Ethanol removal

Filtered or not, the ethanol/isosafrole/(sometimes junk) is relieved of its ethanol by openly boiling it on the stove or by distillation. Any ethanol removed by distillation is saved because it is clean and perfectly reusable (remember, it will still have that 5% water). One should not remove all of the solvent this way because things can get really hot really fast as the last of the ethanol boils away. 

Ethanol removed by the vapor stream can be recovered by condensation, vapor recompression, or scmbbiag. Ia the first two methods, the coaceatratioa of the recovered ethanol depends on the relative humidity of the sweep stream and the ratio of sweep and permeation rates. In scmbbiag, the rate of water deflvery to the Hquid-gas coatactor affects the ethanol concentration ia the recovered stream. 

To 20 g of the above compound dissolved in 300 ml 95% ethanol In a Parr reaction vessel is added 1.5 g Adams catalyst, platinum dioxide, and the mixture shaken under hydrogen at 50 psi for 1 hour at ambient temperature. The mixture Is then filtered and the ethanol removed on a standard rotary evaporator. The resulting oil is dissolved in 200 ml ether and slowly added to 1,200 ml ether with continuous stirring. The product separates as crystals which are removed after 15 to 30 minutes by filtration. The compound melts at 148°C to 147°C and needs no further purification. 

Another measure to improve the removal of ethanol is air injection into the mixer during the silanization step. Air can be injected from the bottom part of the mixer using existing valves without any special outlet for the injected air. In these experiments air injection is switched on once the compound reached the silanization temperature (145°C) and the rotor speed is adjusted in order to maintain the silanization temperature. Figure 29.13 shows the properties of this compound compared to a compound that was silanized under the same conditions except with air injection switched off. Air injection lowers the Payne effect, Mooney viscosity, and water content in the compound, and ethanol removal is more effective. All other properties are comparable to the properties of a standard silica compound. 

Isolation of Sesquiterpene Lactones. The ether extract was evaporated and dissolved in 952 ethanol. Then an equal volume of 42 aqueous lead acetate was added. After 1 hour the mixture was filtered to remove precipitated chlorophyll and phenolic products and the ethanol removed under vacuum. The aqueous layer was extracted with chloroform giving a dark colored oil from which the sesquiterpenes were isolated by a combination of chromatographic procedures, i.e., LH-20 gel permeation, silica gel using both packed columns and thin layer plates. A variety of solvents were also used to purify the individual sesquiterpene lactones, e.g., benzene-acetone (1 1), ethyl acetate, chloroform-methanol (9 1). On thin layer chromatographic plates, spots were visualized by spraying with 22 aqueous KMn04 solution. 

Centrifuge sample at maximum speed for 15 min at 4°. Remove supernatant and wash with ice-cold ethanol. Remove ethanol, air dry sample, and resuspend in sample buffer. 

Syntheses of diastereomerically pure racemates of himachalene derivatives started from cycloheptanone G (Fig. 9). The sequence to I involved dimethyla-tion to yield H followed by bromination/dehydrobromination and conjugate methylation using cuprate chemistry. The sequence furnishing L and M follows a Robinson-annelation type Reaction of I with 3-(trimethylsilyl)but-3-en-2-one yielded K. Refluxing K with potassium hydroxide in ethanol removed the silyl group and cyclized the diketone to form a 97 3 mixture of racemic L and M. Occurring as a volatile in A.flava, L served as a versatile intermediate in the syntheses of other Aphthona compounds. 

For precipitation of DNA and RNA, add 10% of the volume sodium acetate, pH 7 or 5.2, respectively. Add four parts of ice-cold 98% ethanol and mix well. Add 1 pi of linear acrylamide (3%). Incubate for 2 h at -20°C and centrifuge at 12,000 for 30 min in a tabletop centrifuge. Carefully remove the supernatant—the DNA or RNA should be visible against the light as one or several small shiny specks, usually attached to the tube, but they may be loose—and wash the pellet with 200 pi 80% ethanol. Remove the supernatant, and dry the DNA or RNA (3 min in a speed vacuum concentrator) until all visible liquid has gone, but avoid overdrying of the pellet because the DNA or RNA will then be difficult to redissolve. Dissolve the DNA in 100 pi dd H O. 

Privat, E., Roussel, S., Grenier, R, Bellon-Maurel, V. (1998) Techniques for ethanol removal before discrimination of alcoholic drinks using electronic noses. Sci. Aliments 18 459-470. 

After reaction, the slurry product consisted of a liquid mixture together with some insoluble material. This slurry was filtered and the residue thoroughly washed with water. Further separation of the reaction products was carried out as shown in Figure 3. An aliquot of the liquid was acidified, after ethanol removal (if necessary) with 10% (v/v) HC1 to a pH of 1-2, then filtered. The filtrate was extracted with diethyl ether till the aqueous layer was judged colorless by eye. After removal of the ether by rotary evaporation, the extract was analyzed by capillary gas chromatography. 

A reactor charged with sulfopropyldimethylammoniumethyl methacrylate (0.020 mol), a-methoxy-co-methacrylate polyethylene glycol 1000 (0.009 mol), water (398 g), and ethanol (261.90 g) was heated to 78°C. The mixture was then simultaneously treated with ammonium persulfate (0.004 mol) dissolved in water (20 g) over 150 minutes, ammonium persulfate (2.5 g) dissolved in water (60 g) continuously over 120 minutes, sulfopropyldimethyl-ammoniumethyl methacrylate (0.182 mol) over 120 minutes, and a-methoxy-w-meth aery late polyethylene glycol (0.078 mol), and water (205.80 g). Thereafter the reaction was maintained at 70°C for 90 minutes and then cooled. The solution was then treated with water and ethanol removed by distillation. The product was isolated with a solids content of 27.3%, a pH of 2, a Brookfield viscosity of 36 mPa s, and an Mw of 65,000 Da with an M of 8000 Da. 

The principle of extraction is based on a physical chemical phenomenon known as partitioning. If two fluids, one of which contains a solute that is soluble in both, come in contact with one another, the solute will migrate from the original fluid into the other fluid. The extent (but not the rate) to which it will migrate is governed by the relative solubilities of the fluids. See Table 4.2. If the solute is equally soluble in both fluids, half will continue to migrate until the concentrations in both fluids are the same. If the solute is much more soluble in one fluid or the other, the fluid in which the solute is most soluble will accumulate most of the solute. For instance, if ethanol is dissolved in water and contacted with a solvent, the amount of ethanol removed from the water depends on the solvent. 

Prepare a solution of 6 g of potassium permanganate in a mixture of 20 ml of 5 per cent sodium hydroxide solution and 150 ml of water, add 2.0 g of p-cresyl methyl ether and heat under reflux for 2-3 hours. If any permanganate remains at the end of this period, destroy it by the addition of a few drops of ethanol. Remove the precipitated manganese dioxide by filtration at the pump, evaporate the filtrate to a volume of 25-30 ml and acidify it (to Congo red) with dilute sulphuric acid. Anisic acid, m.p. 183-184°C, crystallises out on cooling. 

Wash pellet (usually invisible) with 1 mL of 70% ethanol. Remove supernatant, recentrifuge briefly, and remove supernatant. 

Separation of liquid olefin/paraffin mixtures Removal of 2-chlorophenol Ethanol removal from aqueous solutions Separation of cephalosporin C from fermentation broth Separation of penicillin G from aqueous streams Enrichment of amino acids... 

Place 45 kg of ethyl N-norvalinate hydrochloride approximately 110 liters of water in a vessel equipped with a stirrer. Alkalify, then pour 23 kg of pyruvic acid very gradually into the solution obtained previously and stir the reaction mixture for 30 min. Place an aqueous suspension of charcoal containing 5% palladium and the alkaline solution of ethyl L-norvalinate obtained previously in a hydrogenation apparatus. Hydrogenate under pressure (30 bars) at room temperature for approximately one day. Filter under vacuum and evaporate the filtrate under reduced pressure, filter off and dry. Treat the residue obtained with ethanol remove the insoluble material, consisting of sodium chloride, by filtration and rinse it with ethanol. Combine the ethanolic solutions evaporate off the ethanol under reduced pressure and crystallize the residue from acetonitrile 34.3 kg of N-[(S)-l-carbethoxybutyl]-(S)-alanine are obtained, that is a 63.9% yield. 

A solution of 5-(2-formyl-3-benzyloxyphenoxy)pentanoic acid (1.0 g, 0.003 M) in ethanol containing 5% palladium on charcoal catalyst (0.61 g) was hydrogenated at atmospheric pressure. After 20 min the reaction was complete and the catalyst was filtered off and the ethanol removed in vacuum to give 5-(2-formyl-3-hydroxyphenoxy)pentanoic acid, m.p. 94°C. 

Sacrifice a pregnant mouse (about 15 d postcoitus), moisten the belly with 70% ethanol, remove the uterus and place it in a 10-mm Petri dish containing phosphate-buffered saline (PBS). Dissect the embryos away from the uterus and membranes, and transfer them into a new dish containing PBS. 

The literature on element speciation in water and beverages using ICP-MS detection is summarized in Table 8.3. In most cases, on-line HPLC-ICP-MS is used without the need of any sample treatment, except, for example, ethanol removal under reduced pressure in the case of wine [106]. More details on sample preparation and analytical approaches can be found in a recent review on elemental speciation in beverages [47]. 

The pre-extraction of wood or pulp is routinely performed to remove extraneous substances which would otherwise interfere with the determination. However, as emphasized by Lai and Sarkanen (1971), any advantage gained through inclusion of a pre-extraction step may be offset as a result of extractants such as hot water and ethanol removing a portion of the lignin. According to Brauns (1952), the hot water extraction may be omitted in the case of chemical pulps and the ethanol-benzene extraction may be disregarded for pulps produced under alkaline conditions. 

Beef liver (or lung) was minced and then autolyzed for twenty-four hours before extraction with an alkaline solution saturated with ammonium sulfate. Protein was precipitated by warming the extract, and the heparin-protein complex was precipitated from the supernatant liquor on acidification. Extraction of the complex with ethanol removed fatty material, and tryptic digestion removed most of the protein. The heparin was precipitated with ethanol, redissolved in warm alkaline solution to destroy trypsin, and reprecipitated with acetone. This material, crude heparin, was isolated in a yield of 15-50 g. per 100 lb. of animal tissue. In a later paper," the purification of crude heparin by fractionation successively with Lloyd s reagent, cadmium chloride, and acetone, was described. The purified heparin w-as 100 times as active as the crude material. Scott and Charles" reported the presence of nitrogen... 

Ultrafiltration is conducted to remove precipitating agents such as ethanol, PEG, and caprylic acid through diafiltration and to concentrate the protein to the desired level. It has replaced lyophilization for ethanol removal from albumin and immunoglobulins and size exclusion chromatography for buffer exchange. 

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