organophosphorus Compounds in Complex Samples Combined with Large-Volume Injection-Gas Chromatography/Mass Spectrometric Detection. Anal. Chem. 76, 6029-6038, 2004)
organic solvent input in the legal regulation of the air
organic solvent use in the legal regulation of the air
solvent

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.

stability in organic solvent
percentage of the concentration of the test substance in the solvent extract at a particular time period compared with the initial starting concentration of the test substance at t = 0. Information on the stability of a substance in a solvent is desirable, particularly when samples are to be stored. (http://www.prc.cnrs-gif.fr/reach/en/physicochemical_data.html) A physico-chemical parameter required by REACH for materials manufactured or imported in >100 tons/year. Stability in organic solvents and identity of relevant degradation products only required if stability of the substance is considered to be critical. The study does not need to be conducted if the substance is inorganic.