1. Marine Chemistry Department, National Institute of Oceanography and Fisheries, Elanfoshy, Alexandria, Egypt, Tel. ; Fax:
2. Faculty of Science, Chemistry Department, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321, Egypt, Tel.
3. Environment Department, Institute of Graduate Studies and Research, El-Horrya Road, Alexandria, Egypt, Tel. , Tel.