1. Laboratory of Analytical Chemistry, Chemical Engineering Department, University of Bejaia DZ‐06000, Algeria Fax: (internat.) +213‐3420‐5193
2. Institute for Technology on Rare Elements, Centre for Analyt. Chemistry and Environment, Vietnam Atomic Energy Commission 48 Lang Ha Street, Hanoi, Vietnam Fax: (internat.) +84‐48/835‐0966
3. Freie Universität Berlin, Institute of Chemistry, Inorg. and Analyt. Chemistry Fabeckstr. 34−36, 14195 Berlin, Germany, Fax: (internat.) +49‐30/838‐52424