Mercury biological systems

A. SlOEL and H. SlOEL (eds.) Metal Ions in Biological Systems, Vol. 34, Mercury and its Effects on the Environment and Biology, Dekker, New York, 1997 604 pp. 

Bodaly RA, St. Louis VL, Paterson MJ, Fudge RJP, Hall BD, Rosenberg DM, Rudd JWM. 1997. Bioaccumulation of mercury in the aquatic food chain in newly flooded areas. In Sigel A, Sigel H, editors, Metal ions in biological systems, Vol. 34 Mercury and its effects on environment and biology. New York (NY) Marcel Dekker Inc., p. 259-287. 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

What biotransformation might inorganic mercury undergo in a biological system ... 

Elemental mercury (Hg°) may be absorbed by biological systems as a vapor. Despite being a liquid metal, mercury readily vaporizes at room temperature and in this form constitutes a particular hazard to those who use scientific instruments containing it, for example. 

Like cadmium, mercury(II) has a strong affinity for sulfhydryl groups in proteins, enzymes, hemoglobin, and serum albumin. Because of the abundance of sulfhydryl groups in active sites of many enzymes, it is difficult to establish exactly which enzymes are affected by mercury in biological systems. 

The study of the adsorption of DNA at electrode surfaces is of fundamental interest, since the interaction of DNA with charged surfaces can be expected in biological systems. In fact, a number of studies of the adsorption of DNA were conducted at mercury electrodes [43-51] and carbon electrodes [52] and in general weaker adsorption was observed with native DNA than with denatured DNA. 

The principle of the isotope dilution analysis (IDA) is described in Section 6.4. Due to its advantages as a definitive and accurate analytical method for the determination of element concentration via isotope ratio measurements, IDA is being increasingly applied in mass spectrometry, especially in ICP-MS and LA-ICP-MS as one of the most frequently used techniques. For example, the isotope dilution technique is employed in species analysis in biological systems, " e.g., for the determination of mercury species in tuna material,or in aquatic systems. Further applications of the isotope dilution technique are the determination of selenomethionine in human blood serum by capillary HPLC-ICP (ORC) MS ° or sulfur speciation in gas oil, diesel or heating fuel by LA-ICP-MS. Evans and co-workers have reported on the high accuracy analysis of sulfur in diesel fuel by IDA. ICP-SFMS has been employed for Si species analysis in biological or clinical samples and... 

The marked affinity of mercury for cysteinyl ligands, manifest in these XAS studies, points to a major biochemical perturbation upon incorporation of mercury(II) into a biological system, not least if substitution for copper occurs with a blocking of the activity of Type 1 sites. However, nature has also used this affinity for cysteinyl residues to bind mercury(II) for reduction and to switch on a process that pro-... 

Experimental system Dielectric properties Mercury drop, double layers, biological systems Anodic dissolution Electro- crystallization, corrosion, 3-D electrodes Generators, mixed conductors, redox materials Heterogeneous surfaces... 

Mercury is essentially nontoxic in its elemental form (Hg ). In the absence of any chemical or biological system that chemically alters Hg , it can be consumed orally without any significant side effects. However, once Hg is chemically modified to the ionized, inorganic species, Hg T it becomes toxic. Further bioconversion to an alkyl Hg, such as methyl Hg (CHaHg ), yields a very toxic species of Hg that is highly selective for lipid-rich tissue, such as the neuron. The relative order of toxicity is as follows ... 

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