Alcohol phase

Octahedral crystals of NaCd2 (accurate composition NaCd, ) are prepared by slowing cooling Na-Cd alloys containing xs Na. Excess Na is removed by dissolution in absolute alcohol. Phases with compositions between NaCd, and NaCdj (probably Na2Cdi,) are obtained by titrating Na in NH3 with Cdl2 in NHt ... 

The partition of different lipids between two immiscible solvents (countercurrent distribution) is useful for crude fractionation of lipid classes with greatly differing polarities. Repeated extractions in a carefully chosen solvent pair increase the effectiveness of the separation but in practice mixtures of lipids are still found in each fraction. A petroleum ether-ethanol-water system can be used to remove polar contaminants (into the alcoholic phase) when interest lies in the subsequent analysis of neutral glycerides, which may be recovered from the ether phase. Carbon... 

In the ternary systems, the aqueous phase was filled in the syringe and the drop was formed, with over 10 minutes interval, in the oil (toluene or n-heptane or the n-alcohols) phase. 

When aqueous NaOH is given as a base, isomerization of the product butenoic acids can be extensive depending on the nature and concentration of base. In dilute aqueous solutions alcohols do not react to form the respective esters, however, the reactions are strongly accelerated due to the increased solubility of the substrates in the catalyst-containing aqueous-alcoholic phase. For example, with 23-33 % (v/v) ethanol in water the [PdCl2(TPPTS)2]-catalyzed hydroxycarbonylation of allyl chloride proceeded with TOF-s of 1850-2400 h and with a vinylacetic/crotonic acid ratio of 21 [16]. Addition of [CuCb] increased the overall conversion rate (by a factor of 2 at [Cu]/[Pd] = 8) but at the same time the side reactions... 

Fructan was harvested by precipitation from the culture broth by addition of ethanol or isopropanol. Acetone and methanol can also be used. The yield and consistency of the product varied depending on the amount of alcohol added. The fructan started to precipitate at the medium/alcohol v/v ratio of 1 1.2, and the yield peaked at about 1 1.5. Further increase in the ratio hardened the fructan and made the product less fluid. Slightly less isopropanol was needed than ethanol to precipitate levan (fructan). Although most of the bacterial cells, unfermented sugars, and other solubles remained in the aqueous alcohol phase, pre-removal of microbial cells by centrifuging was needed to obtain a pure form of fructan. The product was further purified by repeated precipitation and dissolution in water, followed by dialysis or ultrafiltration. The final product was an... 

Ultrasound-assisted extraction is a rapid technique that can also be used with mixtures of immiscible solvents hexane with methanol-water (9 1), for example, is a system used for the Brazilian plant Lychnophora ericoides (Asteraceae). The hexane phase concentrated less polar sesquiterpene lactones and hydrocarbons, while the aqueous alcohol phase concentrated flavonoids and more polar sesquiterpene lactones. 

Hydrocarbons, CHCI3, dioxane and tetra-hydrofuran. Not alcohols. Phase must be saturated with trimethylene glycol. 

SL Abidi, TL Mounts. Reversed-phase separations of nitrogenous phospholipids on an octadecanoyl poly(vinyl alcohol) phase. J Chromatogr A 773 93-101, 1997. 

A flavouring essence is a traditional flavouring product prepared by washing a selected oil blend (predominately citrus oils) with an aqueous alcoholic solvent mixture (e.g. 60% ethanol/40% water). It is an extraction process in which the aqueous extract phase becomes the flavouring. The process is earned out under cool temperatures, for example, 5-10°C, either batch-wise or by counter-current extraction. The soluble oxygenated flavouring constituents present in the essential oil blend (e.g. citral in lemon oil) are effectively partitioned between the two phases of the mixture. The low temperatures employed ensure that the transfer of any oil into the hydro-alcoholic phase is minimised as a poorly processed essence will tend to cloud when used in the drink formulation. 

The alcohols may have inhibited the full recovery of the herbicides under these conditions by providing a liquid phase which could solublize the herbicides. The herbicides could then partition themselves between the liquid alcohol phase and the C02/alcohol phase. This would lead to the herbicides being retained on the celite until the all of the alcohol modifier was removed by the CO2 extraction fluid. 

Identification Place about 150 mg of melted sample into a 16- x 125-mm tube equipped with a screw cap having a Teflon liner, and add 4 mL of absolute methanol, 4 drops of a 25% sodium methoxide solution in absolute methanol, and a boiling chip. Cap the tube, reflux for 15 min, and cool to room temperature. Extract as follows Add 8 drops of a 15% potassium acid sulfate solution, 4 mL of water, and 4 mL of n-hexane cap the tube shake for 1 min and centrifuge for 30 to 60 s. Decant and discard the M-hexane layer, and repeat the extraction with three additional 4-mL portions of M-hexane, discarding each extract. Transfer the aqueous alcoholic phase from the tube into a 50-mL round-bottom, glass-stoppered flask place the flask in a water bath at 50° to 55° and evaporate to near dryness (about 0.5 mL of residue) in a rotary film evaporator under full water aspirator vacuum. 

Transfer the solutions into 100-mL separators containing 25 mL of cold water, and rinse the beakers and pH meter electrodes with a few milliliters of cold water, collecting the washings in the respective separator. Add 2 mL of bromine TS, stopper, and mix. Add 2 mL of 2% sodium arsenite solution, stopper, and mix. Add 10 mL of n-butanol to the clear solutions, stopper, and mix. Finally, add 5 mL of p-Phenylenediamine-Pyridine Mixed Reagent, mix, and allow to stand for 15 min. Remove and discard the aqueous phases, and filter the alcohol phases into 1-cm cells. The absorbance of the solution from the Sample Solution, determined at 480 nm with a suitable spectrophotometer, is not greater than that from the Cyanide Standard Solution. 

This means that the phase changes observed have comparatively less Importance for the thermodynamics of the system. On the other hand, the changes and modifications of the association structures within the isotropic liquid hydrocarbon or alcohol phase pose a series of interesting problems. Some of these have recently been treated in review articles by Fendler — who focussed on surfactant inter-association emphasizing consecutive equilibria and their thermodynamics. The following description will focus on the Intermolecular interaction between different kinds of molecules and the Importance of these interactions for the "inverse" association structures. 

The treatment of small ferrous artefacts in a 0.05 M lithium hydroxide dissolved in methanol or ethanol has its advocates, particularly in France. The chlorides present in the rust layers react with lithium hydroxide to form lithium chloride that dissolves in the alcohol phase. Any of the hydroxide left on the metal surface combines with any carbon dioxide to form a solution with pH above 9.5, which maintains any exposed metal in the passive region. Hence, this solution is claimed to cause no corrosion of the underlying metal. The real disadvantage of this solution is that any lithium chloride left on the surface of the artefact is very hygroscopic. Water will form on the surface at a relative humidity above 15% RH and corrosion of the metal will take place. Humidity levels below 15% RH are very difficult to maintain in display cabinets or in storage and is one of the main reasons why this solution has not been more widely employed. 

Amino-4-methoxyphenol 141 4-Methoxy-2-(phenylazo)phenol (100 g) is dissolved in a solution of sodium hydroxide (100 g) in water (11), warmed on the water-bath, and treated, with stirring, with portions of sodium dithionite until the solution is decolorized. The aniline produced is extracted with ether, and the aqueous-alcoholic phase therefrom is neutralized, whereupon the aminophenol is precipitated. This is at once filtered off, dried, and immediately converted into its hydrochloride by ethereal hydrogen chloride. The yield is 57.5 g and the m.p. 205-212° (dec.). A further 7.8 g of somewhat lower m.p. are obtained by extracting the aqueous mother-liquor with ether, the total yield being 85 %. 

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