ISSN:
1612-1112
Keywords:
Column liquid chromatography
;
Solid-phase microextraction (SPME)
;
Headspace solid-phase microextraction (HSPME)
;
Environmental analysis
;
Water analysis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary Solid-phase preconcentration coupled on-line with liquid chromatography, and solid-phase microextraction coupled with gas chromatography have been applied to the determination of trace-level concentrations of benzene and sulfur compounds (tetrahydrothiophene (THT),t-butyl mercaptan (TBM), andn-butyl mercaptan (nBM)) in aqueous media. The first technique uses a microcolumn packed with a styrene-divinylbenzene copolymer. Retention values for THT, TBM, and benzene on this sorbent, expressed as the capacity factors, are 1100, 1600, and 4000, respectively. It is, therefore, possible to preconcentrate them efficiently and this method enables minimum concentrations of 0.05, 0.7, and 0.8 μg L−1, respectively, to be reached. In microextraction, a fine silica fiber coated with a thin layer of polydimethylsiloxane is used. The partition coefficients of the analytes between the polymeric coating and water have been determined to be 40, 115, and 110 for THT, TBM, and benzene, respectively. When sampling is performed from the liquid phase, partition equilibrium is reached within 5 to 20 minutes, or more quickly when the solution is agitated. Using a flame ionization detector, detection limits for THT, TBM, and benzene were 3, 5, and 0.2 μg L−1, respectively. Extraction of volatile or semi-volatile analytes can also be performed from the headspace with very similar detection limits. In addition, the extraction time is shorter since equilibrium is reached within 1 to 1.5 minute, which can again be reduced by agitation of the sample. The advantages and drawbacks of both techniques are gathered and discussed in this paper, which also underlines their complementarity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02318623
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