Niu Lili, Henneberger Luise, Huchthausen Julia, Krauss Martin, Ogefere Audrey, Escher Beate I
Department of Cell Toxicology, UFZ - Helmholtz Centre for Environmental Research, 04318 Leipzig, Germany.
Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China.
ACS Environ Au. 2022 Feb 16;2(3):253-262. doi: 10.1021/acsenvironau.1c00056. eCollection 2022 May 18.
The silicone polymer polydimethysiloxane (PDMS) is a popular passive sampler for and sampling of hydrophobic organic chemicals. Despite its limited sorptive capacity for polar and ionizable organic chemicals (IOC), IOCs have been found in PDMS when extracting sediment and suspended particulate matter. The pH-dependent partitioning of 190 organics and IOCs covering a range of octanol-water partition constants log from -0.3 to 7.7 was evaluated with a 10-day shaking method using mixtures composed of all chemicals at varying ratios of mass of PDMS to volume of water. This method reproduced the PDMS-water partition constant of neutral chemicals from the literature and extended the dataset by 93 neutral chemicals. The existing quantitative structure-activity relationship between the log and could be extended with the measured linearly to a log of -0.3. Fully charged organics were not taken up into PDMS. Thirty-eight monoprotic organic acids and 42 bases showed negligible uptake of the charged species, and the pH dependence of the apparent (pH) could be explained by the fraction of neutral species multiplied by the of the neutral species of these IOCs. Seventeen multiprotic chemicals with up to three acidity constants p also showed a pH dependence of (pH) with the tendency that the neutral and zwitterionic forms showed the highest (pH). (pH) of charged species of more hydrophobic multiprotic chemicals such as tetrabromobisphenol A and telmisartan was smaller but not negligible. Since these chemicals show high bioactivity, their contribution to mixture effects has to be considered when testing passive sampling extracts with bioassays. This work has further implications for understanding the role of microplastic as a vector for organic micropollutants.
有机硅聚合物聚二甲基硅氧烷（PDMS）是一种用于疏水性有机化学品采样和萃取的常用被动采样器。尽管其对极性和可离子化有机化学品（IOC）的吸附能力有限，但在萃取沉积物和悬浮颗粒物时，已在PDMS中发现了IOC。使用由所有化学品按不同质量比的PDMS与水体积组成的混合物，通过10天振荡法评估了190种有机物和IOC的pH依赖性分配，这些有机物和IOC的辛醇-水分配常数log 范围为-0.3至7.7。该方法重现了文献中中性化学品的PDMS-水分配常数 ，并将数据集扩展了93种中性化学品。log 与 之间现有的定量构效关系可以通过测量的 线性扩展到log 为-0.3。完全带电的有机物不会被PDMS吸收。38种一元有机酸和42种碱的带电物种的吸收可忽略不计，表观 （pH）的pH依赖性可以用中性物种的分数乘以这些IOC中性物种的 来解释。17种具有高达三个酸度常数p 的多质子化学品也显示出 （pH）的pH依赖性，趋势是中性和两性离子形式显示出最高的 （pH）。四溴双酚A和替米沙坦等疏水性更强的多质子化学品带电物种的 （pH）较小但不可忽略。由于这些化学品具有高生物活性，在用生物测定法测试被动采样提取物时，必须考虑它们对混合物效应的贡献。这项工作对于理解微塑料作为有机微污染物载体的作用具有进一步的意义。
