Physical Extraction

The mechanism of physical extraction for analytical purposes always involves the bombardment or irradiation of a sample with an ion or laser beam, respectively [58, 59]. These processes are typically known as sputtering and ablation, respectively [60]. The interaction results in the volatilization of matter, in the form of solid fragments, neutral particles, or ions. While solid fragments need to be further divided before being introduced into an analyzer, neutral or charged particles can be detected directly with the appropriate technology. Nonetheless, post-extraction 

A couple of very recent examples are available in the literature of the use of laser-based extraction methodologies for the analysis of EEIs. The motivation for the use of lasers was different in both cases. In one case, matrix-assisted laser desorp-tion/ionization (MALDI) coupled with MS was employed to collect evidence of solvent oligomerization during decomposition on metallic surfaces [24], This technique is popular within the organic chemistry community for its sensitivity and 

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Equipment suitable for reactions between hquids is represented in Fig. 23-37. Almost invariably, one of the phases is aqueous with reactants distributed between phases for instance, NaOH in water at the start and an ester in the organic phase. Such reac tions can be carried out in any kind of equipment that is suitable for physical extraction, including mixer-settlers and towers of various kinds-, empty or packed, still or agitated, either phase dispersed, provided that adequate heat transfer can be incorporated. Mechanically agitated tanks are favored because the interfacial area can be made large, as much as 100 times that of spray towers, for instance. Power requirements for L/L mixing are normally about 5 hp/1,000 gal and tip speeds of turbine-type impellers are 4.6 to 6.1 i7i/s (15 to 20 ft/s). 

When the distribution coefficient for the desired solute from aqueous solutions into even the best of solvents is unfavourable it may become attractive to superimpose reaction. Consider the. separation of citric acid from aqueous solutions, for which physical extraction is unattractive. Here we can use a bulky tertiary amine, e.g. tri-2-ethylhexylamine, which has a very low solubility in water, and dissolve it in a suitable, water-insoluble solvent this will... 

Diamond [38] has shown that considerable amounts of lithium become bound during the hydration process. A study of the influence of hydration on the observable lithium content in cement paste samples was undertaken. In parallel, a traditional approach to lithium content in the pore solution was conducted (physical extraction of the pore solution and subsequent chemical analysis). The relationship between pore solution extraction and bulk MR is shown to be linear (see Figure 3.4.15). This result indicates that MR will be able to image lithium held in the pore solution but not lithium bound to the cement paste matrix. MR and pore solution extraction results also confirm that large amounts of lithium become bound during hydration. 

Hall 1996a b, Geological Survey of Canada (GSC) 2ACME Labs 2009 3Actlabs 2009 4SGS 2009 Physical extraction by suspension and centrifugation in deionized water... 

Table 9.3 gives data of common types of L-L contactors. Since the given range of kLa is more than 100/1, this information is not of direct value for sizing equipment. The efficiencies of various kinds of small liquid-liquid contactors for physical extraction are summarized on Figure 8.1. Larger units may have efficiencies less than half of these values. In some cases, however, enhancement of the L-L mass transfer coefficient by reaction may be as appreciable as in some gas-liquid cases. 

This materialization is achieved by first defining the increment to be extracted - an operation termed increment delimitation. After this, the increment must be physically extracted. These two operations are sampling processes each associated with potential errors which are termed the increment delimitation error (IDE) and the increment extraction error (lEE) respectively. 

When used with physical extraction and separation techniques as part of a treatment train, slurry-phase bioremediation has the following advantages ... 

The nature of reactor operations requires that the technology be coupled with another physical extraction operation, such as groundwater removal, soil excavation,... 

Middaugh, D. P., Mueller, J. G., Thomas, R. L., Lantz, S. E., Hemmer, M.J., Brooks, G. T. Chapman, P. J. (1991)- Detoxification of creosote-and PCP-contaminated groundwater by physical extraction chemical and biological assessment. Archives of Environmental Contamination Toxicology, 21, 233-44. 

The cation and anion exchangers are amphiphilic substances that are adsorbed at the interface. The latter is then rigid and independent of the droplet diameter, since friction forces are shielded. This is similar to physical extraction systems, in which an analogous behavior is caused by surfactants in the aqueous feed accumulated at the interface. 

Oilseeds, oil fruits, their products and by-products rapeseed, expeller and hulls soybean as bean, toasted, expeller and hulls sunflower seed as seed and expeller cotton as seed and seed expeller linseed as seed and expeller sesame seed as expeller palm kernels as expeller pumpkin seed as expeller olives, olive pulp vegetable oils (from physical extraction). (Turnip rapeseed expeller was delisted in 2004.)... 

Figure 2 illustrates the concentration profiles of various species (lactic acid, amine, and lactic acid-amine complex) in the extraction system. Both reactive and physical extractions of lactic acid take place at the interface between the aqueous and organic phases or at the outer membrane surface of the hollow fiber, and the solute flux owing to the extraction, /, can be described by Eq. 1 ... 

In Eq. 1, a first-order reaction kinetics between lactic acid and amine is assumed. The second term is the reverse reaction and the last term is attributed to physical extraction. 

Liquid extraction systems consist either of pure solvents and mixtures, but may also contain additives. The application of single solvent or simple mixtures is well-known in classical physical extractions when using bulk organic chemicals (toluene, butanol, etc.) to extract a solute. Today, a new class of solvents is that of ionic liquids [10], which are low-melting organic salts where the cation is, for example, from... 

An example of coordinative extraction with solvating agents is shown in Eq. (4). The difference with physical extraction is that the capacity and extraction power of the liquid neutral ion exchanger is much higher than with any bulk organic solvent (toluene, xylene, butanol, etc.) used in physical extraction. Alkyl-substituted... 

Reactive extraction is, in many aspects, quite similar to physical extraction. Modem liquid ion exchangers with fast kinetics allow the use of columns for solute recovery. Complex feed mixtures can be efficiently handled in respect to the given selectivity due to the selective chemical reaction involved and the set-up of a process schema, including scrubbing and regeneration steps. Reactive equilibria and mass transfer... 

A study on the hydrolysis of fats with water was conducted at 230 to 260°C (446 to 500°F) and 41 to 48 atm (600 to 705 psi) in a continuous commercial spray tower. A small amount of water dissolved in the fat and reacted to form an acid and glycerine. Most of the glycerine migrated to the water phase. The tower was operated at about 18 percent of flooding at which condition the HETS was found to be about 9 m (30 ft) compared with an expected 6 m (20 ft) for purely physical extraction [Jeffreys, Jenson, and Miles, Trans. Inst. Chem. Eng. 39 389-396 (1961)]. 

The definition of crude olive-pomace oil has been changed because this type of oil is now not only derived by solvent extraction of the olive pomace but also by physical extraction by means of a second centrifugation of the olive paste. The setting of limits for certain chemical criteria, aliphatic alcohols and wax, to differentiate lampante oil and second centrifugation oil, is currently under consideration. 

Bibliography for fusion sciences and plasma physics, extracted from INSPEC. 

We have no difRcully physically extracting the two blocks chosen. 

Because of the behavior of the solvent, solvent-extracted oil contains more minor components at higher levels than those found in physically extracted oil. This provides the basis for designating pomace oil as a commercial product distinct from virgin oil (obtained only by mechanical means) or refined (lower grade) virgin oil mixed with virgin oil (olive oil, Riviera type). 

Unfortunately, these simple methods are not always successful, and cerumenolytics have been developed to help dissolve cerumen and facilitate its removal. In severe cases, flushing the ear canal with a rinsing solution or physical extraction is still required. 

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