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A high-performance countercurrent chromatography system. Countercurrent chromatography (CCC, also counter-current chromatography) is a form of liquid–liquid chromatography that uses a liquid stationary phase that is held in place by inertia of the molecules composing the stationary phase accelerating toward the center of a centrifuge due to centripetal force [1] and is used to separate ...
Countercurrent distribution, therefore, is a method of using a series of vessels (separatory funnels) to separate compounds by a sequence of liquid-liquid extraction operations. Contrary to liquid-liquid extraction, in the CCD instruments the upper phase is decanted from the lower phase once the phases have settled.
Discontinuous mode consists of equilibration, loading, washing, purification and regeneration steps. The discontinuous mode of operation allows exploiting the advantage of solvent gradients, but it implies high solvent consumptions and low productivities with respect to continuous countercurrent processes.
The ionic compound consisting of the cationic species M+ and the anionic species B− can be retained by the stationary phase. Cation exchange chromatography retains positively charged cations because the stationary phase displays a negatively charged functional group:
Periodic counter-current chromatography (PCC) is a method for running affinity chromatography in a quasi-continuous manner. Today, the process is mainly employed for the purification of antibodies in the biopharmaceutical industry [ 1 ] as well as in research and development.
Droplet countercurrent chromatography (DCCC or DCC) was introduced in 1970 by Tanimura, Pisano, Ito, and Bowman. [1] DCCC is considered to be a form of liquid-liquid separation, which includes countercurrent distribution and countercurrent chromatography, that employs a liquid stationary phase held in a collection of vertical glass columns connected in series.
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...
The two liquids (typically an aqueous phase (heavy) and an organic phase (light)) enter the annular mixing zone where a liquid-liquid dispersion is formed and extraction occurs as solutes (e.g. dissolved metal ions) are transferred from one phase into the other. Inside the rotor, the liquids will be separated into a heavy (blue) and a light ...