1. Department of Chemistry, Delta State University, Abraka, Nigeria
2. Department of Chemical Sciences, University of Africa, Toru-Orua, Nigeria
3. Department of Botany & Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
4. Department of Chemistry, University of Nigeria, Nsukka, Nigeria
5. Environment and Quality Control Department, Nigerian Agip Oil Company, Abuja, Nigeria
6. School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa