Use of isotope dilution method to predict bioavailability of organic pollutants in historically contaminated sediments.
Use of isotope dilution method to predict bioavailability of organic pollutants in historically contaminated sediments.
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DOI：
10.1021/es501874f
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发表时间：
2014-07-15
影响因子：
11.4
通讯作者：
Gan, Jay
中科院分区：
文献类型：
--
作者：
Jia, Fang;Bao, Lian-Jun;Crago, Jordan;Schlenk, Daniel;Gan, Jay
许多严重的环境污染案例源于历史事件，在这些事件中，顽固性污染物在环境中停留了很长时间，导致潜在的生物利用度下降。使用生物可利用浓度超过散装化学品水平可改进风险评估，并可在确定补救的必要性或评估风险缓解行动的有效性方面发挥关键作用。在这项研究中，我们应用同位素稀释原理量化了超级基金站点海洋沉积物中遗留污染物滴滴涕和多氯联苯的生物可及性。在沉积物样品中加入13C或氘化类似物后，同位素稀释在混合24小时内达到稳定状态。在稳定状态下，同位素稀释法（IDM）得到的可及分数(E)在0.28 ~ 0.89之间，大多数化合物的可及分数(E)基本上小于1，表明广泛老化残留物的可及性降低。E与顺序Tenax脱附测定的快速（Fr）和慢速（Fs）脱附分数和之间存在较强的线性关系（R2 = 0.86）。idm衍生的可及浓度（Ce）与暴露在相同沉积物中的海洋底栖多毛藻（Neanthes arenaceodentata）的组织残留密切相关。如本研究所示，IDM方法只涉及几个简单的步骤，可以很容易地在配备质谱仪的实验室中采用。这种新方法预计对历史污染的沉积物或土壤特别有用，因为污染物的生物利用度可能由于老化和其他封存过程而发生显著变化。
Many cases of severe environmental contamination arise from historical episodes, where recalcitrant contaminants have resided in the environment for a prolonged time, leading to potentially decreased bioavailability. Use of bioavailable concentrations over bulk chemical levels improves risk assessment and may play a critical role in determining the need for remediation or assessing the effectiveness of risk mitigation operations. In this study, we applied the principle of isotope dilution to quantify bioaccessibility of legacy contaminants DDT and PCBs in marine sediments from a Superfund site. After addition of 13C or deuterated analogues to a sediment sample, the isotope dilution reached a steady state within 24 h of mixing. At the steady state, the accessible fraction (E) derived by the isotope dilution method (IDM) ranged from 0.28 to 0.89 and was substantially smaller than 1 for most compounds, indicating reduced availability of the extensively aged residues. A strong linear relationship (R2 = 0.86) was found between E and the sum of rapid (Fr) and slow (Fs) desorption fractions determined by sequential Tenax desorption. The IDM-derived accessible concentration (Ce) was further shown to correlate closely with tissue residue in the marine benthic polychaete Neanthes arenaceodentata exposed in the same sediments. As shown in this study, the IDM approach involves only a few simple steps and may be readily adopted in laboratories equipped with mass spectrometers. This novel method is expected to be especially useful for historically contaminated sediments or soils, for which contaminant bioavailability may have changed significantly due to aging and other sequestration processes.
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影响因子：
11.4
作者：
Birdwell, Justin E.;Thibodeaux, Louis J.
通讯作者：
Thibodeaux, Louis J.
影响因子：
4.1
作者：
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通讯作者：
Tjeerdema, RS
影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
Bao, Lian-Jun;Jia, Fang;Crago, J.;Zeng, Eddy Y.;Schlenk, D.;Gan, Jay
通讯作者：
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影响因子：
11.4
作者：
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通讯作者：
Alexander, M