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