Diethyl ether solvent extraction

Glycosides can be hydrolyzed by taking the extract to dryness and treating the dry residues with 7.5% hydrochloric acid under reflux for 30 min. The freed aglycones can then be recovered by serial extraction with portions of diethyl ether. The extracted aglycones are then redissolved in a small volume of a suitable solvent, usually acetone or methanol. 

Condition A Air, water, ethyl alcohol, impurity from extraction solvent (observed when the gas chromatograph is set at high sensitivity), diethyl ether, and extraction solvent (MEK/sec.-butyl alcohol). See Fig. 1, If acetone is present, it will elude at approximately the same retention time as the impurity from the extraction solvent. 

The extraction of chlorophylls and carotenoids from water-containing plant materials requires polar solvents, such as acetone, methanol, or ethanol, that can take up water. These extracts must then be transferred to a solvent such as diethyl ether in order to be stored stably. Samples with very high water content, such as juices and macerated plant material, are usually freeze-dried first, and can then be extracted directly with diethyl ether. After extraction, solutions are clarified and diluted to an appropriate volume to measure chlorophyll content by UV-VIS spectrophotometry. Absorption coefficients and equations needed for quantitative determination are given in unitf4.3. 

Dichloromethane is a useful substitute for diethyl ether in extraction processes when it is desired to employ a solvent which is more dense than water. 

Most of the organochlorine pesticides listed in this chapter may be analyzed by NIOSH and U.S. EPA Methods (U.S. EPA 1984-1988, NIOSH, 1984-1989). The method of analysis, in general, involves drawing a measured volume of air through a sorbent cartridge containing polyurethane foam or Chromosorb 102. The pesticides are extracted with an organic solvent such as toluene, hexane, or diethyl ether the extract concentrated and analyzed by GC-ECD. The extract may be cleaned up by florisil to remove any interference (U.S. EPA Method 608). 

Bis[carboxymethyl] Ditellurium5,6 Carboxymethyl tellurium trichloride is suspended in water, a six-fold molar excess of potassium disulfite is added, and the mixture is stirred until evolution of sulfur dioxide has ceased. The mixture is extracted with diethyl ether, solvent is removed from the extract, and the residue is recrystallized from acetone yield 100% m.p. 142° (dec.). 

Nitrophenyl Phenyl Tellurium5 Under nitrogen, 0.29 g (0.70 mmol) of diphenyl ditellurium are reduced with 0.03 g (0.73 mmol) of sodium borohydride in 5 ml of hexamethylphosphoric triamide at 70-80° with stirring for 0.5 h. Then 0.14 g (0,73 mmol) of copper(l) iodide are added whereupon the mixture turns black. 0.18 g (0.73 minol) of l-iodo-2-nitrobenzene are added and the mixture is stirred well and heated at 80 90° for 1.5 h. The mixture is cooled, water is added, the whole is extracted with diethyl ether, the extract is washed with concentrated sodium chloride solution, and the organic layer is dried with anhydrous sodium sulfate. The solvent is evaporated under vacuum and the residue is chromatographed on a short column of alumina with hexane as eluent. Fractions containing the product are combined and evaporated to dryness and the residue is rccrystallized from ethanol yield 0.22 g (95%) m.p. 94°. 

Phenyl 4-(Phenyltelluro)phenyl Tellurium2 A 500-ml, three-necked, round-bottom flask is fitted with a cold-finger condenser charged with dry ice/ethanol, a nitrogen inlet, and a magnetic stirrer. 250 ml of liquid ammonia are condensed into the flask, 1.6 g (4 mmol) of diphenyl ditellurium and then pieces of sodium are added until the blue color persists. A very small amount of diphenyl ditellurium is added to discharge the blue color followed by 1.13 g (4 mmol) of 4-bromoiodobenzene, and the mixture is irradiated for 220 min. The reaction is quenched by addition of 10 ml of distilled water, the ammonia is allowed to evaporate, the residue is diluted with 100 ml of water, and the whole is extracted three times with 100 ml of diethyl ether. The extract is dried with anhydrous sodium sulfate, the solvent is distilled off, and the residue is chromatographed on neutral aluminum oxide with petroleum ether as eluent yield 0.58 g (30%) m.p. 88-907... 

Formylphenyl Methyl Tellurium1 20 g (0.05 mol) of 2-formylphenyl dimethyl telluronium iodide are dissolved in 100 m/of pyridine and the solution is heated under reflux for 3 h. The solution is then cooled and poured into a mixture of ice and dilute hydrochloric acid. The mixture is extracted with diethyl ether, the extract is washed with water, dried with magnesium sulfate, the solvent is distilled off, and the residue is fractionally distilled under vacuum yield 9.8 g (77%) b.p. 120 13070.1 torr (13.3 Pa). 

Butyl 2-Formylphenyl Tellurium5 A well-stirred mixture of 9.0 g (25 mmol) of butyl 2-(diethoxymethyl)-phenyl tellurium and 10 ml of concentrated hydrochloric acid is heated for 0.5 h. The solution is then cooled, extracted with diethyl ether, the extracts are dried with anhydrous magnesium sulfate, the solvent is evaporated, and the residue is distilled under reduced pressure yield 5.5 g (80%) b.p. 140-142°/0.1 torr. 

Methyltellurophene1 To a mixture consisting of 10 m/ of hexamethylphosphoric triamide, 10 m/ of tetrahydrofuran, 0.5 g (6 mmol) of tert.-butanol, and 1.1 g (10 mmol) of potassium rerf.-butoxide are added 9.7 g (50 mmol) of 3-methylene-2,3-dihydrotellurophene. The mixture is heated at 50° for 1 h, water is added, the mixture is extracted with diethyl ether, the extract is washed with water, dried with anhydrous magnesium sulfate, filtered, and the solvent is evaporated. The residue is distilled under vacuum yield 8.7 g (90%) h.p. 72"/14 torr. 

Formyl-3-thienyl Methyl Tellurium (Organo Lithium Method) A mixture of 55 mmol of butyl lithium and 7.8 g (50 mmol) of 4-formylthiophcnc ethylene acetal in diethyl ether is cooled at — 78° for 20 min. A solution of 14.5 g (50 mmol) of dimethyl ditellurium in diethyl ether is added dropwise until the orange color of the ditellurium persists in the mixture. The mixture is allowed to warm to 20° and is then poured onto ice/water. The product is extracted with diethyl ether, the extract is dried with anhydrous magnesium sulfate, filtered, the solvent is distilled from the filtrate and the residue is distilled under vacuum yield 6.3 g (50%) b.p. 120°/0.8 torr m.p. 55°. 

Acetyltellurophene 0.3 g (1 mmol) of tin (IV) chloride are dissolved in 9 g (88 mmol) of acetic anhydride. 6 g (33 mmol) of tellurophene are placed in a 50 ml flask which is then cooled to — 10°. The tin (IV) chloride solution is added dropwise to the stirred tellurophene, the mixture is allowed to warm to 20° and is held at this temperature for 3 h. The mixture is poured into a solution of sodium hydrogen carbonate and extracted with diethyl ether. The extract is washed with water, dried with anhydrous sodium sulfate, filtered, and the solvent is distilled. The residue is chromatographed on alumina with light petroleum ether (b.p. 40-60°)/diethyl ether as the mobile phase yield 2g (27%) b.p. 136°/15 torr. 2-Acetyl-5-methoxycarbonyltellurophene (m.p. 81°) was similarly prepared in 42% yield. 2-Trifluoroacetyltellurophene (b.p. 85°/15 torr) was obtained in 31% yield by heating tellurophene and trifluoroacetic anhydride in 1,2-dichloroethane. ... 

PP Solvent extracts (hexane, ethyl acetate, diethyl ether) Solvent evaporation, reconstituted in chloroform/MEOH Spherisorb ODS-1, 50 X 4.6 mm, 5 pm 15-40% ethyl acetate gradient in 75 25 MEOH/water... 

Two liquid phases may be contacted in different ways to achieve separation. In the laboratory, the simplest example of LLE involves the use of a separatory funnel where a feed mixture, perhaps an aqueous phase from a reactor, is contacted with several washes of solvent (say, diethyl ether) to extract a solute. If the same aqueous phase is contacted repeatedly with fresh amounts of extracting solvent, such a process is said to be crosscurrent. 

Uranyl nitrate containing 1 mol of boron per 100 mol of uranium is to be purified by fractional extraction with diethyl ether from a 10 N solution of ammonium nitrate. The extract is to contain no more than 1 mol of boron per million moles of uranium and is to contain 95 percent of the uranium in the feed. What are the minimum volumes of 10 N ammonium nitrate scrub solution and diethyl ether solvent needed per unit volume of feed ... 

The ability of diethyl ether to extract uranyl nitrate from aqueous solution has been known for a hundred years and was the method chosen by the Manhattan Project to purify the uranium used in the first nuclear chain reactors. This solvent has numerous disadvantages. It is very volatile, very flammable, and toxic, and it requires addition of sodium, aluminum, or calcium nitrate to the aqueous phase to enhance extractions. When solvent extraction was first applied to recovery of uranium and plutonium from irradiated fuel, other oxygenated solvents less volatile than diethyl ether that were first used were methyl isobutyl ketone, dibutyl... 

An alternative procedure for identification of the diamine portion is as follows. The aqueous hydrolysis product of the polyurethane is extracted with diethyl ether. This extract contains both diamine and polyether. After evaporation of the ether, the extracted material is dissolved in a suitable solvent (approximately 10% solution). The sample solution is spotted, and analyzed by thin layer chromatography simultaneously with solutions of known amines. The Rp values and/or elution distances can then be compared to obtain identification. 

Neutraiize the acidic soiution in the receiver, perform the Hinsberg test (Sec. 25.14A), and prepare derivatives of the amine (Sec. 25.14). If the amine is not voiatiie enough to distiii, and thus is not found in the receiver, use small portions of diethyl ether to extract it from the aqueous layer contained in the stillpot. Dry the combined ethereal extracts over potassium hydroxide pellets, decant the solution, and then remove the solvent by one of the techniques described in Section 2.29. Prepare derivatives of the amine from the residue remaining after solvent removal (Sec. 25.14). 

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