A partitioning–based model is presented to estimate the bioconcentration of five munitions compounds and two munition–like compounds in grasses. The model uses polyparameter linear free energy relationships (pp–LFERs) to estimate the partition coefficients between soil organic carbon and interstitial water and between interstitial water and the plant cuticle, a lipid–like plant component. Inputs for the pp–LFERs are a set of numerical descriptors computed from molecular structure only that characterize the molecular properties that determine the interaction with soil organic carbon, interstitial water, and plant cuticle. The model is validated by predicting concentrations measured in the whole plant during independent uptake experiments with a root-mean-square error (log predicted plant concentration–log observed plant concentration) of 0.429. This highlights the dominant role of partitioning between the exposure medium and the plant cuticle in the bioconcentration of these compounds. The pp–LFERs can be used to assess the environmental risk of munitions compounds and munition–like compounds using only their molecular structure as input.

中文翻译：

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从分子结构估算弹药化合物的草土生物浓度

提出了一种基于分区的模型来估计草中5种弹药化合物和2种类似弹药的化合物的生物浓度。该模型使用多参数线性自由能关系（pp–LFERs）估算土壤有机碳与间隙水之间以及间隙水与植物表皮（类脂质植物成分）之间的分配系数。pp–LFERs的输入是一组从分子结构算出的数字描述符，仅描述表征与土壤有机碳，间隙水和植物角质层相互作用的分子特性。该模型通过预测独立摄取实验中整个植物中测得的浓度而得到验证，均方根误差（预测的植物浓度对数观察到的植物浓度对数）为0.429。这突出了暴露介质和植物表皮之间分配在这些化合物生物富集中的主要作用。pp–LFERs可以仅使用其分子结构作为输入来评估弹药化合物和类似弹药的化合物的环境风险。