1. Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, Maribor SI-2000, Slovenia
2. The Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, Koper SI-6000, Slovenia
3. Institute for Environmental Protection and Sensors, Beloruska ulica 7, Maribor SI-2000, Slovenia