Carbohydrates separation mechanism

The second part of the book covers zeolite adsorptive separation, adsorption mechanisms, zeolite membranes and mixed matrix membranes in Chapters 5-11. Chapter 5 summarizes the literature and reports adsorptive separation work on specific separation applications organized around the types of molecular species being separated. A series of tables provide groupings for (i) aromatics and derivatives, (ii) non-aromatic hydrocarbons, (iii) carbohydrates and organic acids, (iv) fine chemical and pharmaceuticals, (v) trace impurities removed from bulk materials. Zeolite adsorptive separation mechanisms are theorized in Chapter 6. 

One of the oldest separations of mono- and disaccharides in HILIC mode was already described in 1976 [72]. The authors used a Partisil PAC column and eluted carbohydrates with an acetonitrile-water eluent (80 20 v/v). Originally perceived as a normal-phase partition mode, this separation mechanism is... 

In LPLC, a mobile phase is allowed to flow through a densely packed sorbent. The separation mechanism is adsorption or size-exclusion depending on the choice of packing material for the stationary phase (adsorption silica gel, bonded-phase silica gel, alumina, polystyrene size-exclusion polyacrylamide, carbohydrates). This is almost similar to... 

It should be possible to use the special properties of chiral structures for particular separation problems. According to Belinski and Tencer, one possible way in which nature solved the ribose problem could have involved an enantioselective and diastereoselective purification process acting on a mixture of biomolecules, which left ribose as the only molecule available for further reactions. The authors propose a theoretical mechanism in which a type of chromatographic process occurs at chiral mineral surfaces. This paper is likely to stimulate new experiments as well as the quest for as yet unknown surfaces which can separate racemic carbohydrate mixtures. The question arises, however, as to whether there were minerals present on the young Earth which are now unknown, as they no longer exist on the Earth of today (Belinski and Tencer, 2007). 

Amorphous adsorbents, 1 587-589 for gas separation, 1 631 properties and applications, l 587t Amorphous aluminum hydroxide, 23 76 Amorphous carbohydrates, material science of, 11 530-536 Amorphous carbon, 4 735 Amorphous cellulose, 5 372-373 Amorphous films, in OLEDs, 22 215 Amorphous germanium (a-Ge), 22 128 Amorphous glassy polymers, localized deformation mechanisms in, 20 350-351... 

Polysaccharides are ubiquitous in nature. They can be classified into three separate groups, based on their different functions. Structural polysaccharides provide mechanical stability to cells, organs, and organisms. Waterbinding polysaccharides are strongly hydrated and prevent cells and tissues from drying out. Finally, reserve polysaccharides serve as carbohydrate stores that release monosaccharides as required. Due to their polymeric nature, reserve carbohydrates are osmotically less active, and they can therefore be stored in large quantities within the cell. 

Ken s geographical transition to the New World was accompanied by a concomitant transition in his research emphasis. Although he maintained an interest in polysaccharide chemistry, the publication record from Queen s University attests to the universality of his interests in carbohydrate chemistry. J. K. made major contributions to synthetic carbohydrate chemistry, stereochemistry, biosynthetic mechanisms, and metabolism of carbohydrates, and the application of such separational techniques as paper and gas-liquid chromatography in the carbohydrate field. The results of his lifetime of research were documented in over 300 scientific publications. Clearly, it would be impractical to review this number of papers individually, and consequently, only a representative sample will be treated. A list of Professor Jones s publications is appended to this article. 

Ni electrodes have also been used in analytical electrochemistry, especially for the electrochemical detection of carbohydrates following separation by HPLC. Both Ni [ii] and Ni alloy [iii] electrodes have been used. The mechanism appears to involve the NiOOH species that oxidizes the carbohydrate in an -> EC catalytic sequence [iii]. 

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