Salt solutions, extraction

Tyj)e of dryer Applicable with dry-product recirculation True and colloidal solutions emulsions. Examples inorganic salt solutions, extracts, milk, blood, waste liquors, rubber latex, etc. Pumpable suspensions. Examples pigment slurries, soap and detergents, calcium carbonate, bentonite, clay sbp, lead concentrates, etc. does not dust. Recirculation of product may prevent sticking Examples filter-press cakes, sedimentation sludges, centrifuged sobds, starch, etc. 

A variation on simple extraction is extraction with a dilute salt solution. In this case, either a dilute solution of calcium or potassium chloride is commonly used. The concept is that these dilute solutions mimic the root environment to some extent. In addition to extraction, these solutions are often used in the determination of soil pH [6], A typical dilute salt solution extraction of soil is given in Procedure 11.3 ... 

Calculation. The difference in pH between water and salt solution extracts is known as the salt effect, and given the symbol A pH. Thus,... 

In the isolation of organic compounds from aqueous solutions, use is frequently made of the fact that the solubility of many organic substances in water is considerably decreased by the presence of dissolved inorganic salts (sodium chloride, calcium chloride, ammonium sulphate, etc.). This is the so-called salting-out effect. A further advantage is that the solubility of partially miscible organic solvents, such as ether, is considerably less in the salt solution, thus reducing the loss of solvent in extractions. 

Transfer the bisulphite compound to a separatory funnel and decompose it with 80 ml. of 10 per cent, sodium hydroxide solution. Remove the liberated cycZohexanone, saturate the aqueous layer with salt and extract... 

On shaking an ether solution of a phenol and a carboxylic acid with dilute sodium bicar bonate the carboxylic acid is converted quantitatively to its sodium salt and extracted into the aqueous phase The phenol remains m the ether phase... 

Biopolymer Extraction. Research interests involving new techniques for separation of biochemicals from fermentation broth and cell culture media have increased as biotechnology has grown. Most separation methods are limited to small-scale appHcations but recendy solvent extraction has been studied as a potential technique for continuous and large-scale production and the use of two-phase aqueous systems has received increasing attention (259). A range of enzymes have favorable partition properties in a system based on a PGE—dextran—salt solution (97) ... 

The purification of the galHum salt solutions is carried out by solvent extraction and/or by ion exchange. The most effective extractants are dialkyl-phosphates in sulfate medium and ethers, ketones (qv), alcohols, and trialkyl-phosphates in chloride medium. Electrorefining, ie, anodic dissolution and simultaneous cathodic deposition, is also used to purify metallic galHum. 

The purified acid is recovered from the loaded organic stream by contacting with water in another countercurrent extraction step. In place of water, an aqueous alkafl can be used to recover a purified phosphate salt solution. A small portion of the purified acid is typically used in a backwashing operation to contact the loaded organic phase and to improve the purity of the extract phase prior to recovery of the purified acid. Depending on the miscibility of the solvent with the acid, the purified acid and the raffinate may be stripped of residual solvent which is recycled to the extraction loop. The purified acid can be treated for removal of residual organic impurities, stripped of fluoride to low (10 ppm) levels, and concentrated to the desired P2 s Many variations of this basic scheme have been developed to improve the extraction of phosphate and rejection of impurities to the raffinate stream, and numerous patents have been granted on solvent extraction processes. 

This shift in emphasis by the mining iadustry has led to the development and use of a variety of improved techniques, in particular the commercial avadabihty of several metal specific extractants. These techniques are particularly useful in the separations and recycling of metals from metal sludges and metal salt solutions. 

Recovery. The principal purpose of recovery is to remove nonproteinaceous material from the enzyme preparation. Enzyme yields vary, sometimes exceeding 75%. Most industrial enzymes are secreted by a microorganism, and the first recovery step is often the removal of whole cells and other particulate matter (19) by centrifugation (20) or filtration (21). In the case of ceU-bound enzymes, the harvested cells can be used as is or dismpted by physical (eg, bead mills, high pressure homogenizer) and/or chemical (eg, solvent, detergent, lysozyme [9001 -63-2] or other lytic enzyme) techniques (22). Enzymes can be extracted from dismpted microbial cells, and ground animal (trypsin) or plant (papain) material by dilute salt solutions or aqueous two-phase systems (23). 

One problem limiting the consideration of salt extractive distillation is the fact that the performance and solubility of a salt in a particiilar system is difficult to predict without experimental data. Some recent advances have been made in modeling the X T.E behavior of organic-aqueous-salt solutions using modified UNIFAC, NRTL, UNIQUAC, and other approaches [Kumar, Sep. Sci. Tech., 28(1), 799 (1993)]. 

Determination of Na " and Na" ions in raw cosmetic materials was conducted with the developed method of flame photometry. A necessity of development of method of samples preparation arose up in the work process, as this spicily-aromatic raw material contained pectin in amount 0.1-0.5% and that prevented preparation of samples by standard method of extracts dilution and required incineration of analyzed sample, time of analysis was increased in 60 times. It was established that CaCl, solution with the concentration 0,4 % caused destmctions of the carbopol gel. It was established that the addition of 0,1% CaCl, and 0,1% NaCl salts solutions into the system intensified the effect of negative action of these salts onto the gel stmcture and the gel destmcted completely. 

The residue is cooled and dissolved in 171 ml. of nitric acid (sp. gr. 1.4) (Note 3), and the solution is warmed for 30 minutes on the steam bath. It is immediately concentrated to complete dryness under reduced pressure (Note 4). The flask is cooled, 300 ml. of benzene is added, and the mixture is refluxed for a short time to render the cake friable. The benzene is removed by decantation, and the cake is pulverized and extracted six times by refluxing it briefly with 300-ml. portions of ether. The combined benzene and ether extracts are filtered and concentrated to a volume of about 225 ml. In the meantime the residual salts are extracted twice by refluxing them vigorously for a short time with 300-ml. portions of benzene. The benzene solutions are separated by decantation and added to the ether concentrate. The distillation is then continued untO about two-thirds of the benzene has been removed, when the benzene solution is poured into a beaker and allowed to cool. The methylsuccinic acid is collected on a filter and is washed by shaking a suspension of it in 150 ml. of chloroform (Note 5). The yield of air-dried product, melting at 110-111 , amounts to 87-93 g. (66-70%) (Note 6). 

The pure salt (mol. wt. 271)15 dissolved in four parts of water the amine is liberated with an excess of 20-25 per cent sodium hydroxide solution, extracted with benzene, and purified as described for the c/-amine. The constants agree closely with those given for the d-amine, and the jdeld is 32-42 g. (94-96 per cent of the theoretical amount based on the pure tartrate or 53-70 per cent based on the total /-amine originally present). 

To a solution of 1.38 g of estradiol 3-methyl ether (mp 118-119°) in 110 ml of anhydrous ether is added 140 ml of liquid ammonia followed by 1.4 g (42 eq per mole) of lithium wire in small pieces, and 10 min later 16 ml of absolute alcohol is added dropwise over a 10- to 20-min period. Occasionally frothing occurs during the last part of this addition but is easily controlled by stopping the stirrer temporarily. After removing most of the ammonia and carefully adding cold water, the product is extracted with ether, washed with Claisen alkali, water and saturated salt solution, and dried over sodium... 

The reduction is effected exactly as in Procedure 8a but using 0.61 g (0.088 g-atom) of lithium. After the crude reaction product has been washed well on the filter with cold water, it is dissolved in ethyl acetate, the solution is filtered through the sintered glass funnel to remove iron compounds from the ammonia, and the filtrate is extracted with saturated salt solution. The organic layer is dried over sodium sulfate and the solvent is removed. The solid residue is crystallized from methanol (120 ml) using Darco. The mixture is cooled in an ice-bath, the solid is collected, rinsed with cold methanol, and then air-dried to give 12.9 g (85%), mp 129-132° reported for the tetrahydropyranyi ether of 3j5-hydroxypregn-5-en-20-one, mp 129-131°. 

A total of 50 ml (0.15 moles) of a 3 ethereal solution of methylmagnesium bromide is added slowly to a vigorously stirred solution of 5.8 g (12.5 mmoles) or 3,3 20,20-bisethylenedioxy-5a,6a-epoxy-5a-pregnane-ll/l,17a,21-triol in 400 ml of tetrahydrofuran. The solution is heated under reflux for 24 hr, cooled and treated with 32 ml of saturated ammonium chloride solution. The supernatant is decanted and the residue is washed with several portions of tetrahydrofuran. The combined supernatants are evaporated and extracted with ethyl acetate, washed with saturated salt solution, dried and concentrated to give 4,55 g (75%) of 3,3 20,20-bisethylenedioxy-6 -methyl-5a-pregnane-5a,ll, 17a,21-tetrol mp 170-172° after crystallisation from acetone-petroleum ether. The analytical sample is crystallized from acetone-petroleum ether mp 175-177° [aJo —11° (CHCI3). 

Bromo-4-methoxy-A-homo-estra-2,4,5(10)-trien-17-one (44 0. 2g), is dissolved in formic acid, 2 ml of boron trifluoride etherate is added and the mixture is stirred vigorously at 0° for 2 hr. A brown mass ca. 0.12 g) is obtained after evaporation of the solvents at reduced pressure. This material is diluted with water and extracted with chloroform. The chloroform extracts are washed successively with water and saturated salt solution, dried over anhydrous magnesium sulfate and evaporated at reduced pressure to give 95 mg of a product which is purified by filtration through a column of neutral alumina and crystallization of the residue after evaporation of the solvent from ethyl acetate-petroleum ether. The resulting A-homo-estra-l(10),2,4a-triene-4,17-dione (45), mp 143-146°, is identical to the tropone (45) prepared from monoadduct 17-ketone (43a). 

Bromo-A-homo-estra-4y5 0)-diene-3, l-dione (49). A solution of silver perchlorate (0.55 g, 5 mole-eq) in acetone (2 ml) is added to a refluxing solution of monoadduct (48 0.28 g) in acetone (30 ml) containing water (0.5 ml). After being heated at reflux for 25 min the reaction mixture is cooled and the precipitated silver bromide is removed by filtration, yield about 0.11 g. The filtrate is diluted with water (500 ml) and is thoroughly extracted with chloroform. The chloroform extracts are washed with water and saturated salt solution, dried over anhydrous magnesium sulfate, and evaporated at... 

A-Homo-estra-, 4, )-triene-3, l-dione (50). A solution of bromo ketone (49 0.2 g), silver perchlorate (0.5 g) and 20% aqueous acetone (30 ml) is heated at reflux with stirring for 30 min and then allowed to cool to room temperature. The mixture is filtered to remove precipitated silver bromide (ca. 0.19 g) and the filtrate is diluted with water (200 ml) and then extracted with chloroform. The chloroform extracts are washed, successively with water, 5% sodium bicarbonate solution, water and saturated salt solution. After being dried over anhydrous magnesium sulfate, the solvents are removed at reduced pressure to give a solid. Recrystallization from ethyl acetate gives A-homo-estra-l,4,5(10)-triene-3,17-dione (50 0.17 g) mp 193-197°. 

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