Ethanol, extraction using

In this study, ethanol extraction using SC CO2 was achieved from 15 to 75 %(v/v) synthetic ethanol solutions and also from fermentation broth. Effects of temperature, pressure, extraction time and initial ethanol concentration on extraction yield were investigated in the ranges of 313 to 333 K and 80 to 160 atmospheres. Optimum conditions for the batch extraction of 15%(v/v) ethanol solution were found using the Box-Wilson optimization method in a linear form. In addition, the effect of consecutive solvent feeding on extraction yield were investigated both with 15 %(v/v) ethanol solution and with fermentation broth. 

Halistanol sulfate was purified by successive chromatography of the water-soluble portion of an aqueous ethanol extract using a TSK G3000S gel, silica gel, and a Sephadex LH-20 stationary phase. Antimicrobial fractions from the LH-20 separation were further purified by recrystallization from Et0H-H20. 

FIGURE 4.6(a) Experimental set-up for ethanol extraction using hollow fiber contactors. (From R. Gawronski and B. Wrzesinska, J. Membr. Sci., 168, 213, 2000. With permission.)... 

The experimental conditions for conducting the above reaction in the presence of dimethylformamide as a solvent are as follows. In a 250 ml. three-necked flask, equipped with a reflux condenser and a tantalum wire Hershberg-type stirrer, place 20 g. of o-chloronitrobenzene and 100 ml. of diinethylform-amide (dried over anhydrous calcium sulphate). Heat the solution to reflux and add 20 g. of activated copper bronze in one portion. Heat under reflux for 4 hours, add another 20 g. portion of copper powder, and continue refluxing for a second 4-hour period. Allow to cool, pour the reaction mixture into 2 litres of water, and filter with suction. Extract the solids with three 200 ml. portions of boiling ethanol alternatively, use 300 ml. of ethanol in a Soxhlet apparatus. Isolate the 2 2- dinitrodiphenyl from the alcoholic extracts as described above the 3ueld of product, m.p. 124-125°, is 11 - 5 g. 

The tightly bound chromophore could be extracted from the protein with methanol [186], and the major component of the extract was determined to have the enediyne structure 116 (Figure 11.21), related to chromophores of other chromoprotein antitumor agents such as neocarzinostatin. Additional minor components were extracted, variously containing an OH group instead of OMe attached to the enediyne core, with Cl instead of OMe when chloride was present in the buffer salt, or with OEt instead of OMe when ethanol was used for the extraction. Another byproduct was isolated in the form of structure 117, consistent with a facile cy-doaromatization reaction as observed for all other enediyne antibiotics. Surprisingly, 117 also displayed antibiotic and antitumor activity, perhaps due to alkylation of DNA or protein by the aziridine. The interpretation of these results was that 116 and the other enediyne byproducts were merely artifacts of the extraction procedure and that the true structure of the maduropeptin chromophore is the aziridine 118. 

Bergeron, C. et al.. Comparison of the chemical composition of extracts from Scutellaria lateriflora using accelerated solvent extraction and supercritical fluid extraction versus standard hot water or 70% ethanol extraction, J. Agric. Food Chem., 53, 3076, 2005. 

A 15% nitric acid solution in ethanol was used to clean a bismuth crystal. The solution decomposed violently after this treatment and projected the content of the container into the extraction hood in which it was placed. Mixtures with less than 10% of nitric acid in alcohol are the only ones to remain stable for short periods of time. They should never be stored. In this particular accident, the presence of bismuth suggests a reaction of type (3). 

Beef kidney samples were analyzed for atrazine by dispersing 0.5-g portions of kidney with 2-g portions of XAD-7 HP resin for matrix solid-phase dispersion. " By using a mortar and pestle, a powder-like mixture was prepared that was subjected to subcritical extraction using ethanol-modified water at 100 °C and 50 atm. The ethanol-water extract was sampled using a CW-DVB SPME fiber for direct analysis using ion-trap GC/MS, and the recoveries were quantitative for atrazine at the 0.2 mg kg fortification level. 

Hydroalcoholic extracts are made when the active constituents are insoluble in water or when a concentrated dosage form is desired. Hydro alcoholic extracts use concentrated alcohol in varying proportions with water as a solvent. Hydroalcoholic extracts are categorized as tinctures or fluid extracts, depending on the amount of alcohol used. Some patients who simply do not like the taste of alcohol may be counseled to put the dosage of tincture drops into a cup of hot liquid and let it stand for a few minutes to evaporate off most of the alcohol before ingestion. An example of an ethanolic extract is echinacea [5,6]. 

Unfortunately, many clinical studies evaluating the efficacy of dietary supplements are flawed. Some of the flaws in the studies include non-randomization, being unblinded, lack of standardized products, small sample sizes, short treatment durations, and poorly defined inclusion and exclusion criteria. Many studies do not give detailed information about the dietary supplement used. When an herb is studied, the following information should be described plant species, part(s) used, product form (e.g., powdered crude herb, aqueous extract, ethanol extract, or aqueous alcohol extract) with stated proportions of water to alcohol, specifically extracted fractions, and quantities or concentrations used [48]. 

When ethanol was used to extract the dye, the efficiency increased to 0.71% the rationale is the higher solubility of the sensitizer in alcohol and minor association which favors a more homogeneous distribution of the anthocyanins on the Ti02 surface. However, exposure to simulated sunlight (AM = 1.5,100 mWcm 2) caused a significant decrease in efficiency after 3h, probably because alcohol favors the photocatalytic decomposition of anthocyanin. 

In the PO-CL system, the compounds showing native fluorescence or that fluoresce after chemical derivatization can be detected. As examples of the PO-CL detection of native fluorescence compounds, dipyridamole and benzydamine in rat plasma [57] and fluphenazine [58] have been reported in the former method, the detection limits of dipyridamole and benzydamine were 345 pM and 147 nM in plasma, respectively. Diamino- and aminopyrenes were sensitively determined using TCPO and their detection limits were in the sub-fmol range [59], Carcinogenic compounds such as 1- nitropyrene and its metabolites, can also be determined by the HPLC-PO-CL system. Nonfluorescent nitropyrenes were converted into the corresponding fluorescent aminopyrenes by online reduction on a Zn column followed by detection 2-50-fmol detection limits were achieved in the determination of ethanol extracts from airborne particulates (Fig. 13) [60],... 

Concentrates are made by extracting water-soluble sugars and other compounds from defatted meals or flours. This is typically a secondary extraction, using acidic ethanol-water in a chain-type or basket-type continuous extractor for processing flakes, or acidic water extraction of flour in vats, followed by spray-drying (8). Acidic polar solvents are used at or near the isoelectric point of the protein to minimize its solubility and loss. The reextracted flakes may then be ground into a flour. Concentrates are more bland than defatted flours, but still contain the fiber components of the kernel. After extraction with acidic ethanol or water, concentrates... 

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. 

Despite the conflicting evidence, Heyes and Trahar (1984) believe there is sufficient evidence to confirm the presence of sulphur on mineral surface. They leached the surface of floated pyrrhotite from a typical test with cyclohexane and have examined the leach solution in a UV spectrophotometer. They found that sulphur could be extracted from the surface of pyrrhotite, which had been floated in the absence of collector. As can be seen from Fig. 2.26, the spectrum from the leached pyrrhotite was compared with the spectrum of sulphur dissolved in cyclohexane indicating that sulphur was present at the siuface. Kelebek and Smith (1989) used UV spectrophotometer to determine sulphur in the ethanol extract from the surface of floated galena and chalcopyrite showing that the amount of sulphur on the minerals can be correlated with their flotation rate which was found to be first order within the critical surface tension range. 

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