Chapter 6 - Separation of Proteins by Ionic Liquid-Based Three-Phase Partitioning

Abstract

Ionic liquid-based three-phase partitioning (ILTPP) is presented in this chapter as a novel technique to recover proteins from waste streams or complex media that overcomes the main drawbacks of conventional methods. This technique uses ionic liquid-based aqueous two-phase systems (ILATPS) to obtain results that are characteristic of three-phase partitioning (TPP). The chapter describes both ILATPS and TPP and studies the suitable systems to carry out ILTPP and the influence of its operating variables. ILTPP can accumulate most of the target protein at the liquid–liquid interface, which makes its recovery easier. The selectivity of the process can be tuned to the operating conditions (e.g., pH) so the applicability of ILTPP is broadened, since it may be applied to enrich the concentration of an individual protein or recover simultaneously a group of them. The separation of lactoferrin from whey is analyzed as an interesting case of ILTPP application.