GA, hydrolysis

M. Kataoka et al., Effect of pedological characteristics on aqueous soil extraction recovery and tert-butyldimethylsilylation yield for gas chromatography-mass spectrometry of nerve gas hydrolysis products from soils. Environ. Sci. Technol. 35, 1823-1829 (2001)... 

M. Kataoka, K. Tsuge and Y. Seto, Efficiency of pretreatment of aqueous samples using a macroporous strong anion-exchange resin on the determination of nerve gas hydrolysis products by gas chromatography-mass spectrometry after tert-butyldimethylsilylation, J. Chromatogr. A, 891, 295-304 (2000). 

M. Noami, M. Kataoka and Y. Seto, Improved tert-butyldimethylsilylation gas chromatographic/ mass spectrometric detection of nerve gas hydrolysis products from soils by pretreatment of aqueous alkaline extraction and strong anion-exchange solid-phase extraction, Anal. Chem., 74, 4709-4715 (2002). 

Decomposition by excess chlorination can be accomplished in about 1 h if the pH is adjusted to 8.0-8.5. Acid hydrolysis usually takes place at pH 2-3. Because care must be taken to avoid the liberation of the toxic cyanogen chloride as a gas, hydrolysis in not usually the chosen option. 

Pham MQ, Harvey SP, Weigand WA et al. (1996). Reactor comparisons for the biodegradation of thiodiglycol, a product of mustard gas hydrolysis. Appl Biochem and Biotechnol 57/58, 779-789. Price CC and von Limbach B (1945). Further data on the toxicity of various CW agents to fish, OSRD No. 5528. Washington DC National Defense Research Committee, Office of Scientific Research and Development. 

Ohsawa I, Kanamori-Kataoka M, Tsuge K et al. (2004). Determination of thiodiglycol, a mustard gas hydrolysis product, by gas chromatography-mass spectrometry after tert-butyldimethylsilylation. J Chromatogr B, 1061, 235-241. 

Acidic and basic hydrolysis of GA result in different products (Fig. 4). Under acidic conditions, ethylphosphoryl cyanidate and dimethylamine are formed under basic and neutral conditions, ethyl A,A-dimethylamido phosphoric acid and hydrogen cyanide are formed. Although the latter pathway is predominant, di-methylphosphoramidate, phosphorocyanidate, and dimethylphosphoramide cyanidate may also be formed (Sanches et al. 1993). The phosphorus-containing compounds are slowly hydrolyzed to phosphoric acid. Although theoretically possible, there is little likelihood of formation of a detectable amount of methyl phosphonic acid from GA. Hydrolysis products are listed in Table 37. 

Kanamori-Kataoka, M., Seto, Y. (2008) Laboratory identification of the nerve gas hydrolysis prodncts alkyl methylphosphonic acids and methylphosphonic acid, by gas chromatography-mass spectrometry after tert-butyldimethylsUylation./oMmoZ of Health Science (Tokyo, /apan), 54(5), 513-523. 

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

The most common situation studied is that of a film reacting with some species in solution in the substrate, such as in the case of the hydrolysis of ester monolayers and of the oxidation of an unsaturated long-chain acid by aqueous permanganate. As a result of the reaction, the film species may be altered to the extent that its area per molecule is different or may be fragmented so that the products are soluble. One may thus follow the change in area at constant film pressure or the change in film pressure at constant area (much as with homogeneous gas reactions) in either case concomitant measurements may be made of the surface potential. 

Lactose on hydrolysis gives glucose and an isomeric monosaccharide galactose, which may be given the symbol Ga-r. The lactose molecule may be represented as Ga-r-G-r, and it has therefore also a free potential aldehyde group and is a reducing sugar like maltose. 

Method 1. Equip a 1 litre three-necked flask (or bolt-head flask) with a separatory funnel, a mechanical stirrer (Fig. II, 7, 10), a thermometer (with bulb within 2 cm. of the bottom) and an exit tube leading to a gas absorption device (Fig. II, 8, 1, c). Place 700 g. (400 ml.) of chloro-sulphonic acid in the flask and add slowly, with stirring, 156 g. (176 ml.) of pure benzene (1) maintain the temperature between 20° and 25° by immersing the flask in cold water, if necessary. After the addition is complete (about 2 5 hours), stir the mixture for 1 hour, and then pour it on to 1500 g. of crushed ice. Add 200 ml. of carbon tetrachloride, stir, and separate the oil as soon as possible (otherwise appreciable hydrolysis occurs) extract the aqueous layer with 100 ml. of carbon tetrachloride. Wash the combined extracts with dilute sodium carbonate solution, distil off most of the solvent under atmospheric pressure (2), and distil the residue under reduced pressure. Collect the benzenesulphonyl chloride at 118-120°/15 mm. it solidifies to a colourless sohd, m.p. 13-14°, when cooled in ice. The yield is 270 g. A small amount (10-20 g.) of diphen3 lsulphone, b.p. 225°/10 mm., m.p. 128°, remains in the flask. 

Dry chlorine has a great affinity for absorbing moisture, and wet chlorine is extremely corrosive, attacking most common materials except HasteUoy C, titanium, and tantalum. These metals are protected from attack by the acids formed by chlorine hydrolysis because of surface oxide films on the metal. Tantalum is the preferred constmction material for service with wet and dry chlorine. Wet chlorine gas is handled under pressure using fiberglass-reinforced plastics. Rubber-lined steel is suitable for wet chlorine gas handling up to 100°C. At low pressures and low temperatures PVC, chlorinated PVC, and reinforced polyester resins are also used. Polytetrafluoroethylene (PTFE), poly(vinyhdene fluoride) (PVDE), and... 

Calcium carbide has been used in steel production to lower sulfur emissions when coke with high sulfur content is used. The principal use of carbide remains hydrolysis for acetylene (C2H2) production. Acetylene is widely used as a welding gas, and is also a versatile intermediate for the synthesis of many organic chemicals. Approximately 450,000 t of acetylene were used aimuaHy in the early 1960s for the production of such chemicals as acrylonitrile, acrylates, chlorinated solvents, chloroprene, vinyl acetate, and vinyl chloride. Since then, petroleum-derived olefins have replaced acetylene in these uses. 

Bromine ttifluoride is commercially available at a minimum purity of 98% (108). Free Br2 is maintained at less than 2%. Other minor impurities are HF and BrF. Free Br2 content estimates are based on color, with material containing less than 0.5% Br2 having a straw color, and ca 2% Br2 an amber-red color. Fluoride content can be obtained by controlled hydrolysis of a sample and standard analysis for fluorine content. Bromine ttifluoride is too high boiling and reactive for gas chromatographic analysis. It is shipped as a Hquid in steel cylinders in quantities of 91 kg or less. The cylinders are fitted with either a valve or plug to faciUtate insertion of a dip tube. Bromine ttifluoride is classified as an oxidizer and poison by DOT. 

Phosphoms oxyfluoride is a colorless gas which is susceptible to hydrolysis. It can be formed by the reaction of PF with water, and it can undergo further hydrolysis to form a mixture of fluorophosphoric acids. It reacts with HF to form PF. It can be prepared by fluorination of phosphoms oxytrichloride using HF, AsF, or SbF. It can also be prepared by the reaction of calcium phosphate and ammonium fluoride (40), by the oxidization of PF with NO2CI (41) and NOCl (42) in the presence of ozone (43) by the thermal decomposition of strontium fluorophosphate hydrate (44) by thermal decomposition of CaPO F 2H20 (45) and reaction of SiF and P2O5 (46). 

Table 4 lists the specifications set by Du Pont, the largest U.S. producer of DMF (4). Water in DMF is deterrnined either by Kad Fischer titration or by gas chromatography. The chromatographic method is more rehable at lower levels of water (<500 ppm) (4). DMF purity is deterrnined by gc. For specialized laboratory appHcations, conductivity measurements have been used as an indication of purity (27). DMF in water can be measured by refractive index, hydrolysis to DMA followed by titration of the Hberated amine, or, most conveniendy, by infrared analysis. A band at 1087 cm is used for the ir analysis. 

This hydrolysis reaction is accelerated by acids or heat and, in some instances, by catalysts. Because the flammable gas hydrogen is formed, a potential fire hazard may result unless adequate ventilation is provided. Ingestion of hydrides must be avoided because hydrolysis to form hydrogen could result in gas embolism. 

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