Speciation von Arsen in biologischen Umweltproben aus aquatischen Ökosystemen mittels HPLC-ICP-MS
Speciation von Arsen in biologischen Umweltproben aus aquatischen Ökosystemen mittels HPLC-ICP-MS
The physicochemical forms of arsenic (arsenic species) which are present in the environment vary significantly with respect to toxicity, bioavailability, stability and transport behaviour. Therefore, it is necessary for an assessment of the toxic potential to humans and the environment to investigat...
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Personal Name(s): | Falk, K. (Corresponding author) |
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Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich, Zentralbibliothek, Verlag
1999
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Physical Description: |
III, 137 p. |
Document Type: |
Report Book |
Research Program: |
Addenda |
Series Title: |
Berichte des Forschungszentrums Jülich
3695 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
The physicochemical forms of arsenic (arsenic species) which are present in the environment vary significantly with respect to toxicity, bioavailability, stability and transport behaviour. Therefore, it is necessary for an assessment of the toxic potential to humans and the environment to investigate not only the total arsenic concentrations but also to differentiate the single species. By that the knowledge about ecological correlations and pathways will be increased. The present thesis reports the results of a Ph.D. study on the development and optimisation of analytical methods for arsenic speciation and their application to biological samples from different aquatic ecosystems in Germany. The method development included separation of 12 naturally occurring arsenic species byhigh-performance liquid chromatography (HPLC) followed by an arsenic selective detection by inductively coupled plasma-mass spectrometry (ICP-MS). The arsenic species As (III), As (V), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), arsenocholine (AC), trimethylarsine oxid (TMAO) and tetramethylarsonium (Tetra) were separated with ion-exchange chromatography, whereas reversed-phase chromatography was used for the separation of four arsenosugars. Because of the partly low arsenic concentration in biological samples a very good detection power was required. Therefore, an HPLC-ICP-MS system was tested with different nebulizers. Using the high efficiency nebulizer HHPN (Hydraulic High Pressure Nebulizer), detection limits in the low pg-range could be achieved. An importarm step in speciation analysis is the extraction of the samples. Specific studies have been performed for comparing the extraction of fresh and freeze-dried material. lt was shown that the extraction efficiencies for fresh samples were almost 100 % whereas for some freezedried samples a lawer extractability was found. The developed analytical methods were applied to arsenic speciation in four marine matrixes, which are representative of different trophic levels in the food chain. All samples originated from an ecosystem in the North Sea. In the extracts of common mussels, eel-pout muscles and sea gell eggs the species AB was found to be the major component of the detected arsenic species beside of small amounts of other known and unknown arsenic compounds. Bladderwrack contained mostly arsenosugars. The contents of the inorganic arsenic species were at a very low level in all analyzed samples. Regarding the mass balances it was found that a certain amount of arsenic could not be detected in most of the matrices. Therefore, it is assumed that these samples contain unknown arsenic species, e. g. arsenolipids or arsenoproteins. Investigations of bream, a limnic fish, showed differences with respect to arsenie species pattern and mass balance in comparison to the marine fish eel-pout. Furthermore, it was found that the arsenic pattern of a specific bioindicator was depending on the ecosystem. As examples, mussels from the North Sea and the Baltic Sea as well as bream from different rivers in Germany were characterized. |