Systematic approach towards solvent system selection for ideal fluid dynamics in Centrifugal Partition Chromatography

The need for efficient and economic downstream processes, such as chromatographic methods, is increasing due to more specific product requirements in chemical and pharmaceutical industry. A promising technique is the Centrifugal Partition Chromatography (CPC), where the operational mode equals a multistage extraction, but enables separation efficiencies comparable to packed-bed chromatographic processes. In CPC operation, one liquid of a biphasic liquid system is held stationary inside a rotor respectively a chamber cascade, by a centrifugal field aligned, while the other phase is pumped through. Injected components distribute between the two phases corresponding to their partition coefficients and elute at different times, leading to separation. The performance of the CPC as a liquid-liquid chromatographic technique strongly depends on the fluid dynamics inside the chambers. Thereby the individual influence of the fluid dynamical phenomena retention of the stationary phase, coalescence of the mobile phase correlating with the stability during operation, and dispersion of the mobile phase in the chambers must be understood to select appropriate solvent systems and operating conditions to reach high separation efficiencies.
In the presented study, an optical measurement system was used to investigate the dependencies of the fluid dynamical phenomena systematically and individually. The investigations aimed at understanding the interrelationships of the fluid dynamical phenomena. With the approach, heuristics for reaching optimal fluid dynamics were phrased, by means of a dimensional analysis and experimental correlations.