| Autor: |
Zambonin, Carlo G., Aresta, Antonella, Nilsson, Torben |
| Předmět: |
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| Zdroj: |
International Journal of Environmental Analytical Chemistry; 2002, Vol. 82 Issue 10, p651, 7p |
| Abstrakt: |
Solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) was optimized for the analysis of hexachlorocyclohexanes, DDD, DDE, DDT and other organochlorine pesticides in aqueous samples. Higher extraction efficiency was observed with the SPME fibre coated with 100μm polydilnethylsiloxane than with the fibres coated with 85 μm polyacrylate or 65 μm polydimethylsiloxane/ divinylbenzene. Equilibration times were longer than 60mira except for the hexachlorocyclohexanes, in spite of rapid stirring of the sample. However, precise quantitative analysis could be performed also under non-equilibrium conditions: i.e. repeatability standard deviations below 20%. Salt addition had a positive effect on the response for the hexachlorocyclohexanes, whereas the extraction of the other analytes was affected negatively. The pH of the sample solution did not influence the extraction efficiency. The desorption was performed for 5 min at 275°C directly in the GC injector. At shorter desorption times or lower temperatures a significant carry-over was observed for the heavier analytes. Generally, detection limits in the ng/L range were obtainable. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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