Adsorption solid

In liquid-solid adsorption chromatography (LSC) the column packing also serves as the stationary phase. In Tswett s original work the stationary phase was finely divided CaCOa, but modern columns employ porous 3-10-)J,m particles of silica or alumina. Since the stationary phase is polar, the mobile phase is usually a nonpolar or moderately polar solvent. Typical mobile phases include hexane, isooctane, and methylene chloride. The usual order of elution, from shorter to longer retention times, is... 

Kovat s retention index (p. 575) liquid-solid adsorption chromatography (p. 590) longitudinal diffusion (p. 560) loop injector (p. 584) mass spectrum (p. 571) mass transfer (p. 561) micellar electrokinetic capillary chromatography (p. 606) micelle (p. 606) mobile phase (p. 546) normal-phase chromatography (p. 580) on-column injection (p. 568) open tubular column (p. 564) packed column (p. 564) peak capacity (p. 554)... 

Many gas streams can be deodorized by using solid adsorption systems to remove the odor before the stream is released to the atmosphere. Such procedures are often both effective and economical. 

Meunier, F., Second law analysis of a solid adsorption heat pump operating on reversible cascade cycles application to the zeolite-water pair. Heat Recovery Systems, 1985, 5, 133 141. 

Thorpe, R.N., Heat transfer by forced convection in beds of granular adsorbent material for solid adsorption heat pumps. Ph.D. Thesis, University of Warwick, UK, 1996. 

R. E. Boehm and D. E. Martiie, A unified theory of retention and selectivity in liquid chromatography. 1. Eiquid-solid (adsorption) clrromatography , J. Phys. Chem. 84 3620-3630(1980). 

Tswett s initial column liquid chromatography method was developed, tested, and applied in two parallel modes, liquid-solid adsorption and liquid-liquid partition. Adsorption ehromatography, based on a purely physical principle of adsorption, eonsiderably outperformed its partition counterpart with mechanically coated stationary phases to become the most important liquid chromatographic method. This remains true today in thin-layer chromatography (TLC), for which silica gel is by far the major stationary phase. In column chromatography, however, reversed-phase liquid ehromatography using chemically bonded stationary phases is the most popular method. 

Initial purification is the rough purification (considered by many people as isolation) to prepare a feed for subsequent high-resolution steps. In initial purification steps the goal is to obtain concentration with partial purification of the product, which is recovered as a precipitate (precipitation), a solution in a second phase (liquid-liquid partitioning), or adsorbed to solids (adsorption, chromatography). 

In gas chromatography the value of the partition coefficient d ends only on the type of stationary phase and the column temperature. It is independent of column type and instrumental parameters. The proportionality factor in equation (l.ll) is called the phase ratio and is equal to the ratio of the volume of the gas (Vg) and liquid (V ) phases in the column. For gas-solid (adsorption) chromatography the phase ratio is given by the volume of the gas phase divided by the surface area of the stationary phase. 

In adsorption processes, contaminated water is contacted with a solid adsorption medium, such as GAC or resin. Based on their equilibrium properties relative to the specific adsorption medium, contaminants will partition from the water to the solid until the system reaches equilibrium.93 The maximum concentration of a given contaminant that can be adsorbed is dependent on... 

The taking up of molecules of a gas or of a dissolved substance by the surface of a solid adsorption is a surface effect only. See Absorption. 

The rate also decreases with an increase in the chain length of the alkene molecule (hex-l-ene > oct-1-ene > dodec-l-ene). Although the latter phenomenon is attributed mainly to diffusion constraints for longer molecules in the MFI pores, the former (enhanced reactivity of terminal alkenes) is interesting, especially because the reactivity in epoxidations by organometallic complexes in solution is usually determined by the electron density at the double bond, which increases with alkyl substitution. On this basis, hex-3-ene and hex-2-ene would be expected to be more reactive than the terminal alkene hex-l-ene. The reverse sequence shown in Table XIV is a consequence of the steric hindrance in the neighborhood of the double bond, which hinders adsorption on the electrophilic oxo-titanium species on the surface. This observation highlights the fact that in reactions catalyzed by solids, adsorption constraints are superimposed on the inherent reactivity features of the chemical reaction as well as the diffiisional constraints. 

Proteins, Solid, Adsorption of Water on (Eley Leslie). Proteins and Nucleic Acids, Electronic Structure Proteins and Nucleic Acids, Influence of Physical Agents on Purine-Pyrimidine Pairs, Steroids, and Polycyclic Aromatic Carcinogens (Pullman). ... 

Procedures for determining fatty acids in sediments involved liquid-liquid extraction, liquid-solid adsorption chromatography followed by gas liquid chromatographic analysis [10-12], Liquid extractions have been performed with methanol-chloroform [13], methylene chloride [14] and benzene-methanol [15, 16]. Typical liquid-solid adsorbents are silicic acid. Standard gas chromatographic separations for complex mixtures employ non-polar columns packed with OV-1, OV-17, OV-101, SE-30, or glass capillary columns containing similar phases. 

Although this concept was originally derived for gas-solid adsorption, it can also be successfully applied to describe a liquid-solid interaction process when using the equations... 

For the reader who is interested in pursuing the mathematical details of CC, I recommend the papers of Smit and his co-workers (15) These researchers published early in the area of CC (16) and continue to contribute regularly to the field (17) Phillips has also been active in the field of CC, which he considers to be a subset of what he calls, multiplex chromatography (18). Some workers have used on-line correlation chromatography to study the thermal decomposition of polymers and compared the results against those using conventional injection procedures (19), while others have applied it to the study of gas-solid adsorption (20) ... 

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