1. University of Sciences and Technology Houari Boumediene, Faculty of Chemistry, Laboratory of Functional Organic Analysis BP 32 El-Alia 16111 Bab-Ezzouar, Algiers Algeria
2. University of LiegeLaboratoire de Spectrometrie de Masse L.S.M Allee du 6 Août, Bât B6c 4000 Liege (Sart-Tilman) Belgium