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)
method to separate components based on their relative solubilities (partition) in two different, immiscible solvents. In extraction" target="_blank">liquid/liquid extraction the solvent (usually organic) dissolves only the desired compounds from the sample solution (usually aqueous solution). In supercritical extraction the solvent is supercritical carbon dioxide. Soxhlet extraction is the tradional way for extracting solid samples, when the sample is connected with freshly boiled solvent in a special apparatus several times. The extraction of soild samples can be intensified by ultrasound (sonication assisted extraction, SAE) or elevated pressure and temperature (pressurized fluid extraction or accelerated fluid extraction, ASE). The solid phase extraction (SPE) is characterized by decreased sample and solvent need. Further miniaturization resulted in solid phase microextraction (SPME), stirbar+extraction and the membrane assisted extraction (MASE) techniques used for sample preparation for chromatography.
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.
an extraction technique (LLE) in which one liquid is shaken with or contacted by an extraction solvent to transfer molecules of interest into the solvent phase. Typical sample preparation (concentration) method e.g. organic contaminants in water are extracted into an organic solvent to be measured by gas or liquid chromatography.
multi-phase extraction uses a vacuum system to remove various combinations of contaminated groundwater, separate-phase petroleum product, and vapors from the subsurface. The system lowers the water table around the well, exposing more of the formation. Contaminants in the newly exposed vadose zone are then accessible to vapor extraction. Once above ground, the extracted vapors or liquid-phase organics and ground water are separated and treated.
Source: US-EPA, Clu-In:http://www.clu-in.org/techfocus/default.focus/sec/Multi-Phase_Extraction/cat/Overview/
soil vapor extraction SVE is used to remediate unsaturated vadose zone soil. A vacuum is applied to the soil to induce the controlled flow of air and remove volatile and some semivolatile organic contaminants from the soil. SVE usually is performed in situ; however, in some cases, it can be used as an ex situ technology.
a chromatographic technique used to prepare samples for subsequent analysis, an effective method to concentrate or isolate the non-volatile analytes. It is a kind of column chromatography. The extract is eluted through the column (cartridge) containing the preconditioned sorbent by applying vacuum. The substance of interest is retained on the column and all the interfering components are eluted or the interfering components are retained and the substance of interest is eluted. This sample preparation technique is suitable for any compounds. The low solvent need, no need of concentration by evaporation and in this way avoiding the concentration of the polluting components, cheap sorbents, saving time, no emulsion formation, enhanced selectivity and potential for automatization are the advantages of SPE over the traditional liquid/liquid extraction (LLE).
an extraction technique of solids in which the sample is repeatedly contacted with solvent over several hours, increasing the extraction efficiency. Soxhlet extraction is a purification technique developed by Franz von Soxhlet in 1879. The solid is put into a paper "thimble" which is then placed into the main chamber of the Soxhlet extractor. The solvent is heated to reflux and then travels up the distillation arm and floods into the main chamber with the thimble. The chamber then slowly fills and some of the pure compound will dissolve into the solvent. The chamber is emptied with the help of the side arm and the cycle repeats. See also http://chemistry.hull.ac.uk/labweb/glossary_soxhlet.php#