Heavy Metal Group

Mutagenicity, Carcinogenicity, and Teratogenicity of Industrial Pollutants (ref. 15) contains summaries of teratogenicity information about industrial pollutants. Discussions of these pollutants are divided into four groups heavy metals, insecticides, monomers, and halogenated hydrocarbon solvents. 

Group Heavy metal Lead Cadmium Nickel Manganese Chromium ... 

In organic chemistry the term refers to compounds containing the NH2 ion or the > NH group. These are prepared by the action of heat on amides or by metathetica reactions in liquid ammonia. The heavy metal imides are explosive. 

Aminodiacetate exchangers have the —N(CH2COOH)2 group which has an unusually high preference for copper, iron, and other heavy metal cations and, to a lesser extent, for alkaline earth... 

Other Reactions of Phospholipids. The unsaturated fatty acid groups in soybean lecithin can be halogenated. Acetic anhydride combined with the amino group of phosphatidylethanolamine forms acetylated compounds. PhosphoHpids form addition compounds with salts of heavy metals. Phosphatidylethanolamine and phosphatidjhnositol have affinities for calcium and magnesium ions that are related to interaction with their polar groups. 

Metals and Metallic Ions. Under appropriate conditions, ozone oxidizes most metals with the exception of gold and the platinum group. When oxidized by ozone, heavy metal ions, such as Fe and Mn , result in the precipitation of insoluble hydroxides or oxides upon hydrolysis (48—50). Excess ozone oxidizes ferric hydroxide in alkaline media to ferrate, and Mn02 to MnO. ... 

Zinc phosphate, Zn2(P0 2> forms the basis of a group of dental cements. Chromium and zinc phosphates are utilized in some metal-treating appHcations to provide corrosion protection and improved paint adhesion. Cobalt(II) phosphate octahydrate [10294-50-5] Co2(P0 2 8H20, is a lavender-colored substance used as a pigment in certain paints and ceramics. Copper phosphates exhibit bioactivity and are used as insecticides and fungicides. Zinc, lead, and silver phosphates are utilized in the production of specialty glasses. The phosphate salts of heavy metals such as Pb, Cr, and Cu, are extremely water insoluble. 

Carboxylate, sulfonate, sulfate, and phosphate ate the polar, solubilizing groups found in most anionic surfactants. In dilute solutions of soft water, these groups ate combined with a 12—15 carbon chain hydrophobe for best surfactant properties. In neutral or acidic media, or in the presence of heavy-metal salts, eg, Ca, the carboxylate group loses most of its solubilizing power. 

The first synthetic organic pigments were used to shade or tone the weaker colorants and became known as toners. Metal toners usually contain one sulfonic acid group and often a carboxyUc acid group. The pigment is rendered iasoluble, ie, laked Ai a heavy metal cation. An example of a calcium salt is Lithol Rubine BK [5858-81-1] Vhl) (Cl Pigment Red 57 Cl 15850). 

Heavy metals Cation Polystyrene matrix Chelating functional groups Mineral acids... 

The application of ammonium molybdophosphate and other unsoluble in water salts of heteropolyacids for preconcentration of heavy metals of first group elements Cs(I), Ag(I), Cu(I) and also T1(I), Hg(I) (M(I)) is described. The shortcomings of ammonium molybdophosphate as ionexchanger are ... 

MIR), requires the introduction of new x-ray scatterers into the unit cell of the crystal. These additions should be heavy atoms (so that they make a significant contribution to the diffraction pattern) there should not be too many of them (so that their positions can be located) and they should not change the structure of the molecule or of the crystal cell—in other words, the crystals should be isomorphous. In practice, isomorphous replacement is usually done by diffusing different heavy-metal complexes into the channels of preformed protein crystals. With luck the protein molecules expose side chains in these solvent channels, such as SH groups, that are able to bind heavy metals. It is also possible to replace endogenous light metals in metal-loproteins with heavier ones, e.g., zinc by mercury or calcium by samarium. 

Heavy metal A general term relating to a specific group of metals, which as suspended and deposited particulates can contaminate the environment. 

World Healdi Organization Recommended Healdi-Based Limits in Occupational Exposure to Heavy Metals, Report of a WHO Study Group, WHO, Geneva, Switzerland, 1980. 

Germanium and Sn are non-toxic (like C and Si). Lead is now recognized as a heavy-metal poison it acts by complexing with oxo-groups... 

Arsenites of the alkali metals are very soluble in water, those of the alkaline earth metals less so, and those of the heavy metals are virtually insoluble. Many of the salts are obtained as meta-arsenites, e.g. NaAs02, which comprises polymeric chain anions formed by comer linkage of pyramidal ASO3 groups and held together by Na ions ... 

By contrast with the water-soluble sulfides of Groups 1 and 2, the corresponding heavy metal sulfides of Groups 11 and 12 are amongst the least-soluble compounds known. Literature values are often wildly discordant, and care should be taken in interpreting the data. Thus, for black HgS the most acceptable value of the solubility product [Hg +][S ] is 10- mol2l-2, i.e. 

Polyelectrolytes such as the ion exchange plastics form an interesting group of materials because of their ability to interact with water solutions. They have been used in medical applications involving the removal of heavy metal ions from the human body. They can be used to interact with external electric fields and change their physical properties drastically as is illustrated by the fact that some electrically active liquid crystals are polyelectrolytes of low molecular weight. 

RAFT polymerization lends itself to the synthesis of polymers with thiol end groups. Several groups have utilized the property of thiols and dilhioesLers to bind heavy metals such as gold or cadmium in preparing brushes based on gold film or nanoparticles1 8 761 763 and cadmium selenide nanoparticles.763 76 1... 

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