Extraction acetone

Figure 8 illustrates one of the processing schemes used for separating various components in a hydrocarbon-containing plant. Acetone extraction removes the polyphenols, glycerides, and sterols, and benzene extraction removes the hydrocarbons. If the biomass species in question contain low concentrations of the nonhydrocarbon components, exclusive of the carbohydrate and protein fractions, direct extraction of the hydrocarbons with benzene or a similar solvent might be preferred. 

Neurotensin. This hormone has been isolated and characterized from acid—acetone extracts of bovine hypothalamus (118) on the basis of its hypotensive activity. Immunoreactive neurotensin is present in mammalian gut and is distributed throughout the central nervous system its highest concentration is in the hypothalamus and in the substantia gelatinosa of the spinal cord (119). Its overall brain distribution is not unlike that of enkephalin ( ) ... 

Poljraer Specific gravity Mooney viscosity Tensde strength, MPa Elongation, % Ash, % Acetone extract, %... 

TABLE 13-22 Comparison of Candidate Solvents for Methanol/Acetone Extractive Distillation... 

FIG. 23-38 Efficiency and capacity range of small-diameter extractors, 50 to 150 mm diameter. Acetone extracted from water with toluene as the disperse phase, V /V = 1.5. Code AC = agitated cell PPC = pulsed packed column PST = pulsed sieve tray RDC = rotating disk contactor PC = packed column MS = mixer-settler ST = sieve tray. (Stichlmair, Chem. Ing. Tech. 52(3), 253-255 [1980]). 

The combined acetone extracts were extracted six times with one-fourth volume of ethylene dichloride and the ethylene dichloride extract was evaporated under vacuum to leave the steroid residue. This steroid residue was taken up in a minimum of methylene chloride and applied to the top of a column packed with 30 grams of silica which had been previously triturated with 21 ml of ethylene glycol. Then various developing mixtures, saturated with ethylene glycol, were passed over the column. Cuts were made as each steroid was eluted as determined by the lowering of the absorption of light at 240 mp on the automatic chromatographic fraction cutter. 

Figure 2 Electron microphotographs of crack surface (a) and (b) and upper surface (c) and (d) of PVAc latex film. Acetone extraction (a) and (c) before, (b) and (d) after.

The PVAc latex containing PVA as a protective colloid prepared in method [III] using the HPO (0.12%)-TA (0,10%) system as an initiator in Table 1 was cast to about 1.8 mm in thickness on a poly(ethylene) plate and dried at room temperature. The dried latex films were 0.7-0.9 mm in thickness and were semi-transparent. The porous film after acetone extraction changed to a white color without a change in the film size. 

This prediction is drawn according to the following model. Figure 5 illustrates that in the latex state the grafting PVA protects hydrophobic PVAc particles in water by concentrating on the surfaces of PVAc particles, but in the porous film after acetone extraction, the insoluble grafting PVAc conversely exists as an important component on the inner surface of spherical cells of PVA. 

There has been a conventional sense that the PVAc latexes prepared in the presence of PVA as a protective colloid contain the graft copolymer of PVA and PVAc, so that PVAc particles in the dried latex film are not extracted at a high ratio with solvents. In this Chapter, it has been defined without an influence by the usual sense that the porous PVA-PVAc composite can be prepared from the PVAc latex film with acetone extraction. The porous film consists of the spherical cells of PVA... 

Abscisin II is a plant hormone which accelerates (in interaction with other factors) the abscission of young fruit of cotton. It can accelerate leaf senescence and abscission, inhibit flowering, and induce dormancy. It has no activity as an auxin or a gibberellin but counteracts the action of these hormones. Abscisin II was isolated from the acid fraction of an acetone extract by chromatographic procedures guided by an abscission bioassay. Its structure was determined from elemental analysis, mass spectrum, and infrared, ultraviolet, and nuclear magnetic resonance spectra. Comparisons of these with relevant spectra of isophorone and sorbic acid derivatives confirmed that abscisin II is 3-methyl-5-(1-hydroxy-4-oxo-2, 6, 6-trimethyl-2-cyclohexen-l-yl)-c s, trans-2, 4-pen-tadienoic acid. This carbon skeleton is shown to be unique among the known sesquiterpenes. 

A fermentation broth of Streptomyces tsukubaensis No. 9993 is filtered and the mycelial cake is extracted with acetone. The filtrate is combined with the acetone extract and passed through a column of Diaion HP-20. The dilution with 75 % aqueous acetone, by evaporation gives an oily residue that is extracted with ethyl acetate and submitted to column chromatography over silica gel. 

A 10-g sample of the homogenized dry sample is soaked in 20 mL of distilled water for 2 h. After adding 100 mL of acetone to the soaked sample and shaking vigorously on a mechanical shaker for 30 min, the extract is filtered. After the addition of a further 100 mL of acetone, the sample homogenate is shaken as before and the acetone extract is filtered. The filtrates are combined and acetone is removed with a rotary evaporator. " ... 

Filter the mixture through a filter paper by suction and collect the filtrate in a 500-mL round-bottom flask. Wash the residue and the beaker with 100 mL of acetone and filter and collect the washings in the same manner. Concentrate the combined acetone extracts in the round-bottom flask to about 60 mL, using a rotary evaporator under reduced pressure at 40 °C. 

Alba et al. used ethyl acetate to extract imidacloprid residues from fruits and vegetables. A 15-g sample of vegetable or fruit is weighed into a blender tube and 60 mL of ethyl acetate and 15g of sodium sulfate are added. The mixture is homogenized for 30 s, using a Polytron, and filtered. The filtrate is evaporated and the residue obtained is dissolved in acetonitrile-water (1 1, v/v). Alba etal. considered the low recoveries of these polar pesticides as the major disadvantage of the acetone extraction method. In their previous work they evaluated the efficacy of ethyl acetate for the extraction of pesticide residues. 

Concentrate the acetonitrile extracts obtained above to dryness below 40 °C with the rotary evaporator. Dissolve the residues in 2 mL of acetone. Quantitatively transfer the acetone extracts to a culture tube with a Teflon screw-cap containing 250 xL of acetone-olive oil keeper (1 1, v/v). Evaporate the acetone on a heating block not exceeding 40 °C under a stream of air. Wrap the threads on the Teflon culture mbe with Teflon tape and add 2.0 mL of 50% (w/w) sodium hydroxide. Cap tightly and heat the Teflon culture tube at approximately 200 °C for 3 h. 

Homogenize 50 g of a prepared sample with a solution containing 50 mL of borate buffer (pH 10) and 50 mL of acetone in a blender for 5 min. Pour the homogenate into an Erlenmeyer flask, add 50 mL of acetone and shake the flask for 10 min using a shaker. Filter the aqueous acetone extract through a 25G-4 glass filter overlaid with 3 g of Celite. Wash the residue on the filter with 50 mL of acetone. Combine the filtrates and remove acetone by rotary evaporation. Transfer the residue with 5 mL of 4% sodium dodecyl sulfate aqueous solution into a separatory funnel, extract the solution with two portions of 50 mL of dichloromethane and collect the organic... 

Extraction. Extract 20 g of sample as described for fruit and vegetables. Evaporate the acetone extract to dryness by rotary evaporation under reduced pressure in a <40 °C water-bath. 

Observation of effects. Seven to 14 days after exposure to test compounds, length, number of leaves and presence of stomata in sprouted winterbuds were determined. FOr sago pondweed tubers, length, number of new daughter plants and presence of roots were determined. Hydrilla explants were evaluated for number of and length of new shoots. In some experiments the chlorophyll-a content of the apical 2 cm on apical explants was determined by 3 successive extractions in 90% acetone using a power-driven Teflon pestle. Absorbance of Millipore-filtered (.45p ) acetone extracts was determined at 6 30, 6 45, 6 6 5 nm on a spectrophotometer. Chlorophyll-a was calculated by equations of Strickland and Parsons (8). 

Figure 6.21 Field desorption mass spectrum of the rubber compound (acetone extract analysis) of Table 6.36. After Lattimer et al. [229]. Reprinted with permission from Rubber Chemistry and Technology. Copyright (1990), Rubber Division, American Chemical Society, Inc.

An effective means to facilitate the mass-spectral analysis of rubber acetone extracts is to use desorp-tion/ionisation techniques, such as FD [92,113] and FAB [92]. FAB mass spectra for rubber extracts are generally more complex (due to fragment ions) than FD spectra of the same materials. Nevertheless, the FAB spectra are often complementary to FD, since ... 

In an acetone extract from a neoprene/SBR hose compound, Lattimer et al. [92] distinguished dioctylph-thalate (m/z 390), di(r-octyl)diphenylamine (m/z 393), 1,3,5-tris(3,5-di-f-butyl-4-hydroxybenzyl)-isocyanurate m/z 783), hydrocarbon oil and a paraffin wax (numerous molecular ions in the m/z range of 200-500) by means of FD-MS. Since cross-linked rubbers are insoluble, more complex extraction procedures must be carried out (Chapter 2). The method of Dinsmore and Smith [257], or a modification thereof, is normally used. Mass spectrometry (and other analytical techniques) is then used to characterise the various rubber fractions. The mass-spectral identification of numerous antioxidants (hindered phenols and aromatic amines, e.g. phenyl-/ -naphthyl-amine, 6-dodecyl-2,2,4-trimethyl-l,2-dihydroquinoline, butylated bisphenol-A, HPPD, poly-TMDQ, di-(t-octyl)diphenylamine) in rubber extracts by means of direct probe EI-MS with programmed heating, has been reported [252]. The main problem reported consisted of the numerous ions arising from hydrocarbon oil in the recipe. In older work, mass spectrometry has been used to qualitatively identify volatile AOs in sheet samples of SBR and rubber-type vulcanisates after extraction of the polymer with acetone [51,246]. 

Table IL Acetone Extractable Percentage of PLA in PLA/EVAc Polyblends ...

A chromatogram obtained for the examination of acetone extractables from an ethylene propylene-based rubber is shown in Figure 3. Excellent separation of the main hydrocarbon components from polar compounding ingredients and curative breakdown products is observed. 

Figure 3 Examination of the acetone extract from an EPDM (ethylene propylene diene monomer) rubber using two-dimensional gas chromatography. (See Color Plate Section at the end of this book.)... 

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