Toxicity arsenical compound

Leermakers, M., W. Baeyens, M. De Gieter, et al. 2006. Toxic arsenic compounds in environmental samples Speciation and validation. Trends Anal. Chem. 25(1) 1-10. 

Among the heavy main group elements arsenic has received the most attention. Arsonium ylides react with carbonyl compounds to yield either the alkenes or epoxides, depending upon the structure of the ylide and the reaction conditions. )espite their toxicity, arsenic compounds can be handled safely. 

Many of the ring-substituted derivatives of (1) have been prepared by the aforementioned coupling reactions, using appropriately substituted precursors.4,8-10,25 Regiospecific aromatic substitution reactions have improved the yields of substituted phenanthrolines, and reduced the dependence on the toxic arsenic compounds employed in the Skraup synthesis. These reactions typically give mixtures of mono- and symmetrically di-substituted phenanthrolines, which must be separated through careful workup. 

Arsenic occurs naturally in small amounts in many foods. Shrimp, for example, contain about 19 parts per million (ppm) arsenic, and corn may contain 0.4 ppm arsenic. The amount of naturally occurring arsenic in foods depends on the surroundings where they are grown and the metabolism of the plant or animal. While many soils contain arsenic, which causes an accumulation of the element as a plant grows, some insecticides also contain arsenic, which causes an arsenic residue when the insecticide is applied. The U.S. Food and Drug Administration (FDA) has set a limit of 76 ppm for arsenic levels in shellfish. In its ionic forms, arsenic is much more toxic than in its covalently bound compounds. The typical toxic arsenic compounds contain ions such as arsenate (AsO ) or arsenite (AsOg). 

SolvH" represents a hydron donor such as water, ammonia or an alcohol, and "Solv-Na+" its sodium salt.) Attractive features of the use of sodium to destroy chemical warfare agents are mentioned in the poster abstracts of Sokolowski and Bilger and of Bunnett (this volume). A potential problem is that adventitious acids that might somehow mix with the products will convert sodium arsenide (Na3As) to the extremely toxic arsine (ASH3). Conversion of Na3As to a much less toxic arsenic compound should immediately follow the sodium treatment. 

For many years, arsenic has been regarded as an important environmental pollutant. It can enter the environment in many ways, for example use as an agrochemical, in smelting operations, and from coal fired power plants. Buchet and Lauwerys [70] list the relative toxicities for several arsenic compounds of high concern. In descending order they give arsine > arsenite > arsenate > methanearsonic acid (MMA) > dimethylarsinic acid (cacodylic acid, DMA). Methods which can accurately assess environmental and occupational exposure to these toxic arsenic compounds are necessary. 

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