Adsorption of hydrophobic organic compounds (HOC) to inorganic surfaces in aqueous solutions

疏水有机物在完全淹没的无机表面上的吸附在环境和水分析中都是一个重要的过程。先前的研究表明，HOC对玻璃有很强的亲和力，当样品储存在玻璃瓶中时，这可能会模糊后续的数据解释。令人惊讶的是，与对有机物的吸附相比，这一过程几乎没有受到关注。因此，预测HOCs在浸没在水中的无机表面上的吸附仍然是不可能的。因此，我们的项目旨在更好地了解这种吸附过程，这可能会对分析和环境科学产生重要的影响。为此，我们将利用化学探针概念，根据化合物的物理化学性质选择合适的化合物，包括多环芳烃(PAHs)和多氯联苯(PCbs)等典型的HOCs及其有助于电化学原位检测的特定衍生物。我们将研究静态和动态体系中的吸附过程，这些过程依赖于溶液化学、表面化学和固体颗粒尺寸等参数。此外，我们希望利用电化学分析的独特能力来原位测定溶液中的浓度梯度。在这里，我们将专注于使用最近才出现的超微电极对扫描电化学显微镜(SECM)进行进一步的改进和实现。

Adsorption of hydrophobic organic compounds (HOCs) to fully submerged inorganic surfaces is an important process both in the environment and in water analysis. Previous investigations have shown that HOCs have a strong affinity for glass, which can obscure subsequent data interpretation when the samples have been stored in glass vials. Surprisingly, this process has nevertheless received rather little attention in comparison with sorption to organic matter. Therefore, the prediction of adsorption of HOCs to inorganic surfaces submerged in water is still hardly possible. Consequently, our project aims at a better understanding of this adsorption process, which may yield important implications for analytical and environmental science. To that end, we will utilize a chemical probe concept where we select suitable compounds based on their physicochemical properties, incorporating typical HOCs such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) and specific derivatives of these that facilitate electrochemical in-situ detection. We will study the adsorption process in static and dynamic systems in dependence of parameters such as solution chemistry, surface chemistry and particle size of the solid. In addition, we want to utilize the unique capabilities of electrochemical analysis for the in-situ determination of concentration gradients in solution. Here, we will focus on a further refinement and implementation of scanning electrochemical microscopy (SECM) using ultramicroelectrodes that only recently has become available.