Ammonium sulfate solution preparation

The SI70 supernatant (220 ml) was made to 40 % saturation with solid ammonium sulfate, stirred for 20 min, and then the precipitate was collected by centrifugation at 15,000 g for 15 min. The precipitate was suspended in small volume of buffer B-50 at pH 7.6 containing 20 mM HEPES/KOH, 0.1 mM EDTA, 1 mM dithiothreitol, 10 % (v/v) glycerol, and 50 mM potassium acetate. The 60 % saturated ammonium sulfate solution was prepared similarly. Protein concentrations for 0 - 40 % and 40 - 60 % ammonium sulfate fractions were 4.2 mg/ml and 4.7 mg/ml, respectively. 

Ferric ammonium sulfate is prepared by mixing an equimolar solution of ferric sulfate, Fe2(S04)3, and ammonium sulfate, (NH4)2S04. Hydrated crystals are obtained following evaporation and cooling of the solution. 

The thiocyanate is prepared in solution by adding ammonium thiocyanate, NPLjSCN to HC1 solutions of the chloride. Both basic and double carbonates are known. The former is precipitated from Sc3+ solutions by adding carbonate solutions, and is probably Sc(OH)CC>3 H O. The latter are obtained by the use of an excess of the soluble carbonate. Normal, basic, and double sulfates are known. The first exists in several degrees of hydration the second is obtained as Sc(0H)S04 - 2H2O. by treating the normal sulfate tetrahydrate with the hydroxide. The alkali double sulfates and alums are obtained by treating the sulfate solution with an excess of the alkali (or ammonium) sulfate solution. 

The present method involves the action of chlorine upon an ammonium sulfate solution accompanied by extraction of the product from the aqueous solution. Solutions of nitrogen chloride (up to 20 per cent) in various solvents may be prepared without fear of explosion.3 The method here described is a reasonably safe one and has been used repeatedly without accident by a number of workers. However, the extremely explosive character of nitrogen trichloride should always be borne in mind. It is advisable, therefore, to carry out the preparation behind a safety screen. 

The dialyzed enzyme solution was now subjected to a repetition of the preceding procedures admixture of suflBcient calcium phosphate gel to adsorb protein but leave the enzyme in solution centrifugation and addition of more gel to the supernatant to adsorb the enzyme elution of the enzyme from the gel with a mixture of 0.15 M acetate and 0.015 M citrate at pH 4.5 addition of solid ammonium sulfate to the eluate to 55% saturation and precipitation of the enzyme. At this stage, the purifications ranged from 650- to 1100-fold with a recovery of approximately 20-30% of the activity present in the crude red cell hemolysate. Solution of this precipitate, dialysis treatment with solid ammonium sulfate and collection of the precipitate appearing between 40 and 55% saturation yielded a preparation that represented a 1500-fold purification. The preparations were stable when left sedimented in the ammonium sulfate solution. 

Prepare a small ion exchange column using 10 cm of SAC resin. H or Na form). The resin is converted to the ammonium form by pas.sing 2 BV of 2 N ammonium sulfate solution slowly through the bed followed by a rin.se with deionized water. Two bed-volumes of ammoniacal copper sulfate solution (0.25 M CUSO4/2.5 M NH OH) is passed through the column which converts the resin to the intense blue copper(ll) tetrammine form, R.) Cu(NHi)4 The resin is rinsed and stored in a tightly stoppered bottle. 

Ammonia gas is injected into treated water using systems and equipment similar to those used for chlorine gas. Aqua ammonia is handled using systems similar to those used for sodium hypochlorite. This form of ammonia is basic and has a strong odor, but is not corrosive. For ammonium sulfate powder, a 25-30% solution is prepared in a plastic or fiberglass container and added to the water by means of a chemical metering pump. Equipment similar to that used for handling calcium hypochlorite can be used for this process. Solutions of ammonium sulfate are stable, but acidic, and, therefore, corrosive to some metals. Materials that withstand dilute sulfuric acid will also withstand the corrosion effects of dilute ammonium sulfate solutions. 

Perbenzoic acid is prepared by dropwise addition of 22 g. (0.45 mole) of 70% hydrogen peroxide to a stirred partial solution of 0.3 mole of benzoic acid in 86.5 g. of methanesulfonic acid in a 500-ml. tail-form beaker with cooling to 25-30". The addition takes about 3(1 min., during which lime the benzoic acid all dissolves. After 2 hrs. more the solution Is cooled to 15°, diluted with Ice and cold saturated ammonium sulfate solution (to decrease the solubilltv). and extracted with benzene. 

An 0.025 M solution of orZ//o-phenanthroline-ferrous ammonium sulfate indicator is prepared by dissolving 1.487 g of orzAo-phenanthroline monohydrate in 100 ml of an aqueous ferrous ammonium sulfate solution, containing 0.980 g of ferrous ammonium sulfate hexahydrate per 100 ml. 

To prepare the ferrous ammonium sulfate solution 75 ml of 70-72% perchloric acid solution is diluted to 750 ml with distilled water 39.21 g of FeSO4(NH4)2 SO4 6H2O is added, mixed, and made up to 1 liter. 

Catalysts preparation. Intercalation solutions were prepared by addition of an ammonium sulfate solution to a fresh zirconium acetate one. The mixture was adjusted to the desired pH using a HCl solution. In another beaker, Na-montmorillonite suspension was adjusted at the same pH than the intercalation solution. 

The solubility of ammonium sulfate [(NH4)2 SOJ changes with temperature. The amount of (NH4)2 S04 needed to saturate 1,000 mL of H20 at 4° C is about 707 g. The saturated ammonium sulfate solution is prepared at room temperature by adding the solid salt to the desired volume of H20 with continuous stirring until some does not dissolve. Continue the stirring overnight. Adjust the pH to 7.4 with... 

Purification of cytochrome 62 has been carried out by various workers S08Jill l4r-217). The cytochrome was first crystallized by Appleby and Morton in 1954 ( 806) as a preparation (type I) containing DNA (214,217). Another crystalline preparation (type II) which contains no DNA was also obtained after dialysis against strong ammonium sulfate solution or by chromatography on DEAE-cellulose (218-221). Another crystalline preparation, which is free from flavin and enzymically inactive, was obtained by Okunuki et al. (222-224). This cytochrome has a molecular weight of about 20,000 and appears to be similar to but different from the cytochrome bt core described later. 

Sample preparation 10 mL Urine -I- 500 pL 100 p,g/mL nalorphine hydrobromide in MeOH -I- 1 mL concentrated HCl, heat at 100° for 1 h, cool, add 500 p-L saturated ammonium sulfate solution, adjust pH to 9 with 25% NaOH, dilute to 20 mL with water, add mixture to an Extrelut 20 column, let stand for 10 min, elute with 40 mL dichloromethane isopropanol 85 15. Add the eluate to 3 mL 200 mM HCl, extract, repeat extraction. Combine the aqueous phases and add them to 500 p.L saturated ammonium sulfate solution, adjust pH to 9.2 with 25% NaOH, dilute to 20 mL with water, add to another Extrelut 20 column, let stand for 10 min, elute with 40 mL dichloromethane isopropanol 85 15. Evaporate the eluate to dryness under a stream of nitrogen at 40°, reconstitute the residue in 100 p-L mobile phase, iiyect a 20 p-L aliquot. 

A belief sometimes expressed by catalysis chemists is that this particular catalyst is not active unless there is present some chromium in a higher oxidation state. The presence of such oxidized chromium is readily detected by extraction of the sample with water, followed by titration of the extract with ferrous ammonium sulfate solution, followed by back titration with standard dichromate. All such tests on the catalyst samples prepared as described above were negative. Chromium in a higher oxidation state is, however, always present if the final step of reduction in hydrogen is omitted. 

Although pure bovine mercaptalbumin prepared by chromatography on sulfoethyl Sephadex C-50 was found to be more homogeneous than parent BSA as shown by its solubility-pH profile and solubility behavior in concentrated ammonium sulfate solutions, it did not yield separate N and F boundaries on electrophoresis however, it exhibited heterogeneity with respect to binding with detergents, and two components were resolvable by electrophoresis (Hagenmaier and Foster, 1971). 

Another feudy common practice is to use ammonium sulfate solution of 8-0-0-9S grade, which is prepared by dissolving criretalline ammonium sulfate in water. 

Using pH paper and a 10% sodium hydroxide solution, adjust the pH of about 1 mL of the stock solution prepared above to pH 13. Add 2 drops of saturated ferrous ammonium sulfate solution and 2 drops of 30% potassium fluoride solution. Boil the solution for about 30 seconds. Then acidify the hot solution by adding 30% sulfuric acid dropwise until the iron hydroxides dissolve. Avoid using excess acid. If nitrogen is present, a dark Prussian blue (not green) precipitate NaFe2(CN) will form, or the solution will assume a dark blue color. 

Compounds resembling cytochrome c of heart muscle have been isolated from many sources. The cytochrome c of skeletal muscle of the king penguin has been purified by the same methods used for ox heart cytochrome c, and has been crystallized from almost saturated ammonium sulfate. A precipitate of the oxidized cytochrome was obtained that exhibited birefringence but was not crystalline addition of reducing agent to the ammonium sulfate solution permitted crystals of reduced cytochrome c to form. Measurements of the catalytic activity and extinction coefficients gave values equivalent to those of the ox heart preparation within the limits of error. In a preliminary report, the... 

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