Arsenite inorganic

Toxicity of the various arsenic compounds in mammals extends over a wide range, determined in part by unique biochemical actions of each compound, but also by absorbability and efficiency of biotransformation and disposition. Overall, arsines present the greatest toxic hazard, followed closely by arsenites (inorganic trivalent compounds). Inorganic pentavalent compounds are somewhat less toxic that arsenites, while the organic (methylated)... 

Other salts include lead arsenates and lead arsenites (see Insect control technology), lead chromates and lead sihcochromates (see Pigments), lead cyanide (see Cyanides), lead 2-ethyIhexanoate (see Driers and metallic soaps), and lead fluoroborate (see Fluorine compounds, inorganic). 

In 1933 Challenger et al. discovered that trimethylarsine was synthesized from inorganic arsenic compounds by molds (93). Recently, McBride and Wolfe (94), have reported the synthesis of dimethylarsine from arsenate by cell extracts of the methanogenic bacterium M. O. H. Methylcobalamin is the alkylating coenzyme for this synthesis which requires reduction of arsenate to arsenite, methylation of arsenite to methylarsonic acid, reduction and methylation of methylarsonic acid to dimethylarsinic acid, and finally a four electron reduction of dimethylarsinic acid to dimethylarsine (Fig. 13). 

The effect of other inorganic anions (sulfate, molybdate, silicate), low molecular mass organic ligands (LMMOLs, such as oxalate, malate, citrate, tartrate and succinate), and fulvic or humic acid on the sorption of arsenate and arsenite onto variable charge minerals and soils has been studied (Roy et al. 1986 Grafe et al. 2001 Liu et al. 2001 Violante et al. 2005a,b). 

The toxicity of arsenicals conforms to the following order, from greatest to least toxicity arsines > inorganic arsenites > organic trivalent compounds (arsenoxides) > inorganic arsenates > organic pentavalent compounds > arsonium compounds > elemental arsenic. 

Several inorganic arsenic compounds are weak inducers of chromosomal aberrations, sister chromatid exchange, and in vitro transformation of mammalian and piscine cells. However, there is no conclusive evidence that arsenic causes point mutations in any cellular system (Pershagen and Valuer 1979 Belton et al. 1985 Lee et al. 1985 Deknudt et al. 1986 Manna and Mukheijee 1989). Studies with bacteria suggest that arsenite is a comutagen, or may inhibit DNA repair (Belton et al. 1985). 

Fruit orchards Inorganic arsenites and arsenates contained up to 17 mg As/kg dry weight in stems, 20 in leaves, and 304 in roots Soils contain 31-94 mg/kg dry weight (vs. 2.4 in untreated 3... 

TERRESTRIAL INVERTEBRATES Honeybee, Apis mellifera Inorganic arsenite Following arsenic spray dusting, dead bees contained 6... 

Chickens rapidly excrete arsenicals only 2% of dietary sodium arsenite remained after 60 h (NAS 1977), and arsanilic acid was excreted largely unchanged (Woolson 1975). Excretion of arsanilic acid by chickens was affected by uptake route excretion was more rapid if administration was by intramuscular injection than if it was oral (NRCC 1978). Studies with inorganic As+5 and chickens indicated that (Fullmer and Wasserman 1986) ... 

Monosodium methane-arsonate, CH4AsNa03 CHICKEN, Gallus gallus Inorganic trivalent arsenite... 

Inorganic arsenate or arsenite Chronic oral toxicity at 1.5 mg/kg BW... 

Manna, G.K. and P.K. Mukherjee. 1989. A study of the genotoxic potentiality of the inorganic weedicide, sodium arsenite in the experimentally treated tilapia fish. Jour. Freshwater Biol. 1 147-159. 

Sakurai, T., Ohta, T., and Fujiwara, K., Inorganic arsenite alters macrophage generation from human peripheral blood monocytes, Toxicol. Appl. Pharmacol., 203, 145, 2005. 

Pi, J. et al., Low level, long-term inorganic arsenite exposure causes generalized resistance to apoptosis in cultured human keratinocytes Potential role in skin co-carcinogenesis, Int. J. Cancer, 116, 20, 2005. 

Generally, inorganic arsenic can occur in the environment in several forms but in natural waters and thus in drinking water, it is mostly found as trivalent arsenite or pentavalent arsenate. Organic arsenic species, abundant in seafood, are very much less harmful to health and are readily eliminated by the body5. 

Inorganic arsenicals such as arsenic trioxide, sodium arsenite, lead arsenate, calcium arsenate and Paris Green have been used for many years as soil sterilants. Organic arsenical herbicides, in which the organic group is bonded directly to the arsenic atom, have been used extensively for post-emergence control of weeds in cotton. Several of the more important herbicides are sodium cacodylate (monosodium dimethylarsenic acid) and sodium salts of methane arsonic acid. The latter compounds exist in two principal forms the monosodium salt (MSMA) at pH6.4 and the disodium salt (DSMA) at pH10.2. 

Kit solution for the determination of toxic anions (e.g., arsenate, arsenite, azide, or cyanide) and other inorganic and organic anions with indirect UV detection... 

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