Arsenical greens

Liquid, bp 105°C. Said to be produced by the mould Penicillium brevicaule growing on wallpaper coloured green with arsenical green pigments. Causes chronic exposure to arsenic. 

Chromium gx een or emerald green is a green hydrate, formed by decomposing a double borate of chromium and pot sium by H,0. It is used in Uie arts as a substitute for the arsenical greens, and is non-poisonoua. 

The detection of copper in the viscera after death is not without interest, especially if arsenic have been found, in which case its discovery or non-discovery enables us to diffei entiate between poisoning by the arsenical greens and that by other arsenical compounds. The detection of mere traces of copper is of no significance, because, although copper is... 

Terry (1893) states that this was manganate of baryta , proposing that it could replace the arsenical greens. He gives several manufacturing routes ... 

Seemingly a copper-arsenic green (q.v.). Terry (1893) describes the process as involving the preparation of copper arsenite from copper sulfate and sodium arsenite ( arsenite of soda ). The precipitate is then treated widi acetic acid or, interestingly, formic acid the former would result in the usual copper acetate arsenite, the latter in copper formate arsenite. Terry comments The pigment thus produced is of good colour, but its superiority would not seem to justify the use of such an expensive article as pure formic acid, nor the minute adjustment of the proportions of die ingredients, in an operation to be conducted on a commercial scale. ... 

Paris green, see Copper acetate arsenate(III) (1/3) Pawellite, see Calcium molybdate(VI)(2—)... 

Nickel Arsenate. Nickel arsenate [7784-48-7] Ni2(As0 2 8H20, is a yellowish green powder, density 4.98 g/cm. It is highly iasoluble ia water but is soluble ia acids, and decomposes on heating to form As20 and nickel oxide. Nickel arsenate is formed by the reaction of a water solution of arsenic anhydride and nickel carbonate. Nickel arsenate is a selective hydrogenation catalyst for iaedible fats and oils (59). 

G. T. Morgan, Organic Compounds of Arsenic and Antimony, Longmans, Green and Co., London, UK, 1918. 

Wood Preservation. The use of chromium compounds ia wood preservation is largely because of the excellent results achieved by chromated copper arsenate (CCA), available ia three modifications under a variety of trade names. The treated wood (qv) is free from bleeding, has an attractive ohve-green color, and is paintable. CCA is widely used, especially ia treating utility poles, bull ding lumber, and wood foundations. About 62% of all the chromic acid produced ia the United States is consumed by the wood preservation industry (77,167) (see Building materials, survey). 

Method A Standardisation with arsenic (III) oxide. Discussion. The most trustworthy method for standardising cerium(IV) sulphate solutions is with pure arsenic(III) oxide. The reaction between cerium(IV) sulphate solution and arsenic(III) oxide is very slow at the ambient temperature it is necessary to add a trace of osmium tetroxide as catalyst. The arsenic(III) oxide is dissolved in sodium hydroxide solution, the solution acidified with dilute sulphuric acid, and after adding 2 drops of an osmic acid solution prepared by dissolving 0.1 g osmium tetroxide in 40mL of 0.05M sulphuric acid, and the indicator (1-2 drops ferroin or 0.5 mL /V-phenylanthranilic acid), it is titrated with the cerium(IV) sulphate solution to the first sharp colour change orange-red to very pale blue or yellowish-green to purple respectively. 

In a 30 minute test the results obtained should not differ by more than 1 minute using different lots of paper. On being exposed to nitric oxide fumes, these papers slowly turn green, followed by a salmon pink coloration Methyl Violet Paper Test (Field Test for Pro pint Powders). This method of testing proplnts using 0.1N methyl violet paper directly in the containers in which the powder is stored, was developed at Picatinny Arsenal in 1928—29 (Refs 1 2), and was adopted by the Ordnance Dept to replace the Observation Test about 1931... 

The use of plant extracts for insect control dates into antiquity the use of Paris green as an insecticide for control of the Colorado potato beetle in 1867 probably marks the beginning of the modern era of chemical control of injurious insects. The development of lead arsenate followed later in the nineteenth century for gypsy moth control. The commercial production of nicotine insecticides, the production of calcium arsenate at the time of the first world war, and the use of fluorine, arsenical, and cyanide compounds, as well as other inorganic chemicals for insect control, were important steps in pest control. These chemicals were applied largely by dilute high pressure sprays or dusts. 

Scott NK, Green FJ, Do DH, McLean JS (1995) Arsenic removed by coagulation. J Am Water Works Assoc 87 114-126... 

Isaeva [181] described a phosphomolybdate method for the determination of phosphate in turbid seawater. Molybdenum titration methods are subject to extensive interferences and are not considered to be reliable when compared with more recently developed methods based on solvent extraction [182-187], such as solvent-extraction spectrophotometric determination of phosphate using molybdate and malachite green [188]. In this method the ion pair formed between malachite green and phosphomolybdate is extracted from the seawater sample with an organic solvent. This extraction achieves a useful 20-fold increase in the concentration of the phosphate in the extract. The detection limit is about 0.1 ig/l, standard deviation 0.05 ng-1 (4.3 xg/l in tap water), and relative standard deviation 1.1%. Most cations and anions found in non-saline waters do not interfere, but arsenic (V) causes large positive errors. 

Green sunfish, Lepomis cyanellus liver Polluted waters (from manufacturer of arsenical defoliants and pesticides), Texas. Mean water concentration 13.5 mg As/L sediment content of 4700 mg/kg ... 

Matsuto, S., H. Kasuga, H. Okumoto, and A. Takahashi. 1984. Accumulation of arsenic in blue-green alga, Phormidium sp. Comp. Biochem. Physiol. 78C 377-382. 

Schoof, R.A., L.J. Yost, E. Crecelius, K. Irgolic, W. Goessler, H.R. Guo, and H. Greene. 1998. Dietary arsenic intake in Taiwanese districts with elevated arsenic in drinking water. Human Ecol. Risk Assess. 4 117-135. 

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