CCC = countercurrent chromatography

CCC Countercurrent Chromatography HPLC High-Performance Liquid... 

The acceptable separation of Am(III) and Cm(III) by countercurrent chromatography (CCC) was achieved using both isocratic elution, and a new approach to the creation of the reagent concentration gradient in the stationary phase [1]. This way allows reduce the experiment length. 

A. Berthold (Ed.), Countercurrent Chromatography (CCC). The Support-Free Liquid Stationary Phase, Elsevier, Amsterdam, 2002. ISBN 044450737X. 

Flash chromatography is widely employed for the purification of crude products obtained by synthesis at a research laboratory scale (several grams) or isolated as extracts from natural products or fermentations. The solid support is based on silica gel, and the mobile phase is usually a mixture of a hydrocarbon, such as hexane or heptane, with an organic modifier, e.g. ethyl acetate, driven by low pressure air. (Recently the comparison of flash chromatography with countercurrent chromatography (CCC), a technique particularly adapted to preparative purposes, has been studied for the separation of nonchiral compounds [90].)... 

Countercurrent chromatography (CCC) refers to a chromatographic technique which allows the separation of solutes in a two-phase solvent system subjected to a gravitational field. Two immiscible liquid phases, constituted by one or more solvents or solutions, are submitted to successive equilibria, where the solutes to be separated... 

Sutherland, I.A. et al.. Countercurrent chromatography (CCC) and its versatile application as an industrial purification and production process, J. Liq. Chromatogr. Relat. TechnoL, 21, 279, 1998. 

Countercurrent chromatography (CCC) is a separation technique that uses a support-free liquid stationary phase [1]. Since the mobile phase is also liquid, biphasic liquid systems are used. Ionic liquids (ILs), as a new class of solvenfs, should be evaluafed in CCC. 

Figure 7.2 Separation of a 10-solute sample with the same liquid system and the same 120 mL CCC column, (a) 108 mL of stationary phase are retained at 1400 rpm and 1 mL/min mobile phase flow rate, (b) Vg = 84 mL at 1100 rpm, 1 mL/min. (c) Vg = 60 mL at 800 rpm, 1 mL/min. (d) Vg = 36 mL at 600 rpm, 1 mL/min. The dotted vertical line corresponds to the column volume and compound 7 with Kq = 1 (Equation 7.2). (Adapted from Berthod, A., Countercurrent Chromatography The Support-Free Liquid Stationary Phase, Elsevier, Amsterdam, 2002.)...

The system relies upon preliminary fractionation of the microbial crude extract by dualmode countercurrent chromatography coupled with photodiode array detection (PDA). The ultraviolet-visible (UV-Vis) spectra and liquid chromatography-mass spectrometry (LC-MS) of biologically active peaks are used for identification. Confirmation of compound identity is accomplished by nuclear magnetic resonance (NMR). Use of an integrated system countercurrent chromatography (CCC) separation, PDA detection, and LC-MS rapidly provided profiles and structural information extremely useful for metabolite identification (dereplication, Figure 14.1). 

Thanks to progress achieved in solid support, LC is utilized mainly as liquid/solid chromatography. Liquid/liquid chromatography is restricted to countercurrent chromatography (CCC). 

Countercurrent Chromatography Countercurrent chromatography (CCC) or centrifugal partition chromatography (CPC) has gained much attention in recent years for isolation of polyunsaturated fatty acids. This new liquid chromatographic technique uses liquid-liquid partition, countercurrent distribution of solute mixmre between two liquid phases, in the absence of a solid support, to perform separation of complex mixture of chemical substances (44, 45). 

Various devices have been used for the partition of substances in ATPS systems. Countercurrent chromatography (CCC) has again revealed its unique features, because it has enabled the use of such very viscous systems at relatively high flow rates while obtaining a satisfactory efficiency and a good resolution for the separation. Many applications have been described in the literature for the use of ATPS systems with CCC devices. 

Countercurrent chromatography has been mainly developed and used for preparative and analytical separations of organic and bio-organic substances [1], The studies of the last several years have shown that the technique can be apphed to analytical and radiochemical separation, preconcentration, and purification of inorganic substances in solutions on a laboratory scale by the use of various two-phase liquid systems [2], Success in CCC separation depends on choosing a two-phase solvent system that provides the proper partition coefficient values for the compounds to be separated and satisfactory retention of the stationary phase. The number of potentially suitable CCC solvent systems can be so great that it may be difficult to select the most proper one. 

Open-column chromatography with silica gel and alumina is not applicable to the fractionation of tanins because of their strong binding to these adsorbents, which induces extensive loss of tannins. Such losses do not occur with countercurrent chromatography, as it does not use a solid stationary phase. Such molecules are very polar, so butanol-based solvent systems can be used. Centrifugal partition chromatography is more adequate in this case, as compared to hydrodynamic CCC, because of the good retention of the stationary phase of a such solvent system. 

Countercurrent chromatography (CCC) can be used for the separation of a variety of enantiomers by adding a chiral selector to the liquid stationary phase [1,2], The method is free of complications arising from the use of a solid support and also eliminates the procedure of chemically bonding the chiral selector to a solid support as in conventional chiral chromatography. 

Countercurrent chromatography (CCC) is a chromatographic method which separates solutes more or less retained in the column by a stationary phase (liquid in this case) and are eluted at the outlet of column by a mobile phase. Two treatments of column effluent have been used until now in CCC. Either the column outlet is directly connected to a detector commonly used in high-performance liquid chromatography (HPLC) (on-line detection) or fractions of the mobile phase are collected and analyzed by spec-trophotometric, electrophoretic, or chromatographic methods (off-line detection). 

The analysis of the mobile-phase fractions collected at the outlet of column is the oldest method used in CCC (droplet countercurrent chromatography and rotation locular countercurrent chromatography) to elucidate the quality of separation and to characterize solutes. With modern CCC, such as CPC, CCC type J, and crossaxis, numerous apphcations have been described for preconcentration and preparative chromatography. 

In all cases, countercurrent chromatography (CCC) utilizes a hydrodynamic behavior of two immiscible liquid phases through a tubular column space which is free of a solid support matrix. The most versatile form of CCC, called the hydrodynamic equilibrium system, applies a rotating coil in an acceleration field (either in the unit gravity or in the centrifuge force field). Two immiscible liquid phases confined in such a coil distribute themselves along the length of the coil to form various patterns of hydrodynamic equilibrium [1],... 

In human activity, industry has to produce material products and goods. The chemical industry produces millions of metric tons of basic chemicals such as soda, ethylene, sulfuric acid, or urea, and a few kilograms or less of fine and/or complicated chemicals such as chiral drugs, catalysts, antibiotics, or delicate perfumes. Countercurrent chromatography (CCC) is useful in the production of the latter class of chemicals. This entry explains the role that CCC can play in industrial processes, revealing concepts and ideas rather than detailing examples that can be found elsewhere. At the moment, only a handful of chemical companies are using CCC in commercial processes. Often, they are, apparently, very successful with the technique, because they purchase more CCC systems and CCC becomes part of the production process. The problem is the companies do not make nor want their chemical competitors to know that CCC works. 

Countercurrent chromatography can be used to extract and to concentrate, in a low volume of stationary phase, a component present in large volumes of mobile phase. It was shown that a 60-mL CCC instrument was able to extract 285 mg of a nonionic surfactant contained in 20 L of water (at 16.5 ppm or mg/L) and to concentrate it into 30 mL of ethyl acetate (at 9500 ppm or 9.5 g/L) [4]. 

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