State-of-the-art analytical methods based on ionic liquids for food and beverage analysis

Abstract

The use of ionic liquids (ILs) in different fields of analytical chemistry has increased exponentially in recent years, leading to the development of new technologies that try to respect the guidelines proposed by Green Chemistry. ILs are considered relatively ecological compounds due to their thermal stability and non-volatility at room temperature, which prevents their release into the atmosphere. However, recent studies have shown that the growing number of applications that involve them has led to pollution to the aquatic and terrestrial compartments. Despite this, ILs have become environmentally friendlier alternatives to conventional toxic organic solvents for their application in microextraction techniques, both as liquid phases or combined with nanomaterials for solid phase extraction. In addition to this, the use of ILs as mobile and stationary phase additives in chromatographic techniques has introduced substantial improvements in these separation techniques. Likewise, advanced electrodes have been obtained thanks to the functionalization of nanomaterials with ILs for more selective and sensitive electrochemical determinations. In this review, the use of ILs in the development of innovative and efficient analytical methods applied for food and beverage analysis is revised. Special emphasis is made on the environmental impact of the reviewed applications, including their analysis via the AGREE software, which allows the obtention of a numerical estimation of the greenness of an analytical method. In addition, critical issues and future challenges arising from the application of ILs in microextraction, chromatography and electrochemical techniques are discussed.