Tri valent arsenic

An intermediate fonn in the transition is black amorphous arsenic, density 4.6-5.2, also obtained by the thermal decomposition of arsine. Brown arsenic, density 3.7-4.2. obtained by reduction of acid solutions of tri valent arsenic, is probably a finely divided fonn of black arsenic. 

Garrett, A. B., Holmes, O., and Laube, A., 1940, The solubility of arsenious oxide in dilute solutions of hydrochloric acid and sodium hydroxide. The character of the ions of tri valent arsenic. Evidence for polymerization of arsenious acid Journal of the American Chemical Society, v. 62, p. 2024-2028. 

The distinction between biopharmaceuticals under the jurisdiction of OBP and ONDG stems from the definition of a biological product in the PHS Act (42 USG 351 [262] (i)) a virus, therapeutic serum, toxin, antitoxin, vaccine, blood, blood component or derivative, allergenic product, or analogous product, or arsphenamine or derivative of arsphenamine (or any other tri-valent organic arsenic compound), applicable to the prevention, treatment, or cure of a disease or condition of human beings. Biopharmaceuticals under the jurisdiction of OBP are analogous products under this definition. 

The ratio of the critical coagulation concentration value for mono, di- and tri-valent ions has been reported to be 500 10 1 as well as 100 20 1 [4]. Coagulation concentrations of various electrolytes for colloidal suspension of arsenic sulfide are listed in Table 5.26. 

Nakamuro K and Sayato Y (1981) Comparative studies of chromosomal aberration induced by tri-valent and pentavalent Arsenic. Mutat Res 88 73 — 80. 

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