Solvent water saturated

Tropane alkaloids in crude drugs can be qualitatively identified, separated by paper chromatography and quantitatively assayed by colorimetric determination (106). Whatman No. 3 filter paper was used and the chromatograms were developed with the solvent water saturated n-butanol-glacial acetic acid (25 1) for 18 hours. Corresponding areas on the chromatograms were identified, cut off, eluted with ethanol and determined colorimetrically. 

Fig. 6. Co-chromatography of putative hydroxyproline with authentic hydroxy-proline. The putative hydroxyproline was eluted from a chromatogram similar to that shown in Fig. 5, mixed with authentic [ C]hydroxyproline and chromatographed in a phenol ammonia ethanol solvent (water-saturated phenol, 15 ml 0.88 ammonia, 1 ml and ethanol, 4 ml). Strips sliced from the chromatogram were eluted with 0.01 M HCl and the radioactivity in H and C was measured for each eluate.

Wheat flour contains 1.5-2.5% fipids, depending on milling extraction rate. Part of this lipid is nonstarch lipid. This portion is extracted with a polar solvent, water-saturated butanol, at room temperature. Nonstarch lipid comprises about 75% of the total lipid of flour (Fig. 15.19). The residual lipids (25%) are bound to starch (cf. 15.2.4.1). Nonstarch- and starch-bound lipids in wheat differ in their composition (cf. Table 15.28 and Table 15.32). In nonstarch-bound lipids the major constituents are the triacylglycerides and digalactosyl diacylglycerides, while in starch-bound lipids, the major constituents are lysophosphatides in which the acyl residue is located primarily in position 1. A decrease in amylose content is accompanied by a decrease in the lipid content (Table 15.28). The ratios of nonstarch-bound lipid classes are dependent... 

Known volumes of crude oil and solvent (water saturated if required) are placed in a centrifuge tube and heated to 60 C 3 C (140 F 5 F). After centrifugation, the volume of the sediment-and-water layer at the bottom of the tube is read. 

The solvent shall be water-saturated at 60 3 C (140 5 F) (see Note 2) but shall be firee of suspended water. See Annex A1 for the solvent-water saturation procedure. 

The diethyl fumarate is readily prepared as follows. Reflux a mixture of 146 g. of fumaric acid (Section 111,143), 185 g. (236 ml.) of absolute ethanol, 450 ml. of boizene and 20 g. of concentrated sulphuric acid for 12 hours. Pour into a large volume of water, separate the benzene layer, wash successively with water, saturated lodium bicarbonate solution and water, dry with anhydrous magnesium sulphate, and remove the solvent on a steam bath. Distil the residue and collect the diethyl fumarate at 213-215° the yield is 150 g. 

A-Homo-estra- Q>),2,Aa-triene-4, l-dione (45) from the l-ketal mono-dibromocarbene adduct (43b). A solution of monoadduct 17-ketal (43b 0.46 g) and dry pyridine (20 ml) is heated at reflux for 2 hr. After cooling the reaction mixture, the pyridine hydrobromide (0.1 g) is removed by filtration and the filtrate is concentrated under reduced pressure. The resultant gum is dissolved in ether and washed successively with water, ice-cold 4 N hydrochloric acid, water, 5% aqueous sodium bicarbonate solution, water, saturated salt solution and dried over anhydrous magnesium sulfate. Evaporation of the solvent at reduced pressure gives 3-bromo-4-methoxy-A-homo-estra-2,4,5(10)-trien-17-one (44 0.22 g) mp 158-162° after crystallization from ether. 

The solvent was evaporated to yield a colorless solid residue, which was taken up In ethyl acetate-ice water. The two layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with water, saturated sodium chloride solution and filtered through anhydrous sodium sulfate. The solvent was evaporated to yield 1.20 grams of light tan crystals, MP 151° to 155°C, ultraviolet maximum at 224 mp (E = 4,095). Two recrystallizations from ethanol afforded 1st crop, 0.619 grams (62%) of colorless crystals (dried at 120°C in vacuo for 17 hours), (VIP 232.8° to 238.0°C, ultraviolet maximum at 224 mp (E = 4,840) 2nd crop, 0.142 gram (14%) of colorless crystals, MP 234° to 242°C. 

The reliability of the experimental A / MX) values was checked for systems containing nitrobenzene, nitromethane, and 1,2-dichlo-roethane as organic solvent by comparing the differences in these values for various pairs of salts with the differences in the Galvani (i.e.,distribution) potemtials, A cp MX) for the same pairs. The differences should be the same. The A cp or Afip data can be used to estimate ion solvation energies in a water-saturated solvent. ... 

In almost all theoretical studies of AGf , it is postulated or tacitly understood that when an ion is transferred across the 0/W interface, it strips off solvated molecules completely, and hence the crystal ionic radius is usually employed for the calculation of AGfr°. Although Abraham and Liszi [17], in considering the transfer between mutually saturated solvents, were aware of the effects of hydration of ions in organic solvents in which water is quite soluble (e.g., 1-octanol, 1-pentanol, and methylisobutyl ketone), they concluded that in solvents such as NB andl,2-DCE, the solubility of water is rather small and most ions in the water-saturated solvent exist as unhydrated entities. However, even a water-immiscible organic solvent such as NB dissolves a considerable amount of water (e.g., ca. 170mM H2O in NB). In such a medium, hydrophilic ions such as Li, Na, Ca, Ba, CH, and Br are selectively solvated by water. This phenomenon has become apparent since at least 1968 by solvent extraction studies with the Karl-Fischer method [35 5]. Rais et al. [35] and Iwachido and coworkers [36-39] determined hydration numbers, i.e., the number of coextracted water molecules, for alkali and alkaline earth metal... 

The reactive crystallization has some peculiar characteristics like insoluble product, initiation of reaction by change in pH and conductivity. In this case the solution becomes saturated and eventually supersaturated with respect to reactant nucleation [30], The ultrasound assisted decomposition precursors includes dissolving metal organic precursors in organic solvents/water with the assistance of surfactants leads to monodisperse and reduced metal/metal oxide nanoparticles. 

The presence of the C15 saturated chain displayed an efficient gelling ability in a wide range of organic solvents, water, and protic solvent mixtures (1 1), whereas the unsaturated derivatives (mixture of four molecules) formed fibrous nanostructures as opposed to stronger gels. The diene and triene components of the cardanyl glycosides in their fully hydrated state formed fluid nanostructures at room temperature and could not self-assemble to form gels. 

LAC from Myceliophthora sp. Flask scale, adsorbed on glass beads in organic solvents (dioxane/water saturated toluene)... 

Roy WR, Griffin RA. 1985. Mobility of organic solvents in water-saturated soil materials. Environ Geol Water Sci 7 241-247. 

Horvath performed experiments using substrates with different solubilities in water and showed that, under optimal conditions, this solubility did not influence the activity [67]. These experiments clearly support the fact that the reaction takes place at the organic-water interphase. Furthermore, he performed a hydroformylation reaction in a continuous system and even under reaction conditions no leaching of rhodium complex was detected. Water obviously leaches if the SAPC is used in a continuous flow system, which in a practical application should be compensated for by using water-saturated organic solvents. 

The program produces in its output dataset a block of results that shows the concentration, activity coefficient, and activity calculated for each aqueous species (Table 6.4), the saturation state of each mineral that can be formed from the basis, the fugacity of each such gas, and the system s bulk composition. The extent of the system is 1 kg of solvent water and the solutes dissolved in it the solution mass is 1.0364 kg. 

Singh utilized anionic dyes to detect gramicidin on paper chromatograms184. Paris and Theallet described three paper chromatographic systems for gramicidin185. Ritschel and Lercher described two solvent systems for antibioticsiOD. The solvent systems were butanol-pyridine-acetic acid-water (15 10 3 12) and water saturated butanol-water saturated ethyl ether-acetic acid (5 1 1) on Schleicher and Schull 2043b paper. The antibiotics were visualized by ninhydrin. 

The cation selectivity in extraction experiments is dependent on differences in both the distribution constants KD and the binding constants Klf) in the water-saturated organic solvent (3). The extractability of alkali cations into... 

Furthermore, the use of a Lewis acid promoter leads to increased stereoselectivities (Table 19, entry C)252,254. Compared to the aprotic reaction, where allyl silane was used instead of allyl bromide and indium chloride, an almost complete reversal of the diastereos-electivity was found. It was demonstrated recently that the Lewis acid catalysed allylation reaction can be carried out efficiently without any organic solvent in saturated ammonium chloride solution255. Finally, Lewis acid catalysed Mannich reactions can be carried out conveniently in mixtures of organic solvents and water. However, the exact role of the Lewis acid catalyst has not been clarified (Table 19, entry D)253. The same reaction can be carried out in pure water with catalysis by indium trichloride256. 

Normal-phase liquid chromatography is thus a steric-selective separation method. The molecular properties of steric isomers are not easily obtained and the molecular properties of optical isomers estimated by computational chemical calculation are the same. Therefore, the development of prediction methods for retention times in normal-phase liquid chromatography is difficult compared with reversed-phase liquid chromatography, where the hydrophobicity of the molecule is the predominant determinant of retention differences. When the molecular structure is known, the separation conditions in normal-phase LC can be estimated from Table 1.1, and from the solvent selectivity. A small-scale thin-layer liquid chromatographic separation is often a good tool to find a suitable eluent. When a silica gel column is used, the formation of a monolayer of water on the surface of the silica gel is an important technique. A water-saturated very non-polar solvent should be used as the base solvent, such as water-saturated w-hexane or isooctane. 

The solvent present in biphasic reactions can still have an effect on the enzyme even though the enzyme functions primarily in an aqueous microenvironment. A particularly dramatic example is the lipase AH (lipase from Burkholderia cepac/fl)-catalysed desym-metrization of prochiral 1,4-dihydropyridine dicarboxylic esters, where either enantiomer can be accessed in high enantioselectivity by using either water-saturated cyclohexane or diisopropyl ether (DIPE) respectively (Scheme 1.60). The acyl group used in acylation and deacylation can also have a dramatic effect on enantioselectivity. " ... 

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