Countercurrent chromatography (CCC) is a preparative separation technique using two immiscible liquids. One carries the sample, forming the mobile phase, while the other serves as the stationary phase. The three types of CCC are droplet (DCCC), hydrostatic or centrifugal-partition chromatography (CPC), and hydrodynamic.

DCCC uses gravity to draw the mobile phase with the sample through the stationary phase. CPC is similar to DCCC but employs centrifugal forces instead of gravity.

In hydrodynamic CCC, tubing wrapped around a drum rotates simultaneously on a planetary axis and a solar axis, creating mixing and settling zones. Hydrodynamic CCC can be divided into high-speed CCC (HSCCC) systems and the more recent high-performance CCC (HPCCC) systems, which use higher G-forces.

CCC can produce more than 99% purity, with over 90% recovery for a wide variety of applications including petroleum extracts and protein purification. Often used for prepurification of complex extracts such as those found in natural products, it can also be an alternative to preparative LC systems such as flash chromatography, low-pressure liquid chromatography or preparative HPLC.

The market is served by only a handful of suppliers. Gilson entered the market in 2013 with the acquisition of Armen (see IBO 10/31/13). Its Spot CPC (SCPC) systems range from semipreparative- to pilot-scale purification. The SCPC-1000 has a 1,000 mL CPC column capacity with an injection range of up to 30 g that operates at a maximum pressure of 80 bar and rotation speeds of up to 1,500 rpm. The company also offers the TCPC-250, which utilizes two 125 mL CPC columns with four pumps for a continuous CPC system.

Dynamic Extractions offers HPCCC instruments for analytical to pilot-scale separations. They are based on coil planet centrifuges containing two identical bobbins mounted on a single rotor. The column is a coil of Teflon or stainless-steel tubing wound in multiple layers on a bobbin. The company offers the Spectrum system for analytical to semipreparative-scale separations and the Midi system for medium-scale (10 g to several hundred grams of sample) separations. It is developing the Maxi system with the ability to separate kilogram-sized samples in a day.

The capacities of Tauto Biotech’s TBE series of HSCCC systems range from 16 mL to 4.8 L. The largest-capacity system has a three-partitioning column and dual six-way valve, and integrates a thermostatic module to control the temperature of the separation process.

Though not a mainstream technology, CCC is gaining a following, particularly for preparative- and pilot-scale separations. The market was estimated at under $10 million and offers solid growth potential driven by demand in natural-product purifications. Innovations such as continuous-processing systems will fuel its growth.

Countercurrent Chromatography at a Glance:

Leading Suppliers

• Armen (Gilson)

• Dynamic Extractions

• AECS-QuikPrep

Largest Markets

• Food and Beverage

• Academic

• Pharmaceutical

Instrument Cost

• $15,000–$650,000