Membrane-Based Microextraction Techniques with Emphasis on Hollow-fiber Microextraction
Pp. 380-405 (26)
Jan Åke Jönsson and Estelle Larsson
Various membrane-based extraction techniques are used in analytical
chemistry mainly for pretreatment before analyte determination using chromatographic
or other techniques. Membrane extraction can also be applied for the extraction of
various metal ions and is then followed by atomic absorption or similar detection
techniques. They allow high selectively for a number of analytes from chemically more
or less complex samples and high concentration enrichment, easily thousands of times.
Currently, the most common format for membrane extraction utilizes hollow-fiber
membranes, which permit easy and versatile operation with a minimum of cost. A
number of applications have been presented involving determination of polar and
medium-polar compounds as acids and bases in samples of environmental and
biological origin, usually in combination with liquid chromatography and mass
spectrometry. For other analytes in which membrane extractions are various metal ions,
the membrane extraction is followed by techniques like atomic absorption and similar.
Also applications to non-polar compounds in mainly environmental samples, followed
by gas chromatography, are described in the literature.
In this chapter, the basic theoretical principles for the common variants of membrane
extraction are described. Guidelines for the selection of operational parameters as well
as concrete advice for the practical implementation are provided.
Biomedical samples, Chromatography, Determination of acids,
Determination of bases, Enrichment, Environmental samples, Extraction, Food
samples, Hollow fibers, Mass spectrometry, Membrane extraction, Sample preparation, Selectivity, Supported liquid membrane (SLM).
Department of Occupational and Environmental Medicine, Skåne University Hospital, SE-221 85 Lund, Sweden.