Countercurrent chromatography method development

Tsai, R.-S., Carrupt, P.-A. and Testa, B. (1995). Measurement of Partition Coefficient Using Centrifugal Partition Chromatography. Method Development and Application to the Determination of Solute Properties. In Modern Countercurrent Chromatography (Conway, WD. and Pet-roski, R.J., eds.), American Chemical Society, New York (NY), pp. 143-154. 

The column and planar configurations just discussed are the most common modes of LC but not the only ones. At least four different methods have been proposed for performing LC without a solid support, and two have survived as viable methods. The term countercurrent chromatography is applied to these techniques, and a review of their development has been written by Ito and Conway.6 Countercurrent chromatography will not be discussed further here, but it should be noted that it has one main advantage it is free from undesirable adsorption and catalytic effects that sometimes result from the use of solid supports. 

Amino acids have high melting or decomposition points and are best examined for purity by paper or thin layer chromatography. The spots are developed with ninhydrin (see Lederer and Lederer, p.44). Customary methods for the purification of small quantities of amino acids obtained from natural sources (i.e. l-5g) are ion-exchange chromatography (see p. 20) or countercurrent distribution (see p. 28). For general treatment of amino acids see Greenstein and Winitz [The Amino Acids, Vols 1-3, J.Wiley Sons, New York 1961]. 

All variations of the ESI use the pressure gradient, countercurrent gas with glass capillary, heated capillary (or heated chamber) and previous high-pressure liquid chromatography (HPLC). Several ionization methods have been developed. In an... 

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