Ionic liquids in liquid chromatography

Abstract

The use of ionic liquids (ILs) in liquid chromatography (LC) is reviewed. ILs have several different types of functionalities, which means that they are prone to multiple simultaneous interactions with stationary phases in LC. ILs have been investigated by LC as analytes and they have been used as mobile phase additives and column stationary phase modifiers in LC. All these applications include a diverse range of interactions with different LC stationary phases. Common reasons for using ILs as mobile phase additives have been to reduce unwanted interactions between analytes and free silanols on the column stationary phase, to act as ion pair reagents to separate polar compounds with reversed phase LC, and to act as UV absorption reagents to detect compounds that do not absorb UV light. The review covers the most important works between 2003–2025.

Keywords

• Additives
• Ionic liquids
• Liquid chromatography
• Mobile phase modifiers