Choline-based aqueous biphasic systems: Overview of applications

Aqueous biphasic systems (ABS) have attracted considerable attention for their unique applications in extraction and purification processes. Choline-based ionic liquids (IL), deep eutectic solvents (DES), or buffers have been studied as replacements to traditional organic solvents because they can be designed to be non-flammable, non-volatile, of low toxicity, and biocompatible. ABS based on the use of choline IL/DES/buffers, thus offer potentially extensive benefits in extraction and separation technology. In this review, the development of choline-based ABS and their application to the extraction and purification of small organic molecules, proteins, and DNA are discussed and the different types of ABS compared and evaluated. The advantages, drawbacks, and further work needed to bring this technology to fruition are also presented. (C) 2019 Elsevier B.V. All rights reserved.