1. Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, 1350K Copenhagen, Denmark
2. University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11000 Belgrade, Serbia
3. University of Oslo, School of Pharmacy, P.O. Box 1068 Blindern, N-0316 Oslo, Norway
4. University of Oslo, Department of Chemistry, P.O. Box 1033 Blindern, N-0315 Oslo, Norway
5. University of Belgrade, Faculty of Mining and Geology, Đušina 7, 11000 Belgrade, Serbia