1. University of Duisburg-Essen, Faculty of Chemistry,
Instrumental Analytical Chemistry, Universitaetsstraße 5 D-45141 Essen, Germany
2. IWW Water Centre, Moritzstraße
26, D-45476 Muelheim
an der Ruhr, Germany
3. University of Duisburg-Essen, Centre for Water and
Environmental Research (ZWU), Universitaetsstraße 5 D-45141 Essen, Germany
4. University of Muenster, Institute of Inorganic and
Analytical Chemistry, Corrensstraße 28-30 D-48149, Muenster, Germany