Purification by extraction

Purification by extraction and then distillation led to violent decomposition. Steam distillation avoided this problem. 

To determine the amount of plutonium in a water sample after radioana-lytical chemical purification by extraction into triisooctyalamine solution and counting by alpha-particle spectrometer. 

Terminal Stream Compositions and Quantities These are basically linked to an arbitrary given the production capacity of the leaching plant (rate of extract production or rate of raw-material purification by extraction). When options are permitted, the degree of solute removal and the concentration of the extract stream chosen are those that maximize process economy while sustaining conformance to regulatory standards. 

Soil, sediment, and biota Ashing fusion with KF and K2S2O7 purification by extraction with triisooctylamine, anion exchange chromatography and coprecipitation. a-Spectroscopy No data No data ERA 1984b... 

Sodium ethylphenylarsenide with carbon dioxide yields crystalline ethylphenylarsino-formic acid (52) after treatment with dilute sulphuric acid . The arsinoformic acid was resolved with (—)-quinine. The less-soluble diastereomer, after three recrystallizations from chloroform, was decomposed with dilute sulphuric acid into (— )-52, which required purification by extraction into benzene to separate it from arsine oxide (Table 2). 

Reduce the conversion of A, thereby reducing S formation, as shown in Fig. 11-4 at reduced mole ratios. This method is commonly used if downstream processing can remove and possibly recycle unreacted A. However, in this case, downstream separation was not feasible since A could not be separated from R in the subsequent purification by extraction. 

Slow addition of B to minimize the concentration of R in solution by allowing time for nucleation and/or growth (particle size is not a key issue in this case because the R is resolubiUzed after completion of the reaction for the subsequent purification by extraction. R is crystallized only for minimizing S and maximizing yield). The effect of addition rate on yield/selectivity is shown qualitatively in Fig. 11-7, where it can be seen that a critical rate can be determined at which the crystallization rate can maintain the minimum concentration of R. At higher addition rates, selectivity decreases as the R concentration increases. 

The analysis of separately synthesized single substances is much simpler than that of compound mixtures. Here, the yield and purity can be determined in the traditional way purification by extraction, crystallization, or chromatography, gravimetric determination of the yield, and confirmation of the purity by elemental analysis, chromatography, or NMR. 

Gibberellins are extracted from fresh or dried plant material using acetone, methanol or ethanol (long-time extraction at low or at room temperature). The substances which have been adsorbed if necessary on charcoal and eluted with acetone [55], can be extracted from the crude aqueous extract at pH 3 by means of ethyl acetate. It appears usually necessary to follow this with purification by extracting with a buffer solution at pH 6, renewed extraction with ethyl acetate at pH 3 and prior separation on columns of cehte/charcoal, ceUte/silica gel, ceHte or silica gel [51, 55, 75, 76]. 

Caustic soda solution, produced in the diaphragm process, is not qualified for many applications, especially in chemical industry, due to its relatively high salt content of 1 wt% NaCI. A further purification by extraction with liquid ammonia is possible but expensive. 

Sin e, Successive and Continuous Extraction of Mustard Gas with Solvents. EAL 11, 24 May 18. (2) Thomas G. Thompson and Harry Odeen, "The Solubility of /S, g -Dichlotoethyl Sulfide in Petroleum Hydrocarbons and Its Purification by Extraction with These Solvents," Industrial and Engineering Chemistry, 12 (1920), 1057-62. 

Also important in the determination of beryllium is the radioisotope Be. It may be obtained carrier-free in the reaction Li (d,2n) Be by bombarding a lithium target with deuterone, with subsequent purification by extraction with acetylacetone or theonyltrifloroacetone. Be is used for analytical control in the extraction of small amounts of beryllium, especially from biological materials and in the analysis of meteorites [17]. 

In most cases the polymers themselves do not present these problems. However, unlike low-molecular-weight products, polymers are not generally subjected to purification by extraction, distillation, or crystallization after they have been formed. The ingredients present dnring formation often remain as part of the final product. Various techniques, bulk, solution, suspension, and emulsion are used to produce polymers. Some of the criteria for using these techniques are connected with thermal effects. 

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