Filter extraction

Add cautiously 15 ml. of concentrated sulphuric acid to 50 ml. of water in a 100 ml. distilling-flask, and then add 10 g. of pinacol hydrate. Distil the solution slowly. When about 40 ml. of distillate (consisting of pinacolone and water) have been collected, and no more pinacolone comes over, extract the distillate with ether. Dry the extract over sodium sulphate. Distil the dry filtered extract carefully, with the normal precautions for ether distillation (p. 164). When the ether has been removed, continue the distillation slowly, rejecting any fraction coming over below 100 . Collect the pinacolone, b.p. 106 , as a colourless liquid having a peppermint odour. Yield, 4 5-5 o g. A small quantity of higher-boiling material remains in the flask. 

Place 80 g, of hydroxylamine sulphate (or 68-5 g. of the hydrochloride), 25 g. of hydrated sodium acetate, and 100 ml. of water in a 500 ml. flask fitted with a stirrer and a reflux water-condenser, and heat the stirred solution to 55-60°. Run in 35 g (42 nil,) of -hexyl methyl ketone, and continue the heating and vigorous stirring for ij hours. (The mixture can conveniently be set aside overnight after this stage.) Extract the oily oxime from the cold mixture twice with ether. Wash the united ethereal extract once with a small quantity of water, and dry it with sodium sulphate. Then distil off the ether from the filtered extract, preferably using a distillation flask of type shown in Fig. 41 (p. 65) and of ca, 50 ml, capacity, the extract being run in as fast as the ether distils, and then fractionally distil the oxime at water-pump pressure. Collect the liquid ketoxime, b.p. 110-111713 mm. Yield, 30-32 g. 

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. 

Benzoates. Dissolve 0-5 g. of the amino acid in 10 ml. of 10 per cent, sodium bicarbonate solution and add 1 g. of benzoyl chloride. Shake the mixture vigorously in a stoppered test-tube remove the stopper from time to time since carbon dioxide is evolved. When the odour of benzoyl chloride has disappeared, acidify with dilute hydrochloric acid to Congo red and filter. Extract the solid with a little cold ether to remove any benzoic acid which may be present. RecrystaUise the benzoyl derivative which remains from hot water or from dilute alcohol. 

Strongly acidify the residual sodium bicarbonate solution to Congo red with dilute sulphuric acid. If a sohd acid forms, filter. Extract the filtrate or the acidified solution with two 20 ml. portions of ether keep the aqueous solution A). Distil off the ether, and add the residual acid (if a sohd) to the solid separated by filtration. Identify the acid. 

A mixture of 50 grams of the above prepared piperazine, 30.1 grams of sodium carbonate and 200 ml of benzene is heated to reflux and treated with 39.5 grams of 3-bromopropanol over 1.5 hours. The resulting mixture is refluxed for 2 hours, then filtered, extracted with dilute hydrochloric acid, basified, extracted with benzene, and the extracts are concentrated and distilled to give 1-benzyloxyethyl-4-(3-hydroxypropyl)-piperazine, BP 1BB°to 190°C (0.15 mm). The free base is converted to the dihydrochloride salt by treatment of an alcoholic solution with ethereal hydrogen chloride to separate the salt. 

The yellowish solution is transferred to a 3-I. round-bottom wide-neck flask and cooled with running water while 300 cc. of concentrated sulfuric acid is added slowly from a separatory funnel. This acidification process requires thirty minutes and the temperature should not rise much above 25 . The liquid froths and about 30 g. of benzoic acid separates but it is not filtered. Extraction of the reaction mixture with 200 cc. portions of ether until 1500 cc. of extract has been collected is now carried out in a separatory funnel. The ether is distilled on a steam bath from a i-l. round-bottom wide-neck flask connected with a water condenser, the extract being added from a separatory funnel as fast as the ether distils. After most of of the ether has been removed, the heating is continued for an additional half hour. 

A mixture of the dibenzodiazepinone 13 (R1 = H 7.0 g, 33 mmol), NaNH2 (1.04 g, 26.7 mmol) and dioxane (200 mL) was refluxed for 1 h, cooled to 60 C and 3-chloro-/V,/V-dimethylpropylamine (3.06 g. 25.2 mmol) in dioxane (40 mL) was added over 30 min. The mixture was boiled under reflux for 4 h, cooled and treated with McOH (10 mL). The filtered solution was evaporated under reduced pressure and the residue was extracted with cold dil HC1. The filtered extract was made alkaline with aq NH3 and extracted with Et20. The dried extract was evaporated to yield the product mp 116-119 C (EtOH/Et20). 

Diheptylnaphthalene-2.3-dicarbonitrile (748 mg, 2 mmol), Fe(OAc)2 (174 mg, 1 mmol), and DBU (1.5 mL) were heated in hexan-1-ol (25 mL) for 3 h under reflux. The mixture was poured into MeOH/H20 (1 1, 150 mL). The black-brown precipitate was filtered, extracted with MeOH, and dried. The residue was stirred in a mixture of t-BuNC (1 mL) and CHC13 (5 mL) for 24 h at 60 C. The solvent and the excess t-BuNC were removed in vacuo. The residue was purified by column chromatography (alumina, CHClj) and dried in vacuo at 80°C to give a green powder yield 280 mg (42%). 

This method requires about 40 g of tobacco which are extracted with ethyl acetate in the presence of ascorbic acid. A trace amount of C-NDELA is added as an internal standard for quantitative analytical work. The filtered extract is concentrated and NDELA is enriched by column chromatography of the concentrate on silica gel. The residues of fractions with p-activity are pooled and redissolved in acetonitrile. Initially, we attempted to separate NDELA on a 3% OV-225 Chromosorb W HP column at 210 C using a GC-TEA system with direct interface similar to the technique developed by Edwards a. for the analysis of NDELA in urine (18). We found this method satisfactory for reference compounds however, it was not useful for an optimal separation of NDELA from the crude concentrate of the tobacco extract (Figure 4). Therefore, we silylated the crude concentrate with BSTFA and an aliquot was analyzed by GC-TEA with direct interface. The chromatographic conditions were 6 ft glass column filled with 3% OV-... 

Cleanup of crude extracts. Inject ca 10 mL of the filtered extract derived from one of the Modules E into the 5-mL sample loop (5.0 mL = Vga). 

Plant material is homogenized in acetone followed by addition of water. The filtered extract is diluted with acetone-water (2 1 v/v) and filtered through a syringe filter. The sample extract is diluted 1 1 with a deuterated azinphos-methyl internal standard and analyzed using LC/MS/MS in the positive-ion selected reaction monitoring (-I-SRM) mode. 

Air (particulate lead) Collection of particulate matter onto filter extraction with HN03/ HCI, heat, and sonication ICP/AES No data No data EPA 1988a... 

A Fuel Aromatics + NO B Filter Extract New Engine c Dilution Tunnel Sediment Extract... 

Ethyl a-bromobutyrate (58.5 g., 0.30 mole) (Note 1) is poured into a stirred mixture of 600 ml. of N,N-dimethylformamide (DMF) (Note 1), 36 g. of sodium nitrite (0.52 mole) (Note 1), and 40 g. of anhydrous phloroglucinol (0.32 mole) (Note 2) contained in a 1-1. three-necked flask equipped with a sealed stirrer. The flask is closed, except for a tube containing calcium chloride, and immersed in a water bath maintained at room temperature (Note 3). Stirring is continued for 2.5 hours (Note 4) then the reaction mixture is poured into 1.2 1. of ice water layered over with 300 ml. of diethyl ether (Note 5). After separation of the upper layer, the aqueous phase is extracted with four 100-ml. portions of ether. The combined extracts are washed with four 100-ml. portions of water and then dried over anhydrous magnesium sulfate. The magnesium sulfate is removed by suction filtration and washed with four 25-ml. portions of ether which are combined with the filtered extract. 

The separation and identification of two novel anthocyanins from red onion, Allium cepa, have also been reported. Scales of 2.37 kg red onion were cut and extracted twice with methanol containing 0.5 per cent TFA. The extract was filtered, extracted with ethyl acetate and the aqueous phase was further purified in an ion-exchange and an SEC column. SEC separation was performed in a Sephadex LH-20 column (100 X 5 cm i.d.) applying methanol-water-TFA (39.6 60 0.4, v/v) as the mobile phase at a flow rate of 2.5 ml/min. 

In this paper, a description will be given of the previous work carried out to find ways to reduce metallic trace elements in the filtered extract to low levels. This will be compared with new work where solvent precipitation was carried out on filtered extract solution as an alternative method of producing low levels of trace elements. 

One of the aims of the work carried out in this laboratory was to investigate the deposition of trace elements on the hydrocracking catalyst. To this end, a continuous laboratory hydrocracker was installed and, to provide feed material for this, a 2-1 autoclave and pressure filter were also installed. It was noticed on the initial runs with the autoclave that the ash level of the filtered extract solution was considerably lower, at 100-200 ppm, than that normally obtained by British Coal, at 500-600 ppm. The reason for this difference was not known, so an investigation was carried out which found that the lower ash levels could be produced by a higher digestion pressure. Table 1 shows some of the results obtained, which have b n previously published (10). Note that throughout all the experiments described in this paper the coals used were Point of Ayr and Calverton, whose analyses are given in Table 2, and that the HAO to coal ratio us was always 2 1. Hence, ash analyses in the coal extract solution are comparable. 

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