Selectivity in supercritical fluid extraction

The selectivity of supercritical fluid extraction is one of its most flexible properties relative to other separation techniques including liquid-liquid extraction and, especially, those starting with a solid sample. Virtually all internal and external parameters of the extraction process can be altered to enhance the selectivity of the overall analytical process. Thus [Pg.329]

As in other techniques, SF extracts are not always free of unwanted matrix components. A number of clean-up methods have been used with and after the extraction step to overcome this problem. Sample clean-up is mandatory with fat-soluble analytes. On the other hand, neat supercritical CO, extracts from environmental samples are often clean enough for direct injection into a gas chromatograph [17]. [Pg.329]

Specific problems such as those posed by the presence of organic matter or sulphur in sediment extracts have elicited a wide range of solutions [144-147] depending on the type of chromatograph, detector and connection (on-line or off) between the SF extractor and the equipment used in the subsequent steps of the analytical process. [Pg.329]

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