Meta-analysis of ionic liquid literature and toxicology

Abstract

A meta-analysis was conducted to compare the total amount of ionic liquid (IL) literature (n = 39,036) to the body of publications dealing with IL toxicity (n = 213) with the goal of establishing the state of knowledge and existing information gaps. Additionally, patent literature pertaining to issued patents utilizing ILs (n = 3,358) or dealing with IL toxicity (n =112) were analyzed. Total publishing activity and patent count served to gauge research activity, industrial usage and toxicology knowledge of ILs. Five of the most commonly studied IL cations were identified and used to establish a relationship between toxicity data and potential of commercial use: imidazolium, ammonium, phosphonium, pyridinium, and pyrrolidinium. Toxicology publications for all IL cations represented 0.55% ± 0.27% of the total publishing activity; compared with other industrial chemicals, these numbers indicate that there is still a paucity of studies on the adverse effects of this class of chemical. Toxicity studies on ILs were dominated by the use of in vitro models (18%) and marine bacteria (15%) as studied biological systems. Whole animal studies (n = 87) comprised 31% of IL toxicity studies, with a subset of in vivo mammalian models consisting of 8%. Human toxicology data were found to be limited to in vitro analyses, indicating substantial knowledge gaps. Risks from long-term and chronic low-level exposure to ILs have not been established yet for any model organisms, reemphasizing the need to fill crucial knowledge gaps concerning human health effects and the environmental safety of ILs. Adding to the existing knowledge of the molecular toxicity characteristics of ILs can help inform the design of greener, less toxic and more benign IL technologies.

Exceptional Solvent Tolerance inYarrowia lipolyticaIs Enhanced by Sterols

“…To test whether the IL-evolved strain YlCW001 exhibits broad IL-tolerant phenotypes, we investigated the following hydrophilic ILs: 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]), 1-ethyl-3-methylimidazolium bromide ([EMIM][Br]), 1-allyl-3-methylimidazolium chloride ([AMIM][Cl]), 1-butyl-3-methylimidazolium acetate ([BMIM][OAc]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl])), and 1-butyl-3-methylimidazolium bromide ([BMIM][Br]). We selected these ILs for testing because they can effectively solubilize various types of recalcitrant lignocellulosic biomass and are known to be very inhibitory to microbial growth (38, 39). Since wildtype growth was inhibited in 10% (v/v) and lethal in 18% (v/v) [EMIM][OAc] (Fig.…”

Green solvents and technologies for oil extraction from oilseeds

“…In other study, the ionic liquid was used as a co-solvent for bio-oil extraction in a single step from microalgae [17]. However, a meta-analysis study reported that the IL’s should be chosen carefully and need to understand their adverse effects [18]. Although, this method is promising but it needs more studies to substantiate the hypothesis of oil extraction from ionic liquids.…”

Ionic liquids for addressing unmet needs in healthcare

“…It remains one of most active and exciting areas of research with over 7,000 contributions in 2017 alone. The field has benefitted from several distinctive breakthroughs including the report of air‐ and water‐stable imidazolium‐based room‐temperature IL by Wilkes and Zaworotko in 1992, which challenged previous concepts, and pushed the frontiers of application beyond catalysis, synthetic chemistry and electrochemistry to new landscapes . Early advances were motivated to develop ILs as green, nonvolatile, nonflammable, and stable solvents, however, recent findings have broadened the field, redefining ILs as low melting salts (melting point <100°C) with an unlimited suite of tunable properties including toxicity, volatility, flammability, and instability .…”