1. Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Universitätsstraße 5, D-45141 Essen, Germany
2. Institute IWAR, Chair of environmental analytics and pollutants, Technical University of Darmstadt, Franziska-Braun-Straße 7, D-64287 Darmstadt, Germany
3. IWW Water Centre, Moritzstraße 26, D-45476 Mülheim an der Ruhr, Germany
4. Centre for Water and Environmental Research (ZWU), Universitätsstraße 5, D-45141 Essen, Germany