1. Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia, Fax: +385‐4836‐082
2. Ruđer Bošković Institute, Bijenička c. 54, P. O. Box 180, 10002 Zagreb, Croatia
3. Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg University of Mainz Duesbergweg 10–14, 55128 Mainz, Germany, Fax: +49‐6131‐3927277