Chloride extraction from

Figures 5 and 6 show how the water extractable chloride and bromide change with storage at 175 C and 200 C for a 1983 and a 1985 vintage flame retarded novolac epoxy. In both of these figures, the chloride, most of which comes from the ECN, changes from an initial concentration of <10 ppm to a maximum concentration of 17 ppm after 1000 hours at 175 C and 23 ppm after 1000 hours at 200 C. The amount of chloride extracted from both epoxies is similar. The water extractable bromide, however, increases for the 1983 epoxy after an induction period of about 168 hours. The bromide from the 1985 epoxy also increases, but at a much slower rate. These results show that the thermal stability problems of the brominated organic can be minimized, provided the flame retardant system is carefully selected.

Fig. 3 TIC from the GC/MS analysis of an elastomer methylene chloride extract. (From Ref., reproduced with permission from American Pharmaceutical Review.)...

Fig. 4 TIC from the GC/MS analysis of a methylene chloride extract from a second type of elastomer (compare with the TIC in Fig. 1).

Chloride extraction from [2-(dichloromethyl)-7r-allyl] palladium chloride gave a trimethylenemethane palladium complex (J71)-. 

Phytuberin has also been found32 in tobacco leaves infiltrated with Pseudomonas Solanacearum. In addition phytuberin was isolated from Pseudomonas Solanacearum U-7. The methylene chloride extract from the callus contained phytuberin (55) and phytuberol (56). Both (55) and (56) were absent from healthy tissues. They were identified33 as stress compounds in leaves ofNocotianatabacum CV SamsunNN. sylvestris. 

A separation of sulphonyl chlorides by selective extraction with a solvent and partial crystallization has been patented280. An example is that of hexadecane-mono-, di- and polysulphonyl chlorides, extracted from benzene with nitromethane, followed by cooling to — 30°C. 

How is potassium chloride extracted from carnallite How would you make a sample of carnallite in the laboratory ... 

C. Alonso, Mathematical modeling of electrochemical chloride extraction from concrete . Magazine of Cement and Concrete Research, 1995,... 

The hen liver nuclei contain both ADP-ribosyltransferase and poly(ADP-ribose) synthetase. To separate the ADP-ribosyltransferase from poly(ADP-ribose) synthetase, the 0.6 M potassium chloride extract from the nuclei was applied to a Sephadex G-200 column and eluted with the 0.1 Af Tris-buffer, pH 8.0. Each fraction was incubated with 1 vaM [adenine- H]NAD and 100 jug of whole histones, in a total volume of 0.2 ml containing 50 mAf Tris-Cl" buffer, pH 9.0, and the radioactivity in the acid-insoluble fraction was determined. The result shows the two fractions containing the enzyme activities which catalyze the incorporation of the ADP-ribose moiety from NAD to the whole histones. From the hydroxyapatite column chromatographic analysis of the products formed by the respective fraction, we found that the former fraction contains poly(ADP-ribose) synthetase and the latter fraction contains poly-... 

Filtered water was extracted on a XAD-2 resin. XAD-2 resin was Soxhlet extracted [90,91] with an acetonediexane (1 1) mixture followed by methylene chloride. Extracts from XAD-2 resin samples were added with water and extracted n-hexane. 

Fig. 11. Thin-layer chromatogram on silica gel of authentic methyl-mercurychloride (1), iodide (3), bromide (5), and cyanide (7) together with the corresponding compounds prepared from methylmercury chloride extracted from pike (2,4,6,8)...

Electrochemical Chloride Extraction from Concrete Bridge Components. Technical Brief 2. Toronto, Canada Canadian Strategic Highway Research Program (C-SHRP), 1995. 

Potassium chloride is mainly produced from mixtures of sodium chloride and potassium chloride extracted from salt mines. It is used in fertilisers. Aluminium alloys are very widely used in mining equipment, where the conditions are particularly aggressive for a large number of materials, and for the transport of the minerals. 

Give the name and formula of one ore of mercury. How is the metal (a) extracted from this ore, (b) purified Starting from the metal, how would you prepare specimens of (c) mercury(I) chloride,... 

The constant K is termed the distribution or partition coefficient. As a very rough approximation the distribution coefficient may be assumed equal to the ratio of the solubilities in the two solvents. Organic compounds are usually relatively more soluble in organic solvents than in water, hence they may be extracted from aqueous solutions. If electrolytes, e.g., sodium chloride, are added to the aqueous solution, the solubility of the organic substance is lowered, i.e., it will be salted out this will assist the extraction of the organic compound. 

Volatile analytes can be separated from a nonvolatile matrix using any of the extraction techniques described in Ghapter 7. Fiquid-liquid extractions, in which analytes are extracted from an aqueous matrix into methylene chloride or other organic solvent, are commonly used. Solid-phase extractions also are used to remove unwanted matrix constituents. 

Trioxane and Tetraoxane. The cycHc symmetrical trimer of formaldehyde, trioxane [110-88-3] is prepared by acid-catalyzed Hquid- or vapor-phase processes (147—151). It is a colorless crystalline soHd that bods at 114.5°C and melts at 61—62°C (17,152). The heats of formation are — 176.9 kJ/mol (—42.28 kcal/mol) from monomeric formaldehyde and —88.7 kJ/mol (—21.19 kcal/mol) from 60% aqueous formaldehyde. It can be produced by continuous distillation of 60% aqueous formaldehyde containing 2—5% sulfuric acid. Trioxane is extracted from the distillate with benzene or methylene chloride and recovered by distillation (153) or crystallization (154). It is mainly used for the production of acetal resins (qv). 

Purification. Extraction from aluminum or 2inc ores produces cmde galHum metal or concentrates. These concentrates are transformed to sodium gallate, galHum chloride, or galHum sulfate solutions which are purified, then electroly2ed. GalHum is deposited as a Hquid. 

Chlorination. In some instances, the extraction of a pure metal is more easily achieved from the chloride than from the oxide. Oxide ores and concentrates react at high temperature with chlorine gas to produce volatile chlorides of the metal. This reaction can be used for common nonferrous metals, but it is particularly useful for refractory metals like titanium (see Titanium and titanium alloys) and 2irconium (see Zirconium and zirconium compounds), and for reactive metals like aluminum. 

Provitamin D. Provitamin is made from cholesterol, and its commercial production begias with the isolation of cholesterol from one of its natural sources. Cholesterol occurs ia many animals, and is generally extracted from wool grease obtained by washing wool after it is sheared from sheep. This grease is a mixture of fatty-acid esters, which contain ca 15 wt % cholesterol. The alcohol fraction is obtained after saponification, and the cholesterol is separated, usually by complexation with 2iac chloride, followed by decomplexation and crystallisation. Cholesterol can also be extracted from the spiaal cords and brains of animals, especially catde, and from fish oils. 

Hydrochloric acid digestion takes place at elevated temperatures and produces a solution of the mixed chlorides of cesium, aluminum, and other alkah metals separated from the sUiceous residue by filtration. The impure cesium chloride can be purified as cesium chloride double salts such as cesium antimony chloride [14590-08-0] 4CsCl SbCl, cesium iodine chloride [15605 2-2], CS2CI2I, or cesium hexachlorocerate [19153 4-7] Cs2[CeClg] (26). Such salts are recrystaUized and the purified double salts decomposed to cesium chloride by hydrolysis, or precipitated with hydrogen sulfide. Alternatively, solvent extraction of cesium chloride direct from the hydrochloric acid leach Hquor can be used. 

A second source of brine is found in terminal lakes. The Dead Sea in Israel and Jordan is an example of a large terminal lake with almost unlimited supphes of magnesium chloride, potassium chloride, and sodium chloride. Mote than two and a half million tons of potassium chloride ate extracted from the Dead Sea each year. 

Seawater. Salt extraction from seawater is done by most countries having coastlines and weather conducive to evaporation. Seawater is evaporated in a series of concentration ponds until it is saturated with sodium chloride. At this point over 90% of the water has been removed, and some impurities, CaSO and CaCO, have been crystallized. This brine, now saturated in NaCl, is transferred to crystallizer ponds where salt precipitates on the floor of the pond as more water evaporates. Brine left over from the salt crystallizers is called bitterns because of its bitter taste. Bitterns is high in MgCl2, MgSO, and KCl. In some isolated cases, eg, India and China, magnesium and potassium compounds have been commercially extracted, but these represent only a small fraction of total world production. 

Recovery Process. Lithium is extracted from brine at Silver Peak Marsh, Nevada, and at the Salar de Atacama, Chile. Both processes were developed by Foote Mineral Corp. The process at Silver Peak consists of pumping shallow underground wells to solar ponds where brines are concentrated to over 5000 ppm. Lithium ion is then removed by precipitation with soda ash to form a high purity lithium carbonate [554-13-2]. At the Atacama, virgin brine with nearly 3000 ppm lithium is concentrated to near saturation in lithium chloride [7447-41 -8]. This brine is then shipped to Antofagasta, Chile where it is combined with soda ash to form lithium carbonate. 

Ghlorohydrination with Nonaqueous Hypochlorous Acid. Because the presence of chloride ions has been shown to promote the formation of the dichloro by-product, it is desirable to perform the chlorohydrination in the absence of chloride ion. For this reason, methods have been reported to produce hypochlorous acid solutions free of chloride ions. A patented method (48) involves the extraction of hypochlorous acid with solvents such as methyl ethyl ketone [78-93-3J, acetonitrile, and ethyl acetate [141-78-6J. In one example hypochlorous acid was extracted from an aqueous brine with methyl ethyl ketone in a 98.9% yield based on the chlorine used. However, when propylene reacted with a 1 Af solution of hypochlorous acid in either methyl ethyl ketone or ethyl acetate, chlorohydrin yields of only 60—70% were obtained (10). 

Prior to the bating process, the hides are delimed with ammonium sulfate and/or ammonium chloride. Proteases are then appUed. The early preparation proposed by Rn hm was pancreatic trypsin. The use of a bating enzyme makes the hides soft and supple to prepare them for tanning. A new microbial protease, Pyrase 250 MP (82) (Novo Nordisk A/S) has been found to be a promising substitute for pancreatic trypsin [9002-07-7] which is more expensive because it must be extracted from pancreatic glands. 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

Extraction from Aqueous Solutions Critical Fluid Technologies, Inc. has developed a continuous countercurrent extraction process based on a 0.5-oy 10-m column to extract residual organic solvents such as trichloroethylene, methylene chloride, benzene, and chloroform from industrial wastewater streams. Typical solvents include supercritical CO9 and near-critical propane. The economics of these processes are largely driven by the hydrophihcity of the product, which has a large influence on the distribution coefficient. For example, at 16°C, the partition coefficient between liquid CO9 and water is 0.4 for methanol, 1.8 for /i-butanol, and 31 for /i-heptanol. 

These acids are less stable, less soluble and less acidic than the corresponding sulfonic acids. The common impurities are the respective sulfonyl chlorides from which they have been prepared, and the thiolsulfonates (neutral) and sulfonic acids into which they decompose. The first two of these can be removed by solvent extraction from an alkaline solution of the acid. On acidification of an alkaline solution, the sulfinic acid crystallises out leaving the sulfonic acid behind. The lower molecular weight members are isolated as their metal (e.g. ferric) salts, but the higher members can be crystallised from water (made slightly acidic), or alcohol. 

Because phenols are weak acids, they can be freed from neutral impurities by dissolution in aqueous N sodium hydroxide and extraction with a solvent such as diethyl ether, or by steam distillation to remove the non-acidic material. The phenol is recovered by acidification of the aqueous phase with 2N sulfuric acid, and either extracted with ether or steam distilled. In the second case the phenol is extracted from the steam distillate after saturating it with sodium chloride (salting out). A solvent is necessary when large quantities of liquid phenols are purified. The phenol is fractionated by distillation under reduced pressure, preferably in an atmosphere of nitrogen to minimise oxidation. Solid phenols can be crystallised from toluene, petroleum ether or a mixture of these solvents, and can be sublimed under vacuum. Purification can also be effected by fractional crystallisation or zone refining. For further purification of phenols via their acetyl or benzoyl derivatives (vide supra). 

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