1. Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka, Nigeria
2. Department of Earth Sciences, Kogi State University, Anyigba, Nigeria
3. Physical Chemistry Research Laboratory, Department of Chemistry, University of Free State, Bloemfontein, South Africa
4. Department of Geology, Federal University of Technology, Owerri, Nigeria
5. Department of Chemical Sciences, Federal University Kashere, Pindiga, Nigeria