Extraction with nitric acid

Miconazole nitrate was prepared by Godefori and co-workers [5-7]. Imidazole 1 was coupled with brominated 2,4-dichloroacetophenone 2 and the resulting ke-tonic product 3 was reduced with sodium borohydride to its corresponding alcohol 4. The latter compound 4 was then coupled with 2,4-dichlorotoluene by sodium borohydride in hexamethylphosphoramide (an aprotic solvent), which was then extracted with nitric acid to give miconazole nitrate. 

Barium Barium pre-concentrated on cation exchange resin, then extraction with nitric acid Graphite furnace AAS [78]... 

Elemental composition 86.96%, C 10.41%, H 2.62%. The compound can be identified from its physical properties, elemental analyses and infrared spectra. Mercury can be identified by cold-vapor AA or ICP/AES after cautious extraction with nitric acid. In a suitable organic solvent, it may be analyzed by GC/MS. The characteristic ions are 217, 215, 202, 200, 232 and 230. 

Tungsten carbonyl may be dissolved in an organic solvent and analyzed by GC/MS. The compound should form mass spectra corresponding to the masses for W(CO)6, CO and W. The compound may be decomposed thermally and product carbon monoxide transported with helium onto a GC column to be analyzed by GC-TCD or GC/MS. Residue tungsten metal is extracted with nitric acid-hydrofluoric acid, diluted with water, and analyzed (See Tungsten). 

Table IV. Nitrogen and Iron Content in Raw and in Treated Coals Before and After Extraction with Nitric Acid.

Detection of Ruthenium in Platinum Alloys.—In order to detect the presence of ruthenium in platinum alloys, a portion of the alloy is fused with lead. The melt is extracted with nitric acid and the residue ignited in contact with air in order to volatilise the osmium. The mass may now contain platinum, iridium, rhodium and ruthenium, and is fused with potassium nitrate and hydroxide. The whole is dissolved in water, treated with excess of nitric acid and allowed to stand in a flask covered with filter-paper. In a few hours (12-24) the filter-paper darkens if ruthenium is present, in consequence of the evolution of vapour of its tetroxide. To confirm the presence of ruthenium, the paper is ignited and the ash fused with potassium nitrate and hydroxide. On extraction with water the orange colour of potassium ruthenate is obtained.1... 

CH2CH2— but was little changed when X was varied from —CH2— to —CH=CH—, Dihexyl Ar,AT-diethylcarbamoylmethylenephosphonate (DHDECMP) has been used to extract trivalent ions from HAW. After back extraction with nitric acid or carbonate solution the lanthanides... 

Econazole nitrate may be synthesised by the reaction pathway shown in Figure 12. This reaction scheme, taken from Godefroi et al, has optional pathways at each stage. Imidazole is coupled with brominated 2,4-dichloroaceto -phenone and the resultant ketone is oxidized with sodium borohydride to the corresponding alcohol. This product is coupled with 2,4-dichlorotoluene by means of sodium hydride in hexamethylphosphoramide (an aprotic solvent) before being extracted with nitric acid to give econazole nitrate. 

For the ion chromatographic analysis of chloride in cement, that cancels out the passivation of steel surfaces in concrete and, thus, is only admitted up to a maximum content of 0.1%, Maurer et al. [93] developed a procedure in which the cement sample is extracted with nitric acid. Since a direct chloride determination is impossible due to the high nitrate concentration in the extract, silver nitrate is added in three-fold excess to the nitric acid extract. The precipitated silver chloride is filtered off and subsequently dissolved in 100 mL of a 0.25% ammonium hydroxide solution. This solution, according to the chloride concentration, can be further diluted with de-ionized water or injected directly. 

Swedish Standard Institution SSI (1997) Soil analysis - determination of trace elements in soils -extraction with nitric acid. 

A simple possibility to obtain a detailed information about the stabilizer system in PVC waste can be seen in the classic analysis methods which are common practice in inorganic chemistry of the separation and determination of cations. The only difficulty is to find an easily practical way to get the metallic cations into water phase. For this purpose, the PVC sample is dissolved in cyclohexanone and the received solution used for a liquid/liquid-extraction with nitric acid containing water. After phase separation, the different cations are found in water solution. 

The primary source of rare earths for agricultural use in China are soluble extracts of mineral ores, that were originally known as Nongle (=happy farmer) but have recently been re-named Changle (=happiness forever). These compounds have usually been extracted with nitric acid and are said to contain an equivalence of 38% RE oxide. As well as the rare earths they also contain a number of elements essential to plant growth (table 8). Trace element deficiencies are common in China, particularly those of B, Fe, Mn, Mo and Zn (Liu et al. 1983, 1984). Many of these soils are also low in REE (Zhu and Liu 1986) and it remains possible that some of the reported effects of rare earths may be due to other trace elements, especially Mo, present in Changle as contaminants. The... 

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