Arsenicals individual compounds

Arsenic vesicants cause instantaneous irritation of the eyes, nose, throat, and skin, which provides warning of their presence. Extended exposures cause violent coughing, sneezing, and regurgitation. The odor of arsenic vesicants varies with the individual compound and ranges from odorless to fruity to flowery. Odors may not be discernable due to irritation. 

Arsenic is most prone to form surface complexes by adsorption on metal (mostly iron and manganese) (oxy)(hydr)oxides, followed by clays and feldspars (Lin and Puls, 2003). As discussed in Chapters 3 and 7, iron (oxy)(hydr)oxides are groups of Fe(III) Fe(II) (hydrous) oxides, (hydrous) hydroxides, and (hydrous) oxyhydroxides. Individual compounds, such as ferrihydrite, often have highly variable and... 

Arsenic [7440-38-2] and arsenic componnds (Vol. 23, Snppl. 7 1987) (NB This eval-nation applies to the gronp of componnds as a whole and not necessarily to all individual compounds within the group) Asbestos [1332-21-4] (Vol. 14, Suppl. 7 ... 

The generally acidic materials in this group may function as oxidants, some rather powerful, under appropriate conditions. Individually indexed compounds are Arsenic pentaoxide, 0106 Arsenic trioxide, 0105 Boron trioxide, 0170 Carbon dioxide, 0557 f Carbon monoxide, 0555... 

In this group of readily oxidised materials, individually indexed compounds are Arsenic trisulfide, 0108 Bis(2,4-dinitrophenyl) disulfide, 3449 Bis(2-nitrophenyl) disulfide, 3465 Boron trisulfide, 0172 f Carbon disulfide, 0560 Carbon sulfide, 0559 f Carbonyl sulfide, 0556... 

The use of all arsenic compounds -- including realgar - is prohibited in "common fireworks" (the type purchased by individuals) by regulations of the U. S. Consumer Product Safety Commission [121. 

An X-ray map of the elements As, Sb, Cu, and Ag, was created for each sample at 500X magnification with a wave dispersive spectrometer (WDS) using Geller dPICT 32 software. The X-ray map was created from 24 individual maps combined for a total mosaic area size of 0.5 mm by 1.0 mm. For WDS analysis, an indium arsenic compound was used as an arsenic standard. Otherwise pure element... 

Not all published and widely accepted thermodynamic values are reliable. Nordstrom and Archer (2003) provide a detailed review of the controversies, uncertainties, and problems related to thermodynamic data for arsenic and its compounds and aqueous species. Many of the data are contradictory and the methods that produce the data are sometimes questionable or have not been thoroughly documented. Too often, data in the literature have been passed from reference to reference without critical evaluations. Some of the data have high measurement errors, were produced under undefined or poorly defined laboratory conditions, and involved unrepresentative sampling (Matschullat 2000, 298 Nordstrom and Archer, 2003). Furthermore, other questionable data originate from obscure documents or are written in languages that many individuals cannot read and properly interpret. Therefore, thermodynamic results must be accepted with a certain amount of caution. The table in this appendix includes thermodynamic data from various sources, which provide users with some idea of their variability. Although sometimes unavoidable, users... 

Bismuth arsphenamine sulphonate (Bismarsen , Fig. 9) a yellow powder readily soluble in water, was first prepared by Raiziss in 1924 [70]. Stokes and Chambers [71] were the first to use the drug clinically, giving two injections a week for 14 weeks. Four such courses separated by intervals of a fortnight were administered in all. Nevertheless the effects were slow compared with the arsphenamines, although the tonic effect was greater and the side effects less numerous. Relapses, particularly in the central nervous system (CNS) were more frequent. Consequently, Rayburn and Boyd emphasized the fact that some individuals with neurosyphilis who were intolerant to arsenic in any other form could nevertheless tolerate it in the form of Bismarsen [72]. The low toxicity, the tonic effect, and the ease of administration were the chief advantages in favor of Bismarsen . The other compounds of bismuth with arsenic were not extensively tested in humans. 

The product obtained in this way is not an absolutely pure chemical individual, and usually contains an appreciable amount of sulfur (2 to 3 per cent), at least a portion of which appears to be present as a sulfonic acid.8 The purity of the product may be controlled by an arsenic determination, or better, by titration with iodine after dissolving m water and acidifying slighdy with hydrochloric acid, one molecule of the arseno compound being1 oxidized to two of 3-amino-4-hydroxy-phenylarsomc acid under these conditions according to the equation ... 

Grabinski has described an ion-exchange method for the separation of four arsenic species on a single column containing both cation and anion exchange resins. Flameless atomic absorption spectrometry with a deuterium arc background correction is used as the detection system because of its linear response and lack of specificity for these compounds combined with its resistance to matrix bias in this tyjw of analysis. Arsenic recoveries ranged from 97% to 104% for typical lake water samples while 96% to 107% were obtained from arsenic-contaminated sediment interstitial water. The detection limit was 10 p.p.b. for each individual arsenic species. 

A number of simple diarsines have been structurally investigated and, although individual molecules are similar to those of the corresponding distibines, the diarsines do not show the extended chain structures and consequent thermochromism often found for the latter. The geometry at the two arsenic atoms is pyramidal, though the angles at arsenic can be asymmetric. The substituents occupy anti (gauche) conformations and in some cases the molecules have imposed Cj symmetry. Parameters for four of the compounds are summarized in Table 2. 

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