N-Ammonia

Cool the flask in ice, acidify with 10 ml. of cold 1 1-hydro-chloric acid and distil under reduced pressure (water pump) until most of the alcohol is removed. Add water to the residue, extract several times with ether, wash the combined ethereal extracts with N ammonia solution until a test portion gives no precipitate upon acidification. Extract the combined alkahne solutions once with a fresh portion of ether, and add the aqueous solution to an excess of dilute hydrochloric acid the final mixture should still be acidic to Congo red. Collect the crystalhne half-ester by filtration at the pump, wash it with water and dry at 100°. The yield is 14-5 g., m.p. 122-125°. Recrystallise by dissolving in about 40 ml. of warm benzene and adding an equal volume of petroleum ether (b.p. 40- 60°) 13 -5 g. of the colourless half-ester, m.p. 125-126°, are obtained. 

Acids that are solids can be purified in this way, except that distillation is replaced by repeated crystallisation (preferable from at least two different solvents such as water, alcohol or aqueous alcohol, toluene, toluene/petroleum ether or acetic acid.) Water-insoluble acids can be partially purified by dissolution in N sodium hydroxide solution and precipitation with dilute mineral acid. If the acid is required to be free from sodium ions, then it is better to dissolve the acid in hot N ammonia, heat to ca 80°, adding slightly more than an equal volume of N formic acid and allowing to cool slowly for crystallisation. Any ammonia, formic acid or ammonium formate that adhere to the acid are removed when the acid is dried in a vacuum — they are volatile. The separation and purification of naturally occurring fatty acids, based on distillation, salt solubility and low temperature crystallisation, are described by K.S.Markley (Ed.), Fatty Acids, 2nd Edn, part 3, Chap. 20, Interscience, New York, 1964. 

Aznmoniak, n. ammonia (in old names of salts equivalent to ammonium, as salzsaures —, ammonium chloride) ammoniac, -alaun, m. ammonia alum. 

Tech.) ammoni acal liquor, -gas, n. ammonia gas. -guinini, m. gum ammoniac, ammoniac. 

Ammoniak-rest, m. ammonia residue (amidogen, NH2). -rohr, n. ammonia tube or pipe, -salpeter, m. ammonia saltpeter (ammonium nitrate), -salz, n. ammonium salt, -selfe,/. ammonia soap, -soda, /. ammonia soda, Solvay soda, -stickstoff, m. ammonia nitrogen. -verbindung, /, ammonia compound ammonium compound, -verfahren, n. ammonia process, -wasche, /. ammonia scrubbing ammonia recovery plant, -wascher,... 

Chatterjee et al. [20] quantitatively separated primaquine from amodiquine by a selective precipitation method. A powdered sample containing primaquine and amodiaquine was dissolved in 0.01 N hydrochloric acid 4 N ammonia was added to precipitate amodiaquine. The mixture was filtered and the combined filtrate and washings containing primaquine was diluted with water and 0.1 N hydrochloric acid. The absorbance of this solution was measured at 282 nm versus a solvent blank. 

At the beginning of this decade, Zewail and coworkers reported a fundamental work of solvation effect on a proton transfer reaction [195]. a-naphthol and n-ammonia molecules were studied in real-time for the reaction dynamics on the number of solvent molecules involved in the proton transfer reaction from alcohol towards the ammonia base. Nanosecond dynamics was observed for n=l and 2, while no evidence for proton transfer was found. For n=3 and 4, proton transfer reaction was measured at pisosecond time scale. The nanosecond dynamics appears to be related to the global cluster behavior. The idea of a critical solvation number required to onset proton transfer... 

Concomitant with PET imaging of FDG, myocardial perfusion is imaged with "N-ammonia [61-63] or with Rb [64]. The combined perfusion FDG images demonstrate several patterns ... 

Pour 3 ml of a 0.1 N ammonia solution into each of two beakers. Add dry ammonium chloride to one beaker until the solution is saturated. Pour 2-3 ml of a magnesium chloride solution into both beakers. Explain the observed phenomenon using the law of mass action. 

Nitrates. —On heating 1 gin. of potiwsiimi clilciralo with 5 cc. of sodium hydroxide solution (sp. gr. 1.3). and u mix-ture of 0.5 gm. of zinc dust and 0.5 gin. of powdered iron, n. ammonia should be evolved (to he ascertained hy moisl litmus paper). 

The [Pt(NH3)4](HC03)2 nanofibers are stable under alkaline conditions in which the pH value may vary between 8 and 11. Under acidic condition, however, the precipitates are unstable, and, therefore, the hydrolysis of TEOS can only be performed in alkaline medium. The alkalinity of the solution (optimum of pH 8.5-9) is controlled by the addition of several ml of 0.2 to 0.8 N ammonia solution. In more alkaline solutions the formation of non-structured Si02 particles is enhanced due to the higher rates of hydrolysis of TEOS and condensation, i.e. more Si02 seeds form and grow in the solution without being in contact with the precipitated [Pt(NH3)4](HC03)2 nanofibers. 

TLC separation of DNP-amino acids may be carried out on cellulose [14] or on polyamide layers [15,16] with several types of solvent systems. A two-dimensional separation of DNP-amino acids on cellulose with toluene—2-chloroethanol—pyridine—5 N ammonia (5 3 1.5 6.5) and saturated ammonium sulfate-water-sodium dodecyl sulfate (25 ml 175 ml 0.144 g) is shown in Fig.4.8. A similar separation on polyamide layers is... 

Toluene-pyridine—2-chloroethanol-0.8 N ammonia solution Toluene-pyridine - 2-chloroethanol- 25% ammonia Chloroform-benzyl alcbhol-glacial acetic acid Chloroform-rerr.-pentanol-glacial acetic acid Benzene-pyridine-glacial acetic add Chloroform-methanol-gladal acetic acid Chloroform-methanol-glacial acetic add 1 3 6 6 50 15 35 7 70 30 3 70 30 3 40 10 1 95 5 1 14 6 1 17,19,20... 

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