Determination of mercury and its forms in soils, sediments and tailings
by atomic absorption spectrometry
Pavel Coufalík
Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, Brno 611 37,
Czech Republic
Abstract
Many circulating organic and inorganic pollutants are involved in the global
environmental contamination. The mercury of anthropogenic origin represents a serious issue
nowadays. The combustion of fossil fuels and industrial production cause an enormous
increase of atmospherically transported mercury which is deposited in all parts of the
ecosystem. The mercury contained in the soil stands in research focus due to potential threat
to the biosphere.
The aim of this thesis is primarily the suggestion of comprehensive analytical
procedure for speciation analysis of the mercury in soils, sediments and tailings including the
sequential extraction of individual mercury forms and the use of thermal desorption analysis.
This research is also aimed to relevant interpretation of the data with regard to the
development of mercury speciation.
The mercury forms were observed using sequential extraction: mercury releasable in
water; mercury releasable under acidic conditions; mercury bound to humic substances;
elemental mercury, mercury bound to complexes and amalgams; mercury sulphide and
residual mercury. Furthermore, the thermal behavior of the six mercury species (Hg0
, HgCl2,
HgO, HgSO4, HgS and humic bound Hg) was studied by means of thermal desorption
analysis from the solid phase. Sequential extraction and thermal desorption used are
complementary methods and their implementation brings all basic knowledge about mercury
fractionation in the sample. Suggested work procedures were verified on the samples of soils,
sediments, tailings and peat. Based on the obtained results, the mercury speciation changes
depending on natural conditions of the material were described.