Amount Of Inorganic Mercury Research Articles

Thermodynamic Study of the Extraction of Inorganic Mercury Compounds in Fish Species of the International Anzali Wetland, Iran

AbstractInorganic mercury concentration was measured in the muscle tissues of four types of fish in the aquatic international Anzali Wetland ecosystem in Guilan. In the same ecosystem, the northern pike is able to concentrate inorganic mercury in its body more than other fish. In each species, a fish with the highest amount of inorganic mercury was selected for determination of thermodynamic parameters of inorganic mercury extraction using calculation of the equilibrium constant and fitting of ln Kc versus inverse temperature at the atmospheric pressure. The origins of thermodynamic parameters were discussed. The extraction processes were done in the range of temperatures from 331.15 to 365.15 K and at atmospheric pressure. Results show that the extraction of mercury compounds from SH groups of sulfhydryl proteins in fish muscle tissue is an endothermic process with a positive value for entropy and Gibbs free energy changes at room temperature.

Voltammetric determination of methylmercury and inorganic mercury with an home made gold nanoparticle electrode

This study outlines the development of a procedure for the determination of methylmercury by anodic stripping voltammetry at a gold nanoparticle-modified glassy carbon electrode (AuNPs-GCE) and for the differentiation between methylmercury and inorganic mercury. The signal of methylmercury was measured in the square wave mode using HCl as the supporting electrolyte. The procedure had good accuracy, repeatability and linearity. The determination of total mercury in solutions containing both methylmercury and inorganic mercury was performed after converting the former into the inorganic form. Different sample solution pre-treatments were tested for this purpose, and an acid digestion in a microwave oven with HNO3 and H2O2 was found to be the most effective. The selective determination of methylmercury in the presence of inorganic mercury was possible after masking the latter through reduction to the elemental state with SnCl2. The amount of inorganic mercury was determined by difference.

Effect of selenium on distribution, demethylation, and excretion of methylmercury by the guinea pig.

The influence of selenium on methylmercury excretion, organ and subcellular distribution, and demethylation was studied in the guinea pig at different times following a single equimolar dose (50 miroM/kg) of CH203 3) HgCl and Na2SeO3 administered separately or concomitantly per os. Excretion of mercury through feces was the dominant clearance pathway in both groups. Selenium significantly decreased excretion of total and organic mercury in feces during the course of the study, but in the urine only on d 13. Selenium also significantly decreased the concentration of total mercury in major organs. The exception was brain on d 1, in which mercury levels were higher in the presence of selenium; however, on d 7 and 13 both cerebrum and cerebellum showed lower mercury levels as compared to the group treated with methylmercury alone. Selenium had no significant effect on the subcellular mercury distribution in the liver, kidney, and cerebrum, other than that which could be accounted for the whole organ uptake. The level of organic mercury in most of the analyzed organs was significantly decreased by the presence of selenium; however, relative proportions of inorganic to organic mercury remain unchanged. The single exception was kidney, where selenium markedly decreased the relative amount of inorganic mercury.

Biotransformation of Hg-203 labelled methyl mercuric chloride in rat brain measured by specific determination of Hg2+.

Adult Wistar rats were injected with Hg‐203 labelled methylmercuric chloride or mercuric chloride. After a methylmercury injection 3‐6 % of the total brain mercury is present in the inorganic form. This represents more inorganic mercury in the brain than after an equal dose of mercuric chloride. The time course of the inorganic mercury content in the brain is dependent on the compound given. Subcellular fractionation shows that the myelin and mito‐chondrial fractions accumulate more inorganic mercury than the other fractions. There is an inverse relationship between the dose of methylmercury given and the amount of inorganic mercury in the brain.