Solvent Extraction from liquids

With egg lecithin, a different manufacturing process must be used since the lecithin in egg yolks is more tightly bound to proteins than in vegetable sources. Egg lecithin is thus obtained by solvent extraction from liquid egg yolks using acetone or from freeze-dried egg yolks using ethanol (95%). ... 

Work is in progress to validate the MAE method, proposed for EPA, in a multi-laboratory evaluation study. Nothing similar has been reported for additives in polymeric matrices. Dean el al. [452] have reviewed microwave-assisted solvent extraction in environmental organic analysis. Chee et al. [468] have reported MAE of phthalate esters (DMP, DEP, DAP, DBP, BBP, DEHP) from marine sediments. The focus to date has centred on extractions from solid samples. However, recent experience suggests that MAE may also be important for extractions from liquids. 

Juang, R. S. Jiang, J. D. Recovery of nickel from a simulated electroplating rinse solution by solvent extraction and liquid surfactant membrane. J. Memhr. Sci. 1995, 100, 163-170. 

Liquid-liquid extraction Analyte extracted from liquid sample into an immiscible solvent Organic compounds in aqueous samples (e.g. pesticides in river water)... 

In Section 2.5, we described separation procedures in which analytes are extracted from solid samples via contact with liquid solvents that selectively dissolve the analyte and leave other components undissolved or unextracted. There are several methods by which analytes can be extracted from liquid matrices as well. 

B1 ood Solvent extraction from acidified blood liquid liquid partition GC/ECD 10 g/L in 1-mL serum speci men 24-7 (blood) 43.2 (serum) Caplan 1979 et al. ... 

Anhydrous Hydrogen Chloride is a colorless gas, which on liquefaction gives colorless (or si yellowish) fuming, strongly corrosive liquid mw 36.47, sp gr of gas at 0° 1.268 (Air) fr p -114.3° bp -111° (Lange) bp -84.8° sol in w, ale, eth benz. It can be prepd by furnace combstn pf hydrogen, methane or water-gas, in chlorine or by solvent extraction from hydrochloric acid (aqueous HC1). 

Castor polyols Castor oil (CO) is mainly available in India and Brazil although the USA also produces a considerable quantity. Castor oil is produced either by expression or by solvent extraction from its seeds, also known as castor beans . It is a viscous liquid with a characteristic unpleasant taste and can be made odorless and tasteless by neutralization and subsequent deodorization. The grade of castor oil is decided by its... 

The separation art is now a continuous band extending from simple distillation through azeotropic distillation, extractive distillation, vapor phase adsorption, and solvent extraction to liquid phase adsorption. 

Diethylstilbestrol is particularly difficult to quantitate below 1.0 ppb in bovine tissues, especially in liver, which is among the last tissues to contain diethystilbestrol after cattle are withdrawn from receiving tire drug (101, 102). Interferences from tissue matrix constitute a major problem that might be due to nonspecific interference of lipids and fatty compounds (103, 104). In addition, problems with false-positive results often appear in urine analysis unless a chromatographic step such as a solid-phase extraction cleanup (105, 106) is introduced. Simple sample preparation procedures such as those based on solvent extraction and liquid-liquid partitioning do not usually give satisfactory results (107, 108). 

Solvent extraction, or liquid—liquid distribution, is the process in which one or more solutes partition selectively between two immiscible liquid phases (Rydbery, Musikas and Choppin 1992). The process is applied industrially in hydrometallurgy e.g., recovery of copper and nickel from ores, in nuclear fuel... 

Another interesting carbonylation that has been carried out in ionic liquids is that of 3-alkyn-l-ols and l-alkyn-4-ols by [Pd(OAc)2]/ PyPPh2(PyPPh2=2-(diphenylphosphino)pyridine) to give evo-a-methylene y- and 8-lactones, respectively.60 The products were isolated in almost quantitative yields by distillation under reduced pressure or by solvent extraction from the ionic liquid with diethyl ether. However, when recycling of the ionic liquid solution was attempted for the carbonylation of 3-butyn-l-ol the yield fell from 99 to 37% after only two runs. 

Solvent extraction, or liquid-liquid extraction, is the separation of impurities (solutes) from a liquid solution by contacting it with another immiscible liquid (solvent) in which the impurities have a high affinity. The high affinity driving the separation can be either physical solubility differences or a chemical reaction. The solvent may be a single component liquid (toluene) or a mixture (isopropyl ether/octanol). 

Ma M, Shen A-H, Luo X-B, Zhu X-L, Chen B, Yao S-Z. Solvent extraction and liquid-membrane transport for separation and purification of Rutaecarpine from... 

In all the cases of extraction from liquids given above, the solute is distributed between the two solvents in such a manner that a definite ratio (the Distribution coefficient or the Partition coefficient) is maintained between the two concentrations i.e. in the instance under consideration. 

Solvent extraction (3) Liquid-liquid extraction is used to separate water and AA. The top of the extractor is forwarded to a solvent separator. The extractor bottom Is sent to the raffinate stripper (5) to recover solvents. Crude acrylic acid (CAA) is separated from the solvents by distillation. The overhead vapor is condensed in an internal thermoplate condenser. The two-phase condensate is separated. The organic phase is recycled. The aqueous phase is sent to the raffinate stripper (5). The column bottom, mostly AA and acetic acid, is routed to the CAA separator (4). 

Pecorelli I, Galarini R, Bibi R, Floridi A, E. Casciarri E, Floridi A, Simultaneous determination of 13 quinolones from feeds using accelerated solvent extraction and liquid chromatography. Ana/. Chim. Acta 2003 483 81-89. 

Raut, D.R., Evaluation of two calix-crown-6 ligands for the recovery of radio cesium from nuclear waste solutions Solvent extraction and liquid membrane studies, J. Membr. Sci. 429, 197, 2013. 

Liquid-liquid stratified flow in microchannel is often used in biological analysis, such as during ion exchange or solvent extraction from one phase to another phase [1]. For liquid flow in microfluidics, the Reynolds number is small and the flows are always laminar. Laminar fluid diffusion interfaces (LFDIs) are generated when two or more streams flow in parallel within a single microstructure [2], as shown in Fig. la. 

In liquid-liquid extraction solvent extraction) two liquid phases take part. From a liquid feed consisting of a carrier phase T and the key component S, the key component is removed by means of a solvent L. The solvent, acting as an auxiliary substance, should essentially be insoluble in the carrier phase T, but the key component S should have good solubility in it. Mechanical phase separation at the end of the extraction process gives a solvent-rich product, the extract, and a purified carrier... 

Antibiotics The AOAC has listed methods for sulfamethazine residues in swine tissues with determination either by GC-MS or GC-ECD of methylated derivatives and for sulfamethazine (and for the class of sulfonamides) in milk with determination by HPLC-UV. There is an AOAC method for the class of sulfonamide antimicrobials in animal tissues using solvent extraction and liquid partitioning with determination by TLC and fluorimetric scanning. For analysis of tetracyclines, AOAC describes methods based on buffer extraction from tissue samples and SPE (Cis) cleanup, or metal chelate affinity binding from milk samples, with determination in both cases by HPLC-UV. USDA/FSIS methods include (1) a method (similar to the AOAC GC-MS method for sulfamethazine) for confirmation of sulfonamide residues in edible tissues using solvent extraction and multiple liquid partitioning with determination of the methylated derivatives by GC-MS (2) methods for determination and confirmation of chloramphenicol in muscle by solvent extraction, liquid partitioning, and determination of the trimethylsilane (TMS) derivative by GC-ECD and GC-MS, respectively and (3) a method for determination of the beta-lactam antibiotic amoxicillin by aqueous extraction, cleanup by tricarboxylic acid precipitation, and ether extraction and formation of a fluorescent derivative for determination by LC. 

Solvent extraction, solid-liquid sorption, ion exchange, and precipitation methods are commonly used for the separation or preconcentration of precious metals from various matrices. 

Carotenoids are commonly extracted from liquid samples (plasma/serum) into lipophilic solvents such as hexane, hexane-ethyl acetate, or diethyl ether, mostly after deproteinization with ethanol or methanol, which also helps to liberate the lipidic substances from protein binding. Extracts should be protected from light and acids and antioxidants may usefully be added. The extract is either used as such or is concentrated under oxygen-free nitrogen. Solid samples, e.g., foods, are either extracted with a solvent miscible with water (acetone, methanol) or, after dehydration of the sample, with a water immiscible solvent. Cleanup of the extract and fractionation of the pigments may involve saponification and/or open-column chromatography. 

The formation of the mesophase by this route has the disadvantage of requiring rather long processing times. An alternative route is the solvent route [18]. Isotropic aromatic pitches contain a separable fraction which, when heated at 230-400°C, develops an optically anisotropic liquid crystal phase in <10 minutes. This mesophase has been called a neomesophase since it is highly soluble in solvents such as pyridine or quinoline, while the mesophase derived by the thermal route is insoluble. The separable fraction of isotropic pitch is insoluble in solvents like benzene, toluene, or mixtures of toluene and heptane. Thus, it can be separated by solvent extraction from isotropic or heat soaked pitches (Figure 5, b and b ). 

There are two types of solvent extraction solid-liquid and liquid-liquid extraction. The former, often called leaching, is the process of removing a substance from a mixture of solids by mixing with a liquid (the solvent) in which the substance it is required to separate is dissolved. Liquid-liquid extraction is based on the same principle, but in this case a solution of a dissolved substance is intimately mixed with another liquid (the solvent). If the two liquids are immiscible, two separate liquid layers are formed when the mixture is allowed to settle, the dissolved substance being concentrated in the second liquid. The liquid now containing the dissolved substance is called the rich layer or extract and the remaining spent layer is called the raffinate. In many cases one of the solvents used is water, and these are termed aqueous extractions. Solvents commonly used in conjunction with water are chloroform, carbon tetrachloride, ethylene dichloride, benzene, toluene, xylene, and petroleum ethers. 

Liquids by liquids. The apparatus represented by Fig. 11, 58, 3 is employed for the extraction of aqueous solutions by solvents lighter than water, such as ether or benzene. The solvent distilled from the flask (attached to the lower end) and condensed by the reflux condenser (fltted to the upper end) passes through the funnel down a narrow tube, partially open at the lower end, into the aqueous solution, then rises to the surface and returns to the flask, having during its passage extracted some portion of the dissolved material from it. To improve the efficiency of the process. 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

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