1. Department of Clinical Pharmacy and Diagnostics, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
2. Kurt Kitzing Co., Hinterm Alten Schloss 21, D-86757 Wallerstein, Germany
3. Department of Microbiology, University of Food Technologies, 26 Maritza Boulevard, 4002 Plovdiv, Bulgaria
4. Department of Biotechnology, University of Food Technologies, 26 Maritza Boulevard, 4002 Plovdiv, Bulgaria
5. Department of GC and GC-MS, Shimadzu Germany, Albert Hahn- Strasse 6–10, D- 47269 Duisburg, Germany