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Spectroscopic Techniques in Actinide Speciation Studies
Geipel, G.; Bernhard, G.;
The determination of the behavior of actinides in the environment needs several spectroscopic techniques, adapted to spectroscopic properties and concentration ranges of these elements in the environment.

New techniques for the speciation of actinides have been developed during the past decades. Three main requirements are of importance:
- License for handling of radioactive elements, especially for α-emitting actinides.
- Availability of actinides, especially the higher actinides are available only in small amounts.
- Speciation methods covering the concentration range of actinides expected or found in nature.

Speciation analysis can be distinguished into two types: non-invasive and invasive methods. Among the first group are spectroscopic methods. They are not restricted to the form of the species (solid, liquid, gas). Non-invasive methods need usually no treatment of the sample and allow the direct speciation of an element in its environment. Invasive methods in general are applicable to solids and solutions. They need normally a pretreatment and a separation of the sample. Sequential extraction can be used for the determination of species in solid systems. Besides for the separation of actinides /1/ extraction techniques are important for the determination of oxidation states of the actinides in solution. For example the oxidation states of plutonium can be determined using α-thenoyltrifluoroacetone (TTA) at pH = 0. Tetravalent plutonium is extracted to the organic phase, whereas all other oxidation states and polymeric plutonium remain in the aqueous phase. The same extraction procedure after addition of chromate allows to separate plutonium(III) and plutonium(IV). Other common extraction agents are tributylphosphate (TPB) and bis(2-ethyl-hexyl)-hydrogen-phosphate (HDEHP).
Keywords: Spectiation, Trace elements, Spectroscopy
  • Invited lecture (Conferences)
    School cum Workshop on Trace Element Speciation (SElS-08), 21.-29.11.2008, Kolkata, India

Publ.-Id: 11944 - Permalink