Erschienen in:Jülich : Forschungszentrum Jülich, Zentralbibliothek, Verlag, Berichte des Forschungszentrums Jülich 3605, 122 p. (1998).
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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 ...