使用氚标记直接测量液-液体系中腐殖质的行为。

Behavior of humic substances in the liquid-liquid system directly measured using tritium label.

机构信息

Lomonosov Moscow State University, Leninskie Gory 1, 119991, Moscow, Russia.

出版信息

Chemosphere. 2020 Jan;238:124646. doi: 10.1016/j.chemosphere.2019.124646. Epub 2019 Aug 22.

DOI:10.1016/j.chemosphere.2019.124646

Abstract

Humic substances (HS) in the aqueous solutions can be considered as colloidal particles formed by amphiphilic units. HS form micelles-like structures at concentrations close to 5 g/L. However colloidal behavior of HS at concentrations below 100 mg/L is unknown. Using radiotracer assay we have shown that in this concentration range HS form rare adsorption layers at the liquid/liquid interface and penetrate into the organic phase with the distribution ratio close to 10. We found that pH and HS molecular weight strongly influence on the distribution ratio but do not significantly change the adsorption. Furthermore, colloidal properties of HS are strongly depending on its origin: the highest surface activity was shown for HS separated from peat and the least was observed for HS separated from soils. We anticipate our assay to be a helpful tool for detailed analysis and modeling HS and humic-like materials colloidal behavior in the environment.

摘要

水中的腐殖物质（HS）可以被认为是由两亲性单元形成的胶体颗粒。在接近 5 g/L 的浓度下，HS 形成胶束状结构。然而，在低于 100 mg/L 的浓度下，HS 的胶体行为尚不清楚。使用放射性示踪剂测定法，我们已经表明，在这个浓度范围内，HS 在液/液界面形成罕见的吸附层，并渗透到有机相中，分配比接近 10。我们发现 pH 值和 HS 分子量强烈影响分配比，但对吸附的影响不大。此外，HS 的胶体性质强烈取决于其来源：从泥炭中分离出的 HS 表现出最高的表面活性，而从土壤中分离出的 HS 表现出最低的表面活性。我们预计，我们的测定方法将成为分析和建模 HS 和腐殖质类物质在环境中胶体行为的有用工具。