Extractability testing ethanol/water extractant

Pour exactly 8mL of extracting solution (f% citric acid in 80% ethanol/water) followed by 4mL of hexane into the test tube. Cap the test tube and shake the mixture, then vortex the mixture for 1 min. 

No irritant effects of an ethanol-water extract of Spanish chestnut leaf were observed in patch testing in healthy volunteers (Almeida et al. 2008). 

Black gel inks from 29 pens and 17 companies were differentiated by TLC on Merck silica gel 60 layers developed with ethyl acetate-ethanol-water (75 35 30) mobile phase. A VSC 2000 HR was used to examine and document the TLC plates in visible, LfV, and near IR reflectance (IRR) modes. Written gel ink lines on filter paper were sampled by extracting 1.3 mm punch holes with 20 pi of ethanol-water (1 1). Spot tests and capillary column GC/MS were also used for ink analyses in this study.A flowchart was developed allowing systematic determination of a questioned ink. 

Accelerated solvent extraction is a new extraction technique and is performed at high temperature and high pressure. It demonstrates high efficiency, short extraction time, and low solvent usage. Diatomaceous earth was extracted on an accelerated solvent extraction extractor [33] and different solvents (dichloromethane, -hexane, methanol, and ethanol/water (80 20)) are tested. The temperature... 

Bukovsky M, Kostalova D, Magnusova R, Vaverkova S (1993) Testing for immunomod-ulating effects of ethanol-water extracts of the above-ground parts of the plants Echinacea (Moench) and Rudheckia L. Cesk-Farm 42 228-231... 

For alcohols of b.p. below 150°, mix 0- 5 g. of 3-nitrophthalic anhydride (Section VII,19) and 0-5 ml. (0-4 g.) of the dry alcohol in a test-tube fitted with a short condenser, and heat under reflux for 10 minutes after the mixture liquefies. For alcohols boiling above 150°, use the same quantities of reactants, add 5 ml. of dry toluene, heat under reflux until all the anhydride has dissolved and then for 20 minutes more remove the toluene under reduced pressure (suction with water pump). The reaction product usually solidifies upon cooling, particularly upon rubbing with a glass rod and standing. If it does not crystallise, extract it with dilute sodium bicarbonate solution, wash the extract with ether, and acidify. Recrystallise from hot water, or from 30 to 40 per cent, ethanol or from toluene. It may be noted that the m.p. of 3-nitrophthalic acid is 218°. 

The mixture was refluxed gently on a steam bath for VA hours. Fifteen minutes after initiating the reaction, the reaction mixture gave a negative ferric chloride test. Most of the ethanol and acetic acid were removed by distillation in vacuo, 300 ml of water and 300 ml of ether were added to the concentrate, and the mixture was shaken. The layers were separated, the aqueous layer extracted with fresh ether, and the combined ether extracts were washed with water, dried over anhydrous sodium sulfate, filtered and evaporated to dryness in vacuo. The residue was crystalli2ed by trituration with ether, and the crystals were collected by filtration, washed with hexane and dried. The mother liquors were concentrated to dryness and dissolved in a minimum amount of acetone, whereupon a second crop was obtained. The two crops were combined, dissolved in ethyl acetate, decolori2ed with activated charcoal, and recovered by concentration. 

Seven individual spots that appeared on the chromatogram were cut from the paper and soaked in 80% ethanol for 2 hours. The extract was evaporated to dryness. To insure removal of formic acid, 3 to 5 ml of 80% ethanol was added and repeatedly evaporated to dryness. After final drying, 16 ml of distilled water was added to each fraction and used for the germination test with birdsfoot trefoil. 

Convert indole to indolyl-3-methyl-ketone (I) by treating indolyl-Mg-Br (preparation already described) with acetyl-Cl, by treating indole in POCl3 with dimethylacetamide (Vilsmeier reaction), or by reacting indole with diketene (ACS 22,1064(1968)). 15.9 g (1) in 50 ml methanol cool, stir and add dropwise 16 g Br2. Reflux 1 Vi hours on water bath cool, filter, wash with ether and recrystallize-methanol to get 18 g indolyl-3-Br-methyl-ketone (II). Dissolve 11.9 g (II) in 60 ml warm isopropanol and add 11 g 3 8% aqueous DMA (or equimoiar amount other amine) reflux one hour on water bath. Filter (recrystallize-ethanol) to get 8.5 g indolyl-3-dimethylamino-methyl ketone (III). Add 4.6 g (0.02 M) (III) in 30 ml tetrahydrofuran to 2.3 g lithium aluminum hydride in 50 ml tetrahydrofuran, stir one-half hour at room temperature and reflux two hours. Add a little water dropwise and extract the precipitate with acetone. Dry, evaporate in vacuum the combined organic phases to get an oil which will precipitate with ether-petroleum ether to give DMT. (Ill) should be tested for psychedelic activity. Dialkyltryptamines BCSJ 11,221 (1936), BSC 2291 (1966)... 

Mix 25 g 2,4,5-trimethoxyphenylacetone, 9.3 g hydroxyl-amine-HCI, 15.6 g K acetate and 400 ml 70% ethanol and reflux 3Vz hours. Evaporate in vacuum and extract the residue with 4X150 ml benzene. Wash combined extracts with 2X75 ml water dry and evaporate in vacuum the benzene (can purify the oil by dissolving in benzene and precipitate by adding petroleum ether) to get aout 20 g precipitate (test for activity). Dissolve 18.1 g precipitate in 200 ml methanol and hydrogenate. Acidify to get about 15 g (I). 

A second SFE-based method for the extraction of NPEC from solid matrices is called subcritical (hot) water extraction [9], The method was applied for NPEi 4C in 0.25 g sludge samples. Subcritical water is used as the extraction solvent, with 30% ethanol as the modifier, yielding quantitative recoveries. Other tested extraction solvent compositions were C02, hot water, methanol-modified hot water, none of which were judged satisfactory. 

A new HP-TLC method has been applied for the quantitative analysis of flavonoids in Passiflora coerulea L. The objective of the experiments was the separation and identification of the compound(s) responsible for the anxiolytic effect of the plant. Samples were extracted with 60 per cent ethanol or refluxed three times with aqueous methanol, and the supernatants were employed for HPTLC analysis. Separation was performed on a silica layer prewashed with methanol and pretreated with 0.1 M K2HP04, the optimal mobile phase composition being ethyl acetate-formic acid-water (9 1 l,v/v). It was established that the best extraction efficacy can be achieved with 60 - 80 per cent aqueous methanol. The HPTLC technique separates 10 different flavonoids, which can be used for the authenticity test of this medicinal plant [121],... 

X 10"3 M G-6-P, 1.6 units G-6-P dH, 5.1 X 10 5 M NADP, 1.0 mg aldrin in 0.2 ml ethanol when used alone, or 1.0 mg aldrin and 1.0 mg PBO, each in 0.1 ml ethanol, when used in combination. In synergism experiments, mixtures were pretreated with PBO for 3-5 min prior to the addition of substrate. The reaction mixtures were incubated with agitation in test tubes at 30 - 1°C in a water bath shaker for 15 min. Reactions were stopped by acidifying with 2 ml 5% TCA. The acidified mixtures were extracted and analyzed by GLC. 

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