Nitric esters determining

It was shown by the above authors that nitrogen content of nitric esters such as NG or NC cannot be determined by the nitrometer method, if stabilizers such as centralite are present, because centralite absorbs some nitrogen oxides thus giving a low result for N. The difference between the nitrometer N content of NG in absence of a stabilizer and N content of NG in presence of a stabilizer may be taken as an index of stabilizing action of the stabilizer the bigger the difference, the better the stabilizer. This difference is called indice nitrometrique... 

CDj) T. Urbanski, Vol 2(1965), pp 22-31 gives methods for determining the Stability of Nitric Esters, which include Abel Heat Test, Litmus Test (Vieille Test), Heat Test at 134.5°C, Silvered Vessel Test, Loss of Weight Test, Will Test, Bergmann Junk Test and Manometric Test... 

The majority of the stability tests for smokeless powder are much the same as the methods used to determine the stability of nitric esters, in particular nitrocellulose (Vol. II). They are based on heating samples of the powder, thus starting decomposition processes or hastening processes already initiated within the powder. The value of such methods is comparative, since at an elevated temperature different reactions occur than those which would arise under normal conditions of storage. Nevertheless experiments over many years have shown that certain interrelations may be established for the stability of powder at various temperatures. Vieille [61] reports that the heating of a sample of powder for 1 hr at a temperature of 110°C involves approximately the same decomposition as ... 

All methods of determining the stability of explosives and particularly of nitric esters consist in examining the behaviour of the substances at an elevated temperature. It is obvious that the most reliable methods of determining stability are those which are carried out at lower temperatures approaching the ordinary room temperature. 

The Bergmann and Junk tubes can be used to determine the pH of the solution obtained after heating nitric esters for varying times, e.g. 1, 2, 4 and 6 hr. This... 

T. Urbanski, Malendowicz and Dybowicz [68] examined the behaviour of nitroglycerine (and of other nitric esters) exposed to ultra-violet rays and established that nitroglycerine irradiated once for a short period with a quartz lamp started to undergo slow decomposition which stopped only after an interval of 2-3 days. A sample of 3 g nitroglycerine was irradiated for 1 hr with rays from quartz lamp passing through a filter permeable to rays of 3200-4100 A whilst maintained at a temperature of 15°C. In order to test the decomposition of the specimen, from time to time 0.25-0.5 g sample of the substance were removed, shaken with water and the pH values determined. The following results have been obtained immediately after irradiation pH = 6.86 after 6, 24, 48 and 72 hr—6.12, 4.66,4.48 and 5.22 respectively. 

Nitrogen in nitrocellulose is determined by means of the nitrometer, an instrument of great usefulness to the chemist who is working with nitric esters or with nitroamines. 

Methods of determining the stability of nitric esters Oualitaiivc tcsis Heal lest (Abel lest)... 

Nitrated cellulose acetate has been prepared, and nucleophilic replacement of nitrate groups of cellulose nitrate with halides has been performed. Oxidative decomposition of cellulose nitrate into a water-soluble material may be brought about by aqueous digestion at high temperature and high pressures, and this finds particular application in the determination of small proportions of the sulfate in cellulose nitrate. A route for the replacement of nitric ester groups in cellulose nitrate by sulfuric ester groups has been reported. ... 

Nitric ester groups Nitrocellulose Saponification, reduction with devades alloy determination of ammonia 204... 

CN is the oldest and most important inorganic ester of cellulose. It is a white, ododess, and tasteless substance. It has found uses in plastics, lacquers, and explosives. CN is manufactured by treating cellulose with nitric acid in the presence of sulfuric acid and water. The amount of water determines the DS attained (11,48,49). 

If chloride is present, saturated aqueous silver acetate solution should be added in amounts slightly more than the calculated quantity prior t o the addition of concentrated sulphuric acid. The procedure may be applied to the routine analysis of mixtures of nitric and sulphuric acids, and to the determination of nitrogen in esters such as nitroglycerine and nitrocellulose the latter are easily hydrolysed by strong sulphuric acid after dispersal in glacial acetic acid. 

A method involving SPE was developed for the determination of ten A-nitroso amino acids in cured meat products. These compounds were derivatized with diazomethane followed by O-acylation of hydroxyl groups with acetic anhydride-pyridine reagent. The methyl esters and their acylated derivatives were separated by GC on a DB-5 fused silica capillary column and quantified with a TEA-CLD specific for the nitric oxide derived from the thermal denitrosation of nitrosamines recovery exceeded 75% at the 10 ppb level579. 

The Lunge nitrometer provides a simple and very useful means for controlling nitrations carried out in concentrated sulfuric acid solution. Its usefulness for the determination of the oxyacids of nitrogen, especially nitric and nitrous acids, depends on the fact that these acids (and their salts and esters) are quantitatively and rapidly reduced to NO by metallic mercury in the presence of concentrated sulfuric acid, even at ordinary temperatures, according to the reaction ... 

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