1. Institute of Chemistry and Environmental Sciences, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-917 01 Trnava, Slovakia
2. Institute of Biology and Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius in Trnava, Nám. J. Herdu 2, SK-917 01 Trnava, Slovakia
3. Department of Chemistry, Faculty of Education, Trnava University in Trnava, Priemyselná 4, P.O. Box 9, SK-918 43 Trnava, Slovakia