THE EFFECT OF pH ON THE UPTAKE AND TOXICITY OF THE BIVALENT WEAK BASE CHLOROQUINE TESTED ON SALIX VIMINALIS AND DAPHNIA MAGNA
THE EFFECT OF pH ON THE UPTAKE AND TOXICITY OF THE BIVALENT WEAK BASE CHLOROQUINE TESTED ON SALIX VIMINALIS AND DAPHNIA MAGNA
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DOI：
10.1002/etc.391
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发表时间：
2011-02-01
影响因子：
4.1
通讯作者：
Trapp, Stefan
中科院分区：
文献类型：
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作者：
Rendal, Cecilie;Kusk, Kresten Ole;Trapp, Stefan
大多数电解质的吸收和积累会随着pH值的变化而变化，因为这些化合物在不同pH值下的形态状态不同。非离子化化合物比相应的带电化合物更容易分配到脂肪相和有机相（如细胞膜），因此可以预期毒性更高。本研究考察了二价弱碱性氯喹（pK（a）：10.47和6.33，log K-OW 4.67）对柳（柳杨柳）和大型蚤（水蚤）的pH依赖性毒性和生物累积性。水培生长的杨柳插条的蒸腾速率被用来确定氯喹的毒性在pH值为6，7，8和9。根浓度因子从溶液测量计算。结果显示，pH 9下的毒性比pH 6下高出10倍以上，根浓缩系数高出4至7倍。使用经修改以适应pH值7、8和9测试的标准经济合作与发展组织急性毒性测试，对大型蚤测试氯喹的毒性。在较高的pH值下观察到毒性增加。当前研究的结果证实，具有中间pKa值的弱碱的毒性在高pH水平下更高。Environ.毒理学. 2011;30：354-359。(C)2010年SETAC
The uptake and accumulation of most electrolytes will change with pH because of the different speciation states of these compounds at various pH. Non-ionized compounds will partition into fatty and organic phases (such as cell membranes) more readily than the corresponding charged compounds, and therefore a higher toxicity can be expected. The current study examines the pH-dependent toxicity and bioaccumulation of the bivalent weak base chloroquine (pK(a): 10.47 and 6.33, log K-OW 4.67) tested on Salix viminalis (basket willow) and Daphnia magna (water flea). The transpiration rates of hydroponically grown willow cuttings were used to determine the toxicity of chloroquine at pH levels of 6, 7, 8, and 9. Root concentration factors were calculated from solution measurements. Results showed more than 10-fold higher toxicity and four to seven times higher root concentration factor at pH 9 than at pH 6. The toxicity of chloroquine was tested on Daphnia magna using the standard Organisation for Economic Co-operation and Development acute toxicity test modified to accommodate testing at pH levels of 7, 8, and 9. Increasing toxicity was seen at higher pH. The results of the current study confirm that the toxicity of weak bases with intermediate pKa values is higher at high pH levels. Environ. Toxicol. Chem. 2011;30:354-359. (C) 2010 SETAC