Mercury Toxicity and Speciation Analysis

To understand the kinetics and toxic mechanisms of mercury (Hg) species in vivo and in vitro, speciation analysis is of important relevance. This chapter focuses on the identification of thiol and/or selenol containing target biomolecules. Recent in vitro studies comparing the transfer across brain barriers as well as the toxicity in human neurons and human astrocytes clearly demonstrate strong variations between inorganic mercuric Hg chloride (HgCl2) and organic methylmercury chloride (MeHgCl) and thiomersal illustrating the need for speciation analysis. Most often, mercury speciation analysis uses hyphenated systems comprising of a separation technique coupled to elementor molecule-selective detection. Main analyzers for Hg are inductively coupled plasma-mass spectrometry (ICP-MS), cold vapor-atomic fluorescence spectrometry (CV-AFS), microwave-induced plasma-atomic emission (MIP-AES) and ICP-atomic emission spectrometry (ICP-AES). Today, a wide variety of instrumentation for total Hg analysis exists, for example, with CV-AFS providing ppt-level limits of detection.