Effect of solvent extraction

Goldsmith LB, Friberg SE, Wahlberg JE. 1988. The effect of solvent extraction on the lipids of the stratum comeum in relation to observed immediate whitening of the skin. Contact Dermatitis 19 348-350. 

Despite the demonstrated effectiveness of solvent-extraction (SX) processes employing conventional organic diluents in nuclear-fuel reprocessing and... 

Figure 35.9 Effect of solvent extraction on XPS spectra of plasma polymer of tetrafluoroethylene deposited on Silastic tube extracted with w-hexane for 3h under continuous flow.

Table 15. Effect of Solvent Extraction on the Photoantioxidant Activity of Bound Antioxidants...

Figure 2. Mossbauer tin intensities (from integrated peak area measurements) as a function of age. Also shown is the effect of solvent extraction. Real-time aged samples were obtainedfrom field trials.

The effectiveness of solvent extraction was evaluated by a lipid-doped polymer study. Selected lipids were dispersed in Biomer. Then, two sample films, one containing 1 mg, the other 10 mg of palmitic acid, cholesterol, and tripalmitin were cast from two consecutive castings each of 10% Biomer in dimethylacetamide (DMAC). Lipid concentrations of the 1-mg- and 10-mg-doped samples were calculated to be 0.1% and 1%, respectively. Following casting, a soxhlet extraction and quantitative analysis of extracted lipids were performed. The final extracted concentrations were compared with initial solution concentrations, resulting in an extraction efficiency ratio for each type of component. 

Many types of separation systems other than solvent extraction have been found to exhibit high cesium selectivity. Such systems represent a point of comparison by which the effectiveness of solvent extraction systems may be measured. Table 1 lists some representative examples. These systems include inorganic ion exchangers, precipitation methods, and ion-exchange resins. For a variety of reasons, these materials have considerable potential for, and application in, cesium separations and may for specific tasks be the method of choice in the nuclear industry. The reader may consult the sampling of references cited in Table 1 for further information. 

Rao and Chakraborty (1988) have studied the effects of solvent extractions on the chemical composition of tobacco. Water extractions significantly reduced the levels of nicotine, reducing sugar and polyphenols. Extractions with methanol reduced the content of solanesol, neophytadiene, hydrocarbons, and steroids. The solvent extractions did not alter the structural identity of the tobacco. There were no significant cellular changes. 

Frosch PJ, Kurte A (1994) Efficacy of skin barrier creams. The repetitive irritations test (RIT) with a set of 4 standard irritants. Contact Dermatitis 31 161-168 Goldsmith LB, Friberg SE, Wahiberg JE (1988) The effect of solvent extraction on the lipids of the stratum corneum in relation to observed immediate whitening of the skin. Contact Dermatitis 19 348-350... 

Figure 6 (a) Effect of solvent extraction on UV embrittlement time of PP containing different concentrations of the nitroxyl (10 R = OH) processed in closed (CM) and open (OM) chamber of a RAPRA-Hampden torque rheometer E (extracted samples), U (unextracted samples), (b) The concentration of (10) left in the polymer after processing and before UV irradiation in the above samples (reproduced from ref. 34 by permission of John Wiley Sons, Inc.)... 

Yong Ju, Z. and Howar, L.R., Effects of solvent and temperature on pressurized liquid extraction of anthocyans and total phenolics from dried red grape skin, J. Agric. Food Chem., 51, 5207, 2003. 

The effect of co-extracted matrix components on the analyte response in the final determination step should be assessed. Normally, this is done by comparing the response of standards in solvent with matrix-matched standards, i.e., standards prepared in the extract of a control sample without residues. Because matrix effects tend to be inconsistent, the guidelines propose the general use of matrix-matched calibration unless it is demonstrated to be unnecessary. 

Solvent extraction is intrinsically dependent on the mass transfer across the interface and the chemical inversion at the interfacial region. Researchers in the field of solvent extraction, especially in the field of analytical chemistry and hydrometallurgy, observed effects of interfacial phenomena in the solvent extraction systems. This gave them a strong motivation to measure what happened at the interface. 

In SEC analysis of additive extracts from polymers, the effect of the extraction solvent on the mobile phase is less critical than in HPLC analysis. The extraction solvents typically employed generally do not interfere with the SEC mobile phases. Moreover, the same solvents are often used both as extraction solvent and as mobile phase. Therefore, there is no need to evaporate the extract to dryness prior to analysis and then to redissolve it in a suitable solvent. Typical extraction procedures often produce extracts that generally contain a small amount of wax. Frequently, removal of such oligomers from an extract is necessary, e.g. by means of precipitation, centrifuging, precolumn filtration or protection (use of a reversed-phase guard column). In SEC separations the presence of polyolefin wax does not usually disturb provided that the MW of the wax is higher than that of the analysed compounds. 

Maljkovic, D. Lenhard, Z. The effect of organophosphoric extractant concentration and initial phase volume ratio on cobalt(II) and nickel(II) extraction. International Solvent Extraction Conference, Cape Town, South Africa, Mar. 17-21, 2002, 982-987. 

The major uses of non-ionizing solvents in chemical analysis are twofold. They may be used simply to provide media for the dissolution and reaction of covalent materials, or they may play a more active part in a chemical process. For example, oxygen-containing organic solvents can be used to effect the solvent extraction of metal ions from acid aqueous solutions the lone pair of electrons possessed by the oxygen atom forming a dative bond with the proton followed by the extraction of the metal ion as an association complex. 

Study the effect of the extraction stage on reactor performance by varying the magnitudes of the the mass transfer coefficient Ka, the equilibrium distribution ratio m, the recycle ratio R, the relative reactor and extraction volumes and solvent flowrate. 

Based on the appropriate partition coefficient of an immiscible solvent pair it is possible to calculate the effectiveness of an extraction . 

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