Selected issues related to the toxicity of ionic liquids and deep eutectic solvents—a review

Abstract

Green Chemistry plays a more and more important role in implementing rules of sustainable development to prevent environmental pollution caused by technological processes, while simultaneously increasing the production yield. Ionic liquids (ILs) and deep eutectic solvents (DESs) constitute a very broad group of substances. Apart from many imperfections, ILs and DESs have been the most promising discoveries in the world of Green Chemistry in recent years. The main advantage of ILs is their unique physicochemical properties-they are very desirable from the technological point of view, but apart from these benefits, ILs appear to be highly toxic towards organisms from different trophic levels. DES areas of usage are very spread, because they cover organic synthesis, extraction processes, electrochemistry, enzymatic reactions and many others. Moreover, DESs seem to be a less toxic alternative to ionic liquids. New possibilities of applications and future development trends are sought and presented, including such important solutions of life branches as pharmaceuticals' production and medicine.

Inorganic Nanomaterials Synthesis Using Ionic Liquids

“…Even the toxicology of ILs is increasingly being studied and structure-toxicity relations keep emerging. 12, 17 As stated in the previous version of this article, 18 organic synthesis in ILs is by now rather well established 1-3,5-7 and, unlike in the earlier edition of this article, 18 the synthesis of inorganic matter in and from ILs has also evolved. [19][20][21][22][23] Interestingly, however, there is a striking correlation between the field of IL-based materials synthesis and the field of biomineralization-inspired materials research: both fields have seen a surge in sheer publication numbers Update based on the original article by Andreas Taubert, Encyclopedia of Inorganic Chemistry © 2011 John Wiley & Sons, Ltd. and many different synthesis protocols for many different materials have been reported.…”

Toxicity mechanisms of ionic liquids

“…Later, they accumulate in the environment and higher organisms and adversely affect homeostasis. Accordingly, sorption, biodegradability, and toxicity of ILs, as well as their degradation products, are of high importance for their impact and final fate in the environment (5,6 (3,4). In general, different test systems have shown different degrees of sensitivity to ILs indicating that the trophic level of test systems determines its susceptibility to ILs (7).…”

“…These publications are related to ionic liquids' preparation; application (in chemistry, chemical engineering, and biotechnology); physical-chemical and biological characterisation; and impact on the environment (source: Web of Science). Since 2010, comprehensive studies on ionic liquids environmental impact including (bio) degradability and toxicity have been published (3)(4)(5)(6)(7). The purpose of this review is to present recent data on the biological effects of these compounds, with a special emphasis on their morphological and physiological changes in different biological systems, from bacteria to animal cells.…”

Natural Deep Eutectic Solvents in Extraction Process

“…Nevertheless, IL "greenness" is often challenged, mainly due to their poor biodegradability, biocompatibility, and sustainability [8,9]. Moreover, ILs appear to be highly toxic towards organisms from different trophic levels [10].…”

“…Deep eutectic solvents are defined as a mixture of two or more components, which may be liquid or solid and that at a particular composition present a high melting point depression becoming liquids at room temperature. Deep eutectic solvents have comparable characteristics to ILs but are cheaper to produce due to lower cost of the raw materials, less toxic, and often biodegradable [10]. However, the high viscosity and solid state of most DES at room temperature restrict their application as extraction solvents [12].…”