ENVIRONMENTAL MONITORING OF MERCURY AND ITS SPECIES
Institute of Analytical and Bioanalytical Chemistry, Ulm University,
Albert-Einstein-Allee 11, D-89081 Ulm, Germany
Mercury is still an increasing and persistent pollutant and is due to its high mobility globally distributed in our environment. Because of its high toxicity it requires analytical monitoring in all environmental compartments, however, it is particularly important in the hydrosphere, where mercury bio-accumulates up to a million times in the aquatic food chain. Accordingly, mercury is classified as one of the 33 most dangerous pollutants in the European Union Water Framework Directive.
Mercury concentrations in natural waters are typically in the sub to low ng L-1 range and extremely sensitive detection techniques are required to obtain robust analytical data. However, efficient and contamination-free sampling and sample storage procedures are equally important and pose a significant challenge. Contamination from stabilizing reagents, storage containers and the ambient environment is likely due to the ubiquity of mercury. Analyte losses can also occur because of the high volatility of Hg species and adsorption to surfaces. Strategies to minimize analyte losses and contamination include the use of in-situ and reagent-free analysis procedures. Specially designed solid phase adsorption materials based on surface-modification with gold nanoparticles that serve as catalytically active substances for degradation of mercury species and at the same time as selective adsorbers for mercury traces by amalgamation, will be presented. Reagent-free determination is performed using thermal desorption and atomic fluorescence spectrometry. Application of different modifications of these materials to seawater, river water, waste waters, and human urine show the feasibility of the approach. Its reagent-free procedure and the possibility to perform in-situ preconcentration stabilize mercury species at the point of collection and ensure highest sensitivity.
Kerstin Leopold is a Professor and Deputy Director at the Institute of Analytical and Bioanalytical Chemistry at Ulm University. She studied Chemistry at the Technical University of Munich and received her PhD in Analytical Chemistry in 2003. After a short appointment in a patent attorney office she re-started her academic career. In 2008 she worked with Prof. Paul Worsfold, head of Biogeochemistry and Environmental Analytical Chemistry Group, at School of Earth, Ocean and Environmental Sciences at Plymouth University. At Technical University of Munich she received her habilitation in 2010 and was called for a Professorship position to Ulm University in 2011.
Her group is developing new methods for trace and nanoparticle analysis.
Her research aims at providing reliable and robust analytical methods to determine and monitor pollutants at trace levels, study the fate and impact of trace substances in the environment, and to investigate migration, bioavailability and (eco-)toxicity of emerging analytes. Thereby, mercury trace anaylsis in the hydrosphere is a main focus.