History of CCC
From TheLiquidPhase
Countercurrent Chromatography or (CCC), being based on the partitioning of individual solutes in immiscible solvent phases, has its origins in Solvent Extraction. This work started as early as 1805 when Bucholz reported the solubility of uranyl nitrate in diethyl ether (. However, many consider the work of Archer John Porter Martin and Richard Laurence Millington Synge (Martin and Synge, 1941; Synge, 1946) as the major starting point in CCC. There work together, carried out in Britain during WWII, provided many advancements to the science of solvent extraction.
Soon after their work appeared, Lyman Creighton Craig and Otto Post developed an apparatus that essentially consisted of a series of Separatory Funnel (“tubes”) (Craig and Post, 1949); they called this Countercurrent Distribution or (CCD). The sample was “automatically” transferred through the apparatus and over 1000 mixing and separation steps could be achieved in a day. Individual components were separated based on their partitioning behavior. Craig and Post continuously improved their apparatus and were commercially quite successful, as judged from the number of publications that appeared citing the use of the “Craig-Post apparatus” (over 1000 publications on “countercurrent distribution” during the period 1950-1970). It should be pointed out that particular solvent systems developed decades ago, for separations on the “Craig-Post apparatus”, are still valid today and can be successfully used with modern machines with little or no modification.
The next major step on the path to modern day CCC was in the early 1970s when Dr. Yoichiro Ito and his colleagues at NIH introduced Droplet Countercurrent Chromatography (DCCC) (Tanimura, Pisano, Ito et al., 1970). This machine used a series of vertical tubes connected by capillaries. The Stationary Phase was held in the tubes by gravity only and the mobile phase was pumped slowly through the system. This machine provided good separations, but due to flow-rate limitations, single runs could take days or even weeks to complete.
It was these long run times that drove the development of the next generation of Countercurrent machines, which are still being produced and developed today. CPC or Centrifugal Partition Chromatography was achieved by basically achieved by creating the equivalent of the tubes and channels from the DCCC in a disk-shaped rotor. Centrifugal force then held the stationary phase in place. Because this force can be many times the force of gravity at high speeds the mobile phase could be pumped through the system much faster, shortening run time. See (Foucault, 1995) for a history of the development of these machines.
Finally, we have HSCCC which was developed by Dr. Yoichiro Ito (of the National Institutes of Health). HSCCC machines are planetary centrifuges that spin spools of Teflon tubing (or stainless steel) at high speeds. This planetary motion creates zones of mixing and zones of settling which progress along the helical coil. The forces promote separation as well as stationary phase retention. This type of machine also allows for high flow rates and fast run times. The term, "high-speed countercurrent chromatography" was coined in the early 1980s to distinguish machines that allowed separations in a few hours from DCCC machines. In modern terms, high-speed countercurrent chromatography refers to planetary coil instruments with high flow rates and complete separations done in less than an hour.
Today, although the utilization of CCC is at comparably low levels, there are several Manufacturers throughout the world making both HSCCC and CPC type units. The technology is rapidly advancing and the user base is growing at an increased rate.
See Also
References
- M. Lederer, Chromatography for Inorganic Chemistry, Wiley, New York, 1994
- Tanimura, Takenori; Pisano, John J.; Ito, Yoichiro; Bowman, Robert L. Droplet countercurrent chromatography. Science 1970, 169, 54-56.
- Craig, Lyman C.; Post, Otto. Apparatus for countercurrent distribution. Anal. Chem. 1949, 21, 500-504.
- Foucault, Alain P., Ed. Centrifugal Partition Chromatography (Chromatographic Science Series, Vol. 68); Marcel Dekker, Inc.: New York, 1995.
- Ito, Y., J. Sandlin, et al. (1982). High-speed preparative counter-current chromatography with a coil planet centrifuge. J Chromatogr. 244: 247-58.