Extraction theory,

If a neutral chelate formed from a ligand such as acetylacetone is sufficiently soluble in water not to precipitate, it may stiH be extracted into an immiscible solvent and thus separated from the other constituents of the water phase. Metal recovery processes (see Mineral recovery and processing), such as from dilute leach dump Hquors, and analytical procedures are based on this phase-transfer process, as with precipitation. Solvent extraction theory and many separation systems have been reviewed (42). 

Section A The following references are recommended for more in-depth readings on absorption and solvent extraction theory, design principles, and practical applications. 

Wagner, J. G. Sedman, A. J., Quantitation of rate of gastrointestinal and buccal absorption of acidic and basic drugs based on extraction theory, J. Pharmacokinet. Biopharm. 1, 23-50 (1973). 

Alders, L., Liquid-Liquid Extraction Theory and Laboratory Practice , 2nd ed., Amsterdam, Elsevier, 1959. 

Pawliszyn J (1997) Sohd phase micro extraction. Theory and practice. Wiley-VCH, New York... 

Scheibel, "Liquid-Solid Extraction (17 refs) 4) T.K. Sherwood Sc R.L, Pigford, "Absorption and Extraction , McGraw-Hill, NY(1952), pp 391—454 (Numerous refs) 5) L. Alders, "Liquid-Liquid Extractions, Theory and Laboratory Experiments , Elsevier, Houston (1955)... 

To understand any extraction technique it is first necessary to discuss some underlying principles that govern all extraction procedures. The chemical properties of the analyte are important to an extraction, as are the properties of the liquid medium in which it is dissolved and the gaseous, liquid, supercritical fluid, or solid extractant used to effect a separation. Of all the relevant solute properties, five chemical properties are fundamental to understanding extraction theory vapor pressure, solubility, molecular weight, hydrophobicity, and acid dissociation. These essential properties determine the transport of chemicals in the human body, the transport of chemicals in the air water-soil environmental compartments, and the transport between immiscible phases during analytical extraction. 

Hinze, W.L., Pramauro, E. A critical review of surfactant-mediated phase separations (cloud point extractions) theory and applications. Crit. Rev. Anal. Chem. 24, 133-177 (1993)... 

Spiegehnan M. (1993) Physics of melt extraction theory, implications and applications. Phil. Trans. Roy. Soc. London A342, 23-41. 

Pawliszyn, J., 1997. Solid Phase Micro extraction Theory and Practice. New York Wiley-VCH Inc. 

INTERACTIONS BETWEEN GUT MICROBES AND OBESITY THE ENERGY EXTRACTION THEORY ... 

The "energy extraction theory" was recently also put to the test in human subjects. Twelve lean and nine obese adult white males were recruited and assigned to either a 2400- or 3400-kcal/day diet for 3 days in a randomized crossover manner, after an initial 3-day period on a weight-maintenance diet. Interestingly, no... 

In this chapter, we will provide a basic overview of the principles, practice, and applications of the major sample preparation techniqnes for gas chromatography. Most are based on variants of extraction theory, so a theoretical overview of liquid and vapor phase extraction theory is also presented. 

The theory of SPME can be extended from the classical liquid-liquid extraction theory described above (61). Since in most SPME analyses, analytes are volatile and dissolved in an aqueous phase, a three-phase system, including the aqueous phase, the fiber phase, and the headspace phase above the aqueous, is described. The mass of analyte extracted into the fiber phase is given by... 

FIGURE 11.19 Flowchart for SPME method development (derived from J. Pawliszyn, Solid Phase Micro-extraction Theory and Practice, Wiley, New York, 1997, Table 4.1, p. 97). 

MA McHugh, VJ Krukonis. Supercritical Fluid Extraction Theory and Applications, 2 ed. Boston Butterworth-Heineman, 1994. 

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