التفاصيل البيبلوغرافية
| العنوان: |
Sorption to Dissolved Humic Acid and Its Impacts on the Toxicity of Imidazolium Based Ionic Liquids. |
| المؤلفون: |
Zhen Zhang1,2, Jing-fu Liu1 jfliu@rcees.ac.cn, Xiao-qiang Cai1, Wei-wei Jiang3, Wen-ru Luo1, Gui-bin Jiang1 |
| المصدر: |
Environmental Science & Technology. 2/15/2011, Vol. 45 Issue 4, p1688-1694. 7p. |
| مصطلحات موضوعية: |
TOXICOLOGICAL chemistry, CHEMISTRY experiments, TOXICITY testing, ADDITION reactions, DISSOLVED organic matter, IONIC liquids, HUMIC acid, CHEMICAL reduction, BIOAVAILABILITY, IMIDAZOLES |
| مستخلص: |
Two typical ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride ([C4MIM]Cl) and 1-octyl-3-methylimidazolium chloride ([C8MIM]Cl), are demonstrated to associate strongly with dissolved organic matter (DOM) with distribution coefficients (KDOC) in the range of 104.2 to 104.6 for Aldrich humic acid (used as model DOM). With the increase of humic acid concentration to 11 μg/mL DOC (dissolved organic carbon), the free fraction (ratio of freely dissolved to total concentration) of [C4MIM]Cl and [C8MIM]Cl reduced to about 0.85 and 0.79, respectively. This reduction of freely dissolved concentration gave rise to remarkable reduction of bioavailability and toxicity of the two ILs. MTT assay with HepG2 cell lines showed that the EC50 values were 459 μmol/L for [C4MIM]Cl and 12 μmol/L for [C8MIM]Cl, respectively, and the cell viability increased about 50% in the presence of trace amount of humic acid (1 μg/mL DOC). The SOS/umu test indicated mutagenicity for [C4MIM]Cl at levels above 664 μmol/L, and the genotoxicity was diminished with the addition of trace humic acid (0.00000374-0.374 μg/mL DOC). The studied ILs showed acute toxicity toward model fish medaka with a 96 h median lethal concentration (LC50) of 2254 μmol/L for [C4MIM]Cl and 366 μmol/L for [C8MIM]Cl. The addition of humic acid (5.49 μg/mL DOC for [C8MIM]Cl, 1.37 μg/mL DOC for [C4MIM]Cl) to IL solutions reduced the death rate of medaka to a minimum value of 25% of that at zero DOC. Our results suggest that DOM may play an important role in determining the environmental fate and toxicity of imidazolium-based ILs, and its effects should be taken into account in assessing the environmental risk of ILs. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
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