1. Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Mlynska dolina B2, 842 15 Bratislava, Slovakia
2. Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Kosice, Park Komenskeho 2, 042 00 Kosice, Slovakia
3. Friedrich-Schiller Universitat Jena, Chemisch-Geowissenschaftliche Fakultat, Institut fur Geowissenschaften, Burgweg 11, 07749 Jena, Germany
4. Chemical Institute of the Slovak Academy of Sciences, Dubravska cesta 3484/9, 841 04 Bratislava, Slovakia
5. Department of Petroleum Technology and Petrochemistry, Faculty of Chemical and Food Technology of Slovak University of Technology, Radlinskeho 9, 812 37 Bratislava, Slovakia