Ammonium sulfate properties

In the countries of the CIS, ammonium sulfate properties should comply with the specifications given in Table 8.28. 

These aspects of solvent property similarly apply to precoated impregnated silica gel plates, e.g., by ammonium sulfate, silver nitrate, or magnesium acetate, as well as to microcrystalline cellulose precoated plates. On preparative RP phases, water has the lowest elution power. Therefore, more polar or aqueous solvents should be preferred. In contrast to HPTLC RP-18 layers, on which such aqueous solutions remain as a drop on the surface and are not able to penetrate through the lipophilic layer, on preparative RP phases, pnre aqneons application solutions can be apphed owing to the minor degree of C18 modification. 

Delincee and Radola100 used a commercial preparation, as well as fresh tomatoes, for the preparation, purification, and characterization of tomato pectinesterase. The tomatoes were pressed and then homogenized directly with ammonium sulfate at 70% saturation. The precipitate obtained was extracted with 0.3 M phosphate and repeatedly salted out with ammonium sulfate, and the product was separated on a column of Sephadex G-75. The pattern of separation was similar to that in preceding work.50,97 A detailed study of the size properties of pectinesterase was conducted by gel-filtration and sedimentation analysis.100 By column and thin-layer gel-filtration on Sephadex G-75, the approximate molecular weight of a number of preparations of tomato pectinesterase was determined, values of 24,000 and 27,000 being obtained. A possible interaction of the... 

Chromic ammonium sulfate, molecular formula, properties, and uses, 6 563t Chromic bromide, physical properties of, 4 328... 

The Cr1 ion readily forms complexes it exists in aqueous solution as CrfH 0)j. and forms other complexes wilh anions, such asCr(H 0).CI , Crother properties due to variation in the bonding. Compounds or the trichloride have been reported with the following arrangements CrtHjOlsClj. [CrfHiOlsCljCIi- HiO. and [Cr(HiO)4Cf CU2 H 0 Trivalenl chromium also forms double salts, notably the chromium alums, hydrated double salts of Cr(III) sulfate and the alkali metal (or thallium or ammonium) sulfates. 

It is apparent from Figure 8.6 that the use of ammonium sulfate for protein precipitation is rationalized with the salt s kosmotropic properties in addition, (NH4)2S04 is highly soluble in aqueous solution. 

The low vapor pressure of H2S0A and ammonium sulfates is an important property, which ensures that they remain as particles under normal atmospheric conditions. In contrast, nitric and hydrochloric acids exist as vapors, and ammonium nitrate tends to be unstable. For this reason, the term "acid aerosol," which is one of the pollutants of current health concern, relates mostly to acidic sulfates (17). 

The only non-mammalian /8-glucuronidase that has been subjected to systematic purification is the enzyme from sheep-rumen microorganisms. After repeated ammonium sulfate fractionation, Marsh101 obtained a colorless preparation with a specific activity of 1,900 (400-fold purification and 2% recovery). The final product gave a linear, specific-property, solubility test from which a figure of 2,200 was derived for the ultimate specific activity of the enzyme, but it was considered that the enzyme may have formed a solid solution with inactive protein. 

Fire-retardant chemicals used by the commercial wood-treating industry are limited almost exclusively to mono- and diammonium phosphate, ammonium sulfate, borax, boric acid, and zinc chloride (4,8). It is believed that some use is also made of the liquid ammonium polyphosphates (9). Some additives such as sodium dichromate as a corrosion inhibitor are also used. Aqueous fire-retardant treatment solutions are usually formulated from two or more of these chemicals to obtain the desired properties and cost advantages For leach-resistant type treatments, the literature shows that some or all of the following are used urea, melamine, dicyandiamide, phosphoric acid, and formaldehyde (10-12) ... 

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