Countercurrent chromatography chromatograph

Maryutina TA, Fedotov PS, Spivakov BY (1999) Application of countercurrent chromatography in inorganic analysis. In Menet JM, Thiebaut D (eds) Countercurrent chromatography, chromatographic science series, vol 68. Marcel Dekker, New York... 

Several chromatographic modes will be reviewed in this respect, and most will make use of a chiral support in order to bring about a separation, differing only in the technology employed. Only countercurrent chromatography is based on a liquid-liquid separation. 

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... 

Y. Ito, B. Mandava (Eds.), Countercurrent chromatography theory and practice, Chromatographic science Series, Vol. 44, Marcel Dekker, New York (1988). 

The three main modes of chromatographic operation are elution chromatography, selective adsorption/desorption, and simulated countercurrent chromatography. Of these, elution chromatography, used as a cyclic batch process, was the first to be developed for large-scale separations. 

Various countercurrent chromatographic techniques have been successfully employed for the separation of flavonoids. Countercurrent chromatography is a separation technique that relies on the partition of a sample between two immiscible solvents, the relative proportions of solute passing into each of the two phases determined by the partition coefficients of the components of the solute. It is an all-liquid method that is characterized by the absence of a solid support, and thus has the following advantages over other chromatographic techniques ... 

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). 

TLC has also been used for the separation of diastereomeric derivatives of enantiomers, but this form of chromatography has not attained widespread use in indirect resolutions. Other chromatographic techniques, for example, supercritical fluid chromatography, capillary electrophoresis, countercurrent chromatography, etc., have not received much attention in indirect enantioseparation. 

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 chromatographic scale-up of countercurrent chromatography appears feasible, but there are engineering challenges ahead which will need to be solved before this promising new technology can be realized. 

Countercurrent chromatography (CCC), as a support-free liquid-liquid partition chromatographic separation tech-... 

Countercurrent chromatography overcomes all of the problems caused by solid support matrix present in most other chromatographic methods. Countercurrent chromatography can purify alkaloids with high recovery and reproducibility. 

High speed countercurrent chromatography (HSCCC) produces highly efficient chromatographic separations of solutes without the use of solid supports Thus the method eliminates all complications caused by the solid support, such as adsorptive loss and deactivation of samples, tailing of solute peaks, contamination, etc. As with other CCC schemes, HSCCC utilizes two immiscible solvent phases, one as a stationary phase and the other as a mobile phase, and the separation is highly dependent on the partition coefficient values of the solutes, i.e., the ratio of the solute concentration between the mobile and stationary phases. Therefore the successful separation necessitates a careful search for the suitable two-phase solvent system that provides an ideal range of the partition coefficient values for the applied sample. 

Mandava, N.B. Ito, Y. Countercurrent Chromatography— Theory and Practice, Chromatographic Science Series, Marcel Dekker Inc. New York, 1988 Vol. 44. 

Maryutina, T. A., Fedotov, P. S., and Spivakov, B. Ya. (1999). Application of counter-current chromatography in inorganic analysis. In Countercurrent Chromatography, ed. Menet, J.-M., Thiebaut, D., Chromatographic Science Series, Vol. 82, Marcel Dekker, New York, 82, 171-221. 

A very recent volume edited by Berthed (2002) is on countercurrent chromatography - the support-free liquid stationary phase. Ebdon et al. (1987) review directly coupled liquid chromatogramphy-atomic spectroscopy. The review by Uden (1995) on element-specific chromatographic detection by atomic absorption, plasma atomic emission and plasma mass spectrometry covers the principles and applications of contemporary methods of element selective chromatographic detection utilizing AA, AES and MS. Flame and furnace are considered for GC and HPLC, while MIP emission is considered for GC and ICPAES for HPLC. Combinations of GC and HPLC with both MIPAES and ICPAES are covered and supercritical fluid chromatographic (SFC) and field flow fractionation (FFF) are also considered. 

Many attempts have been made to detemiine by other means different to the classical shake-flask method, which include countercurrent chromatography [3], and Reversed-Ph e Liquid Chromatography (RPLC) with C8, Cl8, 1-octanol coated Cl8 and phenyl stationary plmses [4], The establishment of a correlation between retention data in RPLC and log P assumes that die extent of chromatographic retention reflects the hydrophobicity of a solute. This approach is known as quantitative structure-retention relationships (QSRR) [5]. Chromatographic techniques offer a number of advantages over the static method. A great amount of relatively precise and reproducible data can be readily obtained, and the determinations are rapid and easy to be automated. Only a very small amount of sample is required, a wide dynamic range may exist and the impurities present in the sample can be simultaneously separated. 

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