Arsenic compound, liquid

Methylarsine, trifluoromethylarsine, and bis(trifluoromethyl)arsine [371-74-4] C2HAsF, are gases at room temperature all other primary and secondary arsines are liquids or solids. These compounds are extremely sensitive to oxygen, and ia some cases are spontaneously inflammable ia air (45). They readily undergo addition reactions with alkenes (51), alkynes (52), aldehydes (qv) (53), ketones (qv) (54), isocyanates (55), and a2o compounds (56). They also react with diborane (43) and a variety of other Lewis acids. Alkyl haUdes react with primary and secondary arsiaes to yield quaternary arsenic compounds (57). 

The simplest analytical method is direct measurement of arsenic in volatile methylated arsenicals by atomic absorption [ 11 ]. A slightly more complicated system, but one that permits differentiation of the various forms of arsenic, uses reduction of the arsenic compounds to their respective arsines by treatment with sodium borohydride. The arsines are collected in a cold trap (liquid nitrogen), then vaporised separately by slow warming, and the arsenic is measured by monitoring the intensity of an arsenic spectral line, as produced by a direct current electrical discharge [1,12,13]. Essentially the same method was proposed by Talmi and Bostick [10] except that they collected the arsines in cold toluene (-5 °C), separated them on a gas chromatography column, and used a mass spectrometer as the detector. Their method had a sensitivity of 0.25 xg/l for water samples. 

With Arsenic —Hydrogen does not directly combine with arsenic, but if an arsenic compound is in solution in a liquid in which hydrogen is being generated, i.e. hydrogen in the nascent state, chemical union takes place. Thus, if arsenious oxide is dissolved in dilute hydrochloric acid and a piece of metallic zinc is added, the hydrogen produced by the action of the add on the zinc will combine with the arsenic, in accordance with the following equation —... 

Arsine is produced by the reaction of arsenic trichloride, arsenic trioxide or any inorganic arsenic compound with zinc and sulfuric acid. It is also made by treating a solution of sodium arsenide or potassium arsenide in liquid ammonia with ammonium bromide ... 

B.6 Speciation of Arsenic Compounds by Ion-Exchange High-Performance Liquid Chromatography with Hydride Generation Atomic Fluorescence Detection. 

Because MIPs are formed at low temperatures, liquid samples cannot be introduced because they extinguish the plasma, even small amounts of organic vapour. However, the on-line coupling of HPEC to MIP-OES has been described for the speciation of mercury and arsenic compounds. Continuous cold vapour (CV) or hydride generation (HG) techniques were used as interfaces between the exit of the HPEC column and the MIP, held in a surfatron at reduced pressure [24]. 

Nitrogen does not react with arsenic. The latter dissolves in aqueous ammonia, apparently forming a complex compound.4 In anhydrous liquid ammonia it dissolves without reaction 5 and from the solution the arsenic may be successfully electrodeposited.6 This is not the case with antimony or bismuth. The solution of arsenic in liquid ammonia does not react with metallic cyanides.7... 

Penicillin [1406-05-9] - [EXTRACTION - LIQUm-LIQUID] (Vol 10) - [ANTIPARASITIC AGENTS - ANTIPROTOZOALS] (Vol 3) - [ARSENIC COMPOUNDS] (Vol 3) - [ANTIBIOTICS- TETRACYCLINES] (Vol 3) -detection of [BIOPOLYMERS - ANALYTICAL TECHNIQUES] (Vol 4)... 

Hansen, S.H., Larsen, E.H., Pritzi, G. and Cornett, C. (1992) Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry./. Anal. At. Spectrom., 1, 629-634. 

Magnuson, M.L., Creed, J.T. and Brockhoffl C.A. (1997) Speciation of arsenic compounds in drinking water by capillary electrophoresis with hydrodynamically modified electro-osmotic flow detected through hydride generation inductively coupled plasma mass spectrometry with a membrane gas-liquid separator./. Anal. At. Spectrom., 12, 689-695. 

Saverwyns, S., Zhang, X.R., Vanhaecke, F., Cornelis, R., Moens, L. and Dams, R. (1997) Speciation of six arsenic compounds using high-performance liquid chromatography inductively coupled plasma mass spectrometry with sample introduction by thermospray nebulisation./. Chromatogr. A, 779, 299-306. 

Most arsenic compounds are colorless powders or crystals. They include arsenites and arsenates of many metals syrupy arsenic acid and arsenic trichloride are liquids.1 All must be considered to be extremely poisonous. The metal itself has not been recognized as a noteworthy hazard.2... 

Arsenic (mfz 75) is known to suffer from an isobaric interference caused by the presence of ArCl+ (m/z 75) during speciation analyses, particularly for samples that contain a high chloride salt content, e.g., sea water and urine. Several groups [37-39] used hydride generation to transform the arsenic compounds into their volatile hydrides before aspiration into the ICP. Selective transportation of the hydrides may thus be achieved by using a gas-liquid separator to eliminate the chloride interference (Fig. 10.6). 

U. Kohlmeyer, J. Kuballa, E. Jantzen, Simultaneous separation of 17 inorganic and organic arsenic compounds in marine biota by means of high-performance liquid chromatography/inductively coupled plasma mass spectrometry, Rapid Commun. Mass Spectrom., 16 (2002), 965D974. 

S. N. Pedersen, K. A. Francesconi, Liquid chromatography electrospray mass spectrometry with variable fragmentor voltages gives simultaneous elemental and molecular detection of arsenic compounds, Rapid Common. Mass Spectrom., 14 (2000), 641-645. 

E. H. Larsen, G. Pritzl, S. H. Hansen, Speciation of eight arsenic compounds in human urine by high-performance liquid chromatography with inductively coupled plasma mass spectrometric detection using antimonate for internal chromatographic standardization, J. Anal. Atom. Spectrom., 8 (1993), 557-563. 

Description Three RAM processes are available to remove arsenic (RAM I) arsenic, mercury and lead (RAM II) and arsenic, mercury and sulfur from liquid hydrocarbons (RAM III). Described above is the RAM II process. Feed is heated by exchange with reactor effluent and steam (1). It is then hydrolyzed in the first catalytic reactor (2) in which organometallic mercury compounds are converted to elemental mercury, and organic arsenic compounds are converted to arsenic-metal complexes and trapped in the bed. Lead, if any, is also trapped on the bed. The second reactor (3) contains a specific mercury-trapping mass. There is no release of the contaminants to the environment, and spent catalyst and trapping material can be disposed of in an environmentally acceptable manner. 

Coelho, N.M.M., CoeUio, L.M., de Lima, E.S., Pastor, A., de la Guardia, M. Determination of arsenic compounds in beverages by high-performance liquid chromatography-inductively coupled plasma mass spectrometry. Talanta 66, 818-822 (2005)... 

---