1. Department of Chemistry, Delta State University, P.M.B. 1, Abraka, Nigeria
2. Department of Chemical Sciences, University of Africa, Toru-Orua, Bayelsa State, Nigeria
3. Institute for Coastal and Marine Research, Department of Botany, Nelson Mandela University, Port Elizabeth 6031, South Africa
4. Environment and Quality Control Department, Nigerian Agip Oil Company, Rumueme, Port Harcourt, Nigeria
5. School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa