Ionic Liquids as Modifying Agents for Protein Separation in Centrifugal Partition Chromatography

Aqueous two-phase systems (ATPSs) can be applied in centrifugal partition chromatography (CPC) to separate biomolecules. Two ionic liquids (ILs) served as modifying agents to tune partition coefficients in the separation of two model proteins, myoglobin and lysozyme. Myoglobin was not affected by the ILs, while the partition coefficient of lysozyme was lowered with addition of IL. High stationary phase retention was achieved with ATPSs in a CPC column with cell size and geometry specially designed for unstable biphasic systems. When ILs were used as modifying agents, no notable decrease in stationary phase retention was observed. The injection volume was increased to 20 % of the total column volume and process simulations indicate that a further increase in the injection volume is possible.