Reagents, adsorbed

To derive a rate of extraction in terms of easily measurable quantities, we express the concentration of the reagent adsorbed at the liquid-liquid interface as function of its bulk organic concentration. This can be done by utilizing the Langmuir s adsorption law that is,... 

When compared with other heterogeneous catalysts, studies of surface conditions of these modified catalysts are quite difficult because the amounts of modifying reagent adsorbed on the catalyst are very small and the catalyst consists mostly of metal. Especially, the physical study of the adsorption mode of the modifying reagent is difficult because it is adsorbed as a mono-layer or close to it. In the next section, the surface conditions of MRNi will be discussed in connection with the adsorbed modifying reagent. 

Solvent-free reactions nsing supported reagents (adsorbed on the snpport, noncovalently linked to it), snch as clays, silica-gel, zeolites and graphite... 

The reagent can be also adsorbed on silica gel [604] or formed with cross-linked poly(vinylpyridine) resin [612]. The yields of carbonyl compounds with the reagent adsorbed on cross-linked resin depend on the relative amounts used, the solvent (dichloromethane, cyclopentane, tetra-hydrofuran, benzene, cycloheptane, and, best of all, cyclohexane), the temperature, and the reaction time [612. ... 

Lipases immobilized on ceramics modified with a chemical silyl reagent adsorb strongly and can be used in aqueous solutions as well as organic solvents. The activity is sometimes ten times the original and the thermostability is increased. These products can be reused more than ten times depending on conditions. 

In the case of redox reagents adsorbed on the electrode surface or confined to the electrode by means of a thin film, the expression for the peak current for a reversible process is [11] ... 

Reversible cyclic voltammograms are not always governed by diffusion-controlled processes. For example, the cases of a redox reagent adsorbed onto an electrode surface or confined to a thin layer of solution adjacent to the electrode surface are also of considerable importance. In fact, the same theory may be applied to both adsorbed layers [52] and processes that occur in thin layers [53] (thinner than the diffusion layer). In both these cases, the current for the reversible process can be derived by substitution of the expression / (f) = E4 p into the Nernst equation (Eq. II. 1.7) and noting thatE (f) = Einmai - vt, [B] c=o = [A]bulk - [A]x=o. and Vis the volume of the thin layer (Eq. II. 1.12a)... 

Thin-layer and gas chromatography are used to study the bile acid content of various fractions during the work-up of a sample. If an extract is found to be too impure, further purification steps must be carried out. It is important to realize that large amounts of many contaminants may come from solvent residues, reagents, adsorbents, glassware, skin surface, and the like. If these sources supply the contaminants, repeated purification steps are of little value. 

Surface, solid (s. a. Reagents, adsorbed), reactions on -s. Catalysts, Chromatography, preparative, under Aluminum oxide. Silica... 

Form Supplied in almost black solid crystals or crystaUine powder also supplied as reagent adsorbed on alumina (approx. 30 wt % CuBr2 on alumina). 

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