Ammonium sulfate reagent

Ammonium sulfate reagent 89 Ammonium thiocyanate reagent 170 Amphetamines 45, 260, 299 Ampicillin 173,174 Amygdalin 179... 

It. is assumed that the strength of the ferric ammonium sulfate reagent will remain constant for an indefinite period... 

G. Ferrous Ammonium Sulfate Reagent. Dissolve 39.214g of reagent grade Fe(S04).(NH4)2S04.-6H20 in 1 9 sulfuric acid(previously boiled... 

M a-ketoglutarate (adjusted to pH 6.0 with NaOH) Saturated ammonium sulfate (reagent grade) solution 0.03 M sodium acetate buffer (pH 5.4)... 

Saturated ammonium sulfate solution—Dissolve 7 kg of ammonium sulfate (reagent grade) in 10 liters of distilled water. Store at room temperature. 

This method can be used for the determination of both free and total active chlorine content in water samples. As mentioned before, the active chlorine reacting with DPD produces a red-colored compoimd. Ferrous ammonium sulfate (Fe(NH4)2(S04)2) reacts with this red compound in a quantitative reaction resulting in a colorless product. So the red compound can be titrated with ferrous ammonium sulfate reagent solution using... 

Procedure 100 cm sample solution, 5 cm DPD reagent solution, and 10 cm buffer solution are mixed together in a titration flask. Immediately following this, the pinkish solution is titrated with ferrous ammonium sulfate reagent solution until the color disappears to measure the free active chlorine content (reagent volume A cm ). At the equivalence, 1 g crystalline potassium iodide is added. If the pinkish color returns, the titration is continued after a 2 min waiting time. The total reagent volume (B cm ) reflects the total free active chlorine content of the sample. 

The homogenized pinkish solution is titrated with ferrous ammonium sulfate reagent solution until the color disappears 1 cm of the titrant added corresponds to 1 mg/1000 cm active chlorine. 

The purity of ferrous ammonium sulfate is determined by a redox titration with K2Gt207, using the weight of the reagents as the signal in place of volume. 

Other Applications. Hydroxylamine-O-sulfonic acid [2950-43-8] h.2is many applications in the area of organic synthesis. The use of this material for organic transformations has been thoroughly reviewed (125,126). The preparation of the acid involves the reaction of hydroxjlamine [5470-11-1] with oleum in the presence of ammonium sulfate [7783-20-2] (127). The acid has found appHcation in the preparation of hydra2ines from amines, aUphatic amines from activated methylene compounds, aromatic amines from activated aromatic compounds, amides from esters, and oximes. It is also an important reagent in reductive deamination and specialty nitrile production. 

The reagent neutralizes the sulfuric acid and decomposes the ammonium sulfate, but it does not react with the amino acid. 

Note The reagent can be employed on silica gel and cellulose layers. When derivatization is carried out from the vapor phase the detection limit for morphine is 10 ng and that for papaverine 1 ng per chromatogram zone [5]. In some cases it has been recommended that ammonium sulfate be added to the layer with subsequent heating to 150 —180 °C [1] after derivatization. It is also possible to spray afterwards with an aqueous solution of potassium iodide (1 %) and starch (1%) [2]. 

Minisci reactions have also been applied to these compounds. formation by exposure to w-CPBA and O-methylation with Meerwein s reagent converted 54 into 55. Nucleophilic attack of the hydroxymethyl radical, generated with ammonium sulfate, provides an alternate route to 2-hydroxymethyl pyridines 56. 

Whereas silylations with trimethylchlorosilane (TCS) 14 (b.p. 57 °C) demand the presence of a base to neutralize the HCl evolved, giving rise to the hydrochloride of the base, the use of hexamethyldisilazane (HMDS) 2 (b.p. 126 °C), in particular in the presence of 0.01-0.05 equivalents of acidic catalysts such as TCS 14 or ammonium sulfate, should normally be preferred as the preparative silylating reagent, because HMDS 2 ... 

The precipitation method of separation involves the addition of salts such as ammonium sulfate or solvents such as polyethylene glycol to the reagent mixture to cause precipitation of the large molecular weight bound species. These methods of precipitation lack specificity and work well only when there is a large difference between the molecular weight of the material being measured and that of the bound complex of it. 

The solubility of Versatic 911 in water has been studied as a function of both pH and salt concentration for a fixed (0.5 mol dm ) concentration of reagent in the solvent [15] and is illustrated in Fig. 7.10. The use of high salt concentrations (4moldm ammonium sulfate) has been shown to be effective in keeping Versatic 911 losses at pH 7-8 to more economic levels (<100 ppm) in the separation of cobalt from nickel [16]. 

Aqueous solutions of ammonium sulfate and ammonium bisulfate were deposited on Fluoropore filters, placed in the direct insertion probe, and analyzed in the chemical ionization mode (H2O reagent) gas. The samples were heated from 100°C to 330 C at 15 C/minute. No sample ions were observed under these anlaysis conditions, even when several micrograms of ammonium salts were analyzed. The thermal decomposition of ammonium salts of sulfate has been the subject of many studies. (29,30) Some pathways include sulfuric acid production at one stage of the decomposition while others suggest ammonia, SO2 and SO3 are the products. None of these accurately simulate the conditions (temperature, pressure, gas flow) present in our chemical ionization source. However, no sulfuric acid ions (H3SO4+, etc.) were ob-served... 

Iron ammonium sulfate is an analytical reagent in titrations and colorimetric measurements to measure oxidizing substances, such as chlorine, or to measure the chemical oxygen demand in waste water. The compound is used to prepare Fe(II) standard solution for these analyses. It also is a cahbration... 

Iron(III) ammonium sulfate is a mordant in dyeing and printing of fabrics and textiles. The compound also is an analytical reagent and is used in medicine. 

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