Hamroun, M.S.E., Centre de Recherche Scientifique et Technique en Analyses Physico-Chimiques, BP 384, Zone Industrielle, Bou-Ismail CP 42004, Tipaza, Algeria and Macromolecular Research Laboratory, Faculty of Sciences, Abou Bekr Belkaid University, Chetouane, P.O. Box 119, 13000 Tlemcen, Algeria, Algeria