Changes in aquatic toxicity of potassium dichromate as a function of water quality parameters
Changes in aquatic toxicity of potassium dichromate as a function of water quality parameters
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DOI：
10.1016/j.chemosphere.2016.11.158
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发表时间：
2017-03-01
期刊：
影响因子：
8.8
通讯作者：
Sawai, Jun
中科院分区：
文献类型：
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作者：
Kikuchi, Mikio;Syudo, Ayaka;Sawai, Jun
重铬酸钾（K2Cr2O7）是水生毒性试验的一般参考毒物，但水质参数对K2Cr2O7对大水蚤毒性的影响研究相对较少。K2Cr2O7对D. magna的急性毒性在1个极硬（M4培养基）、4个硬、1个中硬和1个软稀释水样中进行了比较研究。在使用相同稀释水样的试验中，K2Cr2O7对D. magna的48 h EC50（50%有效浓度）具有重复性（变异系数[CV]: 13%），但在使用7种不同稀释水样的试验中，重复性较差（CV: 62%）。48 h EC50值随水硬度（28 ~ 250 mg CaCO3/L）和Na+浓度（4.3 ~ 19.7 mg Na/L）的增大而增大。Ca2+和Mg2+对K2Cr2O7毒性的影响在摩尔浓度上是相等的。K2Cr2O7的48小时EC50是由6个合同实验室使用M4培养基根据OECD TG 202测定的，并且显示出可重复性（CV: 15%），表明如果保持和稀释水样标准化，可以高精度地确定毒性水平。多元回归分析表明，48 h EC50与稀释水样的Ca2+、Mg2+、Na+浓度和碱度呈显著正相关（r(2) = 0.927）。因此，对水质特征的详细监测有助于实验室内和实验室间毒性数据的比较，并能够预测试验动物的易感性变化。(C) 2016 Elsevier Ltd.版权所有。
Potassium dichromate (K2Cr2O7) is used as a general reference toxicant in aquatic toxicity testing, but relatively little is known regarding the effects of water quality parameters on K2Cr2O7 toxicity to Daphnia magna. The acute toxicity of K2Cr2O7 to D. magna was comparatively examined in one very hard (M4 medium for D. magna assay), four hard, one moderately hard and one soft dilution water samples. The 48-h EC50 (50% effective concentration) of K2Cr2O7 to D. magna was reproducible (coefficient of variation [CV]: 13%) in tests using the same dilution water sample, but reproducibility was poor (CV: 62%) in tests using seven different dilution water samples. The observed 48-h EC50 value increased with increasing water hardness (28-250 mg CaCO3/L) and Na+ concentration (4.3-19.7 mg Na/L). The effect of Ca2+ and Mg2+ on K2Cr2O7 toxicity was equivalent in terms of molar concentration. The 48-h EC50 for K2Cr2O7 was determined according to OECD TG 202 by six contract laboratories using M4 medium and were shown to be reproducible (CV: 15%), indicating that the toxicity level can be determined with high accuracy if holding and dilution water samples are standardized. Multiple regression analysis revealed that the 48-h EC50 was strongly correlated (r(2) = 0.927) with the Ca2+, Mg2+, Na+ concentration, and alkalinity of the dilution water samples. Detailed monitoring of water quality characteristics thus facilitates intra- and inter-laboratory comparisons of toxicity data and enables predictions of changes in the susceptibility of test animals. (C) 2016 Elsevier Ltd. All rights reserved.