Ion-exchange affinity of organic cations to natural organic matter: influence of amine type and nonionic interactions at two different pHs.
Ion-exchange affinity of organic cations to natural organic matter: influence of amine type and nonionic interactions at two different pHs.
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有机阳离子对天然有机物的离子交换亲和力：两种不同 pH 下胺类型和非离子相互作用的影响。
DOI：
10.1021/es3033499
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发表时间：
2013
影响因子：
11.4
通讯作者：
K. Goss
中科院分区：
文献类型：
--
作者：
S. Droge;K. Goss
以标准土壤有机质（SOM）为吸附剂，研究了各种有机阳离子的流动通过方法与全水介质作为洗脱剂。土壤有机质对弱碱（pK（a）4.5-7）的吸附在pH 4.5时比pH 7时强，表明阳离子物种对土壤有机质的离子交换亲和力大于相应中性物种对土壤有机质的体积分配系数。在pH4.5 -7范围内，pH对pK（a）> 7的强碱的吸附系数影响较小，在0.3log单位以内。对于分子式为C（x）H（y）N的阳离子，通过考虑大小（随烷基链长度增加）和带电基团类型（1°胺>4°相同大小的铵）的模型准确预测吸附。除了C（x）H（y）N-模型，几个经验的校正因子来自数据的有机阳离子与极性官能团。基于K（OW）或pK（a）的模型无法解释离子种类的吸附亲和力的差异。我们对80种有机阳离子的离子交换亲和力的数据显示了许多例子，其中特定的化学部分，例如CH（2）-单元，芳环或羟基，与中性化合物的大量分配数据相比，对吸附系数的贡献不同。其他吸附模型进行了评价，以解释化合物之间的变化遭受超过一个对数单位的离群值，并没有减少相对对数平均标准误差低于0.5。更广泛的吸附系数和更多的吸附数据一般需要进一步提高建模工作。
Sorption to standard soil organic matter (SOM) has been studied for a wide variety of organic cations using a flow through method with fully aqueous medium as eluent. SOM sorption for weak bases (pK(a) 4.5-7) was stronger at pH 4.5 than at pH 7, indicating that the ion-exchange affinity of the cationic species to SOM was higher than the bulk partition coefficient of corresponding neutral species to SOM. In the range of pH 4.5-7, the effect of pH on the sorption coefficients for strong bases with pK(a) > 7 was small, within 0.3 log units. For cations with the molecular formula C(x)H(y)N, sorption was accurately predicted by a model accounting for size (increase with alkyl chain length) and type of charged group (1° amine >4° ammonium of equal size). In addition to the C(x)H(y)N-model, several empirical correction factors were derived from the data for organic cations with polar functional groups. Models based on K(OW) or pK(a) fail to explain differences in sorption affinity of the ionic species. Our data on ion-exchange affinities for 80 organic cations show many examples where specific chemical moieties, for example, CH(2)-units, aromatic rings or hydroxyl groups, contribute differently to the sorption coefficient as compared to bulk partitioning data of neutral compounds. Other sorption models that were evaluated to explain variation between compounds suffered from outliers of more than one log unit and did not reduce relative log mean standard errors below 0.5. A wider range of sorption coefficients and more sorption data in general are required to improve modeling efforts further.
影响因子：
11.4
作者：
Li, Xiaolin;Brownawell, Bruce J.
通讯作者：
Brownawell, Bruce J.