Potassium nitrate purification

Sulfuric acid 96% (technical quality) and diethyl ether (technical quality) were purchased from Bie Bemtsen A/S, Sandbaekvej 7, DK-2610 Roedovre, Denmark and used without further purification. Isoquinoline (97%) and potassium nitrate (99%) were purchased from Aldrich Chemical Company, Inc. and used without further purification. 

Charcoal is made from wood ashes, sulfur is mined, and potassium nitrate (called Chilean saltpeter) was mined from dry cliffs on the coast of Chile, where fish-eating seabirds had their nests and restroom facilities. Over many centuries, this source accumulated in layers mary feet thick, and this was adequate for all nitrate needs until the end of the nineteenth century when deposits began to deplete faster than birds could replenish them and transportation and purification (odor is just part of the problem) kept costs high-... 

The photocatalyst was T1O2 Degussa P-25 (mainly anatase, specific surface area 50 m2 g-1). Ti02 in suspension was used in all photocatalytic experiments. Sodium hydrogen phosphate, sodium bicarbonate, sodium nitrate, sodium sulfate, sodium chloride, potassium sulfate, potassium bicarbonate, potassium hydrogen phosphate, potassium sulfate, potassium nitrate, potassium chloride, and iron chloride were used without further purification and were supplied by Fluka (Buchs, Switzerland). 

An account of the elaborate research of Richards and Stahler 2 on potassium chloride appeared in 1907. The salt employed was prepared by the action of hydrogen chloride on potassium nitrate purified by repeated recrystallization with special precautions. After several crystallizations, the chloride was fused in a current of nitrogen. The silver was obtained by reducing the nitrate with ammonium formate. After electrolytic purification, it was fused in a lime-boat in a current of hydrogen, and finally in vacuo. In the analyses the silver required to precipitate the chlorine from a known weight of potassium chloride was determined, and also the weight of silver chloride produced ... 

Method of purification Sulfur compounds are removed by the addition of potassium nitrate to the fused caustic. The purest form is obtained by solution in alcohol, filtration, and evaporation. 

Although Bacon does not tell us the trick of gunpowder, other recipes, such as the purification of potassium nitrate with charcoal, are very clear and could easily be followed, contrasting sharply with alchemical writing in the next century. 

The cmde phthaUc anhydride is subjected to a thermal pretreatment or heat soak at atmospheric pressure to complete dehydration of traces of phthahc acid and to convert color bodies to higher boiling compounds that can be removed by distillation. The addition of chemicals during the heat soak promotes condensation reactions and shortens the time required for them. Use of potassium hydroxide and sodium nitrate, carbonate, bicarbonate, sulfate, or borate has been patented (30). Purification is by continuous vacuum distillation, as shown by two columns in Figure 1. The most troublesome impurity is phthahde (l(3)-isobenzofuranone), which is stmcturaHy similar to phthahc anhydride. Reactor and recovery conditions must be carefully chosen to minimize phthahde contamination (31). Phthahde [87-41-2] is also reduced by adding potassium hydroxide during the heat soak (30). 

For purification the crude product is boiled with glacial acetic acid (preferably in the extraction apparatus shown in Fig. 27). Fine red needles melting point 289°. Sublimation in a vacuum from a sausage flask is also to be recommended the sausage should be fixed low down and the bulb completely immersed in a nitrate bath (equal parts of potassium and sodium nitrates). Much poorer yields of alizarin are obtained by using an open round-bottomed flask at 189°-190°. 

Crystallisation was one of the earliest methods used for separation of radioactive microcomponents from a mass of inert material. Uranium X, a thorium isotope, is readily concentrated in good yield in the mother liquors of crystallisation of uranyl nitrate (11), (33), (108). A similar method has been used to separate sulphur-35 [produced by the (n, p) reaction on chlorine-35] from pile irradiated sodium ot potassium chloride (54), (133). Advantage is taken of the low solubility of the target materials in concentrated ice-cold hydrochloric acid, when the sulphur-35 as sulphate remains in the mother-liquors. Subsequent purification of the sulphur-35 from small amounts of phosphorus-32 produced by the (n, a) reaction on the chlorine is, of course, required. Other examples are the precipitation of barium chloride containing barium-1 from concentrated hydrochloric acid solution, leaving the daughter product, carrier-free caesium-131, in solution (21) and a similar separation of calcium-45 from added barium carrier has been used (60). 

Formerly all the iodine was made from the ash of seaweed, and potash was a remunerative appendix to the iodine industry but just as the Stassfurt salts killed those industries which extracted potash from other sources, so did the separation of iodine from the caliche mother-liquors threaten the industrial extraction of iodine from seaweed with extinction. Iodine in a very crude form was exported from Chili in 1874—e.g. a sample was reported with iodine 52-5 per cent. iodine chloride, 3-3 sodium iodate, 13 potassium and sodium nitrate and sulphate, 15 9 magnesium chloride, 0 4 insoluble matter, 1 5 water, 25-2 per cent. About that time much of the iodine was imported as cuprous iodide. This rendered necessary the purification of the Chilian product but now the iodine is purified in Chili before it is exported. The capacity of the Chilian nitre works for the extraction of iodine is greater than the world s demand. It is said that the existing Chilian factories could produce about 5100 tons of iodine per annum whereas the... 

Uses Of the Stassfurt salts.—The magnesium compounds in the Stassfurt salts are used for the preparation of magnesium and of its salts. The potash salts are an essential constituent of many fertilizers used in agriculture, etc. 22 and potassium chloride is the starting-point for the manufacture of the many different kinds of potassium salts used in commerce—carbonate, hydroxide, nitrate, chlorate, chromate, alum, ferrocyanide, cyanide, iodide, bromide, etc. Chlorine and bromine are extracted by electrolysis and other processes from the mother liquids obtained in the purification of the potash salts. Boric acid and borax are prepared from boracite. Caesium and rubidium are recovered from the crude carnallite and sylvite. 

The purification of the alkali hydroxides.—Numerous impurities have been reported in commercial sodium and potassium hydroxides. Several have commented on the presence of peroxide, particularly in caustic potash.19 Various salts—carbonate, sulphate, nitrate, nitrite, chloride, and phosphate—as well as alumina, silica, organic matters, and metal oxides—e.g. arsenic, vanadium, iron, etc., have been reported. More or less of the other alkalies may also be present. 

To monitor tumor response to capecitabine therapy noninvasively, Zheng and co-workers, from the Indiana University School of Medicine, developed the synthesis of the fluorine- 18-labeled capecitabine as a potential radiotracer for positron emission tomography (PET) imaging of tumors.28 Cytosine (20) was nitrated at the C-5 position with nitric acid in concentrated sulfuric acid at 85°C, followed by neutralization to provide 5-nitrocytosine (27) in moderate yield. This nitro pyrimidine was then carried through the glycosylation and carbamate formation steps, as shown in the Scheme below, to provide the 6/s-protected 5-nitro cytidine 28 in 47% for the three-step process. Precursor 28 was then labeled by nucleophilic substitution with a complex of 18F-labeled potassium fluoride with cryptand Kryptofix 222 in DMSO at 150 °C to provide the fluorine-18-labe led adduct. This intermediate was not isolated, but semi-purified and deprotected with aqueous NaOH in methanol to provide [l8F]-capecitabine in 20-30% radiochemical yield for the 3-mg-scale process. The synthesis time for fluorine-18 labeled capecitabine (including HPLC purification) from end of bombardment to produce KI8F to the final formulation of [18F]-1 for in vivo studies was 60-70 min. 

Further purification may be effected by one or more additional fusions of the metal with potassium hydroxide and nitrate. 

Sediment and biota samples have both been analyzed by Pruell et al. by the same method. About 10 g of sediment or tissue sample were mixed with sodium sulfate. The samples were Soxhlet-extracted with an acetone pentane (30 70, v/v) solvent mixture. Four subsequent column chromatographic purifications with series of layers of activated silica, potassium silicate, sulfuric acid treated silica, sodium sulfate, silver nitrate treated silica, neutral alumina, and activated carbon as adsorbents were used [11]. 

The synthesis- offered below is probably best in terms of availability of starting materials and ease of their purification, using, as it does, silver(I) nitrate, potassium hydrogen carbonate, and high-purity commercial sulfamic acid. 

The latest technologies (especially Toyo Soda) do not include the separation and intermediate purification of acrolein. They employ two trains of reactors in series, operating in different conditions, with catalysts of distinct compositions based on molybdenum oxide, and through which the reaction medium flows. These are multitube systems with molten salt circulation (sodium and potassium nitrites and nitrates) on the shell side, to remove heat generated by the transformation, ensure effective temperature control, and the production of low-pressure steam. The catalyst is placed in a fixed bed in the tubes. 

In the early oxidation nitration preparation of DNPOH, the yield is relatively low (59-63 %), the product needs further purification, there is formaldehyde condensation reaction and other serious problems. Jeong et al. [63] modified the oxidation nitration process to optimize the oxidation nitration conditions of silver nitrate, in which aqueous formaldehyde solution (mass fraction of 35 %) was used for hy-droxymethylation and its reaction conditions were optimized, and a yellow solid DNPOH was obtained after extraction with methylene chloride and distillation. The average yield of DNPOH was more than 90 % and the mass fraction was more than 97 %. Based on these results, Grakauskas et al. [40-42, 65] used potassium ferri-cyanide as catalyst and potassium persulfate as oxidant to synthesize DNPOH. In this method, with potassium(sodium) ferricyanide and over potassium(sodium) persulfate, nitrite substitution reaction of nitroethane with sodium nitrite occurred, and then further reacted with formaldehyde under basic conditions, and finally DNPOH was extracted out with ethyl acetate under acidic conditions. Product was obtained through potassium distillation. The reaction mechanism is ... 

CMC supplied by Sigma-Aldrich with 0.7 degree of substitution was used to graft reactions, without further purification process, same as all other reactives Hydroxyethyl methacrylate (HEMA) (98%) and malic acid, potassium permanganate (KMn04), hydrochloric acid (HCl), methanol, ethanol, sulfuric acid (H2SO4), Cerium ammonium nitrate were from Sigma-Aldrich. Distilled water was used as reaction medium and finally to wash the homopolymer residues. 

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