High purified

Fig. 11-15. Variation with time of aqueous sodium dodecyl sulfate solutions of various concentrations (from Ref. 54). See Ref. 56 for later data with highly purified materials.

Polakowski R, Craig D B, Skelley A and Dovichi N J 2000 Single molecules of highly purified bacterial alkaline phosphatase have identical activity J. Am. Chem. See. 122 4853-5... 

Note. For more delicate work, highly purified solvents are necessary, but for the above experiment dry technical benzene is suitable. 

Frequently one component of a mixture is readily sublimed and so can be obtained in a highly purified condition by this process. 

Zinc cyanide. Solutions of the reactants are prepared by dis solving 100 g. of technical sodium cyanide (97-98 per cent. NaCN) in 125 ml. of water and 150 g. of anhydrous zinc chloride in the minimum volume of 50 per cent, alcohol (1). The sodium cyanide solution is added rapidly, with agitation, to the zinc chloride solution. The precipitated zinc cyanide is filtered off at the pump, drained well, washed with alcohol and then with ether. It is dried in a desiccator or in an air bath at 50°, and preserved in a tightly stoppered bottle. The yield is almost quantitative and the zinc cyanide has a purity of 95-98 per cent. (2). It has been stated that highly purified zinc cyanide does not react in the Adams modification of the Gattermann reaction (compare Section IV,12l). The product, prepared by the above method is, however, highly satisfactory. Commercial zinc cyanide may also be used. 

Commercial zinc cyanide is quite satisfactory. It may be prepared as described in Section 11,50,iS. If the zinc cyanide is too highly purified, it does not react well. 

The process operated by ACl is outlined in Figure 7. Bales of cotton linter are opened, cooked in dilute caustic soda, and bleached with sodium hypochlorite. The resulting highly purified ceUulose is mixed with pre-precipitated basic copper sulfate in the dissolver, and 24—28% ammonium hydroxide cooled to below 20°C is added. The mixture is agitated until dissolution is complete. If necessary, air is introduced to aUow oxidative depolymerization and hence a lowering of the dope viscosity. 

Optical windows of highly purified magnesium fluoride which transmit light from the vacuum ultraviolet (140 nm) into the infrared (7) are recommended for use as ultraviolet optical components for use in space exploration. 

Affinity chromatography is used in the preparation of more highly purified Factor IX concentrates (53—55) as well as in the preparation of products such as antithrombin III [9000-94-6] (56,57). Heparin [9005-49-6], a sulfated polysaccharide (58), is the ligand used most commonly in these appHcations because it possesses specific binding sites for a number of plasma proteins (59,60). 

Natural Product hGH. In 1944 the preparation of a highly purified growth hormone from bovine pituitary glands was reported (37). Subsequendy, growth hormones derived from animal pituitaries were found to be ineffective in humans the existence of specificity among species for growth hormone was thus estabUshed. 

Specifications for hGH products are defined by the governmental licensing authorities, eg, the U.S. Pood and Dmg Administration. Draft monographs for hGH have been prepared by both the EnitedStates Pharmacopia and the European Pharmacopeia commissions and should be formally adopted by 1995. These specifications are suitable for biosynthetic hGH. The much less purified pituitary-derived hGH has virtually disappeared from commercial production. An international reference standard for pituitary-derived hGH (lot 80/505) has been used for caUbration, particularly for bioassay purposes. A highly purified biosynthetic hGH standard (lot 88/624) has been prepared and should be formally adopted by 1995, or before. 

Indium also combines with nonmetaUic elements and with metalloids such as N, P, Sb, As, Te, and Se. Many of the latter compounds ate semiconducting as ate the oxide and sulfide. Indium antimonide [1312-41 -0], InSb indium arsenide [1303-11-3], In As and indium phosphide [22398-80-7], InP, ate the principal semiconducting compounds. These ate all prepared by direct combination of the highly purified elements at elevated temperature under controlled conditions. 

To produce highly purified phosphatidylcholine there are two industrial processes batch and continuous. In the batch process for producing phosphatidylcholine fractions with 70—96% PC (Pig. 4) (14,15) deoiled lecithin is blended at 30°C with 30 wt % ethanol, 90 vol %, eventually in the presence of a solubiHzer (for example, mono-, di-, or triglycerides). The ethanol-insoluble fraction is separated and dried. The ethanol-soluble fraction is mixed with aluminum oxide 1 1 and stirred for approximately one hour. After separation, the phosphatidylcholine fraction is concentrated, dried, and packed. 

These are highly purified petroleum products which have been fully refined by either acid treatment or hydrogenation to remove all unsaturates, aromatics, and coloring materials to meet JnitedSfates Pharmacopoeia (USP) requirements. 

The lanthanum phosphate phosphor is usually prepared by starting with a highly purified coprecipitated oxide of lanthanum, cerium, and terbium blended with a slight excess of the stoichiometric amount of diammonium acid phosphate. Unlike the case of the aluminate phosphor, firing is carried out in an only slightly reducing or a neutral atmosphere of nitrogen at a temperature 1000° C. Also this phosphor is typically made with the addition of a flux,... 

In the 1970s, Solvay iatroduced an advanced TiCl catalyst with high activity and stereoregulahty (6). When this catalyst was utilized ia Hquid monomer processes, the level of atactic polymer was sufftciendy low so that its removal from the product was not required. Catalyst residues were also reduced so that simplified systems for post-reactor treatment were acceptable. Sumitomo has developed a Hquid monomer process, used by Exxon (United States), ia which polymer slurry is washed ia a countercurrent column with fresh monomer and alcohol to provide highly purified polymer (128). 

Using any of the carrier proteins available in highly purified form, eg, TBG or TBPA, a convenient and accurate quantitative determination of and is possible by displacement of radioiodinated or T. This procedure enables their quick determination at low concentrations even in the presence of coundess other substances that occur in body duids (31). In a similar fashion, intact cell nuclei or solubilized proteins from rat fiver cell nuclei, which display high affinities for thyroid hormones, especially T, have been used to establish relative binding affinities of many thyromimetic compounds (7). 

A typical cationic polymeriza tion is conducted with highly purified monomer free of moisture and residual alcohol, both of which act as inhibitors, in a suitably dry unreactive solvent such as toluene with a Eriedel-Crafts catalyst, eg, boron triduoride, aluminum trichloride, and stannic chloride. Usually low temperatures (—40 to —70°C) are favored in order to prevent chain-transfer or sidereactions. 

Polyethers such as monensin, lasalocid, salinomycin, and narasin are sold in many countries in crystalline or highly purified forms for incorporation into feeds or sustained-release bolus devices (see Controlled-RELEASE technology). There are also mycelial or biomass products, especially in the United States. The mycelial products are generally prepared by separation of the mycelium and then drying by azeotropic evaporation, fluid-bed driers, continuous tray driers, flash driers, and other types of commercial driers (163). In countries allowing biomass products, crystalline polyethers may be added to increase the potency of the product. 

Semiconductor Applications. A limited but important demand for metaUic arsenic of 99.99% and greater (exceeding 99.999 + %) purities exists in semiconductor appHcations (see Semiconductors). This high purity arsenic may be prepared by the reduction of a highly purified arsenic compound using a high purity gaseous or soHd reductant. 

Beryllium Sulfate. BeiyUium sulfate tetiahydiate [7787-56-6], BeSO TH O, is produced commeicially in a highly purified state by fiactional crystallization from a berylhum sulfate solution obtained by the reaction of berylhum hydroxide and sulfuric acid. The salt is used primarily for the production of berylhum oxide powder for ceramics. Berylhum sulfate chhydrate [14215-00-0], is obtained by heating the tetrahydrate at 92°C. Anhydrous berylhum sulfate [13510-49-1] results on heating the chbydrate in air to 400°C. Decomposition to BeO starts at about 650°C, the rate is accelerated by heating up to 1450°C. At 750°C the vapor pressure of SO over BeSO is 48.7 kPa (365 mm Hg). 

Purification. Hemoglobin is provided by the red blood ceU in highly purified form. However, the red ceU contains many enzymes and other proteins, and red ceU membranes contain many components that could potentially cause toxicity problems. Furthermore, plasma proteins and other components could cause toxic reactions in recipients of hemoglobin preparations. The chemical modification reactions discussed herein are not specific for hemoglobin and may modify other proteins as well. Indeed, multifimctional reagents could actually couple hemoglobin to nonhemoglobin proteins. 

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