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The interaction between mercury (Hg) and selenium (Se) is one of the best known examples of biological antagonism, yet the underlying mechanism remains unclear. This review focuses on the possible pathways leading to the Hg‐Se antagonism, with an emphasis on the potential Hg‐Se compounds that are responsible for the antagonism at the molecular level (i.e., bis[methylmercuric]selenide, methylmercury selenocysteinate, selenoprotein P‐bound HgSe clusters, and the biominerals HgSexS1−x). The presence of these compounds in biological systems has been suggested by direct or indirect evidence, and their chemical properties support their potentially key roles in alleviating the toxicity of Hg and Se (at high Hg and Se exposures, respectively) and deficiency of Se (at low Se exposures). Direct analytical evidences are needed, however, to confirm their in vivo presence and metabolic pathways, as well as to identify the roles of other potential Hg‐Se compounds. Further studies are also warranted for the determination of thermodynamic properties of these compounds under physiological conditions toward a better understanding of the Hg‐Se antagonism in biota, particularly under real world exposure scenarios.

This review covers the toxicology of mercury and its compounds. Special attention is paid to those forms of mercury of current public health concern. Human exposure to the vapor of metallic mercury dates back to antiquity but continues today in occupational settings and from dental amalgam. Health risks from methylmercury in edible tissues of fish have been the subject of several large epidemiological investigations and continue to be the subject of intense debate. Ethylmercury in the form of a preservative, thimerosal, added to certain vaccines, is the most recent form of mercury that has become a public health concern. The review leads to general discussion of evolutionary aspects of mercury, protective and toxic mechanisms, and ends on a note that mercury is still an \"element of mystery.\"

We report an extremely sensitive and specific detection of mercuric ions (Hg 2+ ) based on graphene assisted laser desorption/ionization mass spectrometry (GALDI-MS). Combining the highly selective coordination interactions between thymine (T) and Hg 2+ , we present a simple, effective, and novel approach, based on π–π interactions of the T-Hg 2+ -T complex and G that can serve as a platform and matrix for GALDI-MS. The present sensor not only exhibits high selectivity and sensitivity (picomolar) to Hg 2+ in aqueous solution, but also can elucidate the chemical structures of the metal complexes. The significant advantage in the current approach is that there is no need for a sophisticated instrument, and no sample pretreatment is required to detect the Hg 2+ ions. Figure ᅟ

Growing evidence has indicated that mercury sulfide nanoparticles (HgS NPs) are the potential precursors for neurotoxic methylmercury. But how and which soil components affect HgS NP retention remains unclear. Here, we examined the retention of uncoated and humic acid coated HgS NPs in 18 natural soils with varied properties. Our results suggested that the K r values (retention coefficients) for uncoated and humic acid HgS NPs were 2.46 × 10 3 to 8.32 × 10 5 L kg − 1 and 3.00 × 10 3 to 2.73 × 10 5 L kg − 1 , respectively. Soil properties (i.e., electrical conductivity, organic matter (OM), oxalate-extractable Fe and Mn) significantly affected the uncoated HgS NP retention, accounting for 69% of the variability in the K r values. Meanwhile, OM exhibited a tendency to reduce coated HgS NP retention. Importantly, HgS NPs exhibited significant dissolution in representative soil porewaters. These findings highlight the soil property-dependent retention of HgS NPs in realistic environment.

Chemical found in 60-year-old cat brain reopens debate over Minamata disaster. The city of Minamata, Japan, is dotted with monuments commemorating victims of an industrial mass poisoning decades ago. High in the hills, a small stone memorial honors other deaths—of cats sacrificed in secret to science. Now, after restudying the remains of one of those cats, a team of scientists is arguing, controversially, that the long-standing explanation for the tragedy is wrong. No one questions the root cause of the disaster, which at minimum poisoned more than 2000 people: mercury in a chemical factory's wastewater that was dumped into Minamata Bay and taken up by seafood eaten by fishermen and their families. At first, the chemical form of the mercury, which ultimately killed many of its victims and left many babies with severe neurological disorders, was unknown. But in 1968, the Japanese government blamed methylmercury, a common byproduct of mercury pollution. Many studies supported that conclusion, finding methylmercury spikes in shellfish, bay sludge, and even hundreds of umbilical cords from babies delivered during the time. Yet researchers at the University of Saskatchewan say methylmercury is not the culprit. Instead, the cat remains point to an obscure organic mercury compound that may say little about the broader threat of mercury pollution.

Reducing mercury emission is hot topic for international society. The first step for controlling mercury in fuel gas is to investigate mercury distribution and during the flue gas treatment process. The mercury transport and transformation in wet flue gas cleaning process of nonferrous smelting industry was studied in the paper with critical important parameters, such as the solution temperature, Hg 0 concentration, SO 2 concentration, and Hg 2+ concentration at the laboratory scale. The mass ratio of the mercury distribution in the solution, flue gas, sludge, and acid fog from the simulated flue gas containing Hg 2+ and Hg 0 was 49.12~65.54, 18.34~35.42, 11.89~14.47, and 1.74~3.54%, respectively. The primary mercury species in the flue gas and acid fog were gaseous Hg 0 and dissolved Hg 2+ . The mercury species in the cleaning solution were dissolved Hg 2+ and colloidal mercury, which accounted for 56.56 and 7.34% of the total mercury, respectively. Various mercury compounds, including Hg 2 Cl 2 , HgS, HgCl 2 , HgSO 4 , and HgO, existed in the sludge. These results for mercury distribution and speciation are highly useful in understanding mercury transport and transformation during the wet flue gas cleaning process. This research is conducive for controlling mercury emissions from nonferrous smelting flue gas and by-products.

Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac–Hartree–Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor–crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg ₂Cl ₂), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from ¹¹⁹Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium.

Mercury sulfide is an insoluble inorganic mercury compound, and it is the main chemical form in traditional oral mercury-containing medicines. Hg2+ has a high affinity for thiols, and small molecule thiols in the gastrointestinal tract may promote mercury dissolution of mercury sulfide by binding to Hg2+. L-cysteine is the only amino acid that possesses a reducing sulfhydryl group (-SH), out of the 20 amino acids. This study investigates the effect of L-cysteine on mercury dissolution of mercury sulfide at pHs ranging from 1.2 to 7.2. The results showed that L-cysteine had different pH-dependent effects on the mercury dissolution of α-HgS and β-HgS. For α-HgS, the dissolved mercury concentration increased from 5.47 ± 0.97 ng/mL to 12.49 ± 0.54 ng/mL when the pH rose from 1.2 to 4.2, and decreased to 3.37 ± 0.70 ng/mL at pH 6.0 and then increased to 9.36 ± 0.79 ng/mL at pH 7.2. For β-HgS, the dissolved mercury concentration increased from 151.09 ± 2.25 ng/mL to 2346.71 ± 62.62 ng/mL when the pH increased from 1.2 to 7.2. In conclusion, L-Cys was distinctly enhanced upon mercury dissolution of α-HgS and β-HgS with increasing pH. These results may contribute to our understanding of the mercury absorption mechanism of traditional oral mercury-containing medicines.

The synthesis of II-VI semiconductor nanoparticles obtained by the thermolysis of certain group 12 metal complexes as precursors is reported. Thermogravimetric analysis of the single source precursors showed sharp decomposition leading to their respective metal sulfides. The structural and optical properties of the prepared nanoparticles were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) UV-Vis and photoluminescence spectroscopy. The X-ray diffraction pattern showed that the prepared ZnS nanoparticles have a cubic sphalerite structure; the CdS indicates a hexagonal phase and the HgS show the presence of metacinnabar phase. The TEM image demonstrates that the ZnS nanoparticles are dot-shaped, the CdS and the HgS clearly showed a rice and spherical morphology respectively. The UV-Vis spectra exhibited a blue-shift with respect to that of the bulk samples which is attributed to the quantum size effect. The band gap of the samples have been calculated from absorption spectra and werefound to be about 4.33 eV (286 nm), 2.91 eV (426 nm) and 4.27 eV (290 nm) for the ZnS, CdS and HgS samples respectively.

Many inorganic pigments contain heavy metals hazardous to health and environment. Much attention has been devoted to the quest for nontoxic alternatives based on rare-earth elements. However, the computation of colors from first principles is a challenge to electronic structure methods, especially for materials with localized f -orbitals. Here, starting from atomic positions only, we compute the colors of the red pigment cerium fluorosulfide as well as mercury sulfide (classic vermilion). Our methodology uses many-body theories to compute the optical absorption combined with an intermediate length-scale modelization to assess how coloration depends on film thickness, pigment concentration, and granularity. We introduce a quantitative criterion for the performance of a pigment. While for mercury sulfide, this criterion is satisfied because of large transition matrix elements between wide bands, cerium fluorosulfide presents an alternative paradigm: the bright red color is shown to stem from the combined effect of the quasi-2D and the localized nature of [Formula] states. Our work shows the power of modern computational methods, with implications for the theoretical design of materials with specific optical properties.