Diethyl ether distribution coefficients

Miscellaneous Pharmaceutical Processes. Solvent extraction is used for the preparation of many products that ate either isolated from naturally occurring materials or purified during synthesis. Among these are sulfa dmgs, methaqualone [72-44-6] phenobarbital [50-06-6] antihistamines, cortisone [53-06-5] estrogens and other hormones (qv), and reserpine [50-55-5] and alkaloids (qv). Common solvents for these appHcations are chloroform, isoamyl alcohol, diethyl ether, and methylene chloride. Distribution coefficient data for dmg species are important for the design of solvent extraction procedures. These can be determined with a laboratory continuous extraction system (AKUEVE) (244). 

Extraction of the thiocyanate complex with higher alcohols, diethyl ether, or DIPE enhances the sensitivity of the method, because the high distribution coefficients facilitate concentration of the complex in a small volume of organic extractant [27]. 

One of the reasons that solvent extraction is so successful in separating and purifying certain elements is that the distribution coefficients of different elements between certain solvents and aqueous solutions differ enormously. Table 4.2 lists distribution coefficients observed by Furman [F2] between diethyl ether and aqueous nitrate solutions. The much higher distribution coefficient for uranium is the reason for the successful use of diethyl ether in purifying uranium. 

In many solvent extraction systems, addition of solutes to the aqueous phase increases the distribution coefficient of extractable components. Data in Table 4.2 and Fig. 4.6 show how addition of nitrates to an aqueous solution of uranyl nitrate increases the distribution coefficient of uranyl nitrate between the aqueous phase and diethyl ether [F2]. The increase in distribution coefficients with increased nitrate concentration is explained as follows Analysis of... 

The next step in purification is separation of uranyl nitrate from the other metallic impurities in the dissolver solution by solvent extraction. Practically aU uranium refineries now use as solvent tributyl phosphate (TBP) dissolved in an inert hydrocarbon diluent. The first U.S. refinery used diethyl ether as solvent and later refineries have used methyl isobutyl ketone or organic amines, but practically all have now adopted TBP. It is nonvolatile, chemically stable, selective for uranium, and has a uranium distribution coefficient greater than unity when the aqueous phase contains nitric acid or inorganic nitrates. 

The concentration distribution coefficient K, for gallic acid (CvHsOj) between diethyl ether (phase... 

Distribution coefficients Di. of 10- can be achieved when pertcchnetate in 1 M H2SO4 is extracted w ith triphenylguanidinium chloride dissolved in /),/ -dichloro-diethyl ether. D ic decreases with increasing H2SO4 concentration, similar to Dr - The separation of TcOj from RcOj and even from MoOj is not possible by a single-stage extraction [146]. 

When a product is very soluble in water, it is often difficult to extract using the techniques described in Sections 12.4 12.7 because of an unfavorable distribution coefficient. In this case, you need to extract the aqueous solution numerous times with fresh batches of an immiscible organic solvent to remove the desired product from water. A less labor-intensive technique involves the use of a continuous liquid-liquid extraction apparatus. One type of extractor, used with solvents that are less dense than water, is shown in Figure 12.15. Diethyl ether is usually the solvent of choice. 

Suppose solute A has a distribution coefficient of 1.0 between water and diethyl ether. Demonstrate that if 4.0 mL of a solution of 0.20 g of A in water were extracted with two 1.0-mL portions of ether, a smaller amount of A would remain in the water than if the solution were extracted with one 2.0-mL portion of ether. 

Quantitative Analysis of Diethyl Ether in Blood Blood/Gas Distribution Coefficients of Diethyl Ether Anesthesiology 27(6) 829-834 (1966) CA 66 8710w... 

Alkane monosulphonates cannot be extracted from an acid medium by a simple separating-funnel technique because they are not sufficiently soluble in hydrocarbon solvents, the distribution coefficient between pentane and aqueous alcohol being only 0.08-0.09. Extraction with diethyl ether, which is effective for other monosulphonates, has apparently not been reported, but may be practicable. 

Only the undissociated form, IHA], can be extracted into a nonpolar or slightly polar solvent such as diethyl ether, the distribution or partition coefficient, K, being given by... 

It Is less soluble in water, less volatile, and has a higher flash point. The distribution coefficient of uranyl nitrate la, however, less for dlbutyi ether than for diethyl ether. 

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