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

• Applicant: Professor Dr. Torsten Schmidt
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2007 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 46588721

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.

• DFG Programme: Research Grants
• Major Instrumentation: Scanning Elecrochemical Microscope (SECM)
• Instrumentation Group: 5050 Mikroskopphotometer