title: (Eco)toxicity and biodegradability of selected protic and aprotic ionic liquids.
abstract: Ionic liquids (ILs) are a promising group of compounds with a large variety of possible structures and uses. They are considered as a potential "green" replacement for traditional volatile organic solvents, but their impact on the environment is often neglected or not studied enough. In the present study, selected representatives of two ILs groups were analyzed: a new family of protic ILs (derived from aliphatic amines and organic acids) and some frequently used aprotic ILs (substituted imidazolium and piridinium chlorides). The aquatic toxicity (test organisms Vibrio fischeri, Pseudokirchneriella subcapitata and Lemna minor) and biodegradability tests were carried out. The additional tests with enzyme (acetylcholinesterase) and leukemia rat cells (IPC-81) provided more in-depth evaluation of toxicity. In our comparative hazard assessment protic ILs have EC50 values >100 mg L(-1) in all of the tests performed, except in the case of three representatives toward Lemna minor. They also show good biodegradability rates. The EC50 values for aprotic ILs are various orders of magnitude lower than the ones for protic ILs in most of the tests and they show a lower biodegradability potential. These findings indicate that protic ILs can be considered as environmentally safer alternatives for more toxic ILs and organic solvents.
authors.affiliation: Unitat d'Edafologia, Faculty of Pharmacy, University of Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain. Electronic address: brezana@hotmail.com.
authors.forename: Brezana
authors.initials: B
authors.lastname: Peric
authors.forename: Jordi
authors.initials: J
authors.lastname: Sierra
authors.forename: Esther
authors.initials: E
authors.lastname: Martí
authors.forename: Robert
authors.initials: R
authors.lastname: Cruañas
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Garau
authors.forename: Jürgen
authors.initials: J
authors.lastname: Arning
authors.forename: Ulrike
authors.initials: U
authors.lastname: Bottin-Weber
authors.forename: Stefan
authors.initials: S
authors.lastname: Stolte
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D029064:Araceae / Q000187:drug effects / Q000254:growth & development; D001673:Biodegradation, Environmental; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development; D003621:Daphnia / Q000187:drug effects / Q000502:physiology; D052578:Ionic Liquids / Q000633:toxicity*; D049449:Luminescence; D051381:Rats
chemical_list: D052578:Ionic Liquids; D000110:Acetylcholinesterase
keywords: Aquatic ecosystems; Biodegradability; Ionic liquids; Toxicity