title: Toxicity assessment of ionic liquids with Vibrio fischeri: an alternative fully automated methodology.
abstract: A fully automated Vibrio fischeri methodology based on sequential injection analysis (SIA) has been developed. The methodology was based on the aspiration of 75 μL of bacteria and 50 μL of inhibitor followed by measurement of the luminescence of bacteria. The assays were conducted for contact times of 5, 15, and 30 min, by means of three mixing chambers that ensured adequate mixing conditions. The optimized methodology provided a precise control of the reaction conditions which is an asset for the analysis of a large number of samples. The developed methodology was applied to the evaluation of the impact of a set of ionic liquids (ILs) on V. fischeri and the results were compared with those provided by a conventional assay kit (Biotox(®)). The collected data evidenced the influence of different cation head groups and anion moieties on the toxicity of ILs. Generally, aromatic cations and fluorine-containing anions displayed higher impact on V. fischeri, evidenced by lower EC50. The proposed methodology was validated through statistical analysis which demonstrated a strong positive correlation (P>0.98) between assays. It is expected that the automated methodology can be tested for more classes of compounds and used as alternative to microplate based V. fischeri assay kits.
authors.affiliation: REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal.
authors.forename: Susana P F
authors.initials: SP
authors.lastname: Costa
authors.affiliation: REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal. Electronic address: ppinto@ff.up.pt.
authors.forename: Paula C A G
authors.initials: PC
authors.lastname: Pinto
authors.affiliation: REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal.
authors.forename: Rui A S
authors.initials: RA
authors.lastname: Lapa
authors.affiliation: REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal. Electronic address: lsaraiva@ff.up.pt.
authors.forename: M Lúcia M F S
authors.initials: ML
authors.lastname: Saraiva
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects*; D000838:Anions; D001331:Automation; D002412:Cations; D002794:Choline / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D005461:Fluorine / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D049449:Luminescence; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D000838:Anions; D002412:Cations; D052578:Ionic Liquids; D000644:Quaternary Ammonium Compounds; D005461:Fluorine; C009405:tetrabutylammonium; D002794:Choline
keywords: Automated SIA system; Ionic liquids; Microplate; Vibrio fischeri