نتایج جستجو برای: supercritical fluid
تعداد نتایج: 228491 فیلتر نتایج به سال:
Modifiers have a broad array of influences on extraction with liquids in standard state, supercritical fluid extraction (SFE), trapping by SFE and supercritical fluid chromatography (SFC). They can significantly change the qualitative and quantitative results. Quantitative and qualitative results can be influenced by different extractants and modifiers in different ways as it was shown by Brond...
The development of automatized hyphenated systems is attractive to avoid sampling error, save time and reduce costs. Among these systems, on-line SFE-SFC allows the extraction, separation, detection molecules in an efficient, quick eco-friendly way. After a historical introduction explanation on use supercritical fluids for extraction or analysis, principles fluid (SFE) chromatography (SFC) wil...
Injecting liquid CO(2) into deep-sea sediments below ca. 3 km of seawater has been suggested for the permanent storage of anthropogenic CO(2). At the pressures and temperature found below 3 km of seawater, CO(2) becomes denser than seawater and so is likely to remain permanently sequestered in the sediment. Deepwater engineering, however, is expensive and seawater depths of greater than 3 km ar...
Figure 3. High performance capillary SDS-PAGE separation of myoglobin and several of its fragments. Conditions: 400 V/cm, 34 AA, 25 'C, migration distance 20 cm; fused-silica capillaries; 75 Am ID, T-12.5%, c=3.3%. Buffer: 0.1 M Tris-HPO0 (pH=6.9), 0.1% SDS, 8 M urea. Supercritical fluid chromatography (SEC) is fast becoming the method of choice for many separations involving nonvolatile, react...
The chemical composition of mentha essential oil and mentha extracts obtained at different pressures/temperatures by supercritical fluid extraction (SFE) were studied by GC–MS. The menthol content was also determined spectrophotometrically. The predominant compounds in the essential oil and in the CO2 extract obtained at 100 bar were L-menthon and menthole but at higher pressures (from 150 to 4...
BACKGROUND Waste animal fat is a promising feedstock to replace vegetable oil that widely used in commercial biodiesel process, however the high content of free fatty acid in waste fat makes it unfeasible to be processed with commercial base-catalytic process. Enzymatic process is preferable to convert waste fat into biodiesel since enzyme can catalyze both esterification of free fatty acid and...
The purpose of this evaluation was to provide an objective evaluation of the use of supercritical carbon dioxide (CO,) as an alternative technology for spray applied in wood finishing processes using reduced solvent formulations. Union Carbide has pioneered this technology under the UNICARBTM trademark. In the UNICARBTM process, the solvent-like properties of supercritical CO, are employed to r...
Supercritical fluid extraction was used to extract the alkaloid N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine from leaves of Piper amalago L. A three-level orthogonal array design matrix, OAD OA9(34), was used for optimization of the parameters of supercritical extraction of the alkaloid, employing supercritical carbon dioxide: extraction time (20, 40, and 60 min), temper...
Supercritical CO2 extraction of the pigments from Bixa orellana seeds was carried out in a flow apparatus at a pressure of 200 bar and a temperature of 40 oC at two fluid flow rates (0.67g/min and 1.12g/min). The efficiency of the extraction was low (only about 1% of the pigment was extracted). The increase in flow rate led to a decrease in pigment recovery. A large increase in recovery (from 1...
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