Ultraspuren- und Isotopenanalyse langlebiger Radionuklide mittels doppelfokussierender Sektorfeld-ICP-Massenspektrometrie
Kerl, W. (Corresponding author)
Publikationen vor 2000; PRE-2000; Retrocat
Jülich Forschungszentrum Jülich, Zentralbibliothek, Verlag 1998
122 p.
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Berichte des Forschungszentrums Jülich 3605
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Please use the identifier: http://hdl.handle.net/2128/22644 in citations.


Within the framework of the present study, new analytical methods were developed for determining long-lived radionuclides with the aid of double-focusing sector field ICP mass spectrometry and applied for the analysis of various radioactive samples. This primarily invoived radioactive waste samples from the nuclear energy sector and a tantalum target from a spallation neutron source. Major priority was given to the ultratrace and isotopic analysis of actinoides, iodine and lanthanoids, the lauer being determined by the on-line coupling of high-performance liquid chromatography (HPLC) and sector field ICP-MS. The detection limits of sector field ICP-MS for actinoid nuclides of anthropogenic origin (e.g. $^{240}$Pu, $^{243}$Am, $^{245}$Cm) are between about 0.4 and 1.1 fg/ml. Under optimum experimental conditions ($^{235}$U/$^{238}$U $\approx$ 1), the precision in $^{235}$SU/$^{238}$U isotopic ratio determinations has been determined as 0.06 % RSD. For the analysis of radioactive samples, comparison measurements with alpha spectrometry have shown good agreement between the values even for isotope ratios in the order of 10$^{-6}$. In order to reduce both the dose rate for the Operator and radioactive contaminations inside the mass spectrometer during the analysis of radioactive sample solutions, an apparatus was constructed for flow-injection analysis in combination with a sector field ICP mass spectrometer (FI-ICP-MS) and optimized with respect to minimal sample volume, low detection limits and good reproducibility of the injection. A sample volume of 2 $\mu$l proved completely sufficient for determining actinoids in the lower pg/rnl concentration range. For the determination of the long-lived radionuclide $^{129}$I as well as the stable occurring in nature, a gas-liquid separator was developed permitting the efficient sample introduction of volatile iodine into the ICP-MS via the gas phase. Using this sample introduction systern it was possible to increase the detection sensitivity about fiftyfold in comparison to the Meinhard nebulizer. In addition to the analysis for radioactive sample solutions purely by mass spectrometry, a new field of application for the an-line coupling of HPLC and ICP-MS was opened up, i.e. the determination of the nuclide abundance and concentration of lanthanoids in an irradiated tantalum target from a spallation neutron source. Since the nuclide abundance of the lanthanoids formed in the tantalum target differ greatly from Chose in nature and therefore a large number of isobaric interferences were to be expected in the mass spectrum, it was necessary to separate chemically the elements before analysing them by mass spectrometry. Ion chromatography was used for this purpose.