1. Centre for Hydrogeology and Geothermics (CHYN); Univ. of Neuchâtel; 2000 Neuchâtel Switzerland
2. Agroscope; Research Division, Agroecology and Environment; 8046 Zürich Switzerland
3. Institute of Groundwater Ecology; Helmholtz Zentrum München; 85764 Neuherberg Germany
4. Neuchâtel Platform of Analytical Chemistry; Univ. of Neuchâtel; 2000 Neuchâtel Switzerland
5. Eawag, Swiss Federal Institute of Aquatic Science and Technology; 8600 Dübendorf Switzerland
6. Analytical Chemistry and Water Chemistry; Technical Univ. of Munich; D-81377 Munich Germany