Methanol benzene extraction

Fig. 5a. A surface rinse of Murchison (benzene-methanol and -hexane at room temperature) contains 4 isoprenoid hydrocarbons (capitalized). For peak identifications, see Studier et al. (1972). b Benzene-methanol extract of the same sample after grinding still yields a variety of alkanes and alkenes, but no isoprenoids. Peak 218 preceding n-Ci7 is not pristane but an alkene. Apparently the heavier isoprenoids are surficial contaminants of terrestrial origin...

This interpretation has been questioned by Chang and Mack (1978), who found that water-soluble organics, especially amino acid extracts from the Murchison meteorite, were almost as heavy as carbonate C [8C (PDB) = -1-23 to -l-44%o vs. +44.4%o], in contrast to the much lighter insoluble polymer (—15.3 to —16.8%o) or benzene-methanol extracts ( + 5.0%o)- They suggested that these various forms of carbon represent several stages of carbon condensation in the solar nebula, in different environments separated in space and possibly in time . 

The first attempt to determine the isotopic composition of the organic fraction was made by Briggs (1963). He found that benzene-methanol extracts of four Cl, C2, and C3V chondrites had variable isotopic compositions, in each case closely resembling the 8D and 8C values measured by Boato (1953) on bulk samples of the same meteorites. This implied that the organic H was isotopically similar to the more abundant inorganic H in the silicates, which dominated the bulk samples of Boato. 

The solid phase resulting from the HC1 extraction (i.e., bitumen, carbonate-free oil shale) was initially neutralized with distilled water to pH 5 and then dried at 85°C for about 24 h in a nitrogen atmosphere. The Soxhlet extraction procedure with benzene/methanol was repeated to assure the complete removal of physically trapped bitumen. The remaining shale was then extracted with a 3 1 mixture of 50% HF 6N HC1 under nitrogen at room temperature for approximately 24 h. Ether extraction of the aqueous HF/HC1 phase generated three different pH fractions as discussed above. The final step of the preparation procedure was another benzene/methanol extraction of the solid fraction (i.e., bitumen, carbonate, silicate-free oil shale) to remove physically trapped bitumen. 

The application of GC-MS to PAH-analysis will allow considerable simplification of the work-up procedure. As far as solubility and dynamic range considerations will permit, the major PAH in airborne particulate matter samples can be accurately measured in the electron impact single or multiple ion monitoring mode, using the molecular ions of the respective PAH as specific ions, in the presence of much larger amounts of aliphatic hydrocarbons and carboxylic acids. Polar and ionic material is first removed from the combined benzene-methanol extract by liquid-liquid partition in water-diethylether. After drying, the addition of diazomethane results in derivatisation of the acidic components and the sample can be injected onto the column (Van Vaeck and Van Cauwenberghe (30)). 

Dialkyltin thiol compounds Titration in benzene methanol extract with standard silver nitrate (in IPA water medium) using sulphide coated wire electrode 95... 

A mixture of 10 g of 4-(2, 4 -difluorophenyl)-phenol and 27.2 g of potassium carbonate is exposed to carbon dioxide at 1,300 psi and 175°C. The dark mass obtained from this car-donation is then dissolved in 300 ml of water and 200 ml of methylene chloride and the two layers separated. The water layer is then extracted with 100 ml of methylene chloride and then acidified with 2.5 N hydrochloric acid. This mixture is then filtered and the cake dried in vacuo to yield 5.32 g of the crude product. The crude product is then recrystallized from benzene-methanol. An additional crystallization of this semipure material from benzene-methanol yields analytically pure 2-hydroxy-5-(2, 4 -difluorophenyl)-benzoic acid (MP 210°-211°C). 

After this reaction-time, the evolution of hydrogen is ceased. Then there are added successively 60 parts dimethylformamide and 8 parts of p-chlorobenzylchloride and stirring and refluxing is continued for another two hours. The tetrahydrofuran is removed at atmospheric pressure. The dimethylformamide solution is poured onto water. The product, 1-[2,4-dichloro-/3-(p-chlorobenzyloxy)phenethyl] imidazole, is extracted with benzene. The extract is washed with water, dried, filtered and evaporated in vacuo. From the residual oily free base, the nitrate salt is prepared in the usual manner in 2-propanol by treatment with concentrated nitric acid, yielding, after recrystallization of the crude solid salt from a mixture of 2-propanol, methanol and diisopropylether, 1-[2,4-dichloro-/3-(p-chlorobenzyl-oxylphenethyl] imidazole nitrate MP 162°C. 

Isolation of Chromenes. The Skellysolve-F extract of yellow starthistle was partitioned between Skellysolve-F/benzene/methanol/water (1 1 4 1). The lower layer was repeatedly chromatographed on silica-gel (column and preparative TLC) with Skellysolve-F/ether to give pure chromenes identified by comparison of physical properties with those reported (14) and by synthesis. 

To 123 g p-anisidine (p-methoxy-aniline) in 1 L 15% HCI add 1 Kg ice and while stirring, quickly add dropwise below the surface, a solution of 75 g NaN02 in 200 mi water (temperature below 5°). Add 5 g activated carbon, stir and filter and quickly add filtrate with stirring to a mix of 160 g ethyl-alpha-methyl-acetoacetate in 1 L methanol, 1 Kg ice and 820 g Na acetate. Stir two hours and extract with 4X500 ml benzene. Wash extract with water, dry and... 

Takada and Ishimatari [20] extracted alkylbenzenes with normal C10-C14 and branched Cn-C13 alkyl chains from marine and coastal sediment and suspended matter in benzene methanol. The extract in benzene was then applied to a Florisil column for removal of copper sulphide and polar materials, and then subjected to silica gel column chromatography. Alkyl benzenes were quantified and identified using gas chromatography with flame ionization detection. The recoveries of alkyl benzenes were 81-94%. 

Procedures for determining fatty acids in sediments involved liquid-liquid extraction, liquid-solid adsorption chromatography followed by gas liquid chromatographic analysis [10-12], Liquid extractions have been performed with methanol-chloroform [13], methylene chloride [14] and benzene-methanol [15, 16]. Typical liquid-solid adsorbents are silicic acid. Standard gas chromatographic separations for complex mixtures employ non-polar columns packed with OV-1, OV-17, OV-101, SE-30, or glass capillary columns containing similar phases. 

For the two insecticides, the soil was extracted with 75, 50 and 50 mL of an acetone benzene methanol (1 2 1 by vol.) mixture. The sample bottles were capped and agitated for 60 minutes on a wrist-action shaker for each extraction. The contents of the bot-... 

Isolation of toxins. The digestive glands of shellfish were extracted with acetone at room temperature. After removal of the acetone by evaporation, the aqueous suspension was extracted with diethyl ether. The ether soluble residue was successively chromatographed twice over silicic acid columns with following solvents benzene to benzene-methanol (9 1), and diethyl ether to diethyl ether-methanol (1 1). To avoid degradation of dinophysistoxin-3 by contaminant acid, the silicic acid was washed with dilute sodium hydroxide solution and then with water prior to activation at 110 C. Toxic residue obtained in the second eluates was separated into two fractions... 

The iridoids cerbinal, cerberic acid and cerberinic acid are found in the methanol extract of the bark of C. manghas [67]. The crude extract obtained by percolation from 4 kg of stem bark and 1.9 kg of root bark were diluted with water to 50% water methanol. The mixture was washed with hexane and partitioned with benzene. Benzene fractions were re-suspended in methanol and cerbinal (120 mg from stem bark extract and 300 mg from root bark extract) precipitated. 

The bark of Plumeria bicolor also contains plumericin and isoplumericin, as described in [86]. The methanol extract (100 g), after washing with acetonitrile, was extracted with chloroform and chromatographed on a column containing 800 g of silica gel G (60-120 mesh). Elution was carried out using gradients of increasing polarities with benzene, chloroform and methanol. Plumericin and isoplumericin was recrystallized from methanol. 

Protoplumericin and plumieride can be extracted from the methanol extract of Allamanda neriifolina stems [117] by droplet counter-current chromatography. Crude extract, obtained from 1.6 kg of plant material, was successively partitioned with benzene, chloro-... 

The root bark of the cultivated mulberry tree was extracted successively with n-hexane, benzene, and methanol. The methanol extract, 1—20 mg, showed a dose-dependent decrease in arterial blood pressure in pentobarbital-anesthetized rabbit, Fig. (4). The extract was fractionated successively by silica gel column chromatography (C.C.), polyamide C.C., silica gel preparative (p.) TLC, and p. HPLC leading to isolated of kuwanons G (1,0.2% yield) [9] and H (2,0.13% yield) [10]. 

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