Extraction, Soxhlet with ether

Cobalt (II) meso-5.10,15,20-tetraphenylporphine complex [14172-90-8] M 671.7. Brown crystals from Et20 or CHCl3-MeOH (cf iron chloride complex). Recrystd by extraction (Soxhlet) with CgHg. Sol in most organic solvents except MeOH and pet ether. [UV, IR J Am Chem Soc 70 1808 7948 81 5111 7959.]... 

Extraction of Phosphatides from Liver. The weighed tissue was ground with sand in a mortar, transferred to a flask, and extracted with alcohol at 55-60 C. for two hours with occasional shaking. Approximately 150 cc. of alcohol were used for 20-25 g. of liver. The supernatant alcohol was decanted through filter paper and the residue extracted with a second portion of alcohol for one hour. The contents of the flask were then poured through the same filter paper and the two alcohol extracts were combined. The tissue residue was then extracted overnight with ether in a Soxhlet apparatus and the ether extract was added to the alcohol extracts. The combined alcohol-ether extracts were concentrated to a small volume (3-4 ml.). This was carried out in a hot water bath (55-60 °) under reduced pressure and in an atmosphere of carbon dioxide. This concentrate was extracted with several portions of petroleum ether (b.p. 30-60 ) and the petroleum ether extract made up to a desired volume by the addition of more petroleum ether. 

Several standard methods for the quantitative analysis of food samples are based on measuring the sample s mass following a selective solvent extraction. For example, the crude fat content in chocolate can be determined by extracting with ether for 16 h in a Soxhlet extractor. After the extraction is complete, the ether is allowed to evaporate, and the residue is weighed after drying at 100 °C. This analysis has also been accomplished indirectly by weighing a sample before and after extracting with supercritical GO2. 

Benzenedimethanol (1,2-bishydroxymethylbenzene) [612-14-6] M 138.2, m 61-64 , 63-64 , 64-65 , 65-66.5 , b 145 /3mm. Recrystd from C6H6, H2O, pet ether or pentane. It has been extracted in a Soxhlet with Et20, evaporated and recrystd from hot pet ether. Also dissolve in Et20, allow to evaporate till crystals are formed, filter off and wash the colourless crystals with warm pet ether or pentane. The diacetate has m 35 , 35-36 . [J Am Chem Soc 69 1197 1947, IR and UV J Am Chem Soc 74 441 7952.]... 

Iron (III) meso-5,10,15,20-tetraphenylporphine chloride complex [16456-81-8] M 704.0. Crystallise by extraction from a thimble (Soxhlet) with CHCI3. Concentrate the extract to ca lOmL and add ca 80mL of hot MeOH. Dark blue crystals separate on cooling. It can be recrystallised several times from CHCl3-MeOH. Avoid prolonged heating. It is quite soluble in organic solvents but insoluble in pet ether. [J Am Chem Soc 70 1808 1948 UV 73 4315 7957.]... 

A. Silver trifluoroacetate. To a suspension of 187 g. (0.81 mole) of silver oxide (Note 1) in 200 ml. of water is added 177 g. (1.55 moles) of trifluoroacetic acid (Note 2). The resulting solution is filtered, and the filtrate is evaporated to dryness under reduced pressure. The dry silver trifluoroacetate thus obtained is purified by placing it in a Soxhlet thimble and extracting with ether, or by dissolving the salt in 1.2 1. of ether, filtering through a thin layer of activated carbon, and evaporating the filtered ether solution to dryness. The yield of colorless crystalline salt obtained after removal of the ether is 300 g. (88%). 

In examining vanilla beans the determination of the vanillin is a matter of importance. Busse recommends the following process for the determination 20 grams of the pods, crushed with sand, are exhausted with ether in a Soxhlet tube, and the ethereal extract is shaken out with 20 per cent, sodium bisulphite solution. From the latter, vanillin is removed by treatment with dilute H SO, the SO2 generated removed by a current of CO, and the vanillin extracted by shaking out with ether, evaporating the solvent and weighing the residue. In East African vanilla the author found 2 16 per cent, of vanillin, in that from Ceylon 1 48 per cent., and in Tahiti vanilla from 1-55 to 2 02 per cent. Tiemann and Haarman found in the best Bourbon vanilla 1 94 to 2-90 per cent., in the best Java vanilla 2 75 per cent., and in Mexican vanilla from 1-7 to 1 9 per cent. Tahiti vanilla sometimes contains less than 1 per cent, of vanilla. 

Hanus has more recently recommended the following method for the determination of vanillin in vanilla beans and in preparations thereof. Three grams of the crushed pods are extracted for three hours in a Soxhlet tube with ether, the solvent distUled off cautiously, and the residue dissolved in a little ether, the solution filtered and the filtrate evaporated cautiously. The residue is treated with 50 c.c. of water at 60° on a water-bath 0 25 gram of weto-nitrobenzhydrazide is then added to the aqueous solution in a stoppered flask, which is kept for two to three hours... 

Lee [42] determined pentachlorophenol and 19 other chlorinated phenols in sediments. Acidified sediment samples were Soxhlet extracted (acetone-hexane), back extracted into potassium bicarbonate, acetylated with acetic anhydride and re-extracted into petroleum ether for gas chromatographic analysis using an electron capture or a mass spectrometric detector. Procedures were validated with spiked sediment samples at 100,10 and lng chlorophenols per g. Recoveries of monochlorophenols and polychlorophenols (including dichlorophenols) were 65-85% and 80-95%, respectively. However, chloromethyl phenols were less than 50% recovered and results for phenol itself were very variable. The estimated lower detection limit was about 0.2ng per g. 

Chlorinated pesticides in seawater (>10 L) (A) wash with distilled water (B) 2 X 18-h Soxhlet extraction with acetonitrile (C) 10 bed volumes of distilled water (1) 1 X 4 bed volumes of acetonitrile or ethyl ether (2) 1 X 500 mL of water (3) combine 1 and 2 (4) extract 3 with 2 X 50 mL of n-hexane 4... 

The ammonium salt may be obtained by extracting ammonium pentasulphide with carbon disulphide in a Soxhlet apparatus, washing first with hot carbon disulphide and then with ether, and centrifuging.4... 

An ethereal solution of 1 kg of cholesterol is added to 100 kg of a 10% aqueous-alcoholic horse extract. The resulting emulsion is stirred at 90°C for 1 hour, while the ether is distilled off. The water insoluble saponin-cholesterol precipitate is centrifuged and washed with cold water until the wash water is colorless. The precipitate is air-dried at room temperature. The resulting dust-fine powder is extracted with ether in a Soxhlet apparatus for 10 days. The residue is treated with 20 kg of methanol and the undissolved material is filtered off. The yellowish methanol solution is treated with activated charcoal until it is colorless. The methanol is distilled off in a vacuum, and the residue is dried over phosphorus pentoxide in a vacuum not exceeding 1 mm Hg. The yield of pure sodium escinate obtained thereby is about 0.8 kg (8%). 

Hydrazine hydrate (29.4 mL, 30.32 g, 0.61 mole) is added dropwise from a pressure-equalizing addition funnel to a cooled (0°) solution of hexachloro-1,3-cyclopentadiene (16 mL, 27.3 g, 0.10 mole) in 200 mL of methanol in a 500-mL Erlenmeyer flask. The solution turns dark red immediately. After the addition, the flask is securely stoppered (with a glass stopper) and the solution is stirred in the dark for 5 days at 5°, during which time a red solid collects on the walls of the flask. The mixture is poured into 5 L of water and filtered. The solid is air dried, dissolved in diethyl ether, and filtered. The filtrate is evaporated to dryness and the residue is extracted with cyclohexane in a Soxhlet extractor. The solution is concentrated and cooled and the red-brown crystals are filtered off. Additional product can be obtained by washing the material remaining in the thimble with water and extracting again with cyclohexane. Total yield 15 g (65%). 

There is a risk for solvolytic reactions during the removal of the extractives. Comparatively mild treatments such as Soxhlet extraction with ether (or dichloromethane) and acetone, complemented with leaching at room temperature with water, should be considered when it is particularly important to avoid such reactions. An alternative mode of milling has been described by Brownell (1965). This entails the use of a porcelain ball mill. While this pro-... 

The dark brown product is filtered and, after drying in the air, is extracted with ether in a Soxhlet apparatus. The ether is removed by evaporation, and the light-colored residue (170 g.) is recrystallized from 1.65 1. of hot methanol. The crystals are washed on a Buchner funnel with methanol until free from colored impurities. The yield is 77-87 g. of material which melts at 187-190°. A second recrystallization from methanol (1.25 cc. per g. of product) gives pure 8-octaacetylgentiobiose, with about 10 per cent loss. The pure substance melts at 196° (corr.). 

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