As203 ARSENIC TRIOXIDE

Before 1914, the US imported most metallic arsenic from Germany (e.g., Smith, 1945). From 1914 to about 1930, the bulk of the arsenic production in the US (marketed for commercial applications as As203, arsenic trioxide, or white arsenic) was derived as a metallurgical by-product of the smelting of copper, lead, and gold. Arsenic trioxide was used in the production of fertilizers, herbicides, and insecticides (Kirk-Othmer, 1992 Ullman s Encyclopedia, 1998), or if transformed to arsenic acid, used in the manufacture of CCA, a preservative of wood products (Mineral Commodity Summaries, 2004). Arsenic metal is also used for solders, ammunition, anti-friction additive to bearings, and in the computer and electronics industry for semiconductors (Mineral Commodity Summaries, 2004). 

As203 ARSENIC TRIOXIDE 35.020 2.0334E-01 -2.6126E-12 4.3024E-15 -2.6100E-18 273 548 solid... 

Although the element is a metalloid, the long, brittle, crystals have a metallic shine. The white, tasteless oxide (arsenic trioxide As203) has been famous and notorious ("inheritance powder") even after centuries traces can be found in bodies. The arsenic compound "Salvarsan" was first used by Paul Ehrlich for the treatment of syphilis — the start of chemotherapy. Popular today as a semiconducting material. Component of LEDs (light-emitting diodes) and lasers. Arsenic hardens lead, used earlier in letter-press printing, today only for lead shot. 

Platinum complexes are cytotoxic agents yet the paradigm in cancer chemotherapy has moved to a more targeted approach, with special emphasis on signaling pathways. In this respect a remarkable story is that of arsenic trioxide, As203 (Trisenox, Cell Therapeutics Inc, Seattle, USA) which was approved by the FDA in September 2000 for treatment of acute promomyelo-cytic leukemia (APL) in patients who have relapsed or are refractory to retinoid and anthracycline chemotherapy. An estimated 1,500 new cases of APL are diagnosed yearly in the US, of which an... 

As203 (c, octahedral). Schuhmann1 measured the electromotive force at various temperatures for the cell in which the reaction was 2 As (c, a) +3 H20 (liq.) =As203 (c, octahedral) +3H2 (g), and computed Q=51.0, from which, for As203 (c, octahedral), Qf= 154.1. Thomsen16 measured the heat of solution of octahedral arsenic trioxide in four normal sodium hydroxide to be 7.52, from which, for As203 (c, octahedral), Qf= 154.1. 

As203 (liq.). The above vapor pressure data yield a surprisingly large value for the heat of fusion of solid arsenic trioxide. 

Arsenic Trioxide As203 Fluorine. Fluorine reacts violently with arsenic trioxide.6... 

Arsenopyrite and loellingite are both arsenic minerals that can be smelted to produce elemental arsenic. Both elemental arsenic and arsenic trioxide (As203) are produced commercially the latter is the raw material for the production of numerous arsenic compounds. Elemental arsenic is used to make alloys with lead and copper. Arsenic compounds have a number of uses, including... 

Warrell R, Soignet S, Maslak P et al (1998) Initial western study of arsenic trioxide (As203) in acute promyelocytic leukemia (APL). Proc Am Soc Clin Oncol 17 6a... 

Chen GQ, Zhu J, Shi XG et al (1996) In vitro studies on cellular and molecular mechanisms of arsenic trioxide (As203) in the treatment of acute promyelocytic leukemia As203 induces NB4 cell apoptosis with downregulation of Bcl-2 expression and modulation of PML-RARa/PML proteins. Blood 88 1052-1061... 

Two series of compounds of arsenic are common that of arsenic(III) and arsenic(V). Arsenic(III) compounds can be derived from the amphoteric arsenic trioxide As203, which yields salts both with strong acids (e.g. arsenic(III) chloride, AsC13), and with strong bases (e.g. sodium arsenite, Na3As03). In strongly acidic solutions therefore the arsenic(III) ion As3+ is stable. In strongly basic solutions the arsenite ion, AsO is the stable one. Arsenic(V) compounds... 

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