Methyl mercury hydroxide

Agent Index A148 Methyl Mercury Hydroxide ... 

Regulatory SARA 313 reportable Manuf./Distrib. Aldrich http./Nmw.sigma-aldrich.com, Alfa Aesar http //www.alfa.com, ICN Biomed. Research Prods. http //www.icnbiomed.com, Pfaltz Bauer http //www.pfaitzandbauer.com, Riedel-deHaen http //WWW. rdh-iab. de Spectrum Quality Prods. http //www.spectrumchemicai.com, Strem Chems. http //www.strem.com TCI Am. http //WWW.tciamerica. com Methyl mercury hydroxide CAS 1184-57-2 UN 2025... 

Diethyl zinc Methanesulfonic acid Methyl mercury hydroxide catalyst, epoxies... 

Amitrole Ammonium thiocyanate But-2-yne-1,4-diol Cacodylic acid Calcium cyanamide 2,4-D Endothall Endothall sodium Magnesium chlorate Methyl mercury hydroxide... 

In studies in vivo (Woods and Fowler 1977 Woods and Southern 1989), treatment of male Sprague Dawley rats with methyl mercury hydroxide (MMH) for 6 weeks at 0.6 or 1.2mg/kg per day by drinking water produced a pronounced coproporphyrinuria characterized by a dose-related increase in the urinary coproporphyrin concentration up to 20 times control levels. Renal coprogen oxidase activity was depressed by as much as 56% of the control value 3 weeks after initiation of MMH treatment, whereas hepatic coprogen oxidase was not affected. Depression of renal coprogen oxidase activity correlated closely with increasing mercury levels in the kidney, suggesting that the interaction of Hg " either with the enzyme itself... 

Figure 5.. Northern blot of spinach leaf poly A RNA probed with RNA transcribed from a synthetic spinach AGP-I gene. Two pg of RNA was separated on a 1.5% agarose gel including 8 mM methyl mercury hydroxide. Size standards (Lane 1) are P labelled Hind III/Eco R1 fragments of lambda DNA. Hybridization was performed at 65° in 4.5 X SSG and 25% formamide.

S. Sora and M. Carbone, Chloral hydrate, methyl mercury hydroxide and ethidium bromide afifect segregation during meiosis of Saccharomyces cerevisiae, Mutat. Res., 1987, 190, 13-17. 

In mercury speciation studies, pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), and supercritical fluid extraction (SEE) are employed [33]. In particular, methyl-mercury is extracted by the Westoo method [33,34], which consists in a leaching process with hydrochloric acid, the extraction of the metal chloride into benzene or toluene, the addition of ammonium hydroxide that converts the metal species to hydroxide and the saturation with sodium sulfate. Most of the HPLC methods reported in literature for the determination of organomercury compounds (mainly monomethyhnercury, monoethyhnercury, and monophenylmercury) are based on reversed... 

Table 9.8 lists the strengths of various bases toward the proton (H ) and the methyl-mercury cation (CH1Hg+). Bases such as the sulfide ion (S ) and triethylphosplune (El,P) are very strong toward both the methylmercury ion and the proton, but about a million times better toward the former hence they are considered soft The hydroxide ion is a strong base toward both acids, but in this case about a million times better toward the proton hence it is hard. The aqueous fluoride ion. F, is not a particularly good base toward either add but slightly better toward the proton as expected from its hard character. 

Mercury used to get into the environment in large amounts from the production of chlorine, from slimicides and fungicides used in the paper industry, and from fumigants. Mercury is one of the electrodes for the electrolysis of salt water to produce chlorine and sodium hydroxide. The contaminated mercury used to be dumped into lakes and rivers (0.45 Ib/ton of CE produced) because it was believed to be so heavy that it would just settle to the bottom. However, it was found that certain microorganisms could convert the mercury to organic mercury compounds, almost exclusively methyl mercury, which can be quite toxic. 

Not aU the available methods extract the mercury species from solid samples (soil, sediment or biological material) with acceptable efficiency. The procedure giving the best recovery for methyl mercury from soil (95 4%) is the distillation method, and from fish tissue it is alkaline digestion using tetramethylammonium hydroxide with focused microwave power (95 to 105%). There is no standardized method to assess the extraction efficiency of a particular method, but several options are described in the subchapter on extraction efficiencies. 

Support a 1500 ml. three-necked flask, equipped with a mercury-sealed stirrer and a double surface reflux condenser, on a water bath, and place a solution of 84 g. of sodium hydroxide in 185 ml. of water, 50 g. (41-5 ml.) of nitrobenzene and 500 ml. of methyl alcohol in the flask. Add 70 g. of zinc powder (1), start the stirrer, and reflux for 10 hours. The solution gradually assumes the reddish colour of azobenzene and then on further... 

Subsequent dehydrohalogenation afforded exclusively the desired (Z)-olefin of the PGI2 methyl ester. Conversion to the sodium salt was achieved by treatment with sodium hydroxide. The sodium salt is crystalline and, when protected from atmospheric moisture and carbon dioxide, is indefinitely stable. A variation of this synthesis started with a C-5 acetylenic PGF derivative and used a mercury salt cataly2ed cyclization reaction (219). Although natural PGI has not been identified, the syntheses of both (6R)- and (65)-PGl2, [62777-90-6] and [62770-60-7], respectively, have been described, as has that of PGI3 (104,216). 

Procedure (indirect method). Weigh out accurately 0.1-0.2 g of the ammonium salt into a 500 mL Pyrex conical flask, and add 100 mL of standard 0.1M sodium hydroxide. Place a small funnel in the neck of the flask in order to prevent mechanical loss, and boil the mixture until a piece of filter paper moistened with mercury(I) nitrate solution and held in the escaping steam is no longer turned black. Cool the solution, add a few drops of methyl red, and titrate with standard 0.1M hydrochloric acid. Repeat the determination. 

The apparatus consists of a 3-]. three-necked flask fitted with a mercury-sealed mechanical stirrer, a reflux condenser, a dropping funnel, and a thermometer which reaches almost to the bottom of the flask. Five hundred grams of potassium hydroxide pellets (85 per cent potassium hydroxide) (7.5 moles) and 750 cc. of commercial absolute methyl alcohol (free from acetone) are placed in the flask and stirring begun. The bulk of the alkali dissolves in a few minutes, with the evolution of heat. The flask is now surrounded by an ample cold-water bath, and, when the internal temperature drops to 6o°, addition of a mixture of 360 g. (353 cc., 3 moles) of -tolualdehyde (Note 1), 300 cc. of formalin (3.9 moles) (Note 2), and 300 cc. of absolute methyl alcohol is begun at such a rate that the internal temperature remains at 60-70°. This addition requires about fifteen minutes. The internal temperature is then maintained at 60-70° for three hours, after which the reflux condenser is replaced by a downward condenser, and the methyl alcohol distilled with the aid of a brine bath until the internal temperature reaches ioi°. Nine hundred cubic centimeters of cold water is then added to the warm residue, and the mixture cooled. The resulting two layers are separated at once (Note 3), and the aqueous layer extracted with three 200-cc. portions of benzene. The combined oil and extracts are washed with five or six 50-cc. portions of water (Note 4), and the combined washings extracted... 

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