ABSTRACT
Selenium is an emerging global metalloid contaminant with potential ecological and human risk second only to mercury. Selenium in marine environments is biomagnified in food webs, with birds and fish being particularly susceptible to the effect of this metalloid. Primary producers, especially phytoplankton, generally concentrate selenium from 102- to 106-fold above ambient dissolved concentrations. In the marine environment, selenium and its compounds are submitted to physical, chemical, and biochemical transformations with or without modification of their oxidation states. Despite the fact that the total selenium content is a fundamental measure in assessing risk, it does not provide a complete picture on its bioavailability and mobility. These characteristics depend on the chemical properties of a specific selenium species. The purpose of this chapter is to summarize and to discuss the existing analytical methods for selenium speciation in marine environments, in order to provide easy access to this topic to all interested researchers. Advantages and limitations of the analytical procedures applied are critically discussed with respect to the sample preparation and speciation analysis. Very recent developments such as the use of nanomaterials as sorbents for the preconcentration of inorganic selenium in water samples are highlighted.
