Water inorganic mercury

Water (inorganic mercury) Reduction of sample with SnCI2 in HN03 purging of mercury to detector CVAAS 0.1 ng/L 99 Lee et al. 1989... 

To help prevent this, the U. S. Public Health Service has recommended a maximum limit of 0.5 ppm mercury in any food. If the fish are to have less than this level of methyl mercury and the concentration factor is 3,000, then the surrounding water in which the fish live should have less than 0.16 ppb (parts per billion). Currently the oceans have about 0.1 ppb, but it is not known whether this is in the form of organic or inorganic compounds.8 It is also not known whether fish can convert inorganic mercury into methyl mercury.8 However, a large number of microorganisms can do this, so possibly its usual form is unimportant. 

Methylmercury in the marine environment may originate from industrial discharges or be synthesised by natural methylation processes. Fish do not themselves methylate inorganic mercury [62,64], but can accumulate methyl mercury from sea water [63]. Methylmercury has been detected in sea water only from Minamata Bay, Japan, an area with a history of gross mercury pollution from industrial discharge. It has been found in some sediments but at very low concentrations, mainly from areas of known mercury pollution. It represents usually less than 1% of the total mercury in the sediment, and frequently less than 0.1% [65-67]. Microorganisms within the sediments are considered to be responsible for the methylation [65,68], and it has been suggested that methylmercury may be released by the sediments to the sea water, either in... 

Fig. 8.39 Distribution coefficients (K and defining the sorption of inorganic Hg(II) to estuarine particles versus salinity (S, in g/L) in the Beaulieu, Mersey, and Plym estuaries. Reprinted with permission from Turner A, Millward GE, LeRoux SM (2001) Sediment-water partitioning of inorganic mercuries in estuaries. Environ Sci Technol 35 4648-4654. Copyright 2001 American Chemical Society...

Mercrobes mercury reduction technology (Mercrobes) is a proprietary, ex situ technology for the treatment of soils, sludges, sediments, and waters contaminated with mercury and mercury compounds. The process uses proprietary microbes to reduce organic and inorganic mercury compounds to elemental mercury. The vendor claims that in addition to reducing charged... 

Li and coworkers synthesized the novel IL l-butyl-3-trimethylsilylimid-azolium hexafluorophosphate and demonstrated its utility for liquid/ liquid extraction of inorganic mercury. Using o-carboxyphenyl diazoamino p-azobenzene as a chelator to form a stable neutral complex with the metal ion, the authors demonstrated selective extraction into the hydrophobic IL phase [19]. When sodium sulfide was added to the IL phase, the mercury ion was back-extracted into the aqueous layer, providing an avenue for recycling the IL. The authors report extraction and back-extraction efficiencies of 99.9 and 100.1%, respectively, for a 5.0 pg/L aqueous mercury standard. The mercury detection limit was 0.01 ng/mL in water and the method was successfully applied to detecting trace mercury in natural water samples. 

S. Rio Segade and J. F. Tyson, Determination of methylmercury and inorganic mercury in water samples by slurry sampling cold vapor atomic absorption spectrometry in a flow injection system after preconcentration on silica C18 modified, Talanta, 71(4), 2007, 1696-1702. 

Nervous System. The nervous system is also a common target of toxic metals particularly, organic metal compounds (see Chapter 16). For example, methylmercury, because it is lipid soluble, readily crosses the blood-brain barrier and enters the nervous system. By contrast, inorganic mercury compounds, which are more water soluble, are less likely to enter the nervous system and are primarily nephrotoxicants. Likewise organic lead compounds are mainly neurotoxicants, whereas the first site of inorganic lead is enzyme inhibition (e.g., enzymes involved in heme synthesis). 

Unithiol has no FDA-approved indications, but experimental studies and its pharmacologic and pharmacodynamic profile suggest that intravenous unithiol offers advantages over intramuscular dimercaprol or oral succimer in the initial treatment of severe acute poisoning by inorganic mercury or arsenic. Aqueous preparations of unithiol (usually 50 mg/mL in sterile water) can be administered at a dose of 3-5 mg/kg every 4 hours by slow intravenous infusion over 20 minutes. If a few days of treatment are accompanied by stabilization of the patient s cardiovascular and gastrointestinal status, it may be possible to change to oral administration at a dose of 4-8 mg/kg every 6-8 hours. Oral unithiol may also be considered as an alternative to oral succimer in the treatment of lead intoxication. 

A field method of pre-concentration and preservation of organo-mercury species extracted from water was described (Jian and McLeod, 1992). Acidified water samples were passed through microcolumns packed with sulfhydryl cotton. The packing retained organo-mercury species, but not inorganic mercury. The contents were analysed later in a laboratory. 

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