Because of their specific physical and chemical properties (amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate. In the methodologies for analysing environmental samples, the isolation and/or preconcentration of analytes constitutes an important step. The usual techniques are liquid-liquid extraction (LLE), solid-phase extraction (SPE - also used for extract clean-up contains following analytes isolated by another technique) or accelerated solvent extraction (ASE). For the analysis of samples/extracts, depending on whether information is required - the total concentration or the levels of particular surface-active compounds in environmental samples - spectrophotometry, tensammetry or electrophoresis, and chromatography may be used. Nowadays, high-performance liquid chromatography (HPLC) is usually coupled with a universal mass spectrometry detector (MS) (or tandem mass spectrometry detector MS-MS), what allows for detection, identification and quantification the various compounds in a particular group of surfactants in suitably prepared solvent extracts.
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