Solid-liquid extraction is an operation with applications in laboratories (sample preparation), industry (extraction from vegetable matrices) and practical applications (cleaning).
For example, in the herbal and various other food preparation industries, when a vegetable matrix necessitates extraction for further processing, it is obviously of fundamental importance to ensure that a high degree of extraction efficiency is reached, that the extract is not oxidised, and so on.
Many laboratory procedures require solid-liquid extraction as a preliminary phase of the preparation of a sample, for example as happens in the analysis of environmental contaminants in vegetables. The operation of solid-liquid extraction must guarantee that all the analytes are retrieved completely and that they are in no way degraded during the extraction process.
Currently, in the food industry there are essentially three different solid-liquid extraction techniques in use:
maceration; percolation; supercritical fluid extraction.
Each of these techniques presents both advantages and disadvantages. This information a more extensive discussion, examples, pictures and graphics can be found here:
See also the following for a nice graphic comparison of solid-liquid and liquid-liquid extraction: