Standard Article

Speciation of Radionuclides in the Environment

Radiochemical Methods

  1. Brit Salbu

Published Online: 15 SEP 2006

DOI: 10.1002/9780470027318.a6308

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Salbu, B. 2006. Speciation of Radionuclides in the Environment. Encyclopedia of Analytical Chemistry. .

Author Information

  1. Agricultural University of Norway, Norway

Publication History

  1. Published Online: 15 SEP 2006

Abstract

To obtain information on physicochemical forms of radionuclides in the environment, speciation techniques should be applied in situ, at-site or in laboratories shortly after sample collection. Among speciation techniques for radionuclides in waters, combined in situ ultrafiltration and exchange chromatography are most promising as radionuclides species are fractionated with respect to nominal molecular mass and change properties simultaneously. However, the fractionation and characterization of chemically well-defined low molecular mass (LMM) species in waters is still a challenge. Surface analytical techniques (e.g. electron microscopy) are useful for characterizing colloids and particles with respect to structure and radionuclide distribution. Recent development within synchrotron-based X-ray microbeam techniques allows detailed information of crystallographic structure (micro-X-ray diffraction (μ-XRD)), oxidation states (micro-X-ray absorption near-edge spectroscopy (μ-XANES)) and volume distribution (μ-XANES tomography) of particle-associated radionuclides on the micrometer scale. Information on radionuclides reversibly or irreversibly associated with solid surfaces (binding mechanisms) is attained by different extraction techniques, while dynamic tracer experiments can provide information on the kinetics involved.