Methyl mercuric chloride

Shaw BP, Dash S, Panigrahi AK. 1991. Effect of methyl mercuric chloride treatment on haematological characteristics and erythrocyte morphology of Swiss mice. Environ Pollut 73 43-52. 

It is interesting to note that exactly the same interference occurred for both organic and inorganic mercury standards, since methyl mercuric chloride does not directly react with sodium sulphide to form mercuric sulphide. Therefore the interference could not be the result of incomplete digestion of mercuric sulphide or CH3Hg+. 

This automated procedure was estimated to have a precision of 0.13-0.21mg Hg kg-1 at the lmg Hg kgr1 level with standard deviations varying from 0.011-0.02mg Hg kg-1, i.e. relative standard deviations of 8.4-12% at the 17.2-32.3mg Hg kg-1 level in sediments. Recoveries in methyl mercuric chloride spiking studies were between 85 and 125%. The detection limit for the automated method is dependent upon the weight of sample taken for analysis. It is 0.1 pg Hg L 1 in the aqueous samples. The results for the automated method are routinely reported to a lower limit of O.lmg kg 1 which corresponds to a dry sample weight of 0.25g. 

Mercurous salt, HgC2H2N202, fine wh ppt obtd from diformylhydrazine, Na methylate mercurous chloride in aq-alcoholic soln (Ref 6)... 

Mercury may be present in air in different chemical states such as the elemental form (as a vapour or adsorbed on particular matter) or in the form of volatile mercury compounds (mercury chloride, methyl-mercuric chloride, and dimethyl mercury). Although elemental mercury is only one of the mercury forms which is not as toxic as its organic or ionic forms, analytical determination of elemental mercury is of special importance. Such analysis is used not only for determination of elemental mercury in environment, but also as a method for determination of other forms of mercury after reductive treatment. 

Methyl mercuric chloride Sodium hydroxide Thiosalicylic acid... 

To a solution or suspension in alcohol of 0.1 mole of methyl mercuric chloride is added 0.1 mole of sodium hydroxide in water and 0.1 mole of thiosalicylic acid in ethanol. The product is poured into water, whereupon the methyl mercurithiosalicylic acid is precipitated, since it is insoluble in water. This precipitate can be collected on a filter, and washed well with water to remove all the alcohol, salts, and free inorganic acids. The washed precipitate may then be dissolved in a water solution of sodium hydroxide, or, better, in a water solution of sodium bicarbonate. This produces the water-soluble salt of the methyl mercurithiosalicylic acid. 

Phosphorus trichloride. Methyl mercuric chloride. Buekton, he. cit. 

Mercury bis-a-acetyl-a-ethylpropyl or Mercury bis-aceto-diethyimethane, [CHgCO.CEta—JaHg, M.pt. 109° C. Aceto-diethyl-methyl-mercuric chloride, [CHgCO.CEtg—lHgCl, M.pt. 77° C. 

Fowler BA. The morphologic effects of dieldrin and methyl mercuric chloride on pars recta segments of rat kidney proximal tubules. Am J Pathol 1972 69 163-74. 

A decrease in heart rate was observed in male rats given 2 gavage doses of 12 mg Hg/kg as methyl-mercuric chloride (Arito and Takahashi 1991). An increase in systolic blood pressure was observed in male rats after daily oral gavage doses of 0.4 mg Hg/kg/day as methylmercuric chloride for 3-4 weeks (Wakita 1987). This effect began approximately 60 days after initiation of exposure and persisted for at least 9 months. No treatment-related histopathological changes were observed in the hearts of rats exposed to 0.1 mg Hg/kg/day as methylmercuric chloride in the diet for up to 2 years (Verschuuren et al. 1976). 

A sensitive test for neurological effects of gestational exposure to methylmercury is operant behavioral performance (i.e., rewarded responses to total lever presses). Bomhausen et al. (1980) reported a significant reduction in operant behavioral performance in 4-month-old rat offspring exposed to methyl-mercuric chloride at 0.008 mg Hg/kg/day on Gd 6-9. A dose of 0.004 mg Hg/kg/day did not alter the behavioral performance of the offspring. No other studies have confirmed this result to date. 

Nielsen JB, Andersen O. 1991a. Methyl mercuric chloride toxicokinetics in mice I. Effects of strain, sex, route of administration and dose. Pharmacol Toxicol 68(3) 201-207. 

Methyl mercuric chloride Irreversible brain damage... 

Andersen, H R., and O. Andersen. 1993. Effects of dietary alpha-tocopherol and beta- carotene on lipid peroxidation induced by methyl mercuric chloride in mice. Pharmacol. Toxicol. 73 (4) 192-201. 

Nielsen, J.B., and O. Andersen. 1991. Methyl mercuric chloride toxicokinetics in mice. II Sexual differences in whole-body retention and deposition in blood, hair, skin, muscles and fat. Pharmacol. Toxicol. 68(3) 208-211. 

The classic experiments of McKim et al. (1976) on the chronic effects of toxicants in which three generations of brook trout (Salvelinus fontinalis) were exposed to methyl mercuric chloride led to a scientifically based appreciation of the fact that the early life stages could be used for assessing chronic toxicity (McKim 1977). Due to the cost of complete life-cycle tests and the time required for their completion, increasing attention has been directed to truncated tests for chronic toxicity, and to the effects of toxicants on sensitive life stages. Nonetheless, there is substantial evidence that clearly exposes the limitations in the conclusions which can be drawn if only early life-cycle stages are examined. 

For example, metallic mercury is insoluble in the stomach and intestinal tract and is excreted almost completely as a result of this non-bioavailability. In contrast, inhaled mercury vapor is incorporated very effectively via the lungs and is strongly toxic in a systemic way. Organic mercury compounds (e.g., methyl mercuric chloride) when in the intestinal tract are sufficiently soluble to behave as orally very toxic substances. 

Ammons et al. studied the adsorption of methyl mercuric chloride from aqueous solutions on Filtrasorb-200 activated carbon at room temperature and found that the adsorption isotherms were nonlinear and did not fit either the Freundlich or the Langmuir isotherm equation. The adsorption was, however, reversible. Carrot et al. carried out adsorptive removal of mercury(ll) ions on five different commercial activated carbons associated with varying amounts of acidic and basic surface complexes. These workers observed that significant amounts of HgC and HgCl were adsorbed, but there was little adsorption of neutral HgCl2 or Hg + ions, hi the case of the basic carbons, the adsorption of the anions decreased with increase in the pH of the solution, but the uptake of cations was very small at pH = 0.2. They are of... 

Ammons, Dougharty, and Smith have studied the adsorption of methyl-mercuric chloride from aqueous solution by activated carbon by both batch and flow techniques. The data were analysed to investigate the factors that control the breakthrough curves. Axial dispersion was found to contribute no more than 15% to the second moment of the breakthrough curve, while liquid-to-particle mass transfer contributed about 60%. On a similar topic Benediktov, Vlasov, and Yurkevich in a paper of which only the title is abstracted, discuss the determination of the degree of exhaustion of active carbon with respect to organic substances during adsorption from aqueous solutions. 

Norseth T (1973) Biliary excretion and intestinal reabsorption of mercury in the rat after injection of methyl mercuric chloride. Acta Pharmacol Toxicol 33 280-288... 

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