In order to get a snapshot of the state of natural products isolation by CCC/CPC I am considering the 11 articles in the JCA special CCC/CPC issue that report separation and isolation of natural products.

Terminology:

Interestingly, there was a lot of confusing over the use of “partition coefficient” and its symbol. Five articles employed the traditional terminology of “partition coefficient.” Three used “distribution constant” or “liquid-liquid distribution constant” instead of “partition coefficient.” Three articles did not mention partition coefficients at all. The most common symbol for partition coefficient was “K” but K_D, K’, and D where also used. There is obviously a profound confusion about CCC/CPC terminology among CCC/CPC practitioners. This is not a good situation. There is no advantage to the promotion of our technology to insist that we use terms with complete disregard to our colleagues.

Sample Parameter Reporting:

All 11 articles report the amount of sample loaded on the CCC/CPC column. The amount of individual compound recovered was reported for 28 of the 45 compounds isolated. The percent recovery of target compounds was reported for 12 compounds. Purity was recorded for 24 of the 45 compounds – typically determined by HPLC. Shake flask partition coefficients were reported for 10 compounds. CCC/CPC partition coefficients were not reported in any of the articles! There is a remarkable under-appreciation of the value of calculating and recording K values. To make matters worse S_F values were reported in only 5 publications.

Instrumentation:

Eleven instruments were used – one for each article. Seven different instruments were used, only one was a hydrodynamic (CPC) machine. Volumes range from 35 to 1,200mL. The instruments definitely reflect the variety of sizes and manufacturers available to chromatographers. The beta values were reported for 8 of the 10 CCC instruments used.

Chromatograms:

Six articles contained chromatograms. Three articles had five or six chromatograms each! In my opinion, chromatograms are part of the language of separation techniques and should be reported whenever possible. This is especially true for articles where the CCC/CPC separation is considered to be a feature technique.