Accelerated Solvent Extraction

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ASE ( narrow. : Accelerated Solvent Extraction , translated accelerated solvent extraction ) is an extraction process for solid and semisolid ingredients samples. The working conditions under pressure and at elevated temperatures lead to a strong acceleration of the reaction kinetics , to faster desorption of the analytes from the matrix, and to an accelerated course of the dissolution process overall.

Organic solvents such as acetone , pentane or ethyl acetate , and also aqueous liquids (for example buffer solutions ), can be used as solvents . Depending on the equipment, up to four solvents can be combined or used alternately for an extraction.

principle

The extraction cell is filled with the solid sample to be examined and placed in a controllable oven. After adding the solvent, the cell is heated at constant pressure (adjustable between 0.3 and 20 MPa) up to a maximum temperature of 200 ° C and kept at constant conditions for a while so that equilibrium can be established. The extract is then transferred to a sample tube. A sample often goes through several extraction cycles. Finally, the extraction cell is rinsed with solvent, the rinsing valve is opened and the cell and all lines are rinsed with nitrogen and the apparatus is prepared for further extractions.

application

The method is used in environmental analysis , for example in soil or sediment investigations.

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