Picric acid development

Fumaks A process for removing hydrogen sulfide from coke-oven gas by oxidation with picric acid. Developed by Sumitomo Metals Industries, and used in 11 units in Japan from 1972 to 1997. 

To a cold aqueous solution of picric acid, add about an equal volume of dilute potassium cyanide solution. An orange coloration develops and rapidly darkens to a deep red. 

Eor the selective pre-concentration of deactivated phenols a new silica-based material with the grafted 2,3,5-triphenyltetrazole was proposed. This method is based on the formation of molecular chai ge-transfer comlexes of 2,3,5-triphenyltetrazole (7t-acceptor) with picric acid (7t-donor) in the phase of the sorbent. Proposed SPE is suitable for HPEC analysis of nitrophenols after their desorption by acetonitrile. Test-system for visual monitoring of polynitrophenols under their maximum concentration limits was developed using the proposed adsorbent. 

In moderately acidic solutions bromocriptine mesilate readily forms ion pairs with anionic dyes such as picric acid, bromothymol blue, methyl orange, which are extractable with an organic solvent. A procedure has been developed both for direct assay and for assay following chromatographic separation from the impurities. Therein bromocriptine mesilate is allowed to react with bromothymol blue at pH 2.5. The resulting ion pair is then extracted with benzene and its concentration determined at 410 nm (25). ... 

Uses Organic synthesis photographic agent manufacture of pesticides, herbicides, explosives, and wood preservatives yellow dyes preparation of picric acid and diaminophenol (photographic developer) indicator analytical reagent for potassium and ammonium ions insecticide. 

Uses. Chemical intermediate in manufacture of dyes, picric acid, lumber preservatives, and diaminophenol hydrochloride (a photographic developer)... 

Cresilite. Mixture of TN-m-Cr (Trinitrometa-cresole) 60 PA (Picric Acid) 40%, used in Italy for loading large-caliber shells. It was developed in France under the name of Cresylite No 2 (Ref 28, p 323 Ref 31, p 292) (See also Ecrasite)... 

Trinitrotoluene (TNT) was the most commonly used conventional military explosive during the twentieth century. Although it had been used extensively in the dye industry during late 1800s, it was not adopted for use as a military explosive until 1902, when the German army used it to replace picric acid. TNT was first used in warfare during the Russo-Japanese War (1904-1905). The US Army began its use in 1912. After an economical process was developed for the nitration of toluene, TNT became the chief artillery ammunition in World War I (1914—1918). The most valuable property of TNT is that it can be safely melted and cast alone or with other explosives as a slurry. 

One type of chemical approach to the analysis of liquid and solid hydrocarbons that will probably see considerable development is that involving reaction or complex formation to yield precipitates that can be separated from the unreacted mass and subsequently be treated to regenerate the hydrocarbons or class of hydrocarbons so precipitated. This field is certainly not extensively developed. In fact very few examples come to mind but among these are Gair s (21) determination of naphthalene by precipitation with picric acid determination of benzene by Pritzker and Jungkunz (52) by an aqueous solution of specially prepared nickel ammonium cyanide Bond s (8) nitrous acid method for styrene and more recently the determination of normal alkanes in hydrocarbons of more than 15 carbon atoms by adduct formation with urea as described by Zimmerschied et al. (71). 

With the development of the organic chemical industry, aromatic nitro compounds of the TNT type were introduced as ingredients of composite explosives. TNT is preferable to picric acid since it has no acidic properties and hence is much less reactive. Mixtures with TNT and similar nitro compounds showed an excellent chemical stability. 

An explosive called tetryl was also being developed at the same time as picric acid. Tetryl was first prepared in 1877 by Mertens and its structure established by Romburgh in 1883. Tetryl (1.3) was used as an explosive in 1906, and in the early part of this century it was frequently used as the base charge of blasting caps. 

DD Explosifs. Fr expls developed before and during WWI. They consisted of Picric Acid Dinitrophenol in various propns PA 60 63 71 75... 

Pure hexanitrocarbanilide crystallizes from acetone-ligroin in pale yellow rosettes which soften and darken at 204° and melt at 208-209° with decomposition. It yields picric acid when warmed with dilute sulfuric acid, and trinitroaniline when boiled with strong ammonia water. A deep ruby-red color is developed when hexanitrocarbanilide is allowed to stand at ordinary temperatures in contact with strong ammonia water. Tetranitrocarbanilide, dinitroaniline, trinitroaniline, picric acid, and dinitro-phenol do not give this color. 

Shimose or Shimoza. Japanese term for Picric Acid, named in honor of Captain I. Shimose, who developed a method for casting PA into shells at the beginning of the century. These shells were successfully used during the Russo-Japanese War, at which time the Russian shells contained pressed NC contg about 18% moisture. Also see Picric Acid in Vol 8, P285-R to P295-L... 

Trimomte. A castable expimixt of Picric Acid (PA) 88—90 and oc-Mononitronaphthalene 10— 12%, developed by the Brit during WWII as an improvement on Tridite (qv in this Vol), to avoid the undesirable tdxicity characteristics of Dinitro-phenol. Both mixts are suitable for melt loading... 

Picric acid has an Rf value of about 0.3, and the bright yellow spot is easily visible. The detection limit can be increased by developing the plate in iodine vapor.8... 

Similarly trinitrophenetole was first obtained by file direct nitration of phenetole, but at present this method is not used, chlorodinitrobenzene being a starting material. Trinitrophenetole is less important then trinitroanisole. Its manufacture never developed beyond the semi-commercial scale. Similarly other picric acid ethers, as for example nitro derivatives of phenyl ether, have not found any practical use. 

No analytical methods specifically used for the determination of tetryl in biological fluids and tissues were located. One attempt to develop a method for detecting tetryl in animal tissues using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was unsuccessful because of suspected metabolism and binding of the parent compound and/or metabolites to macromolecules (Army 1981a). However, methods were located for the detection of the tetryl metabolites, picric acid and picramic acid, in urine and for the analysis of tetryl in hand swabs. Table 6-1 is a summary of methods used to determine tetryl metabolites in urine and tetryl in hand swabs. 

A first requirement for a substance to produce a taste is that it be water soluble. The relationship between the chemical structure of a compound and its taste is more easily established than that between structure and smell. In general, all acid substances are sour. Sodium chloride and other salts are salty, but as constituent atoms get bigger, a bitter taste develops. Potassium bromide is both salty and bitter, and potassium iodide is predominantly bitter. Sweetness is a property of sugars and related compounds but also of lead acetate, beryllium salts, and many other substances such as the artificial sweeteners saccharin and cyclamate. Bitterness is exhibited by alkaloids such as quinine, picric acid, and heavy metal salts. 

The progress in the development of improved monitoring techniques for the heterogeneous synthetic reactions involved in the solid phase method provided the feedback control which was necessary for the full automation of the peptide synthesizers. A monitoring system, which is based on the titration of the unreacted polymer-peptide chains with picric acid 34,35), on coupling with a peptide synthesizer provided an automatic feedback 36). This feedback is to implement the next step in the synthesis if the level of the unreacted peptide chains is below the acceptable preset value, or otherwise to repeat the last step. 

The development of military explosives started approximately since the discovery of black powder. In 1885, Tbrpin discovered picric acid or trini-trophenol, 2, that was found to be a suitable replacement for black powder. 

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