Arsenic acid, III

Arsen-oxyd, n, arsenic oxide, specif, arsenic trioxide, arsemc(III) oxide. -pra parat, n, arsenical preparation, arsenical, -probe, /, arsenic test or sample, -rohr, n, -rShre, /. arsenic tube, -rotgultigerz, n. proustite. -rubin, m. realgar, -salz, n. arsenic salt, arsensauer, a. of or combined with arsenic acid, arsenate of,... 

Arsen-saure, /, arsenic acid, -silber, n, silver arsenide, -silberblende,/, proustite, -spiegel, m. arsenic mirror, -suifid, n, arsenic sulfide, esp. the pentasulfide. -sulfur, n. arsenic trisulfide, arsenic(III) sulfide, -iir, n, (-ous) arsenide, -verbindung, /. arsenic compound, -vergiftung, /. arsenic poisoning, -wasser-stoff, m. arsenic hydride, arseniuretted hydrogen (specif, arsine, AsHa). -zink, n. zinc arsenide. 

The presence of arsenous acid causes a considerable change in the induced reaction the error in the H2O2 determination decreases to a minimum and an As(ril) error appears, while the S2OI error remains practically unchanged. Though reaction between arsenic(III) and peroxydisulphate is about ten times as rapid as that between hydrogen peroxide and peroxydisulphate, the extent of the induced reduction of peroxydisulphate remains practically unchanged. This indicates that, in the induced chain oxidation, reaction (85), is replaced by the more rapid reaction... 

Munoz O, Velez D, Montoro R (1999) Optimization of the solubilization, extraction and determination of inorganic arsenic [As(III) i- As(V)] in seafood products by acid digestion, solvent extraction and hydride generation atomic absorption spectrometry. Analyst 124 601-607. 

Tungsto-arsenic Acids and Tungsto-arsenates.—These compounds are analogous to the phosphotungstic acids and their salts (see this Series, Vol. VII, Part III), but the complex anions are... 

Inorganic As(III) and As(V) were determined by atomic absorption spectrometry using the hydride technique. Total inorganic arsenic, As(III) + As(V), was measured after a prereduction reaction of As(V) to As(III) in acidic solution containing potassium iodide and ascorbic acid. For the selective hydride formation of As(III), samples were maintained at pH 5.0 during the hydride reaction (with 3% NaBH4, 1% NaOH) with a citrate-sodium hydroxide buffer solution (31). As(V) was determined by difference between total As and As(III). The detection limit of As(III) and As(V) was 0.1 nM. The selectivity of this method was checked by additions of As(III) and As(V) to lake water 95-100% recovery of As(III) and As(V) was found (32). 

Inorganic arsenic is eliminated primarily via the kidneys in humans as well as laboratory animals. Studies in adult human males voluntarily ingesting a known amount of either As(III) or As(V) indicate that 45-75 % of the dose is excreted in the urine within a few days to a week (Pomroy et al., 1980 Tam, Char-bonneau and Bryce, 1979 Buchet, Lauwerys and Roels, 1981a Buchet, Lauwerys and Roels, 1981b Lee, 1999). Relatively few studies in volunteers have included the measurement of arsenic in both feces and urine. However, Pomroy et al. (1980) reported that 6% of a single oral dose of arsenic acid was excreted in the feces over a period of seven days compared to 62 % of the dose excreted in urine. No quantitative data are available that directly assess the significance of biliary excretion of As(III) or As(V) in humans. 

The ugly name of the Skraup reaction appropriately applies to the worst witch s brew of all the heterocyclic syntheses. Some workers have added strange oxidizing agents such as arsenic acid, iron (III) salts, tin (IV) salts, nitrobenzenes of various substitution patterns, or iodine to make it go better . 

Zinc and dilute sulphuric acid Phosphites are reduced by the nascent hydrogen to phosphine, PH3, which may be identified as described in the Gutzeit test under Arsenic (Section III.14) the silver nitrate paper is stained first yellow and then black. 

The leaching of arsenic forms is usually performed from soil or from tissues of plants or marine animals. The extraction of materials of biological origin typically involves methanol or mixtures of methanol and water. Solutions obtained by centrifugation and filtration are diluted with water and then loaded into an ion-exchange column. The method is applied for assay of arsenic acid salts and arsenosugars, even though they are more easily soluble in water than in methanol. This method of extraction into a solution involves transfer of a smaller quantity of toxic As(III) and As(V) salts than methylated derivatives and AsB or AsC, which are of markedly lower toxicity [88]. 

Ipolyi I. and Fodor P. (2000) Development of analytical systems for the simultaneous determination of the speciation of arsenic As(III), methylarsonic acid, dimethylarsinic acid, As(V) and selenium Se(IV), Se(VI). Analyt. Chim. Acta 413, 13-23. 

Arsine gas is quickly absorbed through the lungs. Since arsenic in arsine is the fully reduced form of arsenic ( — III), it will be oxidized in the presence of oxygen. Arsine may oxidize in several ways. One is to produce superoxide and arsenous acid (As(III)) as illustrated in this equation ASH3 + 6O2 + 2H2O 6O2 - -HAs02. The standard reduction po-... 

CCA has decades of proven performanee in field trials and in-service. With the correct species and treatment CCA provided an assured in-ground service life in excess of 50 years. Reeently Bull (2001) has proposed that the fixation produets of CCA are dominated by ehromium (III) arsenate, chromium (III) hydroxide and wood-carboxylate-eopper (II) eomplexes. CCA is potent precisely because it is bioavailable - and persistent. Signifieantly the separation of copper from chromium and arsenic is consistent with the observation that acetie aeid and chelating organic acids - and silage or eompost - under eertain eireumstanees ean promote leaching and early failure (Cooper and Ung, 1995 Kazi and Cooper, 1998). 

Sample digestion must yield 80% or greater recovery of added (dimethyl arsenic acid) and 90% or greater recovery of added As(III), As(V). 

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