Extraction concentrated solutions

Chill the concentrated solution of the amine hydrochloride in ice-water, and then cautiously with stirring add an excess of 20% aqueous sodium hydroxide solution to liberate the amine. Pour the mixture into a separating-funnel, and rinse out the flask or basin with ether into the funnel. Extract the mixture twice with ether (2 X25 ml.). Dry the united ether extracts over flake or powdered sodium hydroxide, preferably overnight. Distil the dry filtered extract from an apparatus similar to that used for the oxime when the ether has been removed, distil the amine slowly under water-pump pressure, using a capillary tube having a soda-lime guard - tube to ensure that only dry air free from carbon dioxide passes through the liquid. Collect the amine, b.p. 59-61°/12 mm. at atmospheric pressure it has b.p. 163-164°. Yield, 18 g. 

Note on the laboratory preparation of monoethylaniline. Although the laboratory preparation of monomethyl- or monoethyl-aniline is hardly worth whUe, the following experimental details may be useful to those who wish to prepare pure monoethylaniline directly from amline. In a flask, fitted with a double surface reflux condenser, place 50 g. (49 ml.) of aniline and 65 g. of ethyl bromide, and boU gently for 2 hours or until the mixture has almost entirely sohdified. Dissolve it in water and boil off the small quantity of unreacted ethyl bromide. Render the mixture alkaUne with concentrated sodium hydroxide solution, extract the precipitated bases with three 50 ml. portions of ether, and distil off the ether. The residual oil contains anihne, mono- and di-ethylaniline. Dissolve it in excess of dilute hydrochloric acid (say, 100 ml. of concentrated acid and 400 ml. of water), cool in ice, and add with stirring a solution of 37 g. of sodium nitrite in 100 ml. of water do not allow the temperature to rise above 10°. Tnis leads to the formation of a solution of phenyl diazonium chloride, of N-nitrosoethylaniline and of p-nitrosodiethylaniline. The nitrosoethylaniline separates as a dark coloured oil. Extract the oil with ether, distil off the ether, and reduce the nitrosoamine with tin and hydrochloric acid (see above). The yield of ethylaniline is 20 g. 

Place 45 g. (43 ml.) of benzal chloride (Section IV,22), 250 ml. of water and 75 g. of precipitated calcium carbonate (1) in a 500 ml. round-bottomed flask fltted with a reflux condenser, and heat the mixture for 4 hours in an oil bath maintained at 130°. It is advantageous to pass a current of carbon dioxide through the apparatus. Filter off the calcium salts, and distil the filtrate in steam (Fig. II, 40, 1) until no more oil passes over (2). Separate the benzaldehyde from the steam distillate by two extractions with small volumes of ether, distil off most of the ether on a water bath, and transfer the residual benzaldehyde to a wide-mouthed bottle or flask. Add excess of a concentrated solution of sodium bisulphite in portions with stirring or shaking stopper the vessel and shake vigorously until the odour of benzaldehyde can no longer be detected. Filter the paste of the benzaldehyde bisulphite compound at the pump... 

Method 1. Reflux a mixture of pure nicotinic acid (Section V,22), 84 g. (105 ml.) of absolute ethanol and 90 g. (50 ml.) of concentrated sulphuric acid in a flask for 4 hours on a steam bath. Cool the solution and pour it slowly and with stirring on to 200 g. of crushed ice. Add sufficient ammonia solution to render the resulting solution strongly alkaline generally, some ester separates as an oil but most of it remains dissolved in the alkaline solution. Extract the solution with five 25 ml. portions of ether, dry the combined ethereal extracts with anhydrous magnesium sulphate, remove the ether and distil under reduced pressure. The ethyl nicotinate passes over at 117-118°/ 6 mm. the yield is 34 g. The b.p. under normal pressure is 222-224°. 

The cleanup of this oil is exactly like that which was done in Method 1. The oil is dissolved in about SOOmL of 3N HCl and the solution extracted with TOOmL of DCM. The chemist remembers that in this particular case the MDMA or meth is going to stay in the HCl/water but that unreacted, valuable MD-P2P or P2P is going to be in that DCM so it, of course, is saved. The HCl/MDMA solution is then basified with concentrated NaOH so that at around pH 9 the happy little beads of final, freebase product will appear in the solution. As usual, the oil is extracted with DCM, dried through Na2S04 and the DCM removed by distillation. The final product here is usually a little darker in color than the product achieved in Method 1, but it is still remarkably clean and may be crystallized as is with the crystallization process removing most of the color impurities. Of course the chemist may wish to vacuum distill to afford clear product. The average yield with this method is 60-70%. 

Antibiotics. Solvent extraction is an important step in the recovery of many antibiotics (qv) such as penicillin [1406-05-9] streptomycin [57-92-17, novobiocin [303-81-1J, bacitracin [1405-87-4] erythromycin, and the cephalosporins. A good example is in the manufacture of penicillin (242) by a batchwise fermentation. Amyl acetate [628-63-7] or -butyl acetate [123-86-4] is used as the extraction solvent for the filtered fermentation broth. The penicillin is first extracted into the solvent from the broth at pH 2.0 to 2.5 and the extract treated with a buffet solution (pH 6) to obtain a penicillin-rich solution. Then the pH is again lowered and the penicillin is re-extracted into the solvent to yield a pure concentrated solution. Because penicillin degrades rapidly at low pH, it is necessary to perform the initial extraction as rapidly as possible for this reason centrifugal extractors are generally used. 

In typical processes, the gaseous effluent from the second-stage oxidation is cooled and fed to an absorber to isolate the MAA as a 20—40% aqueous solution. The MAA may then be concentrated by extraction into a suitable organic solvent such as butyl acetate, toluene, or dibutyl ketone. Azeotropic dehydration and solvent recovery, followed by fractional distillation, is used to obtain the pure product. Water, solvent, and low boiling by-products are removed in a first-stage column. The column bottoms are then fed to a second column where MAA is taken overhead. Esterification to MMA or other esters is readily achieved using acid catalysis. 

Solvent Recovery. A mixture of methanol and methyl acetate is obtained after saponification. The methyl acetate can be sold as a solvent or converted back into acetic acid and methanol using a cationic-exchange resin such as a cross-linked styrene—sulfonic acid gel (273—276). The methyl acetate and methanol mixture is separated by extractive distillation using water or ethylene glycol (277—281). Water is preferred if the methyl acetate is to be hydroly2ed to acetic acid. The resulting acetic acid solution is concentrated by extraction or a2eotropic distillation. 

Cochineal Extract. Cochineal extract (Cl Natural Red 4, Cl No. 75470 EEC No. E 120) is the concentrated solution obtained after removing the alcohol from an aqueous-alcohoHc extract of cochineal, which is the dried bodies of the female insect Coccus cacti Dactylopius coccus costd) a variety of field louse. The coloring principle of the extract is beHeved to be carminic acid [1260-17-9] (40), an hydroxyanthraquinone linked to a glucose unit, comprising approximately 10% of cochineal and 2—4% of its extract. 

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. 

In this study we examined the influence of concentration conditions, acidity of solutions, and electrolytes inclusions on the liophilic properties of the surfactant-rich phases of polyethoxylated alkylphenols OP-7 and OP-10 at the cloud point temperature. The liophilic properties of micellar phases formed under different conditions were determined by the estimation of effective hydration values and solvatation free energy of methylene and carboxyl groups at cloud-point extraction of aliphatic acids. It was demonstrated that micellar phases formed from the low concentrated aqueous solutions of the surfactant have more hydrophobic properties than the phases resulting from highly concentrated solutions. The influence of media acidity on the liophilic properties of the surfactant phases was also exposed. 

Methyl 2,4-DI-0-acelyl-3,6-dldeoxy-3-C-methyl-3-nliro-a-L-glucopyrannoslde (4). Methyl-o-L-rhamnopyrannoslde 3 (100 g, 0.55 mol) in water (1000 mL) was treated with Nal04 (200 g, 0 83 mol) at 20°C. After 3 h NaHCOa was added, the mixture poured into EtOH (4000 mL) and filtered The filtrate was concentrated atxl extracted with hot EtOH. The extract was cooled, filtered and treated with nilroethane (104 5 g, 1.4 mol) followed by a solution of Na (12 g, 0.52 at. g) In EtOH (750 mL). After 4 h at 20°C Ihe solution was treated with CO2, filtered and concentrated The mixture was treated with pyridine (400 mL) and AC2O (300 mL) at 20°C lor 12 h. Workup left a residue which dissolved In Et20 petroleum ether (1 1) (500 mL) and cooled afforded 36 g of 4 (19%), rryj 137-138"C, (alQ- O C (c 1). 

Solvent extraction Aqueous or non-aqueous solutions concentrations < 10 % Concentrated solution of organics in extraction solvent... 

The fi-compound is dissolved in 50 c c. pure dry ether, and dry hydiogen chloride is passed in with constant shaking to prevent the delivery tube from becoming blocked. Colourless crystals of the hydrochloride of the /3-o ime separate and aie filtered and washed with dry ether and then placed in a separating funnel and covered with a layer of ether. A. concentrated solution of sodium carbonate is gradually added with constant shaking until no further effervescence is observed. Sodium chloride is precipitated and the /3-oxime dissolves in the ether. The ether extract is sepaiated, dehydrated over sodium sulphate, and the ether remoi ed as rapidly as possible at the ordinary temperature by evaporation in vacuo. The residue crystallises, and when pressed on a porous plate leaves a mass of small silky needles, m. p. 126—130A It may be re-... 

On evaporating the alcoholic solution under reduced pressure from a water bath held at 50-60° (Note 6) the residue weighs about 540 g. A mixture of 600 cc. of absolute alcohol and 10 cc. of concentrated sulfuric acid (Note 7) is then added. The mixture is then heated on the water bath under a reflux condenser for three hours. The excess of alcohol and some of the water formed are removed by distillation under reduced pressure and the residue again heated for two hours with 300 cc. of absolute alcohol and an additional 4 cc. of concentrated sulfuric acid. The alcohol is removed by distillation under reduced pressure, and when the ester has cooled to room temperature, the sulfuric acid is neutralized with a concentrated solution of sodium carbonate the ester (upper layer) is separated, and the aqueous solution extracted with ether, or preferably benzene about one-tenth of the yield is in the extract. The combined products are placed in a i-l. distilling flask and distilled under reduced pressure after the solvent and alcohol and water have been removed. The ester is collected at 94-990, chiefly at 97-98°/x6 mm. (Note 8). The yield of a product analyzing about 97-98 per cent ethyl cyanoacetate amounts to 474-492 g. (77-80 per cent of the theoretical amount) (Note 9). 

An initial solution was prepared by the hydrofluoride method, i.e. melting of a mixture of ammonium hydrofluoride and tantalite, followed by the digestion of soluble components with water and separation of the solution by filtration. The prepared initial solution contained no free HF or any other acid, and had a pH 3. In order to obtain an optimal acidity level, sulfuric acid was added to the solution. Concentrations of Ta2Os (50-60 g/1) and Nb205 ( 30 g/1) were kept approximately constant during the preparation of the solutions. Extraction was performed using a polypropylene beaker and a magnetic stirrer. 

Purification of luciferin (Rudie etal., 1976). The luciferin fractions from the DEAE-cellulose chromatography of luciferase were combined and concentrated in a freeze-dryer. The concentrated solution was saturated with ammonium sulfate, and extracted with methyl acetate. The methyl acetate layer was dried with anhydrous sodium sulfate, concentrated to a small volume, then applied on a column of silica gel (2 x 18 cm). The luciferin adsorbed on the column was eluted with methyl acetate. Peak fractions of luciferin were combined, flash evaporated, and the residue was extracted with methanol. The methanol extract was concentrated (1 ml), then chromatographed on a column of SephadexLH-20 (2 x 80 cm) usingmethanol asthe solvent. The luciferin fractions eluted were combined and flash evaporated. The residue was... 

A concentrated solution of the 3-phcnylsulfinylalcohol in THF (2 mL THF per 0.5 g of sulfinylalcohol) cooled to — 78°C is added to a solution of 2.1 equiv of LDA in THK (10 mL per 3 mmol of L DA). After stirring for 1 min 1.5 equiv of the aldehyde are added to the reddish solution and one minute later, the reaction is quenched with sat. aq NH CI. The mixture is diluted with water, extracted with ElOAc or CI1CI3 and worked up. The product is purified by column chromatography. 

This salt mixture is dissolved in 270 cc. of water, and the acid potassium salt precipitated by adding 8 cc. of concentrated sulfuric acid in 30 cc. of water. After standing for three hours, or overnight, the mixture is filtered with suction (Note 3). The acid salt is then dissolved in 240 cc. of water to which 60 cc. of concentrated sulfuric acid has been added, and the solution extracted with five 100-cc. portions of ether. The combined ether solutions are evaporated to dryness on a steam bath,... 

Conceptual Flowsheet for the Extraction of Actinides from HLLW. Figure 5 shows a conceptual flowsheet for the extraction of all the actinides (U, Np, Pu, Am, and Cm) from HLLW using 0.4 M 0< >D[IB]CMP0 in DEB. The CMPO compound was selected for this process because of the high D m values attainable with a small concentration of extractant and because of the absence of macro-concentrations of uranyl ion. Distribution ratios relevant to the flowsheet are shown in previous tables, IV, V, VI, and VII and figures 1 and 2. One of the key features of the flowsheet is that plutonium is extracted from the feed solution and stripped from the organic phase without the addition of any nitric acid or use of ferrous sulfamate. However, oxalic acid is added to complex Zr and Mo (see Table IV). The presence of oxalic acid reduces any Np(VI) to Np(IV) (15). The presence of ferrous ion, which is... 

The mobile phases that are most effective for use with reverse phases are aqueous mixtures of methanol or acetonitrile and for subtle adjustments, ternary mixtures of water, methanol and acetonitrile or tetrahydrofuran can be used. The greater the water content the more the solutes with dispersive groups will be retained and in fact, in pure water, many substances are irreversibly held on a reverse phase. As already discussed, this characteristic make reverse phases very useful for solute extraction and concentration from aqueous solutions prior to analysis. 

The thermal stability of the anthocyanins from sunflower hulls (genotype Neagra de Cluj) extracted with SO2 in different concentration solutions was verified by heating for various durations at 65 to 95°C and at a pH range from 1 to 5. The degradation increased with the increasing of SO2 in the extraction solvent. "... 

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