Solid phase extraction

The solid phase extraction (english solid phase extraction, SPE short, older designation also sorbent extraction ) is a sample preparation method in relation to a possible enrichment, concentration or isolation of an analyte. It is a physical extraction process that takes place between a liquid and a solid phase ( sorbent ), similarly as in the column chromatography. However, the term is broader and covers a whole range of Sorbens-/Isolat-Wechselwirkungen: polar and non-polar interactions, ionic interactions, interactions through covalent bonds as well as multiple interactions

The component to be analyzed ( isolate) is dissolved in a solvent. Using the PES, it is possible to enrich the component to be determined from very dilute solutions for the actual analysis. The solvent is, or the sample solution is passed through the sorbent, the isolate enriched in the sorbent bed, wherein the solvent, the sorbent passes unhindered. The selection of the sorbent has great influence on the extraction. The most common SPE method is to pack the sorbent in a sort column and direct the sample solution through the sorbent. By a suitable solvent, the isolate is from the sorbent down solved ( elution). Subsequently, this eluate may be further processed or analyzed.

The methods of developing a complete SPE - Analysis - Validation can sometimes appear quite complex and complicated. However, the result is a fast and inexpensive method of analysis, which speaks for large samples and a high degree of automation. For commercial columns are used. Previously operated by hand SPE were used with a vacuum pan. Modern machines allow for a fully automatic enrichment.