Up take of trifluralin and lindane from water by ryegrass
Up take of trifluralin and lindane from water by ryegrass
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DOI：
10.1016/s0045-6535(02)00093-0
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发表时间：
2002-07-01
期刊：
影响因子：
8.8
通讯作者：
Xu, OY
中科院分区：
文献类型：
--
作者：
Li, H;Sheng, GY;Xu, OY
了解植物对有机化学品的吸收对于评估污染物在生态系统中的流动性、对人类的暴露以及植物修复技术至关重要。在这项研究中，我们测量了从水中的氟乐灵和林丹的吸收作为一个函数的吸收时间为96和120小时，分别由黑麦草。三氟呋喃灵在黑麦草体内的浓度在吸收初期急剧上升，在10 h时达到最大值，随后随吸收时间的延长而下降。C-14标记的氟乐灵摄取显示出类似的趋势，但C-14浓度高于提取的母体化合物，表明氟乐灵摄取后代谢和结合残留物的形成。林丹在黑麦草中的浓度随着吸收时间的推移而缓慢增加，并接近一个平台，表明最低限度的新陈代谢和结合残留物的形成。这两种化学品摄取特性的差异可能与其亲脂性以及化学和生物反应性的差异有关。一个两室模型占蒸腾，代谢和形成的结合残留物的整体吸收的贡献，以评估的吸收动力学。该模型充分描述了吸收氟乐灵和林丹进入黑麦草的吸收，释放，蒸腾，代谢和结合残留物形成的一阶速率常数。这些速率常数用于计算植物浓缩因子（PCF）。黑麦草中氟乐灵浓度与其水溶液浓度的比值介于热力学平衡时的PCF和稳态时的PCF之间，表明两种PCF值均具有实用性，（C）2002 Elsevier Science Ltd.保留所有权利。
Understanding of the plant uptake of organic chemicals is essential to assessing contaminant mobility in the ecosystem, exposure to humans, and phytoremediation technologies. In this study, we measured the uptake of trifluralin and lindane from water by ryegrass as a function of uptake time for periods of 96 and 120 h, respectively. Triffuralin concentration in ryegrass increased sharply at the early stage of uptake and reached the maximum at 10 h, and then decreased with uptake time. C-14-labelled trifluralin uptake displayed a similar trend but a higher C-14-concentration than that of extracted parent compound, indicating metabolism and formation of bound residues following trifluralin uptake. Lindane concentration in ryegrass slowly increased with uptake time and approached a plateau, indicating minimal metabolism and formation of bound residues. The difference in the uptake characteristics of these two chemicals may be related to the differences in their lipophilicity, and chemical and biological reactivities. A two-compartment model accounting for the contributions of transpiration, metabolism and formation of bound residues to overall uptake was developed to assess the uptake kinetics. The model adequately described the uptake of trifluralin and lindane into ryegrass by providing the first-order rate constants of uptake, release, transpiration, and metabolism and formation of bound residues. These rate constants are used in calculating plant concentration factor (PCF). The ratios of trifluralin concentrations in ryegrass to its aqueous concentrations are between the PCF at thermodynamic equilibrium and the PCF at steady state, suggesting the utility of both PCF values, (C) 2002 Elsevier Science Ltd. All rights reserved.