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Description
Laser spectroscopy (Resonance Ionisation Mass Spectrometry-RIMS, Time Resolved Laser Inuced Fluorescence-TRLIF, Time Resolved Laser Induced Chemiluminecence-TRLIC,) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) can be very efficient for elemental and isotope composition analysis of various samples, as well as for the determination of the molecular and valence forms of uranium (speciation analysis) [1-5]. A series of reference materials measurements with various isotope compositions ranging from depleted and natural to enriched uranium by RIMS have been previously reported by our collaboration [1,2]. For samples of depleted uranium the $^{235}U/^{238}U < 0.003$ ratio was determined with <7% precision (2σ errors) for the total uranium concentrations not exceeding ∼80 fg per sample [1].
Without mineralization, the limit of uranyl detection (LOD) by TRLIF in blood plasma has been determined $0.1ng/ml$. After mineralization, a lower LOD ranging $0.008ng/ml - 0.01ng/ml$ has been evaluated. The limit of uranyl detection in urine in our TRLIF experiments was up to $0.005ng/ml$. Such LOD are sufficient to allow for studies the dinamics proccesses and behaviour of the of uranium in biologicas objects [3,4]. However, actinides in various valence states do not all exhibit luminescence properties and for such cases the TRLIC methods can be applied [2,5].
A high concentration of uranium we detected by ICP-MS in the bones of dinosaurs $(122mg/kg)$, South mammoth $(220mg/kg)$, prehistoric bear $(24mg/kg)$ and archanthropus $(1.5mg/kg)$ compared to surrounding soils $(3.7mg/kg-7.8 mg/kg)$ and standard bones $(<0.01mg/kg)$ was established. The standart $^{235}U/^{238}U = 0.007$ ratio was detected for all samples, but the $^{234}U/^{238}U$(detected $1.6·10^{-4} ÷5.8·10^{-5}$) ratio differ from secular equilibrium value $^{234}U/^{238}U (5.5·10^{-5})$.
References
1. Strashnov I.M., et al. Anal. Atom. Spectroscopy 2019, 34, 1630.
2. Strashnov I.M., et al. J. of Radioanalytical and Nuclear Chemistry 2019, 322, 1437.
3. Izosimov I.N. Procedia Chemistry 2016, 21, 473.
4. Izosimov I.N. Environmental Radiochemical Analysis VI, pp. 115-130. Royal Society of Chemistry Publishing, 2019.
DOI: 10.1039/9781788017732-00115
5. Izosimov I.N. J. of Radioanalytical and Nuclear Chemistry 2015, 304, 207.
