Beginner's Guide to Convergence Chromatography 6

                                                                               Conclusion

Convergence chromatography is not designed to replace conventional liquid chromatography or gas chromatography. Rather, it is complementary to the other separations techniques.

The improvements made to the ACQUITY UPC² System, finally make separations with CO₂-rich solvents robust and reproducible and as routine as any other separation technique.

CC utilizes the same eluotropic spectrum as normal-phase LC. The flexibility of this technique, however, also allows the use of some conventional reversed-phase columns such as C₁₈, yielding similar retention characteristics to reversed-phase LC when analyzing highly lipophilic compounds. Spanning such a wide range of selectivity gives CC clear advantages.

Together, RPLC and CC overlap in their ability to analyze 80-85% of all compounds. In addition, CC can also analyze any and all compounds analyzed by normal-phase LC today. CC analyzes chiral compounds, stereoisomers, and diasteroisomers. Essentially; any compound soluble in an organic solvent is a candidate for analysis via CC. Unlike normal-phase LC, CC is compatible with gradients, the ultraviolet (UV), photodiode array (PDA), and evaporative light scattering (ELS) detectors as well as the full range of Mass Spectrometers that are in popular use today.

The primary mobile phase in CC is carbon-neutral CO₂ mitigating the use of harmful solvents necessary in normal-phase LC mobile phases. Additionally, since CO₂ is the primary mobile phase component, CC results don’t vary the way they do with those of normal-phase LC due to the adsorption of water by the stationary phase.

Furthermore, CC can dramatically streamline lab operations since CO₂ is miscible with a wide range of solvents, from non-polar hexane/heptane to polar methanol as well as alcohol/water mixtures, and is compatible with a wide range of sample diluents that can be directly injected without any sample preparation step.

Convergence chromatography is the answer to many types of separation challenges, and for many different applications.

Please visit www.waters.com/upc2 for further information on convergence chromatography and the ACQUITY UPC² System.