Mercury EXAFS analysis

In order to gain information on the environments of certain atoms in dissolved species, in melts or in solids (crystalline or noncrystalline), which are not accessible to diffraction studies for one reason or another, X-ray absorption spectrometry (XAS) can be applied, with the analysis of the X-ray absorption near-edge structure (XANES) and/or the extended X-ray absorption fine structure (EXAFS). Surveys of these methods are available 39,40 a representative study of the solvation of some mercury species, ElgX2, in water and dimethylsulfoxide (DMSO) by EXAFS and XANES, combined with quantum-chemical calculations, has been published.41... 

Metallothioneins are a unique and widely distributed group of proteins. They are characterized by their low molecular weight (—6000), high cysteinyl content, and the ability to bind substantial numbers of metal ions (43). The proteins bind copper and zinc, thereby providing a mobile pool as part of the normal metabolism of these elements, and offer protection from the invasion of inorganic forms of the toxic elements cadmium, lead, and mercury. In addition, other metals, such as iron and cobalt, can be induced to bind. XAS is ideally suited to probe the environment of these different metal atoms (see Fig. 1), and the structural interpretations obtained from an analysis of the EXAFS data obtained in several such studies are summarized in Table 1(44). Thus, in each case, the data are consistent with the primary coordination of the metal deriving from the cysteinyl residues. 

EXAFS curve-fitting analysis of the mercury spectra in hair, RBC and serum samples from people living in Wanshan. 2007 Elsevier Inc. 

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